| 1. |
- Engvall, Emma, et al.
(författare)
-
Diet and prey size preference in Razorbills Alca torda breeding at Stora Karlsö, Sweden; [Vilken typ och storlek av bytesdjur föredrar häckande tordmular Alca torda vid Stora Karlsö?]
- 2022
-
Ingår i: Ornis Svecica. - : University of Lund. - 1102-6812 .- 2003-2633. ; 32, s. 87-98
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Tidskriftsartikel (refereegranskat)abstract
- The Razorbill Alca torda is one of three auk species breeding in Sweden, often occurring in colonies with Common Guillemot Uria aalge. The largest colony in the Baltic Sea is situated on the island Stora Karlsö west of Gotland. During the chick-rearing phase, Razorbills forage at sea and return to feed the young with single or multiple prey carried sideways in the bill, unlike Common Guillemots that carry a single fish in the middle of the bill. Clupeids, especially sprat Sprattus sprattus, are the main prey of Baltic Sea Razorbills, but studies are scarce. Here, we investigate the diet preference of Razorbills at Stora Karlsö with regard to prey taxonomy and size, analysing photographs and applying morphometric equations. We show that most feeding attempts involved a single clupeid (88% of known fish taxonomy), in most cases likely sprat. The average prey size (115 mm) and prey species was similar to that of Common Guillemots in the same colony. The variation in size was much smaller in the Razorbill diet than the size distribution of clupeids at sea, indicating a strong prey size selectivity. The Razorbills’ high specialisation underlines the importance of maintaining strong populations of clupeids in their foraging area, as these fish are also targeted by industrial fisheries.
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| 2. |
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| 3. |
- Ahlbeck Bergendahl, Ida, et al.
(författare)
-
Fisk- och skaldjursbestånd i hav och sötvatten 2017 : Resursöversikt
- 2017
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- I rapporten kan du ta del av bedömningen som görs av situationen för bestånd som regleras inom ramen för EU:s gemensamma fiskeripolitik (GFP). Bedömningarna baseras på det forskningssamarbete och den rådgivning som sker inom det Internationella Havsforskningsrådet (ICES).De bestånd som förvaltas nationellt baseras på de biologiska underlagen, och rådgivningen i huvudsak på den forskning och övervakning samt analys som bedrivs av Institutionen för akvatiska resurser vid Sveriges lantbruksuniversitet (SLU Aqua) samt yrkesfiskets rapportering.Rapporten omfattar 41 fiskarter och sju skaldjursarter.Nytt för i år är att vi även beskriver fritidsfisket mer utförligt. Det fisket får allt större betydelse för utvecklingen av många av Sveriges bestånd av fisk- och skaldjur, till exempel sötvattens- och kustlevande arter som abborre, gädda, gös, lax, röding och öring, liksom marina arter som torsk och hummerÖversikten är utarbetad av SLU Aqua på uppdrag av Havs- och vattenmyndigheten.
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| 4. |
- Allard, Anna, et al.
(författare)
-
New and changing use of technologies in monitoring: drones, artificial intelligence, and environmental DNA
- 2023
-
Ingår i: Monitoring Biodiversity : Combining Environmental and Social Data. - London : Routledge. - 9781032015934 ; , s. 148-173
-
Bokkapitel (refereegranskat)abstract
- This chapter shows the emerging uses in monitoring, using new as well as older technology in new or developed ways, finding new ways to collect data at different scales, from space down to genetic material. As has been stressed in other chapters, the planet and its biodiversity are closely linked to humans making decisions on land use, through history, and the research into older landscapes gives insights into the landscape of today. In many ways, the possibilities of data science, including the computer capacity to handle very large datasets, have changed the way environmental data can be modelled and understood. With the new possibilities, new challenges also become evident, such as the enormous amounts of training data needed for modelling using deep learning techniques or to take on the challenge of creating virtual twins of European ecosystems for future policymaking.
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| 5. |
- Björkvik, Emma, 1987-
(författare)
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Stewardship in Swedish Baltic small-scale fisheries : A study on the social-ecological dynamics of local resource use
- 2020
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Sustainability scholars frequently advocate for stewardship as a strategy to foster sustainable development. Stewardship broadly refers to the wise and responsible use of nature, and is considered necessary to ensure the long-term wellbeing of humans and that of life in general. In the academic literature local resource users, like hunters, farmers or fishers, are widely acknowledged to act as stewards of the natural environments their livelihoods depend upon. Research shows that this group of people often are able to use natural resources in a sustainable manner, and that their knowledge of how to do so can improve natural resource management. However, research also emphasizes how different local resource users have different potential to steward natural environments. There is thus a need to better understand what stewardship among local resource users entails more concretely as well as when and how it fosters environmental sustainability. In this thesis, I study stewardship in the case of Swedish Baltic small-scale fisheries. I conceptualize stewardship as an interaction between fishers and the social-ecological context in which they are embedded. This conceptualization implies that stewardship does not exist or emerge from within fishers themselves, but is created, formed and realized through fishing practices. I further define and analyze stewardship using a framework composed of three dimensions: care, agency and knowledge. My findings are contained in four papers. Paper I presents a theoretical model of how local resource users respond to social and ecological change, and shows the model’s empirical relevance. Paper II gives an overview of the diversity and development within present-day Swedish Baltic small-scale fisheries. Paper III investigates the historical development of a Swedish fishery that targets the critically endangered European eel (Anguilla anguilla). Paper IV focuses on fishers’ knowledge and assesses how this knowledge can be applied in fisheries science and management. The papers collectively demonstrate the contextual nature of stewardship and showcase how stewardship varies over time as well as between fishers. The findings illustrate the ambiguous link between stewardship and environmental sustainability, they support the notion that fishers’ knowledge can improve fisheries management, while also suggesting that future research needs to pay more attention to how stewardship is empirically manifested. Overall, the thesis advances the understanding of stewardship by highlighting the social-ecological dynamics of local resource use.
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| 6. |
- Björkvik, Emma, 1987-, et al.
(författare)
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Swedish small-scale fisheries in the Baltic Sea : Decline, diversity and development
- 2020
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Ingår i: Small-Scale Fisheries in Europe. - Cham : Springer. - 9783030373702 - 9783030373719 ; , s. 559-579
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Bokkapitel (refereegranskat)abstract
- Can Swedish small-scale fisheries escape decline and live up to their attributed potential to make fisheries more sustainable? Here we address this question by highlighting diversity within these fisheries. Through a specific focus on the Baltic Sea, we demonstrate that small-scale fisheries, defined by scale of operation, are neither sustainable nor unsustainable and have different social and ecological impacts. Based on our analysis we discuss general opportunities and challenges for future development of Swedish small-scale fisheries. Opportunities exist in connection to the creation of niche-products and branding fish as a local and/or exclusive commodity, while major challenges are linked to complexity and extensiveness of regulations, lack of recruitment of new fishers, and ecological sustainability of fishing practices. We argue that attention to diversity in Swedish small-scale fisheries has to be the starting point for meeting future challenges and fulfilling their attributed potential as a sustainable primary production sector.
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| 7. |
- Björkvik, Emma, 1987-, et al.
(författare)
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Why fishers end up in social-ecological traps : a case study of Swedish eel fisheries in the Baltic Sea
- 2020
-
Ingår i: Ecology and Society. - 1708-3087. ; 25:1
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Tidskriftsartikel (refereegranskat)abstract
- Unsustainable fishing can be surprisingly persistent despite devastating social, economic, and ecological consequences. Sustainability science literature suggests that the persistence of unsustainable fisheries can be understood as a social-ecological trap. Few studies have explicitly acknowledged the role of historical legacies for the development of social-ecological traps. Here, we investigate why fishers sometimes end up in social-ecological traps through a reconstruction of the historical interplay between fishers’ motivations, capacities, and opportunities to fish. We focus on the case of a Swedish fishery targeting the critically endangered European eel (Anguilla Anguilla) in the Baltic Sea. We performed the case study using a unique quantitative data set of social and ecological variables that spans over eight decades, in combination with earlier literature and interviews with fishers and fisheries experts. Our analysis reveals that Swedish archipelago fishers are highly dependent on the eel to maintain their fishing livelihood. The dependence on the eel originates from the 1930s, when fishers chose to intensify fishing for this species to ensure future incomes. The dependence persisted over time because of a series of changes, including improved eel fishing technology, heightened competition over catch, reduced opportunities to target other species, implementation of an eel fishing license, and the fishers’ capacity and motivation to deal with dwindling catches. Our study confirms that social-ecological traps are path-dependent processes. In terms of management, this finding means that it becomes progressively more difficult to escape the social-ecological trap with the passage of time. The longer entrapment endures, the more effort it takes and the bigger change it requires to return to a situation where fishers have more options so that unsustainable practices can be avoided. We conclude that fisheries policies need to be based on the premise that unsustainable fishing emerges through multiple rather than single causes.
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| 8. |
- Boonstra, Wiebren J., et al.
(författare)
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Classifying fishers' behaviour. An invitation to fishing styles
- 2016
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Ingår i: Fish and Fisheries. - : Wiley. - 1467-2960 .- 1467-2979. ; 17:1, s. 78-100
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Tidskriftsartikel (refereegranskat)abstract
- The study and classification of fishers’ behaviour remains a much debated topic. There is a tension between detailed empirical studies, which highlight the variety and diversity of fisheries, and the parsimony and generalization required to satisfy science and policy demands. This study contributes to this debate. The first sec- tion reviews quantitative methods currently used for classifying fishing practices. The review uncovers significant weaknesses in quantitative classification methods, which, we argue, can be improved through the complementary use of qualitative methods. To this purpose, we introduce the concept of ‘fishing style’, which integrates quantitative classification methods with qualitative analysis. We explain the scientific premises of the fishing-style concept, outline a general methodological framework and present a fishing-style analysis of Swedish Baltic Sea fisheries. Based on these results, we conclude that it is possible to classify fishing practices in a rel- atively uniform and limited number of styles that can highlight the rich, empirical diversity of fishers’ behaviour. We therefore propose that fishing-style analysis, based on an integration of quantitative and qualitative methods, can be an impor- tant step towards more effective and sustainable fisheries management.
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| 9. |
- Cardinale, Massimiliano, et al.
(författare)
-
Recent phenological shifts of migratory birds at a Mediterranean spring stopover site: Species wintering in the Sahel advance passage more than tropical winterers
- 2020
-
Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 15
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Tidskriftsartikel (refereegranskat)abstract
- Spring migration phenology is shifting towards earlier dates as a response to climate change in many bird species. However, the patterns of change might not be the same for all species, populations, sex and age classes. In particular, patterns of change could differ between species with different ecology. We analyzed 18 years of standardized bird capture data at a spring stopover site on the island of Ponza, Italy, to determine species-specific rates of phenological change for 30 species following the crossing of the Mediterranean Sea. The advancement of spring passage was more pronounced in species wintering in Northern Africa (i.e. short-distance migrants) and in the Sahel zone. Only males from species wintering further South in the forests of central Africa advanced their passage, with no effect on the overall peak date of passage of the species. The migration window on Ponza broadened in many species, suggesting that early migrants within a species are advancing their migration more than late migrants. These data suggest that the cues available to the birds to adjust departure might be changing at different rates depending on wintering location and habitat, or that early migrants of different species might be responding differently to changing conditions along the route. However, more data on departure time from the wintering areas are required to understand the mechanisms underlying such phenological changes.
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| 10. |
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| 11. |
- Cardinale, Massimiliano, et al.
(författare)
-
Something old, something new: Historical perspectives provide lessons for blue growth agendas
- 2020
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Ingår i: Fish and Fisheries. - : Wiley. - 1467-2960 .- 1467-2979. ; 21, s. 774-796
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Tidskriftsartikel (refereegranskat)abstract
- The concept of "blue growth," which aims to promote the growth of ocean economies while holistically managing marine socioecological systems, is emerging within national and international marine policy. The concept is often promoted as being novel; however, we show that historical analogies exist that can provide insights for contemporary planning and implementation of blue growth. Using a case-study approach based on expert knowledge, we identified 20 historical fisheries or aquaculture examples from 13 countries, spanning the last 40-800 years, that we contend embody blue growth concepts. This is the first time, to our knowledge, that blue growth has been investigated across such broad spatial and temporal scales. The past societies managed to balance exploitation with equitable access, ecological integrity and/or economic growth for varying periods of time. Four main trajectories existed that led to the success or failure of blue growth. Success was linked to equitable rather than open access, innovation and management that was responsive, holistic and based on scientific knowledge and monitoring. The inability to achieve or maintain blue growth resulted from failures to address limits to industry growth and/or anticipate the impacts of adverse extrinsic events and drivers (e.g. changes in international markets, war), the prioritization of short-term gains over long-term sustainability, and loss of supporting systems. Fourteen cross-cutting lessons and 10 recommendations were derived that can improve understanding and implementation of blue growth. Despite the contemporary literature broadly supporting our findings, these recommendations are not adequately addressed by agendas seeking to realize blue growth.
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| 12. |
- Crona, Beatrice I., et al.
(författare)
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Masked, diluted and drowned out : how global seafood trade weakens signals from marine ecosystems
- 2016
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Ingår i: Fish and Fisheries. - : Wiley. - 1467-2960 .- 1467-2979. ; 17:4, s. 1175-1182
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Tidskriftsartikel (refereegranskat)abstract
- Nearly 40% of seafood is traded internationally and an even bigger proportion is affected by international trade, yet scholarship on marine fisheries has focused on global trends in stocks and catches, or on dynamics of individual fisheries, with limited attention to the link between individual fisheries, global trade and distant consumers. This paper examines the usefulness of fish price as a feedback signal to consumers about the state of fisheries and marine ecosystems. We suggest that the current nature of fisheries systems and global markets prevent transmission of such price signals from source fisheries to consumers. We propose several mechanisms that combine to weaken price signals, and present one example - the North Sea cod - to show how these mechanisms can be tested. The lack of a reliable price feedback to consumers represents a challenge for sustainable fisheries governance. We therefore propose three complimentary approaches to address the missing feedback: (i) strengthening information flow through improved traceability and visibility of individual fishers to consumers, (ii) capitalizing on the changing seafood trade structures and (iii) bypassing and complementing market mechanisms by directly targeting citizens and political actors regarding marine environmental issues through publicity and information campaigns. These strategies each havelimitations and thus need to be pursued together to address the challenge of sustainability in global marine fisheries.
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| 13. |
- Cross, Adam D. P., et al.
(författare)
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Isotopic analysis of island House Martins Delichon urbica indicates marine provenance of nutrients
- 2014
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Ingår i: Ibis. - : Wiley. - 0019-1019 .- 1474-919X. ; 156:3, s. 676-681
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Tidskriftsartikel (refereegranskat)abstract
- The presence of one of the largest colonies of House Martins in Europe on the small island of Stora Karlso, Sweden, led us to investigate the source of their food by analysis of stable isotopes of carbon and nitrogen. Carbon isotopic values of House Martin nestlings were the same as those of Common Guillemot Uria aalge nestlings fed on marine fish, but differed from local Collared Flycatcher Ficedula albicollis nestlings fed on woodland insects. We infer that these House Martins fed their chicks almost exclusively on insects that had used nutrients derived from seabirds, indicating a dependence on the presence of a large seabird colony. We suggest by extension that some populations of island passerines of high conservation importance may also be dependent on nutrient subsidies from seabird colonies.
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| 14. |
- Haider, L. Jamila, 1987-, et al.
(författare)
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The undisciplinary journey : early-career perspectives in sustainability science
- 2018
-
Ingår i: Sustainability Science. - : Springer Science and Business Media LLC. - 1862-4065 .- 1862-4057. ; 13:1, s. 191-204
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Tidskriftsartikel (refereegranskat)abstract
- The establishment of interdisciplinary Master’s and PhD programs in sustainability science is opening up an exciting arena filled with opportunities for early-career scholars to address pressing sustainability challenges. However, embarking upon an interdisciplinary endeavor as an early-career scholar poses a unique set of challenges: to develop an individual scientific identity and a strong and specific methodological skill-set, while at the same time gaining the ability to understand and communicate between different epistemologies. Here, we explore the challenges and opportunities that emerge from a new kind of interdisciplinary journey, which we describe as ‘undisciplinary.’ Undisciplinary describes (1) the space or condition of early-career researchers with early interdisciplinary backgrounds, (2) the process of the journey, and (3) the orientation which aids scholars to address the complex nature of today’s sustainability challenges. The undisciplinary journey is an iterative and reflexive process of balancing methodological groundedness and epistemological agility to engage in rigorous sustainability science. The paper draws upon insights from a collective journey of broad discussion, reflection, and learning, including a survey on educational backgrounds of different generations of sustainability scholars, participatory forum theater, and a panel discussion at the Resilience 2014 conference (Montpellier, France). Based on the results from this diversity of methods, we suggest that there is now a new and distinct generation of sustainability scholars that start their careers with interdisciplinary training, as opposed to only engaging in interdisciplinary research once strong disciplinary foundations have been built. We further identify methodological groundedness and epistemological agility as guiding competencies to become capable sustainability scientists and discuss the implications of an undisciplinary journey in the current institutional context of universities and research centers. In this paper, we propose a simple framework to help early-career sustainability scholars and well-established scientists successfully navigate what can sometimes be an uncomfortable space in education and research, with the ultimate aim of producing and engaging in rigorous and impactful sustainability science.
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| 15. |
- Hamann, Maike, et al.
(författare)
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Inequality and the biosphere
- 2018
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Ingår i: Annual Review of Environment and Resources. - : Annual Reviews. - 1543-5938 .- 1545-2050. ; 43, s. 61-83
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Forskningsöversikt (refereegranskat)abstract
- Rising inequalities and accelerating global environmental change pose two of the most pressing challenges of the twenty-first century. To explore how these phenomena are linked, we apply a social-ecological systems perspective and review the literature to identify six different types of interactions (or "pathways") between inequality and the biosphere. We find that most of the research so far has only considered one-directional effects of inequality on the biosphere, or vice versa. However, given the potential for complex dynamics between socioeconomic and environmental factors within social-ecological systems, we highlight examples from the literature that illustrate the importance of cross-scale interactions and feedback loops between inequality and the biosphere. This review draws on diverse disciplines to advance a systemic understanding of the linkages between inequality and the biosphere, specifically recognizing cross-scale feedbacks and the multidimensional nature of inequality.
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| 16. |
- Hentati Sundberg, Jonas
(författare)
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A mechanistic framework to inform the spatial management of conflicting fisheries and top predators
- 2020
-
Ingår i: Journal of Applied Ecology. - : Wiley. - 0021-8901 .- 1365-2664. ; 58, s. 125-134
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Tidskriftsartikel (refereegranskat)abstract
- Conflicts of interest between resource extraction and conservation are widespread, and negotiating such conflicts, or trade-offs, is a key issue for ecosystem managers. One such trade-off is resource competition between fisheries and marine top predators. Managing this trade-off has so far been difficult due to a lack of knowledge regarding the amount and distribution of prey required by top predators.Here, we develop a framework that can be used to address this gap: a bio-energetic model linking top predator breeding biology and foraging ecology with forage fish ecology and fisheries management.We apply the framework to a Baltic Sea colony of common guillemots Uria aalge and razorbills Alca torda, two seabird species sensitive to local prey depletion, and show that densities of forage fish (sprat Sprattus sprattus and herring Clupea harengus) corresponding to the current fisheries management target B-MSY are sufficient for successful breeding. A previously proposed fisheries management target for conserving seabirds, 1/3 of historical maximum prey biomass (B-1/3), was also sufficient.However, the results highlight the importance of maintaining sufficient prey densities in the vicinity of the colony, suggesting that fine-scale spatial fisheries management is necessary to maintain high seabird breeding success.Despite foraging on the same prey, razorbills could breed successfully at lower prey densities than guillemots but needed higher densities for self-maintenance, emphasizing the importance of considering species-specific traits when determining sustainable forage fish densities for top predators.Synthesis and applications. Our bio-energetic modelling framework provides spatially explicit top predator conservation targets that can be readily integrated with current fisheries management. The framework can be combined with existing management approaches such as dynamic ocean management, marine spatial planning and management strategy evaluation to inform ecosystem-based management of marine resources.
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| 17. |
- Hentati-Sundberg, Jonas, 1983-, et al.
(författare)
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Can fisheries management be quantified?
- 2014
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Ingår i: Marine Policy. - : Elsevier BV. - 0308-597X .- 1872-9460. ; 48, s. 18-20
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Tidskriftsartikel (refereegranskat)abstract
- Policy efforts to reduce fisheries impact have often created micro-management. Detailed regulations are restricting the fishing industry, and are also acknowledged to limit the progress towards sustainable management. Industry representatives, political bodies and scientists have therefore argued for more simplicity and transparency. Here, fisheries management is quantified in terms of trends in regulations for different Swedish fisheries in the Baltic Sea during the period 1995–2009. The results suggest that many fisheries are suffering from increased micro-management, but interestingly some fisheries showing a different trend.
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| 18. |
- Hentati Sundberg, Jonas
(författare)
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Correcting Bias in Survival Probabilities for Partially Monitored Populations via Integrated Models
- 2021
-
Ingår i: Journal of Agricultural, Biological, and Environmental Statistics. - : Springer Science and Business Media LLC. - 1085-7117 .- 1537-2693.
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Tidskriftsartikel (refereegranskat)abstract
- We provide an integrated capture-recapture-recovery framework for partially monitored populations. In these studies, live resightings are only observable at a set of monitored locations, so that if an individual leaves these specific locations, they become unavailable for capture. Additional ring-recovery data reduce the corresponding bias obtained in the survival probability estimates from capture-recapture data due to the confounding with colony dispersal. We derive an explicit efficient likelihood expression for the integrated capture-recapture-recovery data, and state the associated sufficient statistics. We demonstrate the significant improvements in the estimation of the survival probabilities using the integrated approach for a colony of guillemots (Uria aalge), where we additionally specify a hierarchical approach to deal with low sample size over the early period of the study.Supplementary materials accompanying this paper appear online.
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| 19. |
- Hentati-Sundberg, Jonas, et al.
(författare)
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COVID-19 lockdown reveals tourists as seabird guardians
- 2021
-
Ingår i: Biological Conservation. - : Elsevier BV. - 0006-3207 .- 1873-2917. ; 254
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Tidskriftsartikel (refereegranskat)abstract
- The widespread lockdowns put in place to limit the spread of the new coronavirus disease (COVID-19) offers a rare opportunity in understanding how human presence influence ecosystems. Using data from long-term seabird monitoring, we reveal a previously concealed guarding effect by tourist groups on an iconic seabird colony in the Baltic Sea. The absence of tourists in 2020 lead to a sevenfold increase in presence of white-tailed eagles Haliaeetus albicilla, a sevenfold increase in their disturbance of breeding common murres Uria aalge and causing 26% lower murre productivity than the long-term average. Eagles did not prey on murres, but their frequent disturbances delayed egg laying and facilitated egg predation from herring gulls Larus argentatus and hooded crows Corvus cornix. Based on our findings, we suggest that human presence could be used as a strategic measure in guarding seabird colonies, and that a social-ecological systems perspective is vital for long-term success in protected area management.
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| 20. |
- Hentati-Sundberg, Jonas, 1983-, et al.
(författare)
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Does fisheries management incentivize non-compliance? Estimated misreporting in the Swedish Baltic Sea pelagic fishery based on commercial fishing effort
- 2014
-
Ingår i: ICES Journal of Marine Science. - : Oxford University Press (OUP). - 1054-3139 .- 1095-9289. ; 71:7, s. 1846-1853
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Tidskriftsartikel (refereegranskat)abstract
- Fisheries management agencies and fishing industry representatives depend on reliable estimates of fish biomass and mortality for the determin- ation of sustainable catch levels. Lack of data or misreporting may be reasons for unreliable stock assessment, which, in turn, may result in advice that does not reflect the availability of fisheries resources. It has been suggested that the mixed pelagic trawl fisheries in the Baltic represent a case of biased estimates of fish biomass and mortality resulting from misreporting. Here, we estimate the degree of misreporting in the Swedish pelagic fishery (1996 – 2009) and propose an approach for reconstructing historical catches based on commercial effort data. The analysis suggests that total catches have been underestimated during part of our study period and that systematic misreporting of species composition has taken place over the whole study period. The analysis also suggests that there is overcapacity in the fishery and that such economic incentive could explain the general patterns of misreporting. Applying our method for fisheries with suspected misreporting could significantly improve assessment accuracy, reduce uncertainty and thereby allow for a better link between catches and resource levels.
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| 21. |
- Hentati Sundberg, Jonas, et al.
(författare)
-
Expeditionsrapport SPRAS 2020-2021
- 2022
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- I rapporten presenteras resultat från de två första åren (2020 och 2021) av den svenska delen av den internationella surveyen Sprat Acoustic Survey (SPRAS-Swe,) i Östersjön. Surveyen har pågått sedan 2001, men Sveriges deltagande började först 2020 efter leveransen av Sveriges nya forskningsfartyg R/V Svea. Expeditionens huvudsyfte är att ta fram fiskerioberoende data på förekomst i antal av skarpsill och sill. Dessa data tillsammans med andra nationers data utgör en grund i bestånduppskattningsarbetet som görs inom ICES arbetsgrupp WGBFAS. Vår målsättning är att testa möjligheten att se SPRAS-Swe som en ekosystemsurvey vilket innebär att utöver den datainsamling som krävs enligt manual även samla in annan typ av data för att öka kunskapen kring ekosystemet Östersjön. Målet är också att utveckla insamlings- och analysmetoder för att på sikt minska dödligheten av fisk.
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| 22. |
- Hentati-Sundberg, Jonas, et al.
(författare)
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FISH AND SEABIRD SPATIAL DISTRIBUTION AND ABUNDANCE AROUND THE LARGEST SEABIRD COLONY IN THE BALTIC SEA
- 2018
-
Ingår i: Marine Ornithology. - 1018-3337 .- 2074-1235. ; 46:1, s. 61-68
-
Tidskriftsartikel (refereegranskat)abstract
- We studied the at-sea distribution of two auks (Common Murre Uria aalge, Razorbill Alca torda), two gulls (Lesser Black-backed Gull Larus fuscus, Herring Gull Larus argentatus), and Great Cormorant Phalacrocorax carbo during the peak breeding season of 2014 around Stora Karlso, the main Baltic Sea seabird colony. Simultaneously, we quantified forage fish abundance and distribution using hydro-acoustics and pelagic trawling. The auks and gulls had a roughly similar distribution, foraging mainly about 40 km west-northwest from the colony. Great Cormorants were found only in inshore areas, close to the colony. Sprat Sprattus sprattus and herring Clupea harengus biomass was, respectively, 1.38 and 2.68 mt/km(2) averaged over the whole study area. These estimates represent a total biomass for small pelagic fish of 17 900 t in the 4 408 km(2) study area. The estimated prey consumption over the breeding season was 2 310 t for Common Murre and Razorbill combined. Thus, auks may have a non-negligible impact on their prey sources in the region. Common Murres foraged closer to the colony (median 36.3 km) than Razorbills (median 41.1 km), but we found no significant correlation between auk at-sea numbers and fish densities. We discuss how new technology can contribute to detailed monitoring of the interactions between seabirds and fish at different spatial and temporal scales, with the ultimate aim of providing a scientific basis for ecosystem-based management.
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| 23. |
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| 24. |
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| 25. |
- Hentati-Sundberg, Jonas, et al.
(författare)
-
Iron triangles and subsidies : understanding the long-term role of the government on Swedish commercial fisheries
- 2019
-
Ingår i: Ecology and Society. - : RESILIENCE ALLIANCE. - 1708-3087. ; 24:4
-
Tidskriftsartikel (refereegranskat)abstract
- Many natural resources have degraded and collapsed despite being managed under rigorous institutional frameworks set up to ensure rational exploitation. Path dependency of dysfunction institutions has been suggested as an explanation for such undesired outcomes. We explore the role of path dependency in natural resource management by studying a 100-year evolution of Swedish fisheries. We rely on three main types of original longitudinal data collected for the period 1914–2016: (A) policy documents, (B) government spending on management and subsidies, and (C) catch and fleet data. Our analysis contrasts the periods before and after the Swedish entrance into the European Union (1995) because this marks the year when fisheries policy became beyond the direct influence of the Swedish government. We uncover four pieces of evidence suggesting the existence of a path dependent dynamic in the pre-EU period: (1) despite increasing insights on the vulnerability of fish stocks to overexploitation, national policy goals in relation to fisheries continuously promoted incompatible goals of social and economic growth but without any reference to the sustainability of the biological resources; (2) the same policy instruments were used over long periods; (3) actor constellations within the fisheries policy subsystem were stable over time; (4) neither political regime nor macroeconomic variables and fisheries performance (industry production, oil price, landing values) could explain observed temporal variation in subsidies. We conclude that key policy actors in the pre-EU period formed an “iron triangle” and thereby prevented necessary policy changes. These national reinforcing feedbacks have been weakened since EU entrance, and the indicators for path dependency show broader involvement of stakeholders, a shift in spending, and policy goals that now explicitly address ecological sustainability.
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| 26. |
- Hentati Sundberg, Jonas, et al.
(författare)
-
Management Forcing Increased Specialization in a Fishery System
- 2015
-
Ingår i: Ecosystems (New York. Print). - : Springer Science and Business Media LLC. - 1432-9840 .- 1435-0629. ; 18:1, s. 45-61
-
Tidskriftsartikel (refereegranskat)abstract
- Fisheries systems are shaped by dynamic social-ecological interactions that determine their capacity to provide ecosystem services. Human adaptation is often considered a key uncertainty, and there are few quantitative empirical analyses that address long-term social and ecological change in the analyses of fisheries systems. The aim of this study was twofold: (i) to understand how different drivers influenced the adaptations by fishers, and (ii) to evaluate different consequences of such adaptations, especially with regard to diversity of social and ecological links. We used the Baltic Sea as a case study, a system with different fisheries, largely managed with a single-stock advice, in a top-down basis. The study period 1995-2009 was characterized by profound inter-annual fluctuations in fish stock status and prices, and introduction of new types of management measures. We used multivariate statistical methods to define longitudinal changes in fishing tactics and strategies based on logbook data. Our results indicate that changes in fishing strategies have mainly been driven by regulations, and there were only weak linkages between fishing activities, fish stocks, and price fluctuations. We found contrasting trends between large- and small-scale fishers, where large-scale fishers became more specialized and inflexible, whereas small-scale fishers diversified over time. We conclude that management has had a dominating role in shaping fishing patterns, leading to a reduction of important qualities related to the resilience in this social-ecological system.
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| 27. |
- Hentati Sundberg, Jonas
(författare)
-
Population trends and status of four seabird species (Uria aalge, Alca torda, Larus fuscus, Larus argentatus) at Stora Karlsö in the Baltic Sea
- 2017
-
Ingår i: Ornis Svecica. - 1102-6812. ; 27, s. 64 - 93
-
Tidskriftsartikel (refereegranskat)abstract
- The island of Stora Karlsö hosts the largest colonies of fish-eating seabirds in the Baltic Sea. However, recent and reliable estimates of the number of breeding pairs of the main species have been missing. Based on a complete census in 2014, we estimated the number of Common Guillemots Uria aalge to 15700 pairs, more than half (up to 70%) of the Baltic Sea population. The number has almost tripled since the early 1970s and the increase has been particularly strong the last 11 years, with an annual increase of 5.1%. We counted 24 600 individual adult Razorbills Alca torda and estimated it to correspond to a maximum of 12 300 pairs in 2015–2016 (census over two seasons). The colony has grown strongly; on average by 5.6% annually since the early 1970s, and Stora Karlsö now hosts up to 30% of the Baltic Sea population. Stora Karlsö also hosts colonies with about 300 pairs each of Lesser Black-backed Gull Larus fuscus and Herring Gull Larus argentatus. The gulls’ trends are negative, with an average annual decline the last 10-year period by 5.0% and 6.2%, respectively
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| 28. |
- Hentati-Sundberg, Jonas, 1983-
(författare)
-
SEA CHANGE : Social-ecological co-evolution in Baltic Sea fisheries
- 2015
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Sustainable management of natural resources requires an in-depth understanding of the interplay between social and ecological change. Linked social-ecological systems (SES) have been described as complex adaptive systems (CAS), which mean that they are irreducible, exhibit nonlinear dynamics, have interactions across scales and are uncertain and unpredictable. These propositions have however rarely been tested empirically, in part due to a lack of methodological approaches and suitable datasets. In this thesis, I address this methodological and empirical gap in a study of long-term change of Baltic Sea fisheries. In Paper I, we develop the concept of fishing style through integrating multivariate statistical analysis and in-depth interviews. We thereby identify an intermediate level of detail for analyzing social-ecological dynamics, embracing the case specific and context dependent approaches of the social sciences with the generalizable and quantifiable approaches from the natural sciences. In Paper II we ask: How has the Baltic Sea fishery been regulated over time, and can we identify a way to quantify regulations in order to be able to analyze their effects? We analyze all regulatory changes in Sweden since 1995 with a new methodology and conclude that there is a clear trend towards increased micro-management. In Paper III, we use the fishing styles developed in Paper I and examine how they have changed over time. We relate these changes to the dynamics of regulation (Paper II), as well as to the dynamics of fish stocks and prices. We conclude that regulation has been the main driving force for observed changes, but also that regulation has prompted significant specialization and decline in flexibility for fishers over time. These changes are unintended consequences and may represent a looming risk for the long-term sustainability of this social-ecological system. Paper IV zooms in on a particular fishery, the pelagic trawl fishery for sprat Sprattus sprattus and Atlantic herring Clupea harengus, mainly targeted for the production of fishmeal and fish oil. Suspicions of non-compliance in this fishery motivated us to apply a statistical approach where we used socioeconomic data to re-estimate the historical catches in this fishery (a novel approach to catch-reconstruction estimates). We found that catches had been significantly underreported over several years, with consequences for the quality of stock assessments and management. The study underlines the importance of understanding linked social, economic and ecological dynamics for sustainable outcomes. Finally, Paper V takes a longer historical look at the Baltic Sea fishery, using regionally disaggregated data from 1914-2009 (96 years), which were analyzed with a novel type of nonlinear statistical time-series methods (Empirical Dynamical Modeling). Our analysis explicitly recognized the potential nonlinear dynamics of SES and showed high predictability across regions of catches and prices of cod Gadus morhua and herring. The signal was generally nonlinear and predictability decreased strongly with time, suggesting that the dynamics of this SES are ever-changing. To our knowledge, this is the first long-term analysis of a SES using empirical data and methods developed from the CAS field of research. The main contributions of this thesis are the integrated analysis of social and ecological data, the development of novel methods for understanding SES dynamics, insights on the ever-changing nature of CAS and the quantitative analysis of management outcomes. Future work should focus on assessing the generality of these findings across a broad range of SES and evaluate alternative governance approaches given the complexity and uncertainty of SES suggested by this thesis.
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| 29. |
- Hentati Sundberg, Jonas
(författare)
-
Seabird-induced natural mortality of forage fish varies with fish abundance: Evidence from five ecosystems
- 2021
-
Ingår i: Fish and Fisheries. - : Wiley. - 1467-2960 .- 1467-2979. ; 22, s. 262-279
-
Tidskriftsartikel (refereegranskat)abstract
- Forage fish populations often undergo large and rapid fluctuations in abundance. However, most of their predators are buffered against such fluctuations owing to their slower pace of life, which allows them to maintain more stable populations, at least during short periods of food scarcity. In this study, we investigated top-down processes exerted by seabirds on forage fish stocks in five contrasted marine ecosystems, compiling numerous data sets on seabird counts, diets, energetic needs and prey energy content and abundance. Off Norway, South Africa, Peru, Sweden and Scotland, we found that predation pressure-estimated as the proportion of a fish stock consumed by seabirds-was generally low (median = 1%), but increased sharply at low levels of prey abundance. When prey biomass decreased below 15-18% of its maximum recorded value, predation by seabirds became a source of important additional pressure on prey stocks (similar to 20% of prey biomass is consumed by seabirds). An earlier empirical study advocated for keeping forage stocks from falling below a threshold of 33% of long-term maximum prey biomass in order to safeguard seabird breeding success, but here we further suggest that a threshold of 18% should be considered as a limit not to be exceeded for the sake of the forage fish themselves, and below which extra cautious management of fisheries may be required. Nevertheless, despite exceptionally high rates of predation on some occasions, predation pressure was not correlated with prey dynamics, suggesting an absence of prey entrapment due to seabirds alone in these five ecosystems.
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| 30. |
- Hentati-Sundberg, Jonas, et al.
(författare)
-
Seabird surveillance: combining CCTV and artificial intelligence for monitoring and research
- 2023
-
Ingår i: Remote Sensing in Ecology and Conservation. - : Wiley. - 2056-3485. ; 9:4, s. 568-581
-
Tidskriftsartikel (refereegranskat)abstract
- Ecological research and monitoring need to be able to rapidly convey information that can form the basis of scientifically sound management. Automated sensor systems, especially if combined with artificial intelligence, can contribute to such rapid high-resolution data retrieval. Here, we explore the prospects of automated methods to generate insights for seabirds, which are often monitored for their high conservation value and for being sentinels for marine ecosystem changes. We have developed a system of video surveillance combined with automated image processing, which we apply to common murres Uria aalge. The system uses a deep learning algorithm for object detection (YOLOv5) that has been trained on annotated images of adult birds, chicks and eggs, and outputs time, location, size and confidence level of all detections, frame-by-frame, in the supplied video material. A total of 144 million bird detections were generated from a breeding cliff over three complete breeding seasons (2019–2021). We demonstrate how object detection can be used to accurately monitor breeding phenology and chick growth. Our automated monitoring approach can also identify and quantify rare events that are easily missed in traditional monitoring, such as disturbances from predators. Further, combining automated video analysis with continuous measurements from a temperature logger allows us to study impacts of heat waves on nest attendance in high detail. Our automated system thus produces comparable, and in several cases significantly more detailed, data than those generated from observational field studies. By running in real time on the camera streams, it has the potential to supply researchers and managers with high-resolution up-to-date information on seabird population status. We describe how the system can be modified to fit various types of ecological research and monitoring goals and thereby provide up-to-date support for conservation and ecosystem management.
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| 31. |
- Hentati Sundberg, Jonas
(författare)
-
Sillgrisslorna på Stora Karlsö
- 2016
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Ingår i: Fauna och flora. - 0014-8903. ; 111, s. 30-34
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Tidskriftsartikel (populärvet., debatt m.m.)
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| 32. |
- Hentati-Sundberg, Jonas, 1983-
(författare)
-
Social-ecological dynamics in a highly regulated fisheries system - Sources of resilience and limits to command-and-control management
- 2013
-
Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Sustainable governance of natural resources is challenged by the poor understanding of complex human-nature couplings. Major advancements in resilience theory, acknowledging the importance of social-ecological linkages and the self-organizing capacity of social-ecological systems, provides a new perspective on research in sustainability science. Yet, limitations in methods and data for integrated studies of social-ecological systems limit progress in science and management. This PhD project aims to generate and test specific hypotheses building on social-ecological systems theory using a variety of methods and a long-term, multidimensional empirical dataset of the Baltic Sea social-ecological fisheries system.In paper 1, we ask which factors have impacted change in fisheries patterns in the Baltic Sea over a 15 year period, 1995-2009. We conclude that the responses of fishers are largely driven by top-down management regulations, which has favoured increasing scale of operations and specialization, and that the capacity of fishers to engage in ecosystem stewardship is low. Resilience could be enhanced through an increased focus on governance actions that can stimulate the self-organising capacity of the systemPaper 2 focuses on one particular fishery, whose long-term dynamics have been strongly driven by an ecological regime-shift in the Baltic Sea. High potential profits and weak control has raised suspicions of widespread misreporting in this fishery. By developing a new method for reconstructing catches, we suggest that under-reporting has been significant, and likely driven by high economic incentives created by ill-designed policy. This misreporting risks contributing to a negative feed-back that substantially alters the management cycle, and thereby constitutes a part of a social-ecological trap in this fishery.The research within this project so far indicates that there are good prospects for using the Baltic Sea as case for integrated social-ecological studies, aiming at informing resilience theory. Some ideas on future direction of the research are outlined.
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| 33. |
- Hentati-Sundberg, Jonas, 1983-, et al.
(författare)
-
Strong nonlinearities in an ever-changing social-ecological system : A data-driven empirical study of the historical development of the Baltic Sea
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Understanding linked social and ecological dynamics is a pre-requisite for sustainable use of natural resources. Integrated quantitative studies of such linked systems have however been scarce due to lack of suitable methods and data. In this paper, we apply state-of-the-art nonlinear time series methods (EDM) to nine decades of spatially explicit fisheries data to investigate their empirical dynamics. We found that fish prices, and to a less extent fish catches, were predictable beyond linear change or temporal correlations, and highly nonlinear. Moreover, we found that the system appeared to be drifting, indicating gradual changes in internal feedback strength and thus limiting predictability over long time periods. Our results indicate that predictability in social-ecological systems may be relatively modest, which may call for an adaptive, risk-averse approach to ecosystem management.
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| 34. |
|
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| 35. |
- Hentati-Sundberg, Jonas, 1983-, et al.
(författare)
-
The Karlsö Murre Lab methodology can stimulate innovative seabird research
- 2012
-
Ingår i: Marine Ornithology. - 1018-3337 .- 2074-1235. ; 40, s. 11-16
-
Tidskriftsartikel (refereegranskat)abstract
- Studies of seabirds have contributed substantially to theoretical and applied ecology, but practical limitations in the field and lack of knowledge of the life history of studied birds often constitute significant hurdles to progress in research. In the middle of the largest seabird colony in the Baltic Sea, on the island of Stora Karlsö, we have built an artificial breeding site for Common Murres Uria aalge. The Karlsö Murre Lab enables high-resolution studies with minimal disturbance of the breeding birds. It became operational, with the first recruitment of breeding murres, in 2009. Building materials and location were chosen to minimize environmental impact. The lab was constructed to allow future outfitting with a range of high-technology devices. Since most of the fledged chicks in the subcolony have been ringed over the last 10 years, this will enable recruitment and studies using advanced technology of birds with known life history. Hence, we will be able to perform seabird studies with a resolution that is impossible in a strictly natural environment. Better knowledge of links between seabirds and their environment facilitates the use of seabirds as indicators, which in turn can improve marine ecosystem-based management.
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| 36. |
- Hentati Sundberg, Jonas
(författare)
-
Variation and correlation in the timing of breeding of North Atlantic seabirds across multiple scales
- 2022
-
Ingår i: Journal of Animal Ecology. - : Wiley. - 0021-8790 .- 1365-2656. ; 91, s. 1797-1812
-
Tidskriftsartikel (refereegranskat)abstract
- Timing of breeding, an important driver of fitness in many populations, is widely studied in the context of global change, yet despite considerable efforts to identify environmental drivers of seabird nesting phenology, for most populations we lack evidence of strong drivers. Here we adopt an alternative approach, examining the degree to which different populations positively covary in their annual phenology to infer whether phenological responses to environmental drivers are likely to be (a) shared across species at a range of spatial scales, (b) shared across populations of a species or (c) idiosyncratic to populations. We combined 51 long-term datasets on breeding phenology spanning 50 years from nine seabird species across 29 North Atlantic sites and examined the extent to which different populations share early versus late breeding seasons depending on a hierarchy of spatial scales comprising breeding site, small-scale region, large-scale region and the whole North Atlantic. In about a third of cases, we found laying dates of populations of different species sharing the same breeding site or small-scale breeding region were positively correlated, which is consistent with the hypothesis that they share phenological responses to the same environmental conditions. In comparison, we found no evidence for positive phenological covariation among populations across species aggregated at larger spatial scales. In general, we found little evidence for positive phenological covariation between populations of a single species, and in many instances the inter-year variation specific to a population was substantial, consistent with each population responding idiosyncratically to local environmental conditions. Black-legged kittiwake Rissa tridactyla was the exception, with populations exhibiting positive covariation in laying dates that decayed with the distance between breeding sites, suggesting that populations may be responding to a similar driver. Our approach sheds light on the potential factors that may drive phenology in our study species, thus furthering our understanding of the scales at which different seabirds interact with interannual variation in their environment. We also identify additional systems and phenological questions to which our inferential approach could be applied.
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| 37. |
- Hentati Sundberg, Jonas, et al.
(författare)
-
Övervakning av havsfåglar i Östersjön.
- 2009
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Ingår i: Havet 2009. - Stockholm : Naturvårdsverket. ; , s. 61-64
-
Bokkapitel (populärvet., debatt m.m.)
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| 38. |
- Kadin, Martina, et al.
(författare)
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Common Guillemot Uria aalge parents adjust provisioning rates to compensate for low food quality
- 2016
-
Ingår i: Ibis. - : Wiley. - 0019-1019 .- 1474-919X. ; 158:1, s. 167-178
-
Tidskriftsartikel (refereegranskat)abstract
- The quantity and quality of food available within the foraging area set important constraints for chick-rearing birds, but responses to low quality are not well understood. This study explored the potential for parent birds to adjust quantity (feeding rate) and quality (energy content) in chick provisioning, by studying Common Guillemots Uria aalge on Stora Karlso, Baltic Sea, predominantly utilizing Sprat Sprattus sprattus, during conditions of high food quantity but reduced food quality. Quality is central to reproductive success in this single-prey loader. From the chick's perspective, provisioning rates should be increased to compensate for low food quality and to fulfil its growing needs with increasing age. However, the high energy cost of flying in Guillemots makes it important for parent birds to minimize commutes to feeding areas. Provisioning parameters were recorded during three dawn-to-dusk watches each breeding season from 2005 to 2013, when clupeids, presumably Sprat, constituted 98% of chick diet. Generalized additive mixed models showed that both feeding rate and size of clupeids (a proxy for energy content) varied between years and changed non-linearly with chick age, but that there was no change within breeding seasons. Chick age and year explained 36% of the variation in feeding rate but only 2% of the variation in the size of clupeids in chick diets. We conclude that parent birds tried to adjust both feeding rate and prey size, but were less successful with the latter. A strong negative correlation was found between annual feeding rates and size of clupeids, evaluated as the differences relative to the baseline year, and adjusted for the effects of chick age. Although the differences between years were small, the relationship indicates a compensation mechanism that does not seem to impact adult survival, and by which increased feeding rates can partly counteract reduced chick energy intake when food quality is low.
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| 39. |
- Kadin, Martina, et al.
(författare)
-
Contrasting effects of food quality and quantity on a marine top predator
- 2012
-
Ingår i: Marine Ecology Progress Series. - : Inter-Research Science Center. - 0171-8630 .- 1616-1599. ; 444, s. 239-249
-
Tidskriftsartikel (refereegranskat)abstract
- Overfishing of predatory fish has contributed to an increase in forage-fish stocks. At the same time, a rising demand for forage fish to supply fishmeal markets, in combination with climate change, has put strong pressure on these stocks, and this, in turn, has had an impact on marine top predators. We examined how inter-annual variation in food quality (sprat Sprattus sprattus weight-at-age) and quantity (sprat abundance) influenced Baltic Sea common murres Uria aalge during chick-rearing. Fledging success, i.e. survival from hatching to fledging, showed a positive relationship with food quality, but we found no effect of food quantity. We found no relationship between food quality and parental behaviour or chick feeding parameters, but a negative relationship between food quantity and trip duration. Our data indicate that there was room for parental birds to increase their effort to compensate for reduced food quality, but we found no signs of such compensation. We analysed different types of fish and seabird life-history data to separate effects of food quantity and quality on a top predator. Understanding such effects can contribute to clarifying causes and consequences for observed changes in life-history parameters and population dynamics of top predators.
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| 40. |
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| 41. |
- Lade, Steven J., et al.
(författare)
-
An empirical model of the Baltic Sea reveals the importance of social dynamics for ecological regime shifts
- 2015
-
Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 112:35, s. 11120-11125
-
Tidskriftsartikel (refereegranskat)abstract
- Regime shifts triggered by human activities and environmental changes have led to significant ecological and socioeconomic consequences in marine and terrestrial ecosystems worldwide. Ecological processes and feedbacks associated with regime shifts have received considerable attention, but human individual and collective behavior is rarely treated as an integrated component of such shifts. Here, we used generalized modeling to develop a coupled social-ecological model that integrated rich social and ecological data to investigate the role of social dynamics in the 1980s Baltic Sea cod boom and collapse. We showed that psychological, economic, and regulatory aspects of fisher decision making, in addition to ecological interactions, contributed both to the temporary persistence of the cod boom and to its subsequent collapse. These features of the social-ecological system also would have limited the effectiveness of stronger fishery regulations. Our results provide quantitative, empirical evidence that incorporating social dynamics into models of natural resources is critical for understanding how resources can be managed sustainably. We also show that generalized modeling, which is well-suited to collaborative model development and does not require detailed specification of causal relationships between system variables, can help tackle the complexities involved in creating and analyzing social-ecological models.
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| 42. |
- Olin, Agnes, et al.
(författare)
-
Breeding failures and reduced nest attendance in response to heat stress in a high-latitude seabird
- 2024
-
Ingår i: Marine Ecology Progress Series. - : Inter-Research Science Center. - 0171-8630 .- 1616-1599. ; 737, s. 147-160
-
Tidskriftsartikel (refereegranskat)abstract
- Climate change research on seabirds has so far focused mainly on indirect effects acting via impacts at lower trophic levels. However, seabirds that breed in exposed sites may also be vulnerable to direct impacts from extreme weather events such as heatwaves, which are projected to increase in both severity and frequency with climate change. Yet there are relatively few field studies of how breeding seabirds respond to heatwaves. Here, we used video footage from a breeding colony of common guillemots Uria aalge in the Baltic Sea over 4 consecutive breeding seasons (2019−2022) to explore responses to air temperature and sun exposure. We found a positive relationship between temperature and 2 thermoregulatory behaviours: panting and postural changes. In addition, we show that as temperatures increase, breeding partners spend less time together at the colony. At the highest temperatures, some birds even temporarily abandon their eggs and chicks. Of 48 breeding failures recorded on video over 4 breeding seasons, we documented 13 cases directly associated with heat stress (corresponding to ca. 9% of all 150 breeding attempts recorded); 11 of these occurred during 2 periods with sunshine and particularly high temperatures in 2020 and 2022. Using a larger data set (>500 breeding attempts over 12 seasons), we also identified a clear increase in the probability of egg loss at higher temperatures. As such, the responses of breeding seabirds to heatwaves could have important demographic consequences in some populations, especially as heatwaves continue to increase in frequency and magnitude.
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| 43. |
- Olsson, Olof, et al.
(författare)
-
Global COVID-19 lockdown highlights humans as both threats and custodians of the environment
- 2021
-
Ingår i: Biological Conservation. - : Elsevier BV. - 0006-3207 .- 1873-2917. ; 263
-
Tidskriftsartikel (refereegranskat)abstract
- The global lockdown to mitigate COVID-19 pandemic health risks has altered human interactions with nature. Here, we report immediate impacts of changes in human activities on wildlife and environmental threats during the early lockdown months of 2020, based on 877 qualitative reports and 332 quantitative assessments from 89 different studies. Hundreds of reports of unusual species observations from around the world suggest that animals quickly responded to the reductions in human presence. However, negative effects of lockdown on conservation also emerged, as confinement resulted in some park officials being unable to perform conservation, restoration and enforcement tasks, resulting in local increases in illegal activities such as hunting. Overall, there is a complex mixture of positive and negative effects of the pandemic lockdown on nature, all of which have the potential to lead to cascading responses which in turn impact wildlife and nature conservation. While the net effect of the lockdown will need to be assessed over years as data becomes available and persistent effects emerge, immediate responses were detected across the world. Thus, initial qualitative and quantitative data arising from this serendipitous global quasi-experimental perturbation highlights the dual role that humans play in threatening and protecting species and ecosystems. Pathways to favorably tilt this delicate balance include reducing impacts and increasing conservation effectiveness.
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| 44. |
- Patterson, Allison, et al.
(författare)
-
Foraging range scales with colony size in high-latitude seabirds
- 2022
-
Ingår i: Current Biology. - : Elsevier BV. - 0960-9822 .- 1879-0445. ; 32:17, s. 3800-3807
-
Tidskriftsartikel (refereegranskat)abstract
- Density-dependent prey depletion around breeding colonies has long been considered an important factor controlling the population dynamics of colonial animals.1, 2, 3, 4 Ashmole proposed that as seabird colony size increases, intraspecific competition leads to declines in reproductive success, as breeding adults must spend more time and energy to find prey farther from the colony.1 Seabird colony size often varies over several orders of magnitude within the same species and can include millions of individuals per colony.5,6 As such, colony size likely plays an important role in determining the individual behavior of its members and how the colony interacts with the surrounding environment.6 Using tracking data from murres (Uria spp.), the world’s most densely breeding seabirds, we show that the distribution of foraging-trip distances scales to colony size0.33 during the chick-rearing stage, consistent with Ashmole’s halo theory.1,2 This pattern occurred across colonies varying in size over three orders of magnitude and distributed throughout the North Atlantic region. The strong relationship between colony size and foraging range means that the foraging areas of some colonial species can be estimated from colony sizes, which is more practical to measure over a large geographic scale. Two-thirds of the North Atlantic murre population breed at the 16 largest colonies; by extrapolating the predicted foraging ranges to sites without tracking data, we show that only two of these large colonies have significant coverage as marine protected areas. Our results are an important example of how theoretical models, in this case, Ashmole’s version of central-place-foraging theory, can be applied to inform conservation and management in colonial breeding species.
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| 45. |
- Sarzo, Blanca, et al.
(författare)
-
Bayesian Immature Survival Analysis of the Largest Colony of Common Murre (Uria aalge) in the Baltic Sea
- 2019
-
Ingår i: Waterbirds (De Leon Springs, Fla.). - : Waterbird Society. - 1524-4695 .- 1938-5390. ; 42:3, s. 304-313
-
Tidskriftsartikel (refereegranskat)abstract
- In long-lived species, such as seabirds, immature survival is the most important life history parameter after adult survival. The assessment of immature survival has often been difficult due to extended periods in which young birds remain unobservable at sea. This study presents results on survival of immature Common Murre (Uria aalge) obtained from an extensive mark-recapture study of a large colony at Stora Karlso in the Baltic Sea, Sweden. This colony, in contrast with other colonies, has the unique feature that many 1-year-old birds return to the colony (12%). Between 2006 and 2016, 28,930 chicks were marked at fledging, of which 5,493 individuals were later resighted in the colony. Annual survival and recapture probabilities were estimated using Bayesian Cormack-Jolly-Seber models with four age classes for survival probability, and recapture probability being age and time dependent. Informative prior distributions were used to correct partial observability problems in older age classes (observed at breeding ledges). The estimated survival probability of 1-year-old birds was 0.53 (95% CI = 0.49-0.58), 2-year-old birds was 0.87 (0.79-0.96), 3-year-old birds was 0.96 (0.90-0.99), and 4-to-10-year old bird survival probability was 0.63 (0.61-0.64). Survival estimates for younger age classes were consistent with previous studies. Several biological factors may contribute to the observed decline in survival for older age classes.
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| 46. |
- Snoeijs-Leijonmalm, Pauline, 1956-, et al.
(författare)
-
Review of the research knowledge and gaps on fish populations, fisheries and linked ecosystems in the Central Arctic Ocean (CAO)
- 2020
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This report presents a review of the research knowledge and gaps on fish populations, fisheries and linked ecosystems in the Central Arctic Ocean (CAO). The CAO comprises the deep basins of the Arctic Ocean beyond the shelf break, which largely overlap with the High Seas of the Arctic Ocean, i.e. the marine areas outside the Exclusive Economic Zones (EEZs) of the Arctic coastal nations. The authors of the report are members of the European Fisheries Inventory in the Central Arctic Ocean (EFICA) Consortium. This study was funded by the European Commission as an EU contribution to the international cooperation within the Agreement to Prevent Unregulated High Seas Fisheries in the Central Arctic Ocean.
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| 47. |
- Snoeijs-Leijonmalm, Pauline, 1956-, et al.
(författare)
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Unexpected fish and squid in the central Arctic deep scattering layer
- 2022
-
Ingår i: Science Advances. - : American Association for the Advancement of Science (AAAS). - 2375-2548. ; 8:7
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Tidskriftsartikel (refereegranskat)abstract
- The retreating ice cover of the Central Arctic Ocean (CAO) fuels speculations on future fisheries. However, very little is known about the existence of harvestable fish stocks in this 3.3 million-square kilometer ecosystem around the North Pole. Crossing the Eurasian Basin, we documented an uninterrupted 3170-kilometer-long deep scattering layer (DSL) with zooplankton and small fish in the Atlantic water layer at 100- to 500-meter depth. Diel vertical migration of this central Arctic DSL was lacking most of the year when daily light variation was absent. Unexpectedly, the DSL also contained low abundances of Atlantic cod, along with lanternfish, armhook squid, and Arctic endemic ice cod. The Atlantic cod originated from Norwegian spawning grounds and had lived in Arctic water temperature for up to 6 years. The potential fish abundance was far below commercially sustainable levels and is expected to remain so because of the low productivity of the CAO.
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| 48. |
- Svenson, Anders, et al.
(författare)
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Expeditionsrapport SPRAS 2022 : Ekosystemundersökning i Östersjön
- 2023
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Denna rapport presenterar resultat för Östersjön 2022 från den svenska delen av den internationella undersökningen Sprat Acoustic Survey (SPRAS-Swe). Den internationella undersökningen har pågått sedan 2001, men Sveriges deltagande började först 2020 i och med leveransen av Sveriges nya forskningsfartyg R/V Svea. Undersöknigens syfte är att samla in fiskerioberoende data för beräkning av mängden skarpsill och sill i Östersjön. Det sammanställda resultatet utgör grunden för arbetet med beståndskattning av sill och skarpsillinom ICES arbetsgrupp WGBFAS. I en pilotstudie har vi därtill undersökt möjligheten att utnyttja SPRAS-Swe som en ekosystemexpedition vilket inneburit att utöver den datainsamling som krävs för arbetet med beståndsskattning av sill och skarpsill (WGBFAS) även registrera andra typer av insamlade data för att öka kunskapen kring ekosystemet Östersjön. Ytterligare en målsättning har varit att utveckla insamlings- och analysmetoder för att på sikt minska dödligheten av fisk i samband med vetenskapliga undersökningar.
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| 49. |
- Svensson, Filip, et al.
(författare)
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Rapport för 2018 års kusttrålningsundersökning av kustnära fiskbestånd längs den svenska västkusten
- 2019
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Kusttrålningar har genomförts längs svenska kusten i Västerhavet sedan 2001. En huvudsaklig målsättning sedan starten har varit att övervaka utvecklingen av lokala bestånd och kustkomponenter av bestånd för ett urval av fiskarter med särskild fokus på torsk. Sedan 2009 är provtagningen fokuserad till kustavsnittet med skärgård mellan Fladen banken i söder och Singlefjorden i norr och sedan 2013 är provtagningen anpassad för att även övervaka fisksamhällets utveckling för Havsmiljödirektivet vad det gäller biologisk mångfald och marina näringsvävar. Årets kusttrålning genomfördes den 3-13 september 2018 då sammanlagt 32 trålstationer besöktes i norra Västerhavet. I kustområden gjordes 24 tråldrag och i utsjön gjordes åtta tråldrag. Fångsterna av torsk längs kusten under 2018 låg i stort sätt på samma låga nivå som föregående år. Förekomsten av stor könsmogen torsk längs kusten var fortsatt mycket låg; den största torsken som fångades i kustområdena under 2018 var 56 cm lång och fångades i Askeröfjorden. Fångsterna av torsk i utsjön under 2018 indikerar i jämförelse med 2017 års provtagning en fortsatt minskning. Fångsterna av torsk i utsjön 2018 var de lägsta som registrerats sedan provtagningen började. Vitling är en av de vanligaste fiskarterna som fångas i kusttrålningen under de senaste åren (2013-2018). De negativa trenderna för vitling både i utsjön och i kustområdena fortsatte under 2018 på samma sätt som under 2017. Fångstnivåerna för kolja i kustområdena var på en liknande nivå som under 2017 års kusttrålning samtidigt som koljan i utsjön befann sig på den lägsta nivå som registrerats sedan kusttrålningen startade. Generellt, vad det gäller torskfiskar så utgjordes fångsterna nästan uteslutande av juvenil fisk. Två arter av rocka fångades – knaggrocka och klorocka. Totalt fångades 48 olika fiskarter.
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| 50. |
- Weidner, Elizabeth, et al.
(författare)
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Tracking the spatiotemporal variability of the oxic-anoxic interface in the Baltic Sea with broadband acoustics
- 2020
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Ingår i: ICES Journal of Marine Science. - : Oxford University Press (OUP). - 1054-3139 .- 1095-9289. ; 77:7-8, s. 2814-2824
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Tidskriftsartikel (refereegranskat)abstract
- Anoxic zones, regions of the water column completely devoid of dissolved oxygen, occur in open oceans and coastal zones worldwide. The Baltic Sea is characterized by strong salinity-driven stratification, maintained by occasional water inflows from the Danish Straights and freshwater input from rivers. Between inflow events, the stratification interface between surface and deep waters hinders mixing and ventilation of deep water; consequently, the bottom waters of large regions of the Baltic are anoxic. The onset of the anoxic zone is closely coincident with the depth of the halocline and, as a result, the interface between oxic and anoxic waters corresponds to a strong impedance contrast. Here, we track acoustic scattering from the impedance contrast utilizing a broadband split-beam echosounder in the Western Gotland Basin and link it to a dissolved oxygen level of 2ml/l using ground truth stations. The broadband acoustic dataset provides the means to remotely observe the spatiotemporal variations in the oxic-anoxic interface, map out the extent of the anoxic zone with high resolution, and identify several mechanisms influencing the vertical distribution of oxygen in the water column. The method described here can be used to study other systems with applications in ongoing oceanographic monitoring programs.
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