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Increased sensitivity of subantarctic marine invertebrates to copper under a changing climate - Effects of salinity and temperature
2019
Holan, Jessica R. | King, Catherine K. | Proctor, Abigael H. | Davis, Andrew R.
Stressors associated with climate change and contaminants, resulting from the activities of humans, are affecting organisms and ecosystems globally. Previous studies suggest that the unique characteristics of polar biota, such as slower metabolisms and growth, and the generally stable conditions in their natural environment, cause higher susceptibility to contamination and climate change than those in temperate and tropical areas. We investigated the effects of increased temperature and decreased salinity on copper toxicity in four subantarctic marine invertebrates using realistic projected conditions under a future climatic change scenario for this region. We hypothesised that these relatively subtle shifts in environmental stressors would impact the sensitivity of cold-adapted species to copper. The four test species were: a copepod Harpacticus sp.; isopod Limnoria stephenseni; flatworm Obrimoposthia ohlini; and bivalve Gaimardia trapesina. These species occupy a range of ecological niches, spanning intertidal and subtidal nearshore zones. We predicted that species would differ in their tolerance to stressors, depending on where they occurred within this ecological gradient. Organisms were exposed to the multiple stressors in a factorial design in laboratory based toxicity tests. Sensitivity estimates for copper (LC50) were calculated using a novel statistical approach which directly assessed the impacts of the multiple stressors. In three of the four species tested, sensitivity to copper was amplified by small increases in temperature (2-4 °C). The effects of salinity were more variable but a decrease of as little as 2 ppt caused a significant effect in one species. This study provides some of the first evidence that high latitude species may be at increased risk from contaminants under projected future climate conditions. This interaction, between contaminants and the abiotic environment, highlights a potential pathway to biodiversity loss under a changing climate.
Afficher plus [+] Moins [-]Assessment of the benthic macrofauna in an artificial shell reef zone in Shuangdao Bay, Yellow Sea
2017
Liu, Guoshan | Li, Wen-Tao | Zhang, Xiumei
The effects of artificial shell reef (ASR) on the benthic macroinvertebrates were studied in Shuangdao Bay, Yellow Sea, China. Results showed that the biomass of macroinvertebrates in the ASR increased with the age of the ASR. Based on self-organizing map (SOM), the macroinvertebrate community of short-term artificial reef (SAR), medium-term artificial reef (MAR) and long-term artificial reef (LAR) emerged as a cluster, which may indicate that the benthic community in the ASR formed after three years. The age of the ASR was the main factor affecting the benthic community. The macroinvertebrates belonged to six phyla, Platyhelminthes, Nemertea, Annelida, Mollusca, Arthropoda and Echinodermata, among which the latter four were the ones that contributed the most for abundance. The biomass of Mollusca increased dramatically with age. The dissimilarity of the species composition of Mollusca was mainly caused by Meretrix meretrix and Protothaca jedoensis. The two species accounted for 15.61%, 28.05% and 75.11% of the macroinvertebrate biomass found in SAR, MAR and LAR, respectively. The ASR might be served as a bivalve stock enhancement tool. We conclude that ASR could assemble macrobenthos effectively and increase the environmental quality of the adjacent area, being a valid option for marine habitat restoration purposes.
Afficher plus [+] Moins [-]Freshwater planarians (Turbellaria) of North America
1972
Kenk, Roman,
Freshwater planarians (Turbellaria) of North America
1972
Kenk, Roman