scholarly journals Environmental stressors, complex interactions and marine benthic communities’ responses

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Charlotte Carrier-Belleau ◽  
David Drolet ◽  
Christopher W. McKindsey ◽  
Philippe Archambault
Keyword(s):  
Nutrient Enrichment ◽  
Multiple Stressors ◽  
Energy Content ◽  
Benthic Communities ◽  
Ecosystem Functions ◽  
Salinity Variation ◽  
Complex Interactions ◽  
Marine Habitats ◽  
Biological Responses ◽  
Negative Impacts

AbstractThe increasing number and diversity of anthropogenic stressors in marine habitats have multiple negative impacts on biological systems, biodiversity and ecosystem functions. Methods to assess cumulative effects include experimental manipulations, which may identify non-linear responses (i.e. synergies, antagonisms). However, experiments designed to test these ideas are uncommon, generally focusing on single biological responses. We conducted a manipulative experiment to investigate the isolated and combined effects of warming (+ 6 °C), salinity variation (freshwater pulses or presses), and nutrient enrichment (natural or enriched) following one and three month’s exposure, on responses measured at multiple levels of biological complexity in a simple bivalve assemblage. More specifically, we determined effects on bivalve mortality, growth, shell mineralization, and energy content, as well as microphytobenthos biomass. Salinity variation and nutrient enrichment, individually and combined, caused strong impacts on some of the measured variables and their effect varied through time. In contrast, warming had no effect. Our work highlights the prevalence of antagonistic interactions, the importance of examining effects of single and multiple stressors through time, and of considering multiple responses to understand the complexity behind stressor interactions.

scholarly journals Cumulative impacts of anthropogenic stressors on macrobenthic communities at a bay-scale: an experimental approach

2018 ◽  
Author(s):  
Charlotte Carrier-Belleau ◽  
Philippe Archambault ◽  
Christopher W. McKindsey
Keyword(s):  
Experimental Approach ◽  
Multiple Stressors ◽  
Benthic Communities ◽  
Species Conservation ◽  
Environmental Stressors ◽  
Cumulative Impacts ◽  
Anthropogenic Stressors ◽  
Biological Responses ◽  
Manipulative Experiments

Human activities such as maritime transport, fishing and aquaculture create environmental stressors affecting the structure and the functioning of benthic communities. While these disturbances can act individually, they can also act synergistically and lead to changes more difficult to predict. The bay of Sept-Îles hosts a harbour receiving the most important ballast volume in North America and represents one of the most eutrophic bays in the Gulf of St. Lawrence. This project is part of the Canadian healthy oceans network (CHONe II) and attempts to identify the effect of the interaction of anthropogenic stressors on the macrobenthic invertebrate communities in the bay of Sept-Îles. In situ and laboratory manipulative experiments will be conducted to determine the influence of stressors on biological responses when taken individually, and when these stressors interact through time at different intensities. In that way, these experiments will improve our knowledge of cumulated impacts of multiple stressors on the structure of benthic communities. It will also eventually contribute to species conservation and the management of maritime resources.

scholarly journals Cumulative impacts of anthropogenic stressors on macrobenthic communities at a bay-scale: an experimental approach

2018 ◽  
Author(s):  
Charlotte Carrier-Belleau ◽  
Philippe Archambault ◽  
Christopher W. McKindsey
Keyword(s):  
Experimental Approach ◽  
Multiple Stressors ◽  
Benthic Communities ◽  
Species Conservation ◽  
Environmental Stressors ◽  
Cumulative Impacts ◽  
Anthropogenic Stressors ◽  
Biological Responses ◽  
Manipulative Experiments

Human activities such as maritime transport, fishing and aquaculture create environmental stressors affecting the structure and the functioning of benthic communities. While these disturbances can act individually, they can also act synergistically and lead to changes more difficult to predict. The bay of Sept-Îles hosts a harbour receiving the most important ballast volume in North America and represents one of the most eutrophic bays in the Gulf of St. Lawrence. This project is part of the Canadian healthy oceans network (CHONe II) and attempts to identify the effect of the interaction of anthropogenic stressors on the macrobenthic invertebrate communities in the bay of Sept-Îles. In situ and laboratory manipulative experiments will be conducted to determine the influence of stressors on biological responses when taken individually, and when these stressors interact through time at different intensities. In that way, these experiments will improve our knowledge of cumulated impacts of multiple stressors on the structure of benthic communities. It will also eventually contribute to species conservation and the management of maritime resources.

scholarly journals Nitrogen enrichment offsets direct negative effects of ocean acidification on a reef-building crustose coralline alga

2018 ◽  
Vol 14 (7) ◽  
pp. 20180371 ◽  
Author(s):  
Maggie D. Johnson ◽  
Robert C. Carpenter
Keyword(s):  
Ocean Acidification ◽  
Nutrient Enrichment ◽  
Multiple Stressors ◽  
Crustose Coralline Alga ◽  
Nitrogen Enrichment ◽  
Coralline Alga ◽  
Ambient Conditions ◽  
Negative Effects ◽  
Near Shore ◽  
Near Future

Ocean acidification (OA) and nutrient enrichment threaten the persistence of near shore ecosystems, yet little is known about their combined effects on marine organisms. Here, we show that a threefold increase in nitrogen concentrations, simulating enrichment due to coastal eutrophication or consumer excretions, offset the direct negative effects of near-future OA on calcification and photophysiology of the reef-building crustose coralline alga, Porolithon onkodes . Projected near-future pCO 2 levels (approx. 850 µatm) decreased calcification by 30% relative to ambient conditions. Conversely, nitrogen enrichment (nitrate + nitrite and ammonium) increased calcification by 90–130% in ambient and high pCO 2 treatments, respectively. pCO 2 and nitrogen enrichment interactively affected instantaneous photophysiology, with highest relative electron transport rates under high pCO 2 and high nitrogen. Nitrogen enrichment alone increased concentrations of the photosynthetic pigments chlorophyll a , phycocyanin and phycoerythrin by approximately 80–450%, regardless of pCO 2 . These results demonstrate that nutrient enrichment can mediate direct organismal responses to OA. In natural systems, however, such direct benefits may be counteracted by simultaneous increases in negative indirect effects, such as heightened competition. Experiments exploring the effects of multiple stressors are increasingly becoming important for improving our ability to understand the ramifications of local and global change stressors in near shore ecosystems.

scholarly journals Unusually variable paleocommunity composition in the oldest metazoan fossil assemblages

Paleobiology ◽  
2019 ◽  
Vol 45 (02) ◽  
pp. 235-245 ◽  
Author(s):  
Seth Finnegan ◽  
James G. Gehling ◽  
Mary L. Droser
Keyword(s):  
Fossil Record ◽  
Benthic Communities ◽  
Benthic Assemblages ◽  
Β Diversity ◽  
Marine Habitats ◽  
Fossil Assemblages ◽  
Early Metazoan ◽  
Insight Into ◽  
Faunal Variability ◽  
Ecological Differences

AbstractRecent excavations of Ediacaran assemblages have revealed striking bed-to-bed variation in diversity–abundance structure, offering potential insight into the ecology and taphonomy of these poorly understood early Metazoan ecosystems. Here we compare faunal variability in Ediacaran assemblages to that of younger benthic assemblages, both fossil and modern. We decompose the diversity of local assemblages into within-collection (α) and among-collection (β) components and show that β diversity in Ediacaran assemblages is unusually high relative to younger assemblages. Average between-bed ecological dissimilarities in the Phanerozoic fossil record are comparable to within-habitat dissimilarities typically observed over meter to kilometer scales in modern benthic marine habitats, but dissimilarities in Ediacaran assemblages are comparable to those typically observed over 10–100 km scales in modern habitats. We suggest that the unusually variable diversity–abundance structure of Ediacaran assemblages is due both to their preservation as near snapshots of benthic communities and to original ecological differences, in particular the paucity of motile taxa and the near lack of predation and infaunalization.

Subtidal assemblages associated with a geotextile reef in south-east Queensland, Australia

2005 ◽  
Vol 56 (2) ◽  
pp. 133 ◽  
Author(s):  
Rhys A. Edwards ◽  
Stephen D. A. Smith
Keyword(s):  
Fish Assemblages ◽  
Benthic Communities ◽  
Artificial Reef ◽  
Demersal Fish ◽  
Diverse Range ◽  
Marine Habitats ◽  
Sessile Invertebrates ◽  
Hard Structures ◽  
Asymmetrical Design ◽  
Natural Reefs

In marine habitats, the use of geotextile materials as a ‘soft-engineering’ solution is increasingly being considered as an alternative to hard structures. However, very little is known about biological assemblages that develop on geotextile structures. This study provides the first ecological comparison of subtidal assemblages between Narrowneck Artificial Reef (NAR), a geotextile reef in south-east Queensland, Australia, and three nearby natural reefs. Benthic community structure, fish assemblages and habitat complexity were compared between reef types using an asymmetrical design. Although natural reefs supported distinct biotic assemblages, as a class, these reefs differed significantly from NAR. The artificial reef was dominated by macroalgae and supported fewer benthic categories, whereas the natural reefs were characterised by a diverse range of sessile invertebrates. Benthic and demersal fish assemblages were less diverse on NAR, but pelagic fish assemblages were similar on both reef types. The substratum of NAR was less complex than that of the natural reefs; this physical variable was correlated with some of the differences in benthic communities and benthic and demersal fish assemblages. It is likely that the key determinants of the biotic patterns observed in this study are interactions between the age of NAR and the physical properties of geotextile substratum.

scholarly journals Detection of Stones in Marine Habitats Combining Simultaneous Hydroacoustic Surveys

Geosciences ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 279 ◽  
Author(s):  
Svenja Papenmeier ◽  
H. Hass
Keyword(s):  
Marine Protected Area ◽  
Benthic Communities ◽  
Sediment Surface ◽  
Sidescan Sonar ◽  
Marine Biodiversity ◽  
Outer Reef ◽  
Single Beam ◽  
Marine Deposits ◽  
Marine Habitats ◽  
High Backscatter

Exposed stones in sandy sublittoral environments are hotspots for marine biodiversity, especially for benthic communities. The detection of single stones is principally possible using sidescan-sonar (SSS) backscatter data. The data resolution has to be high to visualize the acoustic shadows of the stones. Otherwise, stony substrates will not be differentiable from other high backscatter substrates (e.g., gravel). Acquiring adequate sonar data and identifying stones in backscatter images is time consuming because it usually requires visual-manual procedures. To develop a more efficient identification and demarcation procedure of stone fields, sidescan sonar and parametric echo sound data were recorded within the marine protected area of “Sylt Outer Reef” (German Bight, North Sea). The investigated area (~5.900 km2) is characterized by dispersed heterogeneous moraine and marine deposits. Data from parametric sediment echo sounder indicate hyperbolas at the sediment surface in stony areas, which can easily be exported. By combining simultaneous recorded low backscatter data and parametric single beam data, stony grounds were demarcated faster, less complex and reproducible from gravelly substrates indicating similar high backscatter in the SSS data.

scholarly journals Impaired benthic macrofauna function 4 years after sediment capping with activated carbon in the Grenland fjords, Norway

2020 ◽  
Author(s):  
Caroline Raymond ◽  
Göran S Samuelsson ◽  
Stefan Agrenius ◽  
Morten T Schaanning ◽  
Jonas S Gunnarsson
Keyword(s):  
Activated Carbon ◽  
Biological Effects ◽  
Benthic Communities ◽  
Ecosystem Functions ◽  
Sediment Surface ◽  
Sediment Remediation ◽  
Vital Functions ◽  
Southern Norway

AbstractThe sediments in the Grenland fjords in southern Norway are heavily contaminated by large emissions of dioxins and mercury from historic industrial activities. As a possible in situ remediation option, thin-layer sediment surface capping with powdered activated carbon (AC) mixed with clay was applied at two large test sites (10,000 and 40,000 m2) at 30-m and 95-m depths, respectively, in 2009. This paper describes the long-term biological effects of the AC treatment on marine benthic communities up to 4 years after treatment. Our results show that the capping with AC strongly reduced the benthic species diversity, abundance, and biomass by up to 90%. Vital functions in the benthic ecosystem such as particle reworking and bioirrigation of the sediment were also reduced, analyzed by using novel bioturbation and bioirrigation indices (BPc, BIPc, and IPc). Much of the initial effects observed after 1 and 14 months were still present after 49 months, indicating that the effects are long-lasting. These long-lasting negative ecological effects should be carefully considered before decisions are made on sediment remediation with powdered AC, especially in large areas, since important ecosystem functions can be impaired.

scholarly journals A review of the effects of Bythotrephes longimanus and calcium decline on zooplankton communities — can interactive effects be predicted?

2015 ◽  
Vol 23 (4) ◽  
pp. 395-413 ◽  
Author(s):  
Shakira S.E. Azan ◽  
Shelley E. Arnott ◽  
Norman D. Yan
Keyword(s):  
Multiple Stressors ◽  
Current Knowledge ◽  
Canadian Shield ◽  
Interactive Effects ◽  
Bythotrephes Longimanus ◽  
Negative Impacts ◽  
The Individual ◽  
Zooplankton Communities ◽  
Shield Lakes ◽  
Review Current

Anthropogenic stressors including acid deposition, invasive species, and calcium (Ca) decline have produced widespread damage to Canadian Shield lakes, especially to their zooplankton communities. Here, we review current knowledge on the individual effects on zooplankton by the non-indigenous predator Bythotrephes longimanus and Ca decline; we identify knowledge gaps in this literature and examine the likely interactive impacts of Bythotrephes invasions and Ca decline on zooplankton. The negative impacts of Bythotrephes longimanus on zooplankton communities are well known, whereas current understanding of the effects of declining Ca on zooplankton is restricted to Daphnia spp.; hence, there is a large knowledge gap on how declining Ca may affect zooplankton communities in general. The co-occurring impacts of Bythotrephes and declining Ca have rarely been studied at the species level, and we expect daphniids, particularly Daphnia retrocurva and Daphnia pulicaria, to be the most sensitive to both stressors. We also expect a synergistic negative interaction on cladocerans in lakes with both stressors, leaving a community dominated by Holopedium glacialis and (or) copepods. Our predictions form testable hypotheses but since species and ecosystem response to multiple stressors are difficult to predict, we may actually see ecological surprises in Canadian Shield lakes as Bythotrephes continues to spread and Ca levels continue to fall.

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