| 1. |
- Carstensen, Jacob, et al.
(author)
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Factors regulating the coastal nutrient filter in the Baltic Sea
- 2020
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In: Ambio. - : Springer Science and Business Media LLC. - 0044-7447 .- 1654-7209. ; 49:6, s. 1194-1210
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Journal article (peer-reviewed)abstract
- The coastal zone of the Baltic Sea is diverse with strong regional differences in the physico-chemical setting. This diversity is also reflected in the importance of different biogeochemical processes altering nutrient and organic matter fluxes on the passage from land to sea. This review investigates the most important processes for removal of nutrients and organic matter, and the factors that regulate the efficiency of the coastal filter. Nitrogen removal through denitrification is high in lagoons receiving large inputs of nitrate and organic matter. Phosphorus burial is high in archipelagos with substantial sedimentation, but the stability of different burial forms varies across the Baltic Sea. Organic matter processes are tightly linked to the nitrogen and phosphorus cycles. Moreover, these processes are strongly modulated depending on composition of vegetation and fauna. Managing coastal ecosystems to improve the effectiveness of the coastal filter can reduce eutrophication in the open Baltic Sea.
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| 2. |
- Meysick, Lukas, et al.
(author)
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Context-dependent community facilitation in seagrass meadows along a hydrodynamic stress gradient
- 2019
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In: Journal of Sea Research. - : Elsevier BV. - 1385-1101 .- 1873-1414. ; 150, s. 8-23
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Journal article (peer-reviewed)abstract
- Foundation species host diverse associated communities by ameliorating environmental stress. The strength of this facilitative effect can be highly dependent on the underlying biotic and abiotic context. We investigated community level patterns of macrofauna associated with and adjacent to the marine foundation species eelgrass (Zostera marina) along a hydrodynamic stress gradient. We could demonstrate that the relative importance of this foundation species for its infaunal community increases with environmental variables associated with increasing hydrodynamic stress (depth, sand ripples formation, sediment grain size and organic content). Faunal assemblages in proximity to the Zostera patch edges, however, showed no (infauna) or negative (epifauna) response to hydrodynamic stress. Our study highlights that the facilitative outcome of a foundation species is conditional to the faunal assemblage in question and can be highly variable even between positions within the habitat.
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| 3. |
- Andersen, Jesper H., et al.
(author)
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Long-term temporal and spatial trends in eutrophication status of the Baltic Sea
- 2017
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In: Biological Reviews. - : Wiley. - 1464-7931 .- 1469-185X. ; 92:1, s. 135-149
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Journal article (peer-reviewed)abstract
- Much of the Baltic Sea is currently classified as 'affected by eutrophication'. The causes for this are twofold. First, current levels of nutrient inputs (nitrogen and phosphorus) from human activities exceed the natural processing capacity with an accumulation of nutrients in the Baltic Sea over the last 50-100 years. Secondly, the Baltic Sea is naturally susceptible to nutrient enrichment due to a combination of long retention times and stratification restricting ventilation of deep waters. Here, based on a unique data set collated from research activities and long-term monitoring programs, we report on the temporal and spatial trends of eutrophication status for the open Baltic Sea over a 112-year period using the HELCOM Eutrophication Assessment Tool (HEAT 3.0). Further, we analyse variation in the confidence of the eutrophication status assessment based on a systematic quantitative approach using coefficients of variation in the observations. The classifications in our assessment indicate that the first signs of eutrophication emerged in the mid-1950s and the central parts of the Baltic Sea changed from being unaffected by eutrophication to being affected. We document improvements in eutrophication status that are direct consequences of long-term efforts to reduce the inputs of nutrients. The reductions in both nitrogen and phosphorus loads have led to large-scale alleviation of eutrophication and to a healthier Baltic Sea. Reduced confidence in our assessment is seen more recently due to reductions in the scope of monitoring programs. Our study sets a baseline for implementation of the ecosystem-based management strategies and policies currently in place including the EU Marine Strategy Framework Directives and the HELCOM Baltic Sea Action Plan.
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| 4. |
- Gladstone-Gallagher, Rebecca V., et al.
(author)
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Identifying “vital attributes” for assessing disturbance–recovery potential of seafloor communities
- 2021
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In: Ecology and Evolution. - : Wiley. - 2045-7758. ; 11:11, s. 6091-6103
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Journal article (peer-reviewed)abstract
- Despite a long history of disturbance-recovery research, we still lack a generalizable understanding of the attributes that drive community recovery potential in seafloor ecosystems. Marine soft-sediment ecosystems encompass a range of heterogeneity from simple low-diversity habitats with limited biogenic structure, to species-rich systems with complex biogenic habitat structure. These differences in biological heterogeneity are a product of natural conditions and disturbance regimes. To search for unifying attributes, we explore whether a set of simple traits can characterize community disturbance-recovery potential using seafloor patch-disturbance experiments conducted in two different soft-sediment landscapes. The two landscapes represent two ends of a spectrum of landscape biotic heterogeneity in order to consider multi-scale disturbance-recovery processes. We consider traits at different levels of biological organization, from the biological traits of individual species, to the traits of species at the landscape scale associated with their occurrence across the landscape and their ability to be dominant. We show that in a biotically heterogeneous landscape (Kawau Bay, New Zealand), seafloor community recovery is stochastic, there is high species turnover, and the landscape-scale traits are good predictors of recovery. In contrast, in a biotically homogeneous landscape (Baltic Sea), the options for recovery are constrained, the recovery pathway is thus more deterministic and the scale of recovery traits important for determining recovery switches to the individual species biological traits within the disturbed patch. Our results imply that these simple, yet sophisticated, traits can be effectively used to characterize community recovery potential and highlight the role of landscapes in providing resilience to patch-scale disturbances.
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| 5. |
- Hajializadeh, Parima, et al.
(author)
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Species Composition and Functiona Traits of Macrofauna in Different Mangrove Habitats in the Persian Gulf
- 2020
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In: Frontiers in Marine Science. - : Frontiers Media SA. - 2296-7745. ; 7
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Journal article (peer-reviewed)abstract
- Macrofauna play a key role in the functioning of mangrove ecosystems. Nevertheless, our understanding of the diversity and functional structure of macrofaunal communities across different habitats in the mangrove forests of the Persian Gulf is limited. In this study, we investigated species diversity and biological trait patterns of macrofauna in different mangrove-associated habitats, i.e., encompassing actual mangrove forests, and adjacent Beaches and Creeks, which exhibit different levels of habitat heterogeneity. Samples were collected from the different habitats in five different locations, over four seasons. A total of 122 macrofauna taxa were identified. The diversity of species was higher in summer than in winter. In the Beach habitats, species diversity showed an increasing trend from land toward the mangrove, whereas in Creek habitats diversity decreased from the Creek toward the mangrove. Multivariate community analysis showed differences in the distribution of abundant species and biological traits across all habitats. Deposit-feeding, crawlers, medium-size, and free-living were the dominant trait modalities in all habitats. The similarities within habitats over the four seasons had the same specific pattern of species and biological trait abundance in the Beach and the Creek, increasing from the non-covered habitat into the mangrove trees. Although many species shared similar traits, the abundance-driven differences in trait expression between habitats showed the importance of habitat filtering. The results of this study will be useful in the conservation of mangrove forests and they give a deeper understanding of the ecological patterns and functions of benthic macrofaunal communities in the Persian Gulf.
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| 6. |
- Kauppi, Laura, et al.
(author)
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Marine heatwaves of differing intensities lead to distinct patterns in seafloor functioning
- 2022
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In: Proceedings of the Royal Society of London. Biological Sciences. - : The Royal Society. - 0962-8452 .- 1471-2954. ; 289:1986
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Journal article (peer-reviewed)abstract
- Marine heatwaves (MHWs) are increasing in frequency and intensity due to climate change. Several well-documented effects of heatwaves on community structure exist, but examples of their effect on functioning of species, communities or ecosystems remain scarce. We tested the effects of short-term, moderate and strong MHWs on macrofauna bioturbation and associated solute fluxes as examples of ecosystem functioning. We also measured macrofaunal excretion rates to assess effects of temperature on macrofauna metabolism. For this experiment, we used unmanipulated sediment cores with natural animal communities collected from a muddy location at 32 m depth in the northern Baltic Sea. Despite the mechanistic effect of bioturbation remaining unchanged between the treatments, there were significant differences in oxygen consumption, solute fluxes and excretion. Biogeochemical and biological processes were boosted by the moderate heatwave, whereas biogeochemical cycling seemed to decrease under a strong heatwave. A prolonged, moderate heatwave could possibly lead to resource depletion if primary production cannot meet the demands of benthic consumption. By contrast, decreased degradation activities under strong heatwaves could lead to a build-up of organic material and potentially hypoxia. The strong variability and the complexity of the response highlight the context dependency of these processes complicating future predictions.
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| 7. |
- Mäkelin, Saara, et al.
(author)
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Corrigendum : Food sources drive temporal variation in elemental stoichiometry of benthic consumers
- 2022
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In: Limnology and Oceanography. - : Wiley. - 0024-3590 .- 1939-5590. ; 67:8, s. 1891-1893
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Journal article (peer-reviewed)abstract
- The paper published in Limnology and Oceanography 67: 784-799 (2022) contains a calculation error. This error concerns the result and discussion sections “Stoichiometric variation in the benthic community”. The benthic community biomass and consequently the community C, N and P content were miscalculated. The corrected benthic community C, N and P content is approximately three times higher than the values presented in the original paper. However, the correction in biomass had no major effect on the community C: N: P ratios. Statistical analysis was performed (two-way PERMANOVA) again for the community stoichiometry, but the results did not change. Importantly, corrections of the community biomass did not affect the main results or the conclusion of the paper. The corrected version of Table 3, Fig. 7 and Supplementary Table 7 are presented below. These corrections change the following: 3 Corrected Table Seasonal variation in the magnitude of the benthic community carbon, nitrogen, and phosphorus pools (g m−2) and elemental ratios. Tot C, N, and P present the values with bivalve shells included, whereas tissue C, N, and P content were calculated without the shells. Molar C:N:P ratios of the community are not accounting for bivalve shells. (Table presented.) 7 Corrected Fig. (Figure presented.) Average community total carbon (C) content g m−2 ± SD over the sampling occasions, and the contribution of the main taxonomic groups to the total biomass. The nitrogen and phosphorus followed the same trend as carbon. 7 Corrected Supplementary Table Results of two-way PERMANOVA show the effect of season and site on community C, N and P content and C:N:P ratios. (Table presented.) Methods: Stoichiometric variation in the benthic community. p. 787: the text should read “The model was based on Euclidean distances, calculated on total C, N, and P content g m-2 and log10(x + 1) transformed C: N: P data (Anderson et al. 2008)”. Results: Stoichiometric variation in the benthic community. p. 791: the corrected values for the benthic community are “At the sheltered site IH4, the C, N, and P content of the benthic community was highest in August and lowest in October (Table 3, Fig. 7). In contrast, at the exposed site XXVI, the community tissue C and N content was highest in January and lowest in May and March, while P showed little variation (Table 3). The maximum measured content was 37.8 g C m−2, 4.3 g N m−2 and 0.4 g P m−2 when accounting for both organic and inorganic carbon bound to community biomass (i.e., bivalves with shell; Table 3)". p. 791: “The elemental content of the community followed the variation of the total biomass and was strongly linked to the population structure of the clam L. balthica, that contributed with ca. 90 % to the total biomass, and ca. 80 % to the tissue biomass (except in October at IH4, Fig. 7)”. p. 791: the corrected elemental ratios are “on both sites the C: N ratios were highest in May (sheltered IH4 7.2, exposed XXVI 7.3), whereas C: P (IH4 230.4, XXVI 236.4) and N: P (IH4 34.9, XXVI 33.6) ratios peaked in August (Table 3). We measured the lowest C: N (5.0), C: P (110.4) and N: P (20.6) during winter (Table 3)”. p. 791: "The yearly average C: N, C: P and N: P ratios of the benthic fauna were 6, 163 and 27 at the sheltered site (IH4), and 6, 152, and 24 at the more exposed site (XXVI)." Discussion: Stoichiometric variation in the benthic community. p. 795: “On a yearly average, the studied soft-sediment benthic communities stored 25 390 kg C km-2, 2 720 kg N km-2 and 230 kg P km-2 (bivalve shells included). If excluding bivalve shells, the content is lower, measuring 10 690 kg C km-2, 2 010 kg N km-2 and 180 kg P km-2. At its maximum, the magnitude of the pool reached up to 13 600 kg C km-2, 2900 kg N km-2, and 300 kg P km-2 (shells excluded) at the exposed site XXVI. In comparison, the estimated magnitude for the average organic benthic faunal carbon and nutrient pool in the entire Gulf of Finland is 5333 kg C km-2, 733 kg N km-2 and 60 kg P km-2 (Carman and Cederwall 2001). We measured higher values from the aphotic coastal benthic communities than previously estimated (Carman and Cederwall 2001; Scheffold and Hense 2020).” p. 795: “L. balthica, which contributed with ca. 90% (shells included)”. p. 796: “We measured that the yearly average C: N, C: P and N: P ratios of the Baltic benthic fauna were 6, 163 and 27 (sheltered IH4) or 6, 152 and 24 (exposed site XXVI)”. p. 796: “whereas the corresponding values we measured for the benthic consumers in beginning of May were 156: 22: 1 (sheltered) and 156: 21: 1 (exposed)”. In addition, the unit for sediment Chl-a and pheopigments should be μg g−1 instead of mg g−1 as presented in the main text and Supplementary Table 1. Conflicts of interest The authors declare that there is no conflict of interest.
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| 8. |
- Mäkelin, Saara, et al.
(author)
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Food sources drive temporal variation in elemental stoichiometry of benthic consumers
- 2022
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In: Limnology and Oceanography. - : Wiley. - 0024-3590 .- 1939-5590. ; 67:4, s. 784-799
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Journal article (peer-reviewed)abstract
- Benthic fauna plays an important role in mediating biogeochemical cycles in coastal areas by storing carbon (C), nitrogen (N), and phosphorus (P) in their body tissues at theoretically homeostatic rates. To maintain homeostasis, the benthic consumers need to be in balance with their resource supply or alter their stoichiometric traits in response to environmental change. However, we lack an understanding regarding the potential variation in the C : N : P content ratios of benthic consumers, especially in marine coastal areas where stoichiometric shifts in macrofauna could have strong effects on sediment carbon and nutrient cycling. By monitoring two sites over a year, we quantified the magnitude and temporal stability of benthic faunal carbon and nutrient pools in coastal soft-sediment habitats. Our results show that benthic fauna is not strictly homeostatic, but instead expresses temporal variation in C : N : P content. These aquatic consumers undergo ontogenetic changes in diet and morphology, which alter their stoichiometric characteristics. In addition, the faunal C : N : P ratios showed strong seasonal variation at both species and community level, and our results suggest that the stoichiometric traits of benthic consumers shift in response to food sources and environmental conditions. The ability to adapt to varying stoichiometric conditions is essential in face of the growing C : N : P imbalance occurring in marine and coastal ecosystems as a consequence of anthropogenic activities. Therefore, it is critically important to identify the stoichiometric plasticity of different species, before environmental change causes a shift in benthic community composition that will alter functions on an ecosystem level.
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| 9. |
- Mäkelin, Saara, et al.
(author)
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Linking Resource Quality and Biodiversity to Benthic Ecosystem Functions Across a Land-to-Sea Gradient
- 2024
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In: Ecosystems. - 1432-9840 .- 1435-0629. ; 27:2, s. 329-345
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Journal article (peer-reviewed)abstract
- Benthic macrofauna modifies carbon and nutrient retention and recycling processes in coastal habitats. However, the contribution of benthic consumers to carbon and nutrient storage and recycling shows variation over spatial scales, as the benthic community composition changes in response to differences in environmental conditions. By sampling both shallow sandy and deep muddy sediments across a land-to-sea gradient in the northern Baltic Sea, we explored if benthic community composition, stoichiometry and process rates change in response to alterations in environmental conditions and food sources. Our results show that benthic faunal biomass, C, N, and P stocks, respiration rate and secondary production increase across the land-to-sea gradient in response to higher resource quality towards the open sea. The seston δ13C indicated terrestrial runoff and δ15N sewage input at the innermost study sites, whereas more fresh marine organic matter towards the open sea boosted benthic faunal carbon storage, respiration rate, and secondary production, that is, the generation of consumer biomass, which are essential processes for carbon turnover in this coastal ecosystem. Also, biological factors such as increasing species richness and decreasing biomass dominance of the clam Macoma balthica were significant in predicting benthic faunal C, N, and P stocks and process rates, especially at sandy sites. Interestingly, despite the variation in food sources, the benthic faunal C:N:P ratios remained stable across the gradient. Our results prove that human activities in the coastal area can influence the important links between biodiversity, structure, and process rates of benthic communities by modifying the balance of available resources, therefore hampering the functioning of coastal ecosystems.
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| 10. |
- Rodil, Iván F., et al.
(author)
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The role of dispersal mode and habitat specialization for metacommunity structure of shallow beach invertebrates
- 2017
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In: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 12:2
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Journal article (peer-reviewed)abstract
- Metacommunity ecology recognizes the interplay between local and regional patterns in contributing to spatial variation in community structure. In aquatic systems, the relative importance of such patterns depends mainly on the potential connectivity of the specific system. Thus, connectivity is expected to increase in relation to the degree of water movement, and to depend on the specific traits of the study organism. We examined the role of environmental and spatial factors in structuring benthic communities from a highly connected shallow beach network using a metacommunity approach. Both factors contributed to a varying degree to the structure of the local communities suggesting that environmental filters and dispersal-related mechanisms played key roles in determining abundance patterns. We categorized benthic taxa according to their dispersal mode (passive vs. active) and habitat specialization (generalist vs. specialist) to understand the relative importance of environment and dispersal related processes for shallow beach metacommunities. Passive dispersers were predicted by a combination of environmental and spatial factors, whereas active dispersers were not spatially structured and responded only to local environmental factors. Generalists were predicted primarily by spatial factors, while specialists were only predicted by local environmental factors. The results suggest that the role of the spatial component in metacommunity organization is greater in open coastal waters, such as shallow beaches, compared to less-connected environmentally controlled aquatic systems. Our results also reveal a strong environmental role in structuring the benthic metacommunity of shallow beaches. Specifically, we highlight the sensitivity of shallow beach macrofauna to environmental factors related to eutrophication proxies.
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