1. |
- Gullström, Martin, et al.
(author)
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Blue Carbon Storage in Tropical Seagrass Meadows Relates to Carbonate Stock Dynamics, Plant–Sediment Processes, and Landscape Context : Insights from the Western Indian Ocean
- 2018
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In: Ecosystems (New York. Print). - : Springer Science and Business Media LLC. - 1432-9840 .- 1435-0629. ; 21:3, s. 551-566
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Journal article (peer-reviewed)abstract
- Globally, seagrass ecosystems are considered major blue carbon sinks and thus indirect contributors to climate change mitigation. Quantitative estimates and multi-scale appraisals of sources that underlie long-term storage of sedimentary carbon are vital for understanding coastal carbon dynamics. Across a tropical–subtropical coastal continuum in the Western Indian Ocean, we estimated organic (Corg) and inorganic (Ccarb) carbon stocks in seagrass sediment. Quantified levels and variability of the two carbon stocks were evaluated with regard to the relative importance of environmental attributes in terms of plant–sediment properties and landscape configuration. The explored seagrass habitats encompassed low to moderate levels of sedimentary Corg (ranging from 0.20 to 1.44% on average depending on species- and site-specific variability) but higher than unvegetated areas (ranging from 0.09 to 0.33% depending on site-specific variability), suggesting that some of the seagrass areas (at tropical Zanzibar in particular) are potentially important as carbon sinks. The amount of sedimentary inorganic carbon as carbonate (Ccarb) clearly corresponded to Corg levels, and as carbonates may represent a carbon source, this could diminish the strength of seagrass sediments as carbon sinks in the region. Partial least squares modelling indicated that variations in sedimentary Corg and Ccarb stocks in seagrass habitats were primarily predicted by sediment density (indicating a negative relationship with the content of carbon stocks) and landscape configuration (indicating a positive effect of seagrass meadow area, relative to the area of other major coastal habitats, on carbon stocks), while seagrass structural complexity also contributed, though to a lesser extent, to model performance. The findings suggest that accurate carbon sink assessments require an understanding of plant–sediment processes as well as better knowledge of how sedimentary carbon dynamics are driven by cross-habitat links and sink–source relationships in a scale-dependent landscape context, which should be a priority for carbon sink conservation.
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2. |
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3. |
- Alati, Victor Mwakha, et al.
(author)
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Gender analysis in fisheries : The case of the shelled mollusc fisheries in Kenya
- 2023
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In: Marine Policy. - : Elsevier. - 0308-597X .- 1872-9460. ; 158
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Journal article (peer-reviewed)abstract
- Analysing gender in small-scale fisheries (SSF) is vital for understanding the contributions of women and men and detecting potential inequalities. In this study, the shelled mollusc fishery was examined through the gender lens using quantitative and qualitative data collected from 132 shelled mollusc fishers accross five sites in coastal Kenya. In Kenya, both women and men participate in shelled mollusc fisheries. The study incorporated in its analyses the main components that intersect with gender to investigate whether similarities and differences exist in SSF in coastal Kenya in terms of access to shelled mollusc fisheries resources and the distribution of monetary benefits from the fishery. Most women respondents (73%, n = 91) relied on shelled mollusc fishing as their primary occupation compared to men (17%, n = 41) whose primary occupation was finfish fishing (69%, n = 41). There was no significant difference (p > 0.05) between women and men fishers in terms of income per individual fisher, time spent fishing, the number of species caught per individual fisher, as well as the monetary value of shells caught. There are several similarities between women and men in this fishery, but with a very important distinction that women more often consider this fishery their primary occupation. Thus, women constitute a large and important part of this fishery in Kenya. To advance coastal and fisheries management, it is essential that women, as well as gender aspects, are included in policy and decision-making processes related to SSF.
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4. |
- Alati, Victor Mwakha, et al.
(author)
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Mollusc shell fisheries in coastal Kenya : Local ecological knowledge reveals overfishing
- 2020
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In: Ocean and Coastal Management. - : ELSEVIER SCI LTD. - 0964-5691 .- 1873-524X. ; 195
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Journal article (peer-reviewed)abstract
- There is limited documentation on the status and dynamics of fished marine shelled mollusc species in many countries. Some of the challenges are due to obscure documentation of species, extensive unregulated and unrecorded fishing and unawareness of drivers behind declining stocks. The lack of understanding makes it difficult to formulate effective management plans. Here, we assess the fishers' perceptions on changes in abundance of targeted marine shelled mollusc species and status of associated fished habitats. We interviewed 132 marine shelled mollusc gleaners (fishing by walking) at five sites in coastal Kenya. We established that a multispecies marine shelled mollusc fishery is present in Kenya and that this fishery is conducted by both women and men. We distinguished 158 different shelled mollusc species being targeted. The gleaners perceived a temporal decline of gleaned species. The main causes for the decline were perceived to be overfishing of shells, elevated sea-surface temperature and habitat destruction. The more experienced gleaners perceived a greater decline indicating a baseline shift in perceptions. Our findings suggest that local ecological knowledge is useful to understand historic changes in fisheries lacking long-term scientific data. Furthermore, it highlights the potential benefits of a collaboration between ecologists and gleaners to improve our understanding of the status and dynamics of fishing of marine shelled molluscs as well as other types of fishing.
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5. |
- Alonso Aller, Elisa, et al.
(author)
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Monitoring of a protected multi-specific tropical seagrass meadow reveals a pattern of decline and recovery
-
Other publication (other academic/artistic)abstract
- In a changing environment, there is an increasing interest to monitor ecosystems to understand their responses to environmental change. Seagrass meadows are highly important ecosystems, but at the same time they are under a constant threat from human activities, as well as climate impacts, and marked declines have been observed worldwide. Despite increasing efforts, monitoring of multi-specific tropical seagrass meadows is scarce, particularly in developing regions. Here we analysed data from the first 10 years of a monitoring programme in a marine protected area in Zanzibar (Tanzania) to assess temporal changes in seagrass cover and species composition and to detect potential drivers of change. The seagrass meadow experienced a strong gradual decline in seagrass cover and changes in species composition, followed by a period of recovery. However, the timing and length of these temporal patterns varied in space (between transects). Of the climate variables considered, cloud cover, temperature, storm occurrence, sunspot activity and the height of the diurnal low tide seemed to influence seagrass cover, although only to a small extent, suggesting that the monitored seagrass meadow may be influenced by other unmeasured factors. Considering our results, seagrass meadows seem to be highly dynamic at small spatial scales even in the absence of major local anthropogenic impacts. Further monitoring programmes should be developed in the region to gain a better understanding of seagrass temporal variability and causes of change.
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6. |
- Alonso Aller, Elisa, et al.
(author)
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Single and joint effects of regional- and local-scale variables on tropical seagrass fish assemblages
- 2014
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In: Marine Biology. - : Springer Science and Business Media LLC. - 0025-3162 .- 1432-1793. ; 161:10, s. 2395-2405
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Journal article (peer-reviewed)abstract
- Seagrass beds are highly important for tropical ecosystems by supporting abundant and diverse fish assemblages that form the basis for artisanal fisheries. Although a number of local- and regional-scale variables are known to influence the abundance, diversity and assemblage structure of seagrass-associated fish assemblages, few studies have evaluated the relative and joint (interacting) influences of variables, especially those acting at different scales. Here, we examined the relative importance of local- and regional-scale factors structuring seagrass-associated fish assemblages, using a field survey in six seagrass (Thalassodendron ciliatum) areas around Unguja Island (Zanzibar, Tanzania). Fish density and assemblage structure were mostly affected by two regional-scale variables; distance to coral reefs, which positively affected fish density, and level of human development, which negatively affected fish density. On the local scale, seagrass biomass had a positive (but weaker) influence on fish density. However, the positive effect of seagrass biomass decreased with increasing level of human development. In summary, our results highlight the importance of assessing how multiple local and regional variables, alone and together, influence fish communities, in order to improve management of seagrass ecosystems and their services.
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7. |
- Alonso Aller, Elisa, et al.
(author)
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Temporal variability of a protected multispecific tropical seagrass meadow in response to environmental change
- 2019
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In: Environmental Monitoring and Assessment. - : Springer Science and Business Media LLC. - 0167-6369 .- 1573-2959. ; 191
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Journal article (peer-reviewed)abstract
- In a changing environment, there is an increasing interest to monitor ecosystems to understand their responses to environmental change. Seagrass meadows are highly important ecosystems that are under constant pressure from human activities and climate impacts, with marked declines observed worldwide. Despite increasing efforts, monitoring of multispecific tropical seagrass meadows is scarce, particularly in low-income regions. Based on data from a monitoring programme in a marine protected area in Zanzibar (Tanzania), we assessed temporal changes in seagrass cover and species composition during a 10-year period in relation to local variability in environmental variables. We observed a strong, gradual decline in seagrass cover and changes in species composition, followed by a period of recovery. However, the timing and length of these temporal patterns varied in space (between transects). Multiple environmental variables—cloud cover, temperature, storm occurrence, sunspot activity, and tidal amplitude and height—influenced seagrass cover, although only to a minor extent, suggesting that the monitored seagrass meadow may be influenced by other unmeasured factors (e.g. water currents and sediment movement). Our results show that seagrass meadows can be highly dynamic at small (10–50m) spatial scales, even in the absence of major local anthropogenic impacts. Our findings suggest that high-resolution monitoring programmes can be highly valuable for the detection of temporal changes in multispecific seagrass meadows; however, to understand the causes of change, there is a need of long-term (> 10years) data series that include direct measurements of environmental variables and extreme events.
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8. |
- Berkström, Charlotte, et al.
(author)
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Fishers' Local Ecological Knowledge (LEK) on Connectivity and Seascape Management
- 2019
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In: Frontiers in Marine Science. - : Frontiers Media SA. - 2296-7745. ; 6
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Journal article (peer-reviewed)abstract
- In developing countries where data and resources are lacking, the practical relevance of local ecological knowledge (LEK) to expand our understanding of the environment, has been highlighted. The potential roles of the LEK varies from direct applications such as gathering environmental information to a more participative involvement of the community in the management of resources they depend on. Fishers' LEK could therefore be useful in order to obtain information on how to advance management of coastal fisheries. Many targeted fish species migrate between habitats to feed, spawn or recruit, connecting important habitats within the seascape. LEK could help provide answers to questions related to this connectivity and the identification of fish habitat use, and migrations for species and areas where such knowledge is scarce. Here we assess fishers' LEK on connectivity between multiple habitats within a tropical seascape, investigate the differences in LEK among fisher groups and the coherence between LEK and conventional scientific knowledge (CSK). The study was conducted in 2017 in Zanzibar, Tanzania, a tropical developing country. One hundred and thirty-five semi-structured interviews were conducted in six different locations focusing on fish migrations, and matching photos of fish and habitats. Differences between fisher groups were found, where fishers traveling further, exposed to multiple habitats, and who fish with multiple gears had a greater knowledge of connectivity patterns within the seascape than those that fish locally, in single habitats and with just one type of gear. A high degree of overlap in LEK and CSK was found, highlighting the potential benefits of a collaboration between scientists and fishers, and the use of LEK as complementary information in the management of small-scale fisheries.
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9. |
- Charisiadou, S., et al.
(author)
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Coastal aquaculture in Zanzibar, Tanzania
- 2022
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In: Aquaculture. - : Elsevier. - 0044-8486 .- 1873-5622. ; 546
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Journal article (peer-reviewed)abstract
- This study provides an overview of the multi-sectoral coastal aquaculture development in Zanzibar (Tanzania) over the last thirty years based on empirical evidence from interviews, field observations, policy reports and literature reviews. Despite the immense potential of aquaculture for food and livelihoods, only seaweed farming has so far established into commercial-scale production. This activity is dominated by women and became widespread in the early 1990s as a small but regular source of income. However, seaweed farming constraints such as frequent seaweed die-offs, as well as economic and institutional constraints inhibit its development. Other types of aquaculture activities such as fish farming, mud crab fattening, half-pearl farming, sea cucumber farming and sponge and coral cultures are under development with limited production or in experimental stages. Common constraints among these activities are economic limitations, lack of technical infrastructure and skills, small and irregular production, and limited trade and market availabilities. At the same time, there is a lack of sufficient management and monitoring systems, while there are no formal regulations or clear strategies to boost aquaculture at the national level. In addition, new aquaculture initiatives are often dominated by donor-driven projects instead of local entrepreneurships. This situation does not encourage engagement in aquaculture and thus such activities are outcompeted by other already established sectors (e.g. agriculture and fisheries). We conclude that aquaculture has great potential to evolve due to high environmental capacity. Nevertheless, achieving profitable production and a stronger commitment within local communities, as well as developing effective mariculture governance through support mechanisms and clear strategies to boost the sector at the national level, are essential for sustainable mariculture development in Zanzibar.
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10. |
- Duffy, J. Emmett, et al.
(author)
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Toward a Coordinated Global Observing System for Seagrasses and Marine Macroalgae
- 2019
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In: Frontiers in Marine Science. - : Frontiers Media S.A.. - 2296-7745. ; 6
-
Research review (peer-reviewed)abstract
- In coastal waters around the world, the dominant primary producers are benthic macrophytes, including seagrasses and macroalgae, that provide habitat structure and food for diverse and abundant biological communities and drive ecosystem processes. Seagrass meadows and macroalgal forests play key roles for coastal societies, contributing to fishery yields, storm protection, biogeochemical cycling and storage, and important cultural values. These socio-economically valuable services are threatened worldwide by human activities, with substantial areas of seagrass and macroalgal forests lost over the last half-century. Tracking the status and trends in marine macrophyte cover and quality is an emerging priority for ocean and coastal management, but doing so has been challenged by limited coordination across the numerous efforts to monitor macrophytes, which vary widely in goals, methodologies, scales, capacity, governance approaches, and data availability. Here, we present a consensus assessment and recommendations on the current state of and opportunities for advancing global marine macrophyte observations, integrating contributions from a community of researchers with broad geographic and disciplinary expertise. With the increasing scale of human impacts, the time is ripe to harmonize marine macrophyte observations by building on existing networks and identifying a core set of common metrics and approaches in sampling design, field measurements, governance, capacity building, and data management. We recommend a tiered observation system, with improvement of remote sensing and remote underwater imaging to expand capacity to capture broad-scale extent at intervals of several years, coordinated with strati fied in situ sampling annually to characterize the key variables of cover and taxonomic or functional group composition, and to provide ground-truth. A robust networked system of macrophyte observations will be facilitated by establishing best practices, including standard protocols, documentation, and sharing of resources at all stages of work flow, and secure archiving of open-access data. Because such a network is necessarily distributed, sustaining it depends on close engagement of local stakeholders and focusing on building and long-term maintenance of local capacity, particularly in the developing world. Realizing these recommendations will producemore effective, efficient, and responsive observing, a more accurate global picture of change in vegetated coastal systems, and stronger international capacity for sustaining observations.
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11. |
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12. |
- Hedberg, Nils, et al.
(author)
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Habitat preference for seaweed farming - A case study from Zanzibar, Tanzania
- 2018
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In: Ocean and Coastal Management. - : Elsevier BV. - 0964-5691 .- 1873-524X. ; 154, s. 186-195
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Journal article (peer-reviewed)abstract
- Global marine seaweed aquaculture is growing rapidly. In Zanzibar, Tanzania, seaweed farming, primarily conducted by women, is the main coastal aquaculture activity. Many types of aquaculture are linked to a specific ecosystem (e.g. shrimp-mangrove), and understanding if such a coupling exists for seaweed farming important for further development. A prerequisite to understand if farming affects coastal habitats is the need to know where, and on which habitat, the farms are located. In this study, we investigated the habitat preferences of seaweed farmers by interviews, field observations and satellite imagery analysis. We found that the majority of the farms were distributed in a narrow corridor (380-600 m from shore) along the coast where water depth (x) over bar = 2 m) and tidal regime (+/- 2 m) allow for a suitable environment for both the algae and the farmers. Within this corridor, thus defined by depth, the water is deep enough for the algae not to be overexposed to sunlight but also sufficiently shallow for the women to access and work on the farms at low tide. The farmers accordingly expressed depth as the major limiting factor when choosing the site for their farms, and the preferred habitat type was seagrass beds. Most farms (92%) were partly located on seagrass meadows, but also other habitats, such as sand. The total area of the studied seaweed farms was 65.6 ha, with 39% of this being seagrass meadow, which is significantly more than the seagrass cover in the farming corridor. The farms also covered 43% sand; however, the interviews indicate that a substantial part of the sandy areas was, in fact, also recently covered by seagrasses. Our findings are relevant for improved management, conservation, and marine spatial planning, as we show where and on which habitats seaweed farms are preferably located. This information can be used to further investigate the ecological impact on the habitats and their associated fauna and in order to provide more effective management actions. Furthermore, this is much-needed baseline information for investigating the increased production of seaweed, i.e. if the habitat has any effect on the algae growth.
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13. |
- Jahnke, Marlene, et al.
(author)
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Population genetic structure and connectivity of the seagrass Thalassia hemprichii in the Western Indian Ocean is influenced by predominant ocean currents
- 2019
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In: Ecology and Evolution. - : John Wiley & Sons. - 2045-7758. ; 9:16, s. 8953-8964
-
Journal article (peer-reviewed)abstract
- This study is the first large-scale genetic population study of a widespread climax species of seagrass, Thalassia hemprichii, in the Western Indian Ocean (WIO). The aim was to understand genetic population structure and connectivity of T. hemprichii in relation to hydrodynamic features. We genotyped 205 individual seagrass shoots from 11 sites across the WIO, spanning over a distance of similar to 2,700 km, with twelve microsatellite markers. Seagrass shoots were sampled in Kenya, Tanzania (mainland and Zanzibar), Mozambique, and Madagascar: 4-26 degrees S and 33-48 degrees E. We assessed clonality and visualized genetic diversity and genetic population differentiation. We used Bayesian clustering approaches (TESS) to trace spatial ancestry of populations and used directional migration rates (DivMigrate) to identify sources of gene flow. We identified four genetically differentiated groups: (a) samples from the Zanzibar channel; (b) Mozambique; (c) Madagascar; and (d) the east coast of Zanzibar and Kenya. Significant pairwise population genetic differentiation was found among many sites. Isolation by distance was detected for the estimated magnitude of divergence (D-EST), but the three predominant ocean current systems (i.e., East African Coastal Current, North East Madagascar Current, and the South Equatorial Current) also determine genetic connectivity and genetic structure. Directional migration rates indicate that Madagascar acts as an important source population. Overall, clonality was moderate to high with large differences among sampling sites, indicating relatively low, but spatially variable sexual reproduction rates. The strongest genetic break was identified for three sites in the Zanzibar channel. Although isolation by distance is present, this study suggests that the three regionally predominant ocean current systems (i.e., East African Coastal Current, North East Madagascar Current, and the South Equatorial Current) rather than distance determine genetic connectivity and structure of T. hemprichii in the WIO. If the goal is to maintain genetic connectivity of T. hemprichii within the WIO, conservation planning and implementation of marine protection should be considered at the regional scale-across national borders.
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14. |
- Jones, Benjamin L. H., et al.
(author)
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Dependence on seagrass fisheries governed by household income and adaptive capacity
- 2022
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In: Ocean and Coastal Management. - : Elsevier BV. - 0964-5691 .- 1873-524X. ; 225
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Journal article (peer-reviewed)abstract
- Seagrass meadows, like other tropical coastal ecosystems, are highly productive and sustain millions of people worldwide. However, the factors that govern the use of seagrass as a fishing habitat over other habitats are largely unknown, especially at the household scale. Using socioeconomic factors from 147 villages across four countries within the Indo-Pacific, we examined the drivers of household dependence on seagrass. We revealed that seagrass was the most common habitat used for fishing across villages in all the countries studied, being preferred over other habitats for reliability. Using structural equation modelling, we exposed how household income and adaptive capacity appears to govern dependence on seagrass. Poorer households were less likely to own motorboats and dependent on seagrass as they were unable to fish elsewhere, whereas wealthier households were more likely to invest in certain fishing gears that incentivised them to use seagrass habitats due to high rewards and low effort requirements. Our findings accentuate the complexity of seagrass social-ecological systems and the need for empirical household scale data for effective management. Safeguarding seagrass is vital to ensure that vulnerable households have equitable and equal access to the resource, addressing ocean recovery and ensuring sustainable coastal communities.
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15. |
- Jones, Benjamin L. H., et al.
(author)
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Unintended consequences of sustainable development initiatives : risks and opportunities in seagrass social-ecological systems
- 2022
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In: Ecology and Society. - : Resilience Alliance, Inc.. - 1708-3087. ; 27:2
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Journal article (peer-reviewed)abstract
- Conserving biodiversity with a growing human population is a key sustainability challenge. Consequently, a vast number of development initiatives across the globe have been designed to combine social, economic, and environmental perspectives. For the most part, the development community is well acquainted with the negative experiences and unintended consequences that some projects have or may bring. However, in tropical coastal ecosystems, this aspect is not completely acknowledged, studied, or understood. Here, we use tropical seagrass meadows as a model social-ecological system to investigate how sustainable development initiatives result in unintended consequences with both positive and negative outcomes for environment and society. We analyze the initiatives and their effects in terms of a typology encompassing ???flow???, ???addition???, and ???deletion??? effects and investigate them across four types of sustainable development initiatives that occur within tropical coastal environments: (1) megafauna conservation, (2) alternative livelihood programs, (3) mosquito net malaria prophylaxis, and (4) marine protected areas. Using these four initiatives as examples, we show that sustainable development initiatives can produce unintended effects with major consequences. Further, we illustrate how not assessing such effects may ultimately undermine the initial goals of the sustainable development intervention. Our study suggests that acknowledging unintended effects and transitioning them so that they become sustainable is more effective than ignoring effects or viewing them as trade-offs. We strongly stress the need for an a priori process in which positive effects, negative effects, and potential uncertainties and surprises are considered when planning the development intervention, and we argue for greater social-ecological monitoring of initiatives. As such, this contribution links to contemporary approaches dealing with the sustainability of natural resources and social-ecological systems and bridges with the importance of development initiatives in the context of the United Nations Sustainable Development Goals.
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16. |
- Jones, Benjamin L., et al.
(author)
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Local Ecological Knowledge Reveals Change in Seagrass Social–Ecological Systems
- 2022
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In: Oceans. - : MDPI AG. - 2673-1924. ; 3:3, s. 419-430
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Journal article (peer-reviewed)abstract
- It is widely recognized that humanity is currently facing multiple planetary crises, including the widespread loss of biodiversity and a rapidly changing climate. The impacts of these crises are often far reaching and threaten food security (SDG goal two: zero hunger). Small-scale fisheries are estimated to provide livelihoods for over one hundred million people and sustenance for approximately one billion people but face a plethora of threats and challenges linked to planetary crises. In this multi-country assessment (150 coastal villages across five countries within the Indo-Pacific), household interviews revealed how seagrass meadows are important to small-scale fisheries, particularly as a place to find and collect a reliable source of food. Interviews also revealed that habitat loss and the over-exploitation of these resources are placing people and their food security at risk. This study exposed how dynamic local ecological knowledge can be, uncovering personal opinions and responsibilities that result in the hybridization of knowledge. Here, we demonstrate the importance of using local ecological knowledge to incorporate shared values into management but also highlight that an integrated approach, pairing local and conventional scientific knowledge, is needed urgently if we are to meet the needs of people while simultaneously conserving biodiversity.
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17. |
- Jones, Benjamin L., et al.
(author)
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Seagrass Structural Traits Drive Fish Assemblages in Small-Scale Fisheries
- 2021
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In: Frontiers in Marine Science. - : Frontiers Media SA. - 2296-7745. ; 8
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Journal article (peer-reviewed)abstract
- Seagrasses - a group of foundation species in coastal ecosystems - provide key habitat for diverse and abundant faunal assemblages and support numerous ecosystem functions and services. However, whether the habitat role of seagrasses is influenced by seagrass diversity, by dominant species or both, remains unclear. To that end, we sought to investigate the specific seagrass characteristics (e.g., species diversity, seagrass traits) that influence tropical fish assemblages, and place this in the context of small-scale fishery use. We surveyed seagrass variables at 55 plots, nested within 12 sites around Zanzibar (Tanzania) in the Western Indian Ocean, and used Baited Remote Underwater Video (BRUV) systems to assess fish assemblages across plots. Using linear mixed models, we reveal that seagrass structural complexity and depth were the best predictors of fish abundance, with higher abundance occurring in deeper meadows or meadows with high canopy, leaf length and number of leaves per shoot. Moreover, an interaction between seagrass cover and land-use was the best predictor of fish species richness, where sites closer to human impacts were less affected by cover than sites with lower human impact. Overall, models with seagrass species richness or functional diversity as predictors poorly explained fish assemblages. Fish taxa that were important for small-scale fishery sectors (e.g., emperors, snappers, rabbitfish, and parrotfish) were primarily driven by seagrass structural complexity. Our results provide a unique analysis of the relationship between seagrass habitat and its associated fish assemblages in that we show that seagrass species diversity had little effect on seagrass fish assemblages, which instead appear driven by specific seagrass traits and seagrass cover. If conserving high value species that support adjacent fisheries is the priority for protecting seagrass meadows, then seagrass areas should be chosen with high cover and structural complexity that are in deeper waters. Any conservation measures also need to balance the needs of fishers that use the resources supported by seagrasses.
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18. |
- Jones, Benjamin, 1991-
(author)
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Of seagrass and society : Exploring contributions of tropical seagrass meadows to food security
- 2022
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Doctoral thesis (other academic/artistic)abstract
- Conserving biodiversity while simultaneously feeding a growing population is one of the grand challenges of the Anthropocene. Recently, global assessments have shone a light on the importance of the marine environment for the supply of food (often termed blue food), as well as the diverse and many livelihood opportunities associated to it. Small-scale fisheries (SSF) are essential to this, in which the pursuit of fish and invertebrates are central. If we are to look to blue foods to tackle food insecurity, we need deeper understanding of how coastal habitats function at the nexus of biodiversity, people, and food. Simply put, we need to know how habitats contribute to the supply of food, both in terms of ecological functions and social-economic drivers. Seagrass meadows, diverse and abundant across the Indo-Pacific region, are one of numerous coastal ecosystems that provide food and livelihoods opportunities. Using these systems as a setting, this thesis aims to explore how seagrass meadows and their associated SSF contribute to food security. Comprised of five papers, this thesis relies on a mixed-methods approach to understand seagrass social-ecological systems. The papers range in their dependence on empirical data, their scale as well as the methods employed. Paper I used biodiversity ecosystem function theories to assess the influence of seagrass biota on the production of associated fish in the context of SSF in Tanzania. It highlighted that structural seagrass traits, rather than species richness, are key for driving the abundance and richness of species that are key for food. Paper II investigated the socio-economic drivers that influence seagrass use at the household level. It revealed that household use of seagrass meadows for food and income was higher than all other habitats, and that people use seagrass meadows because they are reliable. It also revealed that household income was key in shaping why people use seagrass meadows as fishing grounds, where both low- and high-income households were dependent on the habitat; low income as a safety-net and high income for high rewards. Paper III examined two key elements of food security, food quantity and quality, and revealed how seagrass meadows contribute to both in the context of micronutrients that are vital for human health. Data from across East Africa showed that seagrass meadows played a more important role than other habitats in providing micronutrient-rich fish species. Paper IV used local ecological knowledge to reveal perceived temporal change in fish and invertebrate abundance and size, but simultaneously identified potential contrasting cognitions that place human communities at risk. Finally, Paper V provided a synthesis of past studies that explored how certain sustainable development initiative result in unintended consequences that influence the supply of blue food. It revealed a number of unintended effects which place the people that use seagrass meadows at risk while at the same time lessening the positive effects of the sustainable development initiative itself. This thesis describes the dynamic interactions between biodiversity, people and food, and place seagrass meadows – habitats that exist globally – at the forefront of the blue food agenda. It highlights how seagrass meadows represent many of the qualities we hope for in a food system – a system that provides sufficient, safe, and nutritious food for multiple and diverse individuals across society.
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19. |
- Jung, Christian, et al.
(author)
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A comparison of very old patients admitted to intensive care unit after acute versus elective surgery or intervention
- 2019
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In: Journal of critical care. - : W B SAUNDERS CO-ELSEVIER INC. - 0883-9441 .- 1557-8615. ; 52, s. 141-148
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Journal article (peer-reviewed)abstract
- Background: We aimed to evaluate differences in outcome between patients admitted to intensive care unit (ICU) after elective versus acute surgery in a multinational cohort of very old patients (80 years; VIP). Predictors of mortality, with special emphasis on frailty, were assessed.Methods: In total, 5063 VIPs were induded in this analysis, 922 were admitted after elective surgery or intervention, 4141 acutely, with 402 after acute surgery. Differences were calculated using Mann-Whitney-U test and Wilcoxon test. Univariate and multivariable logistic regression were used to assess associations with mortality.Results: Compared patients admitted after acute surgery, patients admitted after elective surgery suffered less often from frailty as defined as CFS (28% vs 46%; p < 0.001), evidenced lower SOFA scores (4 +/- 5 vs 7 +/- 7; p < 0.001). Presence of frailty (CFS >4) was associated with significantly increased mortality both in elective surgery patients (7% vs 12%; p = 0.01), in acute surgery (7% vs 12%; p = 0.02).Conclusions: VIPs admitted to ICU after elective surgery evidenced favorable outcome over patients after acute surgery even after correction for relevant confounders. Frailty might be used to guide clinicians in risk stratification in both patients admitted after elective and acute surgery.
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20. |
- Knudby, Anders, et al.
(author)
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Remote sensing of seagrasses in a patchy multi-species environment
- 2011
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In: International Journal of Remote Sensing. - : Informa UK Limited. - 0143-1161 .- 1366-5901. ; 32:8, s. 2227-2244
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Journal article (peer-reviewed)abstract
- We tested the utility of IKONOS satellite imagery to map seagrass distribution and biomass in a 4.1 km2 area around Chumbe Island, Zanzibar, Tanzania. Considered to be a challenging environment to map, this area is characterized by a diverse mix of inter- and subtidal habitat types. Our mapped distribution of seagrasses corresponded well to field data, although the total seagrass area was underestimated due to spectral confusion and misclassification of areas with sparse seagrass patches as sparse coral and algae-covered limestone rock. Seagrass biomass was also accurately estimated (r2 = 0.83), except in areas with Thalassodendron ciliatum (r2 = 0.57), as the stems of T. ciliatum change the relationship between light interception and biomass from that of other species in the area. We recommend the use of remote sensing over field-based methods for seagrass mapping because of the comprehensive coverage, high accuracy and ability to estimate biomass. The results obtained with IKONOS imagery in our complex study area are encouraging, and support the use of this data source for seagrass mapping in similar areas.
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21. |
- Knudby, Anders, et al.
(author)
-
Using multiple Landsat scenes in an ensemble classifier reduces classification error in a stable nearshore environment
- 2014
-
In: International Journal of Applied Earth Observation and Geoinformation. - : Elsevier BV. - 1569-8432 .- 1872-826X. ; 28, s. 90-101
-
Journal article (peer-reviewed)abstract
- Medium-scale land cover maps are traditionally created on the basis of a single cloud-free satellite scene, leaving information present in other scenes unused. Using 1309 field observations and 20 cloud- and error-affected Landsat scenes covering Zanzibar Island, this study demonstrates that the use of multiple scenes can both allow complete coverage of the study area in the absence of cloud-free scenes and obtain substantially improved classification accuracy. Automated processing of individual scenes includes derivation of spectral features for use in classification, identification of clouds, shadows and the land/water boundary, and random forest-based land cover classification. An ensemble classifier is then created from the single-scene classifications by voting. The accuracy achieved by the ensemble classifier is 70.4%, compared to an average of 62.9% for the individual scenes, and the ensemble classifier achieves complete coverage of the study area while the maximum coverage for a single scene is 1209 of the 1309 field sites. Given the free availability of Landsat data, these results should encourage increased use of multiple scenes in land cover classification and reduced reliance on the traditional single-scene methodology.
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22. |
- Leinartaité, Lina, 1982-, et al.
(author)
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Folding catalysis by transient coordination of Zn2+ to the Cu ligands of the ALS-associated enzyme Cu/Zn superoxide dismutase 1
- 2010
-
In: Journal of the American Chemical Society. - : American Chemical Society (ACS). - 0002-7863 .- 1520-5126. ; 132:38, s. 13495-504
-
Journal article (peer-reviewed)abstract
- How coordination of metal ions modulates protein structures is not only important for elucidating biological function but has also emerged as a key determinant in protein turnover and protein-misfolding diseases. In this study, we show that the coordination of Zn(2+) to the ALS-associated enzyme Cu/Zn superoxide dismutase (SOD1) is directly controlled by the protein's folding pathway. Zn(2+) first catalyzes the folding reaction by coordinating transiently to the Cu ligands of SOD1, which are all contained within the folding nucleus. Then, after the global folding transition has commenced, the Zn(2+) ion transfers to the higher affinity Zn site, which structures only very late in the folding process. Here it remains dynamically coordinated with an off rate of ∼10(-5) s(-1). This relatively rapid equilibration of metals in and out of the SOD1 structure provides a simple explanation for how the exceptionally long lifetime, >100 years, of holoSOD1 is still compatible with cellular turnover: if a dissociated Zn(2+) ion is prevented from rebinding to the SOD1 structure then the lifetime of the protein is reduced to a just a few hours.
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23. |
- McKenzie, Len J., et al.
(author)
-
The global distribution of seagrass meadows
- 2020
-
In: Environmental Research Letters. - : IOP Publishing. - 1748-9326. ; 15:7
-
Journal article (peer-reviewed)abstract
- Seagrass meadows globally are under pressure with worldwide loss and degradation, but there is a growing recognition of the global importance of seagrass ecosystem services, particularly as a major carbon sink and as fisheries habitat. Estimates of global seagrass spatial distribution differ greatly throughout the published literature, ranging from 177 000 to 600 000 km(2)with models suggesting potential distribution an order of magnitude higher. The requirements of the Paris Climate Agreement by outlining National Determined Contributions (NDC's) to reduce emissions is placing an increased global focus on the spatial extent, loss and restoration of seagrass meadows. Now more than ever there is a need to provide a more accurate and consistent measure of the global spatial distribution of seagrass. There is also a need to be able to assess the global spread of other seagrass ecosystem services and in their extension, the values of these services. In this study, by rationalising and updating a range of existing datasets of seagrass distribution around the globe, we have estimated with Moderate to High confidence the global seagrass area to date as 160 387 km(2), but possibly 266 562 km(2)with lower confidence. We break this global estimate down to a national level with a detailed analysis of the current state of mapped distribution and estimates of seagrass area per country. Accurate estimates, however, are challenged by large areas remaining unmapped and inconsistent measures being used. Through the examination of current global maps, we are able to propose a pathway forward for improving mapping of this important resource. More accurate measure of global #seagrass distribution, critical for assessing current state and trends.
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24. |
- Mtwana Nordlund, Lina, et al.
(author)
-
Global significance of seagrass fishery activity
- 2018
-
In: Fish and Fisheries. - : Wiley. - 1467-2960 .- 1467-2979. ; 19:3, s. 399-412
-
Journal article (peer-reviewed)abstract
- Seagrass meadows support fisheries through provision of nursery areas and trophic subsidies to adjacent habitats. As shallow coastal habitats, they also provide key fishing grounds; however, the nature and extent of such exploitation are poorly understood. These productive meadows are being degraded globally at rapid rates. For degradation to cease, there needs to be better appreciation for the value of these habitats in supporting global fisheries. Here, we provide the first global scale study demonstrating the extent, importance and nature of fisheries exploitation of seagrass meadows. Due to a paucity of available data, the study used a global expert survey to demonstrate the widespread significance of seagrass-based fishing activity. Our study finds that seagrass-based fisheries are globally important and present virtually wherever seagrass exists, supporting subsistence, commercial and recreational activity. A wide range of fishing methods and gear is used reflecting the spatial distribution patterns of seagrass meadows, and their depth ranges from intertidal (accessible by foot) to relatively deep water (where commercial trawls can operate). Seagrass meadows are multispecies fishing grounds targeted by fishers for any fish or invertebrate species that can be eaten, sold or used as bait. In the coastal communities of developing countries, the importance of the nearshore seagrass fishery for livelihoods and well-being is irrefutable. In developed countries, the seagrass fishery is often recreational and/or more target species specific. Regardless of location, this study is the first to highlight collectively the indiscriminate nature and global scale of seagrass fisheries and the diversity of exploitative methods employed to extract seagrass-associated resources. Evidence presented emphasizes the need for targeted management to support continued viability of seagrass meadows as a global ecosystem service provider.
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25. |
- Mtwana Nordlund, Lina, et al.
(author)
-
Intertidal Zone Management in the Western Indian Ocean : Assessing Current Status and Future Possibilities Using Expert Opinions
- 2014
-
In: Ambio. - : Springer Science and Business Media LLC. - 0044-7447 .- 1654-7209. ; 43:8, s. 1006-1019
-
Journal article (peer-reviewed)abstract
- This expert opinion study examined the current status of the intertidal zone in the Western Indian Ocean (WIO) and ranked and discussed future management approaches. Information was gathered from scientists, practitioners, and managers active in the WIO region through a questionnaire and a workshop. The experts stated that the productive intertidal environment is highly valuable for reasons such as recreation, erosion protection, and provision of edible invertebrates and fish. Several anthropogenic pressures were identified, including pollution, harbor activities, overexploitation, and climate change. The experts considered the WIO intertidal zone as generally understudied, undermanaged, and with poor or no monitoring. The most important management strategies according to the expert opinions are to develop and involve local people in integrated coastal zone management (ICZM), to increase knowledge on species-environment relationships, and to develop awareness campaigns and education programs. To improve coastal environmental management and conservation, we argue that the intertidal zone should be treated as one organizational management unit within the larger framework of ICZM.
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26. |
- Mtwana Nordlund, Lina, et al.
(author)
-
Seagrass ecosystem services - What's next?
- 2018
-
In: Marine Pollution Bulletin. - : Elsevier BV. - 0025-326X .- 1879-3363. ; 134, s. 145-151
-
Journal article (peer-reviewed)abstract
- Seagrasses, marine flowering plants, provide a wide range of ecosystem services, defined here as natural processes and components that directly or indirectly benefit human needs. Recent research has shown that there are still many gaps in our comprehension of seagrass ecosystem service provision. Furthermore, there seems to be little public knowledge of seagrasses in general and the benefits they provide. This begs the questions: how do we move forward with the information we have? What other information do we need and what actions do we need to take in order to improve the situation and appreciation for seagrass? Based on the outcomes from an international expert knowledge eliciting workshop, three key areas to advance seagrass ecosystem service research were identified: 1) Variability of ecosystem services within seagrass meadows and among different meadows; 2) Seagrass ecosystem services in relation to, and their connection with, other coastal habitats; and 3) Improvement in the communication of seagrass ecosystem services to the public. Here we present ways forward to advance seagrass ecosystem service research in order to raise the profile of seagrass globally, as a means to establish more effective conservation and restoration of these important coastal habitats around the world.
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27. |
- Mtwana Nordlund, Lina, 1979-
(author)
-
Teaching ecology at university—Inspiration for change
- 2016
-
In: Global Ecology and Conservation. - : Elsevier BV. - 2351-9894. ; 7, s. 174-182
-
Research review (peer-reviewed)abstract
- How do you, as a university lecturer, change from teacher-centered teaching to a more student-centered, active teaching? This paper aims to inspire you to make a change, big or small, to increase your students’ engagement and learning, by presenting suggestions on what you can do. The ideas and suggestions synthesized here are based on several different teaching philosophies and methods, which are well tested and shown to be effective in the right setting. The selection of suggestions is believed to be specifically suitable for ecology.The paper includes suggestions on how to plan a course or a lecture by setting a good learning environment. Both pre-lecture activities and during lecture activities are included, with a focus on activities to engage students and encourage increased discussion and reflections, as well as what to think about when choosing learning activities and how and why it is important to teach students to think and act like professionals in ecology. While changing teaching methods takes investment of time, time that is limited for many researchers, even small changes in your teaching can make big differences in learning, and the investment will hopefully pay back by making teaching more fun and rewarding. The suggestions presented are understandable without being be conversant in the ‘education literature’, but will provide you with a vocabulary of teaching activities that will be useful if you are inspired to find more information and learn more about teaching.
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28. |
- Nordlund, Anna, et al.
(author)
-
Functional features cause misfolding of the ALS-provoking enzyme SOD1
- 2009
-
In: Proceedings of the National Academy of Sciences. - : Proceedings of the National Academy of Sciences. - 1091-6490 .- 0027-8424. ; 106:24, s. 9667-9672
-
Journal article (peer-reviewed)abstract
- The structural integrity of the ubiquitous enzyme superoxide dismutase (SOD1) relies critically on the correct coordination of Cu and Zn. Loss of these cofactors not only promotes SOD1 aggregation in vitro but also seems to be a key prerequisite for pathogenic misfolding in the neurodegenerative disease amyotrophic lateral sclerosis (ALS). We examine here the consequences of Zn2+ loss by selectively removing the Zn site, which has been implicated as the main modulator of SOD1 stability and disease competence. After Zn-site removal, the remaining Cu ligands can coordinate a non-native Zn2+ ion with mu M affinity in the denatured state, and then retain this ion throughout the folding reaction. Without the restriction of a metallated Zn site, however, the Cu ligands fail to correctly coordinate the nonnative Zn2+ ion: Trapping of a water molecule causes H48 to change rotamer and swing outwards. The misligation is sterically incompatible with the native structure. As a consequence, SOD1 unfolds locally and interacts with neighboring molecules in the crystal lattice. The findings point to a critical role for the native Zn site in controlling SOD1 misfolding, and show that even subtle changes of the metal-loading sequence can render the wild-type protein the same structural properties as ALS-provoking mutations. This frustrated character of the SOD1 molecule seems to arise from a compromise between optimization of functional and structural features.
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29. |
- Nordlund, Lina, 1979-, et al.
(author)
-
Changes in an East African social-ecological seagrass system : invertebrate harvesting affecting species composition and local livelihood
- 2010
-
In: Aquatic Living Resources. - : EDP Sciences. - 0990-7440 .- 1765-2952. ; 23:4, s. 399-416
-
Journal article (peer-reviewed)abstract
- Seagrass meadows support high biodiversity and are important for invertebrate harvesting activities in developing countries. The aim of this study was to estimate the social and ecological effects of invertebrate harvesting, i.e. how this exploitation may affect/has affected seagrass variables (biomass, shoot density and canopy height), macrofaunal community structure, the use and importance of these resources for the livelihood of local people over time. A multi-disciplinary approach was used, including interviews with harvesters, observations of the number/activities of invertebrate harvesters, and a biological field study in Zanzibar, Tanzania. The study showed that women/children harvest invertebrates, and they prefer large seagrass patches, high to medium shoot density, and high seagrass cover. All interviewees said they had noticed a decline in seagrass distribution over the last decade, >20% considered it a large decline. Interviewees also reported decreased numbers of animals, but no change in the number of animal species over the last decade. The main reasons for the decline of seagrass and animals according to interviewees, are an increase in the number of harvesters, and a change in attitude, i.e. people being less careful about the intertidal zone and seagrasses. Invertebrate harvesting was found important for food security and provision of cash income. The current average catch weight was ca. 2 kg/collection day/person, and 3 kg and 5 kg, 5–10 and 30 years ago respectively according to interviewees. At present, the harvesting women earn ca 60–70% and ca 40% of what they would have if catches were the same sizes as they were 5–10 and 30 years ago respectively, according to our calculations. The field sampling within seagrass beds showed that an inaccessible/remote site had significantly higher invertebrate abundance and species richness/diversity than an exploited site (ANOVA). Multivariate statistics further revealed weak but significant differences for animal abundance and biomass between these sites. By combining findings from both interviews and field sampling this study shows that invertebrate harvesters can influence macrofaunal community structure in seagrass meadows, which in turn results in negative impacts on local harvesters’ economy and livelihood.
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30. |
- Nordlund, Lina Mtwana, et al.
(author)
-
Biodiversity loss in seagrass meadows due to local invertebrate fisheries and harbour activities
- 2013
-
In: Estuarine, Coastal and Shelf Science. - : Elsevier BV. - 0272-7714 .- 1096-0015. ; 135, s. 231-240
-
Journal article (peer-reviewed)abstract
- Seagrass meadows provide a wide variety of ecosystem services, but their distribution and health are adversely affected by man. In the present study, we examined the influence of coastal exploitation in terms of invertebrate harvesting and harbour activity on invertebrate community composition in subtropical seagrass meadows at Inhaca Island, Mozambique, in the Western Indian Ocean. There was a fivefold higher invertebrate density and biomass, and clearly higher invertebrate species richness, in the protected (control) site compared to the two exploited sites. The causes for the clear differences between protected and exploited sites were probably a result of (1) the directional outtake of large edible or saleable invertebrates (mostly molluscs) and the absence of boat traffic in the harvested site, and (2) harbour activities. Invertebrate community composition in the two exploited sites also differed (although less clear), which was likely due to inherent distinction in type of disturbance. Our findings revealed that protection of seagrass habitat is necessary and that disturbances of different origin might require different forms of management and conservation. Designing protected areas is however a complex process due to competition for use and space with activities such as invertebrate harvesting and harbours.
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31. |
- Nordlund, Lina Mtwana, et al.
(author)
-
One hundred priority questions for advancing seagrass conservation in Europe
- 2024
-
In: PLANTS PEOPLE PLANET. - 2572-2611.
-
Journal article (peer-reviewed)abstract
- Societal Impact StatementSeagrass ecosystems are of fundamental importance to our planet and wellbeing. Seagrasses are marine flowering plants, which engineer ecosystems that provide a multitude of ecosystem services, for example, blue foods and carbon sequestration. Seagrass ecosystems have largely been degraded across much of their global range. There is now increasing interest in the conservation and restoration of these systems, particularly in the context of the climate emergency and the biodiversity crisis. The collation of 100 questions from experts across Europe could, if answered, improve our ability to conserve and restore these systems by facilitating a fundamental shift in the success of such work.SummarySeagrass meadows provide numerous ecosystem services including biodiversity, coastal protection, and carbon sequestration. In Europe, seagrasses can be found in shallow sheltered waters along coastlines, in estuaries & lagoons, and around islands, but their distribution has declined. Factors such as poor water quality, coastal modification, mechanical damage, overfishing, land-sea interactions, climate change and disease have reduced the coverage of Europe's seagrasses necessitating their recovery. Research, monitoring and conservation efforts on seagrass ecosystems in Europe are mostly uncoordinated and biased towards certain species and regions, resulting in inadequate delivery of critical information for their management. Here, we aim to identify the 100 priority questions, that if addressed would strongly advance seagrass monitoring, research and conservation in Europe. Using a Delphi method, researchers, practitioners, and policymakers with seagrass experience from across Europe and with diverse seagrass expertise participated in the process that involved the formulation of research questions, a voting process and an online workshop to identify the final list of the 100 questions. The final list of questions covers areas across nine themes: Biodiversity & Ecology; Ecosystem services; Blue carbon; Fishery support; Drivers, Threats, Resilience & Response; Monitoring & Assessment; Conservation & Restoration; Governance, Policy & Management; and Communication. Answering these questions will fill current knowledge gaps and place European seagrass onto a positive trajectory of recovery. Seagrass ecosystems are of fundamental importance to our planet and wellbeing. Seagrasses are marine flowering plants which engineer ecosystems that provide a multitude of ecosystem services, for example, blue foods and carbon sequestration. Seagrass ecosystems have largely been degraded across much of their global range. There is now increasing interest in the conservation and restoration of these systems, particularly in the context of the climate emergency and the biodiversity crisis. The collation of 100 questions from experts across Europe could, if answered, improve our ability to conserve and restore these systems by facilitating a fundamental shift in the success of such work. image
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32. |
- Nordlund, Lina Mtwana, et al.
(author)
-
Seagrass Ecosystem Services and Their Variability across Genera and Geographical Regions
- 2016
-
In: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 11:10
-
Journal article (peer-reviewed)abstract
- Threats to and loss of seagrass ecosystems globally, impact not only natural resources but also the lives of people who directly or indirectly depend on these systems. Seagrass ecosystems play a multi-functional role in human well-being, e. g. food through fisheries, control of erosion and protection against floods. Quantifying these services reveals their contributions to human well-being and helps justify seagrass conservation. There has been no comprehensive assessment as to whether seagrass ecosystem services are perceived to vary over the globe or amongst genera. Our study compiles the most complete list of ecosystem services provided by seagrasses so far, including bioregional-and genus-specific information from expert opinion and published studies. Several seagrass ecosystem services vary considerably in their (known) provision across genera and over the globe. Seagrasses genera are clearly not all equal with regard to the ecosystem services they provide. As seagrass genera are not evenly distributed over all bioregions, the presence of an ecosystem service sometimes depends on the genera present. Larger sized seagrass genera (e. g. Posidonia, Enhalus) are perceived to provide more substantial and a wider variety of ecosystem services than smaller species (e. g. Halophila, Lepilaena). Nevertheless, smaller species provide important services. Our findings point out data gaps, provide new insight for more efficient management and recommend caution in economic valuation of seagrass services worldwide.
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33. |
- Pike, Felicity, 1993-, et al.
(author)
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Intertidal gleaning fisheries : Recognising local-scale contributions and management scenarios
- 2024
-
In: Marine Policy. - : Elsevier. - 0308-597X .- 1872-9460. ; 162
-
Journal article (peer-reviewed)abstract
- Intertidal gleaning is a widespread means through which women participate in the fishery harvest sector. However, the fishery is often under recognised in management and policy-making. Accordingly, there is a need to further our understanding of the fishery, and how local factors may help or hinder effective management. This study focuses on Zanzibar, Tanzania, using focus group discussions (FGDs) and interviews to investigate local-scale contributions from gleaning in seagrass dominated areas – which are particularly frequented gleaning grounds locally, and more widely in the Indo-Pacific region. The study also gathered insight into how gleaners perceived different management scenarios used elsewhere within the small-scale fishery sector. Despite being typically viewed as a sustenance means, gleaning was found to be primarily an economic activity, mainly through catching the bivalve, Anadara antiquata, and commercial gastropod species (Chicoreus ramosus and Pleuroploca spp). FGD respondents held positive pre-conceived ideas about rotating no-take zone scenarios as a management strategy, as well as indicating preferences for community-based measures. In order for no-take zones to have a higher chance of success, further investigation is needed to understand the life histories of commonly gleaned species in order to inform rotation periods, as well as developing means of cross-community cooperation due to the shared, open access nature of intertidal zones. These results demonstrate the economic importance of gleaning for coastal women in Zanzibar, who have invaluable insights, built on lived experience and local knowledge, which could enable and benefit a more inclusive management system.
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34. |
- Stiepani, Johann, et al.
(author)
-
Social-ecological system analysis of an invertebrate gleaning fishery on the island of Unguja, Zanzibar
- 2023
-
In: Ambio. - : Springer Nature. - 0044-7447 .- 1654-7209. ; 52:1, s. 140-154
-
Journal article (peer-reviewed)abstract
- Invertebrate gleaning is a small-scale fishery that commonly occurs in the intertidal zone across the tropical Indo-Pacific. In this study, we investigated and analyzed several components of this fishery on the island of Unguja, Zanzibar by employing the social-ecological systems framework from Ostrom 2009. In doing so, we conducted ecological surveys, catch assessments, interviews with gleaners, household surveys, focus group interviews and analyzed the governance structure. This social-ecological systems analysis showed that gleaning is important for food security, local culture and livelihood. Yet, the multiple approaches in our study revealed that the local intertidal zone is degrading and that the gleaned catch is changing. Local narratives indicate that economically important bivalves (Modiolus spp.) and gastropods (Strombus spp.) are in decline, which was paralleled with low abundances of both genera within the ecological survey of the intertidal and catch landing assessment. We recommend that invertebrate gleaning, a fishery mainly comprised of women should be included in fisheries management.
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35. |
- Unsworth, Richard K. F., et al.
(author)
-
A changing climate for seagrass conservation?
- 2018
-
In: Current Biology. - : Elsevier BV. - 0960-9822 .- 1879-0445. ; 28
-
Journal article (peer-reviewed)abstract
- Tropical coral reefs are threatened and in decline, and their future is highly uncertain. With increasing rates of climate change and rising global temperatures, people looking to coral reefs for food and income may increasingly have to rely on resources from other habitats. Efforts to protect and conserve the coral reefs we have left are critical for a suite of economic, ecological, cultural and intrinsic reasons, but there is also an urgent need to take heed of the future scenarios from coral reefs and broaden the focus of tropical marine conservation. Seagrass meadows in particular are becoming ever more important for people and planet as coral reef health declines, but these systems are also globally under stronger anthropogenic threat. We need to increase and reprioritize our conservation efforts and use our limited conservation resources in a more targeted manner in order to attain sustainable systems. For seagrass, there are practicable conservation opportunities to develop sustainable ways to respond to increased resource use. Targeted action now could restore and protect seagrass meadows to maintain the many ecosystem services they provide.
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36. |
- Unsworth, Richard K. F., et al.
(author)
-
Global challenges for seagrass conservation
- 2019
-
In: Ambio. - : Springer Science and Business Media LLC. - 0044-7447 .- 1654-7209. ; 48:8, s. 801-815
-
Journal article (peer-reviewed)abstract
- Seagrasses, flowering marine plants that form underwater meadows, play a significant global role in supporting food security, mitigating climate change and supporting biodiversity. Although progress is being made to conserve seagrass meadows in select areas, most meadows remain under significant pressure resulting in a decline in meadow condition and loss of function. Effective management strategies need to be implemented to reverse seagrass loss and enhance their fundamental role in coastal ocean habitats. Here we propose that seagrass meadows globally face a series of significant common challenges that must be addressed from a multifaceted and interdisciplinary perspective in order to achieve global conservation of seagrass meadows. The six main global challenges to seagrass conservation are (1) a lack of awareness of what seagrasses are and a limited societal recognition of the importance of seagrasses in coastal systems; (2) the status of many seagrass meadows are unknown, and up-to-date information on status and condition is essential; (3) understanding threatening activities at local scales is required to target management actions accordingly; (4) expanding our understanding of interactions between the socio-economic and ecological elements of seagrass systems is essential to balance the needs of people and the planet; (5) seagrass research should be expanded to generate scientific inquiries that support conservation actions; (6) increased understanding of the linkages between seagrass and climate change is required to adapt conservation accordingly. We also explicitly outline a series of proposed policy actions that will enable the scientific and conservation community to rise to these challenges. We urge the seagrass conservation community to engage stakeholders from local resource users to international policy-makers to address the challenges outlined here, in order to secure the future of the world’s seagrass ecosystems and maintain the vital services which they supply.
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37. |
- Unsworth, Richard K. F., et al.
(author)
-
Seagrass meadows support global fisheries production
- 2019
-
In: Conservation Letters. - : Wiley. - 1755-263X. ; 12:1
-
Journal article (peer-reviewed)abstract
- The significant role seagrass meadows play in supporting fisheries productivity and food security across the globe is not adequately reflected in the decisions made by authorities with statutory responsibility for their management. We provide a unique global analysis of three data sources to present the case for why seagrass meadows need targeted policy to recognize and protect their role in supporting fisheries production and food security. (1) Seagrass meadows provide valuable nursery habitat to over 1/5th of the world's largest 25 fisheries, including Walleye Pollock, the most landed species on the planet. (2) In complex small-scale fisheries from around the world (poorly represented in fisheries statistics), we present evidence that many of those in proximity to seagrass are supported to a large degree by these habitats. (3) We reveal how intertidal fishing activity in seagrass is a global phenomenon, often directly supporting human livelihoods. Our study demonstrates that seagrasses should be recognized and managed to maintain and maximize their role in global fisheries production. The chasm that exists between coastal habitat conservation and fisheries management needs to be filled to maximize the chances of seagrass meadows supporting fisheries, so that they can continue to support human wellbeing.
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38. |
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