Effects Of Climate Change Stressors Research Articles

Bioluminescence in cephalopods: biodiversity, biogeography and research trends

Numerous terrestrial and marine organisms, including cephalopods, are capable of light emission. In addition to communication, bioluminescence is used for attraction and defense mechanisms. The present review aims to: (i) present updated information on the taxonomic diversity of luminous cephalopods and morphological features, (ii) describe large-scale biogeographic patterns, and (iii) show the research trends over the last 50 years on cephalopod bioluminescence. According to our database (834 species), 32% of all known cephalopod species can emit light, including oegopsid and myopsid squids, sepiolids, octopuses, and representatives of several other smaller orders (bathyteuthids, and the monotypic vampire “squid”, Vampyroteuthis infernalis and ram’s horn “squid”, Spirula spirula). Most species have a combination of photophores present in different locations, of which light organs on the head region are dominant, followed by photophores associated with the arms and tentacles and internal photophores. Regarding the biogeographic patterns of cephalopod species with light organs, the most diverse ocean is the Pacific Ocean, followed by the Atlantic and Indian Oceans. The least diverse are the Southern and the Arctic Oceans. Regarding publication trends, our systematic review revealed that, between 1971 and 2020, 277 peer-reviewed studies were published on bioluminescent cephalopods. Most research has been done on a single species, the Hawaiian bobtail squid Euprymna scolopes. The interest in this species is mostly due to its species-specific symbiotic relationship with the bacterium Vibrio fischeri, which is used as a model for the study of Eukaryote–Prokaryote symbiosis. Because there are many knowledge gaps about the biology and biogeography of light-producing cephalopods, new state-of-the-art techniques (e.g., eDNA for diversity research and monitoring) can help achieve a finer resolution on species’ distributions. Moreover, knowledge on the effects of climate change stressors on the bioluminescent processes is nonexistent. Future studies are needed to assess such impacts at different levels of biological organization, to describe the potential broad-scale biogeographic changes, and understand the implications for food web dynamics.

Combined effects of climate change stressors and predators with contrasting feeding-digestion strategies on a mussel species

We investigated the combined effects of Ocean Warming (OW), Acidification (OA) and predator cues (Non-Consumptive Effects; NCEs) of two predators with contrasting feeding-digestion strategies on the mussel Perumytilus purpuratus. We considered starfish-NCEs (partially external digestion) and snail-NCEs (internal digestion). Mussels were exposed for 13 weeks to cross-factored OA (~500 and ~1400 μatm, pCO2) and OW (~15 and ~20 °C) conditions, in the presence/absence of NCEs from one or both predators. Mussels exposed to both NCEs exhibited smaller length and buoyant weight growth than those under control or snail-NCEs conditions. Mussels exposed to starfish-NCEs exhibited smaller wet mass than control mussels. OW and starfish-NCEs in isolation or combined with snail-NCEs increased mussel oxygen consumption. Byssal biogenesis was affected by the three-factors interaction. Clearance rates were affected by the OW × OA interaction. We suggest that mainly starfish-NCEs, in isolation or interacting with OA or/and OW, can threat mussel traits and the associated community.

Eutrophication on Coral Reefs: What Is the Evidence for Phase Shifts, Nutrient Limitation and Coral Bleaching

Abstract Coral reefs continue to experience extreme environmental pressure from climate change stressors, but many coral reefs are also exposed to eutrophication. It has been proposed that changes in the stoichiometry of ambient nutrients increase the mortality of corals, whereas eutrophication may facilitate phase shifts to macroalgae-dominated coral reefs when herbivory is low or absent. But are corals ever nutrient limited, and can eutrophication destabilize the coral symbiosis making it more sensitive to environmental stress because of climate change? The effects of eutrophication are confounded not just by the effects of climate change but by the presence of chemical pollutants in industrial, urban, and agricultural wastes. Because of these confounding effects, the increases in nutrients or changes in their stoichiometry in coastal environments, although they are important at the organismal and community level, cannot currently be disentangled from each other or from the more significant effects of climate change stressors on coral reefs.

Climate Change and Shell-Boring Polychaetes (Annelida: Spionidae): Current State of Knowledge and the Need for More Experimental Research.

AbstractAnthropogenic climate change is considered to be one of the greatest threats facing marine biodiversity. The vast majority of experimental work investigating the effects of climate change stressors on marine organisms has focused on calcifying organisms, such as corals and molluscs, where cross-generational phenotypic changes can be easily quantified. Bivalves in particular have been the subject of numerous climate change studies, in part because of their economic value in the aquaculture industry and their important roles as ecosystem engineers. However, there has been little to no work investigating the effects of these stressors on the symbionts associated with these bivalves, specifically, their shell-boring polychaete parasites. This is important to understand because climate change may shift the synergistic relationship between parasite and host based on the individual responses of each. If such a shift favors proliferation of the polychaete, it may very well facilitate extinction of host bivalve populations. In this review I will (i) provide an overview of research completed thus far on the effects of climate change stressors on shell-boring polychaetes, (ii) discuss the technical challenges of studying these parasites in the laboratory, and (iii) propose a standardized framework for carrying out future in vitro and in vivo climate change experiments on shell-boring polychaetes.

The combined effects of climate change stressors and predatory cues on a mussel species

In order to make adequate projections on the consequences of climate change stressors on marine organisms, it is important to know how impacts of these stressors are affected by the presence of other species. Here we assessed the direct effects of ocean warming (OW) and acidification (OA) along with non-consumptive effects (NCEs) of a predatory crab and/or a predatory snail on the habitat-forming mussel Perumytilus purpuratus. Mussels were exposed for 10–14 weeks to contrasting pCO2 (500 and 1400 μatm) and temperature (15 and 20 °C) levels, in the presence/absence of cues from one or two predator species. We compared mussel traits at sub-organismal (nutritional status, metabolic capacity-ATP production-, cell stress condition via HSP70 expression) and organismal (survival, oxygen consumption, growth, byssus biogenesis, clearance rates, aggregation) levels. OA increased the mussels' oxygen consumption; and OA combined with OW increased ATP demand and the use of carbohydrate reserves. Mussels at present-day pCO2 levels had the highest protein content. Under OW the predatory snail cues induced the highest cell stress condition on the mussels. Temperature, predator cues and the interaction between them affected mussel growth. Mussels grew larger at the control temperature (15 °C) when crab and snail cues were present. Mussel wet mass and calcification were affected by predator cues; with highest values recorded in crab cue presence (isolated or combined with snail cues). In the absence of predator cues in the trails, byssus biogenesis was affected by OA, OW and the OA × OW and OA × predator cues interactions. At present-day pCO2 levels, more byssus was recorded with snail than with crab cues. Clearance rates were affected by temperature, pCO2 and the interaction between them. The investigated stressors had no effects on mussel aggregation. We conclude that OA, OW and the NCEs may lead to neutral, positive or negative consequences for mussels.

Warmer temperature increases mercury toxicity in a marine copepod.

Marine biota have been co-challenged with ocean warming and mercury (Hg) pollution over many generations because of human activities; however, the molecular mechanisms to explain their combined effects are not well understood. In this study, a marine planktonic copepod Pseudodiaptomus annandalei was acutely exposed to different temperature (22 and 25°C) and Hg (0 and 118μg/L) treatments in a 24-h cross-factored experiment. Hg accumulation and its subcellular fractions were determined in the copepods after exposure. The expression of the genes of superoxide dismutase (SOD), glutathione peroxidase (GPx), metallothionein1 (mt1), heat shock protein 70 (hsp70), hsp90, hexokinase (hk), and pyruvate kinase (pk) was also analyzed. Both the Hg treatment alone and the combined exposure of warmer temperature plus Hg pollution remarkably facilitated Hg bioaccumulation in the exposed copepods. Compared with the Hg treatment alone, the combined exposure increased total Hg accumulation and also the amount of Hg stored in the metal-sensitive fractions (MSF), suggesting elevated Hg toxicity in P. annandalei under a warmer environment, given that the MSF is directly related to metal toxicity. The warmer temperature significantly up-regulated the mRNA levels of mt1, hsp70, hsp90, and hk, indicating the copepods suffered from thermal stress. With exposure to Hg, the mRNA level of SOD increased strikingly but the transcript levels of hsp90, hk, and pk decreased significantly, indicating that Hg induced toxic events (e.g., oxidative damage and energy depletion). Particularly, in contrast to the Hg treatment alone, the combined exposure significantly down-regulated the mRNA levels of SOD and GPx but up-regulated the mRNA levels of mt1, hsp70, hsp90, hk, and pk. Collectively, the results of this study indicate that ocean warming will potentially boost Hg toxicity in the marine copepod P. annandalei, which is information that will increase the accuracy of the projections of marine ecosystem responses to the joint effects of climate change stressors and metal pollution on the future ocean.

Climate change and aquaculture: considering biological response and resources

AEI Aquaculture Environment Interactions Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections AEI 11:569-602 (2019) - DOI: https://doi.org/10.3354/aei00332 REVIEW Climate change and aquaculture: considering biological response and resources Gregor K. Reid1,2,*, Helen J. Gurney-Smith1,3, David J. Marcogliese1,4, Duncan Knowler5, Tillmann Benfey6, Amber F. Garber7, Ian Forster8, Thierry Chopin2,9, Kathy Brewer-Dalton10, Richard D. Moccia11, Mark Flaherty12, Caitlin T. Smith13, Sena De Silva14 1St. Andrews Biological Station, Fisheries and Oceans Canada, St. Andrews, NB E5B 0E4, Canada 2Canadian Integrated Multi-Trophic Aquaculture Network (CIMTAN), University of New Brunswick, Saint John, NB E2L 4L5, Canada 3Department of Biology, University of Victoria, Victoria, BC V8P 5C2, Canada 4Science and Technology Branch, Environment and Climate Change Canada, Montreal, QC K1A 0H3, Canada 5School of Resource and Environmental Management, Simon Fraser University, Burnaby, BC V5A 1S6, Canada 6Department of Biology, University of New Brunswick, Fredericton, NB E3B 5A3, Canada 7Huntsman Marine Science Centre, St. Andrews, NB E5B 2L7, Canada 8Pacific Science Enterprise Centre, Fisheries and Oceans Canada, West Vancouver, BC V7V1N6, Canada 9Department of Biological Sciences, University of New Brunswick, Saint John, NB E2L 4L5, Canada 10New Brunswick Department of Agriculture, Aquaculture and Fisheries, Fredericton, NB E3B 5H1, Canada 11Department of Animal Biosciences, University of Guelph, Guelph, ON N1G 2W1, Canada 12Department of Geography, University of Victoria, Victoria, BC V8P 5C2, Canada 13Port of Prince Rupert, BC V8J 1A2, Canada 14School of Life and Environmental Sciences, Deakin University, Warrnambool, VIC 3280, Australia *Corresponding author: gregor.reid@dfo-mpo.gc.ca ABSTRACT: The heavy reliance of most global aquaculture on the ambient environment suggests inherent vulnerability to climate change effects. This review explores the potential effects of climate change stressors on aquaculture biology and resources needed to support decision-making for vulnerability assessment, planned adaptation, and strategic research development. Climate change-mediated physiochemical outcomes important to aquaculture include extreme weather, precipitation and surge-based flooding, water stress, ocean acidification, sea-level rise, saltwater intrusion, and changes to temperature, salinity, and dissolved oxygen. Culture practices, environment, and region affect stressor exposure, and biological response between species or populations are not universal. Response to a climate change stressor will be a function of where changes occur relative to optimal ranges and tolerance limits of an organism’s life stage and physiological processes; the average magnitude of the stressor over the production cycle; stressor rate of change; variation, frequency, duration, and magnitude of extremes; epigenetic expression, genetic strain, and variation within and between populations; health and nutrition; and simultaneous stressor occurrence. The effects of simultaneous stressors will frequently interact, but may not be fully additive or synergistic. Disease is a major aquaculture limiter, and climate change is expected to further affect plant and animal health through the host and/or infectious agents. Climate change may introduce further complexity to the aquaculture-wild fishery relationship, with over two-thirds of animal aquaculture production dependent on external feed inputs. Higher production costs could be an economic outcome of climate change for many aquaculture sectors. Some aquaculture practices may inadvertently reduce resiliency to climate change, such as a reduction of coastal vegetation, coastal ground-water pumping, and reduction of population variability in pursuit of consistent production traits. Information from the largest aquaculture producers such as China and the top 3 global culture species is still sparse in the literature. This potentially limits thorough understanding of climate change effects on some regional aquaculture sectors. KEY WORDS: Nutrition · Algae · Genetics · Fish health · Acclimation · Economics · Ocean acidification · Extreme weather Full text in pdf format PreviousNextCite this article as: Reid GK, Gurney-Smith HJ, Marcogliese DJ, Knowler D and others (2019) Climate change and aquaculture: considering biological response and resources. Aquacult Environ Interact 11:569-602. https://doi.org/10.3354/aei00332 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in AEI Vol. 11. Online publication date: November 28, 2019 Print ISSN: 1869-215X; Online ISSN: 1869-7534 Copyright © 2019 Inter-Research.

Reduced up-regulation of gene expression in response to elevated temperatures in the mid-Atlantic population of Calanus finmarchicus

Climate change is affecting numerous species worldwide, including dominant and important copepods of the genus Calanus. Despite the growing body of studies that examine effects of climate change stressors on Calanus species, comparative intraspecific studies are lacking. Importantly, acclimatization and genetic adaptation can modify the stress response, thus leading to a differential response of separated populations to the same stressor. The molecular and physiological responses of a C. finmarchicus population from the mid-Atlantic, with an in situ temperature of 8.5°C, were investigated under experimental thermal conditions of 0°C, 5°C, 10°C, 15°C, and 20°C for durations of 3h and 6days. This experimental set-up mirrored previously published experiments conducted on C. finmarchicus at the northern limit of its distribution allowing a comparison between two populations. The greatest physiological response, assessed as fecal pellet production, was seen after 3h exposure at 10°C and 15°C, and after 6days exposure at 5°C, 10°C and 15°C. Molecular response was assessed by the change in expression of 5 selected genes: hsp70_2, dnaja1, nap 1l1, rps11, and gdh. Only two out of the five genes (gdh and nap1l1) showed significant up-regulation with increased temperature and duration of exposure. These findings differ from the results obtained in the northern population where all 5 genes were differently expressed. Overall, the results suggest population-specific response to temperature in C. finmarchicus, however determining the source of such variation (genetic adaptation or acclimatization) requires more detailed studies.

Multitaxon activity profiling reveals differential microbial response to reduced seawater pH and oil pollution.

There is growing concern that predicted changes to global ocean chemistry will interact with anthropogenic pollution to significantly alter marine microbial composition and function. However, knowledge of the compounding effects of climate change stressors and anthropogenic pollution is limited. Here, we used 16S and 18S rRNA (cDNA)-based activity profiling to investigate the differential responses of selected microbial taxa to ocean acidification and oil hydrocarbon contamination under controlled laboratory conditions. Our results revealed that a lower relative abundance of sulphate-reducing bacteria (Desulfosarcina/Desulfococcus clade) due to an adverse effect of seawater acidification and oil hydrocarbon contamination (reduced pH-oil treatment) may be coupled to changes in sediment archaeal communities. In particular, we observed a pronounced compositional shift and marked reduction in the prevalence of otherwise abundant operational taxonomic units (OTUs) belonging to the archaeal Marine Benthic Group B and Marine Hydrothermal Vent Group (MHVG) in the reduced pH-oil treatment. Conversely, the abundance of several putative hydrocarbonoclastic fungal OTUs was higher in the reduced pH-oil treatment. Sediment hydrocarbon profiling, furthermore, revealed higher concentrations of several alkanes in the reduced pH-oil treatment, corroborating the functional implications of the structural changes to microbial community composition. Collectively, our results advance the understanding of the response of a complex microbial community to the interaction between reduced pH and anthropogenic pollution. In future acidified marine environments, oil hydrocarbon contamination may alter the typical mixotrophic and k-/r-strategist composition of surface sediment microbiomes towards a more heterotrophic state with lower doubling rates, thereby impairing the ability of the ecosystem to recover from acute oil contamination events.