Posts Tagged 'socio-economy'

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A proteomic analysis of the effect of ocean acidification on the haemocyte proteome of the South African abalone Haliotis midae

Published 17 August 2021 Science Closed
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Highlights

  • 227 proteins were differentially expressed in response to ocean acidification conditions.
  • Under OA conditions, H. midae underwent a metabolic shift to generate ATP via energy-efficient mechanisms.
  • Haemocyte stabilisation and homeostasis in response to OA was reflected by up-regulation of oxidative stress and cytoskeletal proteins.
  • An interplay between the stress and immune response was observed through up-regulation of proteins involved in protein synthesis and turnover, as well as intracellular signalling and transport.

Abstract

As a result of increasing CO2 emissions and the prevalence of global climate change, ocean acidification (OA) is becoming more pervasive, affecting many trophic levels, particularly those that rely on succinctly balanced ocean chemistry. This ultimately threatens community structures, as well as the future sustainability of the fishing/aquaculture industry. Understanding the molecular stress response of key organisms will aid in predicting their future survivability under changing environmental conditions. This study sought to elucidate the molecular stress response of the South African abalone, Haliotis midae, an understudied organism with high economic value, utilising a high throughput iTRAQ-based proteomics methodology. Adult abalone were exposed to control (pH 7.9) and experimental (pH 7.5) conditions for 12, 72 and 168 h, following which protein was isolated from sampled haemocytes and subsequently processed. iTRAQ-labelled peptides were analysed using mass spectrometry, while an array of bioinformatics tools was utilised for analysing the proteomic data. COG analysis identified “Cytoskeleton”, “Translation, ribosomal structure and biogenesis”, “Post-translational modification, protein turnover, chaperones”, and “Intracellular trafficking, secretion and vesicular transport” to be the most enriched functional classes, while statistical analysis identified a total of 33 up-regulated and 23 down-regulated effectors of OA stress in abalone. Several of the up-regulated proteins that were identified function in central metabolism (ENO1, PGK, DUOX1, GPD2), the stress/immune response (CAMKI, HSPA5/GRP78, MAPKI), and cytoskeleton, protein sorting and signal transduction (IQGAP1, MYO9B, TLN1, RDX, TCP-1/CCT, SNX6, CHMP1a, VPS13a). Protein-protein interactions were predicted using STRING DB, Cytoscape and Ingenuity Pathway Analysis, providing a model of the effects of OA on the H. midae haemocyte proteome. The data indicated that H. midae underwent a metabolic shift under OA conditions to utilize more energy-efficient mechanisms of ATP generation, while attempts at restoring haemocyte stabilisation and homeostasis were reflected by up-regulation of oxidative stress and cytoskeletal proteins. Our results support other molluscan studies that report a complex array of overlapping functions of both the stress and immune response systems. This interplay of the mounted stress and immune response is maintained and observed through the up-regulation of proteins involved in protein synthesis and turnover, as well as intracellular signalling and transport. The data presented in this study highlight the value of employing sensitive and robust -omics technologies for assessing the effects of changing environmental conditions on marine organisms.

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A method for studying acidification and eutrophication potentials of a residential neighbourhood

Published 12 August 2021 Science Closed
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Acidification and eutrophication are two environmental impacts that have a significant effect on air pollution and human health. The quantitative analysis of these two impacts remains hitherto unknown at the scale of new neighbourhoods. The main purpose of this research is to evaluate, analysis and compare the acidification and eutrophication potentials of one neighbourhood initially located in Belgium. To perform this comparison, the same neighbourhood design is applied to in 150 countries, but four parameters are adapted to each country: energy mix, local climate, building materials, and occupants’ mobility. In addition, this research evaluates the induced environmental costs of the neighbourhood over 100 years and examines the impact of the photovoltaic panel on these environmental impacts. This research, extended to the scale of several nations, will enable new researchers, and especially policy-makers, to measure the effectiveness of sustainable neighbourhoods. Eutrophication and acidification potentials were assessed under different phases (construction, use, renovation, and demolition), with Pleiades ACV software. Among the four local parameters (energy mix, local materials, climate, and transport, the energy mix has the most significant effect on the two studied environmental impacts. The results show that 72 %, and 65% of acidification, and eutrophication potentials are produced during the operational phase of the neighbourhood. In the case of sustainable neighbourhoods, the acidification potential is 22.1% higher in the 10 top Low incomes countries than the 10 top High-income countries. At the neighbourhood scale the main eutrophication potential component is water (34.2%), while, the main source of acidification potential is electricity production (45.1%)

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Sustainable management of the coastal water pH of Pulau Tuba using the Inverse Distance Weighted (IDW) method

Published 5 August 2021 Science Closed
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Ocean acidification can be managed and monitored effectively through the application of spatial interpolation methods. The purpose of this study is to evaluate the precision of the Inverse Distance Weighted (IDW) interpolation method to estimate and map the coastal water pH for the sustainability of Pulau Tuba, Langkawi, Kedah. About 30 sampling points have been set up during two sampling activities in November 2018. The pH meter has been calibrated and lowered to 1 meter below the water surface to measure the reading of pH. The development of the spatial model was developed using the spatial analyst tool available in ArcGIS Software. Several types of statistical analyses were carried out to compare the observed and predicted value of pH. such as correlation analysis, regression analysis, and error analysis. Accuracy assessment was conducted later after the transformation of a spatial model into a surface map. The study found that the IDW interpolation method successfully interpolated the pH readings. The result showed that there is a strong positive correlation between the observed and predicted values. For error analysis, Mean Absolute Error (MAE) and Root Mean Square Error (RMSE) were recorded at 0.033 and 0.044, respectively. After the transformation of the spatial model to the surface map, the accuracy of the map is recorded at 81.25%. The study also outlines the sustainable mechanisms and opportunities for the government to implement in combatting the ocean acidification processes. The map produced can be used for social and economic development and the protection of biodiversity for the coastal water of Pulau Tuba.

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Effects of elevated pCO2 on the physiological energetics of Pacific oyster, Crassostrea gigas

Published 3 August 2021 Science Closed
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Ocean acidification is predicted to have significant implications for marine calcifying organisms. However, little is known about the physiological responses of Pacific oyster, Crassostrea gigas, to elevated partial pressure of atmospheric carbon dioxide (pCO2) under natural fluctuations associated with a farm environment. The present study evaluated the effect of two pCO2 levels (i.e. ambient ∼625 μatm and elevated ∼1432 μatm) on the physiological processes and growth of C. gigas in in situ mesocosms that simulated the farm environment. Oysters were exposed for 30 days over a sensitive period during their production cycle when they are first exposed to natural coastal conditions. Despite this being a well-known “bottleneck” in production, it remains understudied with respect to climate change. Results showed that elevated pCO2 levels decreased clearance rate, ingestion rate, absorption efficiency, and oxygen to nitrogen ratio, while increasing oxygen consumption and ammonia-N excretion rates. These physiological responses of oysters resulted in a reduction in energy available for growth (scope for growth). No mortality was observed in the control or elevated pCO2 treatments, indicating that although oyster may survive future coastal acidification, the allocation of energy towards production within aquaculture systems will decrease in the future, affecting the culture of these economically important marine bivalves.

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Understanding and advancing natural resource management in the context of changing ocean conditions

Published 3 August 2021 Science Closed
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Changing ocean conditions, such as ocean acidification, hypoxia, and ocean warming, are impacting marine ecosystems and posing a variety of immediate and future challenges for natural resource managers and affiliated industries. In order to successfully facilitate adaptation and mitigation responses to changing ocean conditions, research efforts and synthesis products should be developed in collaboration with resource managers and decision makers. Using interviews and surveys, we sought to advance collaborative science approaches by identifying the most pressing concerns, barriers, and research and monitoring needs of natural resource managers in Washington State, USA, where marine waters are particularly vulnerable to changing ocean conditions. Survey participants indicated that they are most concerned by ocean acidification, followed by water temperature and hypoxia. Our findings reveal a desire to prioritize laboratory and in situ studies to identify survival thresholds of ecologically or commercially important organisms, specifically zooplankton, fish, Dungeness crab, and conditions that promote harmful algal blooms. Scientific literature and in-person workshops and meetings were the preferred way for survey participants to learn about new science and affiliated results. Our findings highlight a need for continued and expanded monitoring and research efforts, the development of interpretive science products for resource managers, and enhanced communication between entities before information on changing ocean conditions can be effectively incorporated into resource management and policy decisions.

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Effects of ocean acidification on young-of-the-year golden king crab (Lithodes aequispinus) survival and growth

Published 30 July 2021 Science Closed
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Ocean acidification, a reduction in the pH of the oceans caused by increasing CO2, can have negative physiological effects on marine species. In this study, we examined how CO2-driven acidification affected the growth and survival of juvenile golden king crab (Lithodes aequispinus), an important fishery species in Alaska. Juveniles were reared from larvae in surface ambient pH seawater at the Kodiak Laboratory. Newly molted early benthic instar crabs were randomly assigned to one of three pH treatments: (1) surface ambient pH ~ 8.2, (2) likely in situ ambient pH 7.8, and (3) pH 7.5. Thirty crabs were held in individual cells in each treatment for 127 days and checked daily for molting or death. Molts and dead crabs were photographed under a microscope and measured using image analysis to assess growth and morphology. Mortality was primarily associated with molting in all treatments, differed among all treatments, and was highest at pH 7.5 and lowest at ambient pH. Crabs at pH 7.5 were smaller than crabs at ambient pH at the end of the experiment, both in terms of carapace length and wet mass; had a smaller growth increment after molting; had a longer intermolt period. Carapace morphology was not affected by pH treatment. Decreased growth and increased mortality in laboratory experiments suggest that lower pH could affect golden king crab stocks and fisheries. Future work should examine if larval rearing conditions affect the juvenile response to low pH.

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Econometric modelling of carbon dioxide emissions and concentrations, ambient temperatures and ocean deoxygenation

Published 29 July 2021 Science Closed
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This paper analysed several longitudinal data sets for investigating the dynamic inter-relationships between CO2 emissions and atmospheric concentrations, ambient temperatures and ocean acidification and deoxygenation. The methodological framework addressed issues such as the use of temperature ‘anomalies’, diffusion of CO2 to atmospheric stations, distributional misspecification and non-stationarity of errors affecting empirical models, and use of spline functions for modelling trends in temperatures. Longitudinal data on CO2 emissions for 163 countries and atmospheric CO2 concentrations at 10 stations, ambient temperatures from over 8,500 weather stations and seawater composition from over 380,000 oceanographic stations were analysed for 1985–2018 by estimating dynamic random effects models using maximum likelihood methods. The main findings were that CO2 emissions exhibited rapid upward trends at the country level, while minimum and maximum temperatures showed cyclical patterns; economic activity and population levels were associated with higher CO2 emissions. Second, there were gradual upward trends in annual and seasonal temperatures compiled at weather stations, and atmospheric CO2 concentrations were significantly associated with higher temperatures in the hemispheres. Third, there was a steady decline in dissolved oxygen levels, and the interactive effects of water temperatures and pH levels were significant. Overall, the results underscore the benefits of reducing CO2 emissions for ambient temperatures and for ocean deoxygenation. Synergies between CO2 emissions, ambient temperatures and ocean acidification are likely to exacerbate the melting of polar ice.

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Evaluating the impact of climate and demographic variation on future prospects for fish stocks: an application for northern rock sole in Alaska

Published 28 July 2021 Science Closed
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Climate-enhanced stock assessment models represent potentially vital tools for managing living marine resources under climate change. We present a climate-enhanced stock assessment where environmental variables are integrated within a population dynamics model assessment of biomass, fishing mortality and recruitment that also accounts for process error in demographic parameters. Probability distributions for the impact of the associated environmental factors on recruitment and growth can either be obtained from Bayesian analyses that involve fitting the population dynamics model to the available data or from auxiliary analyses. The results of the assessment form the basis for the calculation of biological and economic target and limit reference points, and projections under alternative harvest strategies. The approach is applied to northern rock sole (Lepidopsetta polyxystra), an important component of the flatfish fisheries in the Eastern Bering Sea. The assessment involves fitting to data on catches, a survey index of abundance, fishery and survey age-compositions and survey weight-at-age, with the relationship between recruitment and cold pool extent and that between growth increment in weight and temperature integrated into the assessment. The projections also allow for an impact of ocean pH on expected recruitment based on auxiliary analyses. Several alternative models are explored to assess the consequences of different ways to model environmental impacts on population demography. The estimates of historical biomass, recruitment and fishing mortality for northern rock sole are not markedly impacted by including climate and environmental factors, but estimates of target and limit reference points are sensitive to whether and how environmental variables are included in stock assessments and projections.

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Impacts of large-scale aquaculture activities on the seawater carbonate system and air-sea CO2 flux in a subtropical mariculture bay, southern China

Published 23 July 2021 Science Closed
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In this study, the variations of the seawater carbonate system parameters and air-sea CO2 flux (FCO2) of Shen’ao Bay, a typical subtropical aquaculture bay located in China, were investigated in spring 2016 (March to May). Parameters related to the seawater carbonate system and FCO2 were measured monthly in 3 different aquaculture areas (fish, oyster and seaweed) and in a non-culture area near the bay mouth. The results showed that the seawater carbonate system was markedly influenced by the biological processes of the culture species. Total alkalinity was significantly lower in the oyster area compared with the fish and seaweed areas, mainly because of the calcification process of oysters. Dissolved inorganic carbon (DIC) and CO2 partial pressure ( pCO2) were highest in the fish area, followed by the oyster and non-culture areas, and lowest in the seaweed area. Oysters and fish can have indirect influences on DIC and pCO2by releasing nutrients, which facilitate the growth of seaweed and phytoplankton and therefore promote photosynthetic CO2 fixation. For these reasons, Shen’ao Bay acts as a potential CO2 sink in spring, with an average FCO2 ranging from -1.2 to -4.8 mmol m-2 d-1. CO2 fixation in the seaweed area was the largest contributor to CO2 flux, accounting for ca. 58% of the total CO2 sink capacity of the entire bay. These results suggest that the carbonate system and FCO2 of Shen’ao Bay were significantly affected by large-scale mariculture activities. A higher CO2 sink capacity could be acquired by extending the culture area of seaweed.

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Long-term effects of high CO2 on growth and survival of juveniles of the striped venus clam Chamelea gallina: implications of seawater carbonate chemistry

Published 14 July 2021 Science Closed
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Ocean acidification (OA) will decrease shellfish growth and survival, with ecological and economic consequences for fisheries and aquaculture. However, the high variability of results among experiments, and the lack of long-term studies, make it difficult to predict the effect that OA will have on bivalve species. We tested the long-term effect of high CO2 on growth, calcification rates, and survival of juveniles of the commercial bivalve species Chamelea gallina from Southern Portugal. The local high alkalinity of seawater probably buffered the negative effect of the pH drop, and after 75 days juveniles increased their growth and calcification rates with CO2. However, after 217 days, the situation reversed, bivalves under control conditions had the highest growth and calcification rates, while individuals under high CO2 presented negative calcification rates. The biometric variable that responded first was the width of the individuals, followed by the height and length of the shells. Survival was unaffected except for a mortality peak of juveniles under control and intermediate conditions as a consequence of a temperature drop. In the short term, C. gallina will increase their calcification rates to compensate for OA. However, in the long term, the additional energy expended will be translated into growth losses with negative repercussions for the fisheries and aquaculture. The cultivation of shellfish on high alkaline seawater should be further explored as a bioremediation measure to mitigate the negative effect of OA on shellfish aquaculture.

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Taxing interacting externalities of ocean acidification, global warming, and eutrophication

Published 22 June 2021 Science Closed
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We model a stylized economy dependent on agriculture and fisheries to study optimal environmental policy in the face of interacting external effects of ocean acidification, global warming, and eutrophication. This allows us to capture some of the latest insights from research on ocean acidification. Using a static two-sector general equilibrium model we derive optimal rules for national taxes on urn:x-wiley:08908575:media:nrm12317:nrm12317-math-0001 emissions and agricultural run-off and show how they depend on both isolated and interacting damage effects. In addition, we derive a second-best rule for a tax on agricultural run-off of fertilizers for the realistic case that effective internalization of urn:x-wiley:08908575:media:nrm12317:nrm12317-math-0002 externalities is lacking. The results contribute to a better understanding of the social costs of ocean acidification in coastal economies when there is interaction with other environmental stressors.

Recommendations for Resource Managers:

  • Marginal environmental damages from urn:x-wiley:08908575:media:nrm12317:nrm12317-math-0003 emissions should be internalized by a tax on urn:x-wiley:08908575:media:nrm12317:nrm12317-math-0004 emissions that is high enough to not only reflect marginal damages from temperature increases, but also marginal damages from ocean acidification and the interaction of both with regional sources of acidification like nutrient run-off from agriculture.
  • In the absence of serious national policies that fully internalize externalities, a sufficiently high tax on regional nutrient run-off of fertilizers used in agricultural production can limit not only marginal environmental damages from nutrient run-off but also account for unregulated carbon emissions.
  • Putting such regional policies in place that consider multiple important drivers of environmental change will be of particular importance for developing coastal economies that are likely to suffer the most from ocean acidification.
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Nonlinearity, irreversibility, and surprise – managing Atlantic cod under climate change

Published 9 June 2021 Science Closed
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Climate change is at the forefront of today’s global challenges with its potential to turn into a runaway process. Fishing pressure acts in concert and exacerbates the impacts of climate change. The North Atlantic Ocean is no exemption of the increasing anthropogenic stress with Atlantic cod, Gadus Morhua, one of its most prominent fish species, displaying the ocean’s state. Most Atlantic cod stocks have experienced high rates of fishing and biomass declines, leading to renovation of fishing regulations and the implementation of rebuilding strategies. Today, the cod stocks differ considerably in trends and commercial status with 8 stocks considered collapsed and 57 % of today’s landings supplied by one single stock, the North East Arctic cod. What drives the collapse and what drives the recovery of a stock? Elucidating drivers of Atlantic cod productivity at low abundance is inevitable for sustainably managing the species in its changing habitat. This thesis attempts a comprehensive study on climate change impacts by addressing rising ocean temperature (paper I-III), temperature variability (paper II), acidification (paper III) and uncertainty (of the biology and as risk in management under the precautionary approach [paper IV]). Individual and synergistic impacts of climate change are discussed with a particular focus on nonlinear dynamics, including the potential for Allee effects (paper I-III). Allee effects describe the decrease in per capita growth rate at small population size, which can hinder population recovery by reinforcing degradation. Such a shift in the underlying biology can be irreversible and demands proactive and precautionary management measures. Application of precautionary measures to protect the environment and manage risks in situations of high uncertainty is a central tenet of the “precautionary approach”, a guiding principle in fisheries management. The poor state of various commercial fish stocks worldwide stands in contrast to the precautionary approach and suggests a subordinate role of science in fisheries management. In paper IV, Canada’s fisheries policy and advisory process is contrasted with the EU’s Common Fisheries Policy in regard to the precautionary approach and the role of science, in order to identify policy and institutional constraints that have hindered sustainable, precautionary management practices. Drawing from insights on climate change driven productivity changes (paper I-III) and the importance of a policy and institutional framework that acknowledges these (paper IV), this thesis ends with suggestions for scientifically informed, precautionary and sustainable fisheries management practices that can speed up recovery and allow for a vital fishery in the future.

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Projecting ocean acidification impacts for the Gulf of Maine to 2050: new tools and expectations

Published 3 June 2021 Science Closed
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Ocean acidification (OA) is increasing predictably in the global ocean as rising levels of atmospheric carbon dioxide lead to higher oceanic concentrations of inorganic carbon. The Gulf of Maine (GOM) is a seasonally varying region of confluence for many processes that further affect the carbonate system including freshwater influences and high productivity, particularly near the coast where local processes impart a strong influence. Two main regions within the GOM currently experience carbonate conditions that are suboptimal for many organisms—the nearshore and subsurface deep shelf. OA trends over the past 15 years have been masked in the GOM by recent warming and changes to the regional circulation that locally supply more Gulf Stream waters. The region is home to many commercially important shellfish that are vulnerable to OA conditions, as well as to the human populations whose dependence on shellfish species in the fishery has continued to increase over the past decade. Through a review of the sensitivity of the regional marine ecosystem inhabitants, we identified a critical threshold of 1.5 for the aragonite saturation state (Ωa). A combination of regional high-resolution simulations that include coastal processes were used to project OA conditions for the GOM into 2050. By 2050, the Ωa declines everywhere in the GOM with most pronounced impacts near the coast, in subsurface waters, and associated with freshening. Under the RCP 8.5 projected climate scenario, the entire GOM will experience conditions below the critical Ωa threshold of 1.5 for most of the year by 2050. Despite these declines, the projected warming in the GOM imparts a partial compensatory effect to Ωa by elevating saturation states considerably above what would result from acidification alone and preserving some important fisheries locations, including much of Georges Bank, above the critical threshold.

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Acid–base balance in the hæmolymph of European abalone (Haliotis tuberculata) exposed to CO2-induced ocean acidification

Published 1 June 2021 Science Closed
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Highlights

  • The effects of ocean acidification (OA) on extra-cellular acid–base parameters are reported in the European abalone H. tuberculata, a commercially and ecologically important gastropod.
  • Adult abalone were exposed for 15 days to three different pH levels (7.9, 7.7, 7.4) representing current and predicted near-future conditions.
  • Abalones are able to buffer a moderate acidification of seawater (−0.2 pH units).
  • Haemolymph pH was significantly decreased after 5 days of exposure to pH 7.4 (−0.5 pH units) indicating that abalone do not compensate for higher decreases of in seawater pH.
  • OA would impact both the ecology and aquaculture of H. tuberculata in the near future.

Abstract

Ocean acidification (OA) and the associated changes in seawater carbonate chemistry pose a threat to calcifying organisms. This is particularly serious for shelled molluscs, in which shell growth and microstructure has been shown to be highly sensitive to OA. To improve our understanding of the responses of abalone to OA, this study investigated the effects of CO2-induced ocean acidification on extra-cellular acid–base parameters in the European abalone Haliotis tuberculata. Three-year-old adult abalone were exposed for 15 days to three different pH levels (7.9, 7.7, 7.4) representing current and predicted near-future conditions. Hæmolymph pH and total alkalinity were measured at different time points during exposure and used to calculate the carbonate parameters of the extracellular fluid. Total protein content was also measured to determine whether seawater acidification influences the composition and buffer capacity of hæmolymph. Extracellular pH was maintained at seawater pH 7.7 indicating that abalones are able to buffer moderate acidification (−0.2 pH units). This was not due to an accumulation of HCO3− ions but rather to a high hæmolymph protein concentration. By contrast, hæmolymph pH was significantly decreased after 5 days of exposure to pH 7.4, indicating that abalone do not compensate for higher decreases in seawater pH. Total alkalinity and dissolved inorganic carbon were also significantly decreased after 15 days of low pH exposure. It is concluded that changes in the acid–base balance of the hæmolymph might be involved in deleterious effects recorded in adult H. tuberculata facing severe OA stress. This would impact both the ecology and aquaculture of this commercially important species.

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Recycling of induction furnace steel slag in concrete for marine environmental applications towards ocean acidification studies

Published 26 May 2021 Science Closed
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In the present investigation, induction furnace (IF) steel slag as coarse aggregate with 0%, 20% and 40% replaced concrete specimens of size 150 × 150 × 150 mm was prepared as an initiative to utilize iron-rich IF steel slag. The casted concrete specimens were cured for 28 days at room temperature (28 °C) in freshwater, and the obtained compressive strength is 22.5, 24.0 and 29.2 N/mm2, respectively. The blocks were then immersed in seawater under laboratory condition for 28 days, and variation in pH was monitored at regular intervals. The composition and mineralogical phases [quartz (SiO2), iscorite (Fe7SiO10), hematite (ε-Fe2O3) and almandine (Fe3Al2Si3O10)] present in IF steel slag were identified using XRF and XRD analysis, respectively. Surface morphology and elemental composition were studied using FESEM with EDAX analysis for before and after immersion of concrete blocks in seawater. Structural bonding of concrete blocks before and after immersion was studied using FTIR analysis. Compressive strength of concrete specimens after the immersion in seawater was evaluated and compared with before immersion in seawater. This initiative will be a major support for induction furnace steel industries via economic benefits. Utilization of iron-rich IF steel slag in marine concrete can be a vital candidate for the betterment of marine ecosystem via primary production of marine resources.

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Responses of Southern ocean seafloor habitats and communities to global and local drivers of change

Published 17 May 2021 Science Closed
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Knowledge of life on the Southern Ocean seafloor has substantially grown since the beginning of this century with increasing ship-based surveys and regular monitoring sites, new technologies and greatly enhanced data sharing. However, seafloor habitats and their communities exhibit high spatial variability and heterogeneity that challenges the way in which we assess the state of the Southern Ocean benthos on larger scales. The Antarctic shelf is rich in diversity compared with deeper water areas, important for storing carbon (“blue carbon”) and provides habitat for commercial fish species. In this paper, we focus on the seafloor habitats of the Antarctic shelf, which are vulnerable to drivers of change including increasing ocean temperatures, iceberg scour, sea ice melt, ocean acidification, fishing pressures, pollution and non-indigenous species. Some of the most vulnerable areas include the West Antarctic Peninsula, which is experiencing rapid regional warming and increased iceberg-scouring, subantarctic islands and tourist destinations where human activities and environmental conditions increase the potential for the establishment of non-indigenous species and active fishing areas around South Georgia, Heard and MacDonald Islands. Vulnerable species include those in areas of regional warming with low thermal tolerance, calcifying species susceptible to increasing ocean acidity as well as slow-growing habitat-forming species that can be damaged by fishing gears e.g., sponges, bryozoan, and coral species. Management regimes can protect seafloor habitats and key species from fishing activities; some areas will need more protection than others, accounting for specific traits that make species vulnerable, slow growing and long-lived species, restricted locations with optimum physiological conditions and available food, and restricted distributions of rare species. Ecosystem-based management practices and long-term, highly protected areas may be the most effective tools in the preservation of vulnerable seafloor habitats. Here, we focus on outlining seafloor responses to drivers of change observed to date and projections for the future. We discuss the need for action to preserve seafloor habitats under climate change, fishing pressures and other anthropogenic impacts.

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Risk assessment for key socio-economic and ecological species in a sub-arctic marine ecosystem under combined ocean acidification and warming

Published 30 March 2021 Science Closed
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The Arctic may be particularly vulnerable to the consequences of both ocean acidification (OA) and global warming, given the faster pace of warming and acidification. Here, we use the Atlantis ecosystem model to assess how the trophic network of marine fishes and invertebrates in the Icelandic waters is responding to the combined pressures of OA and warming. We develop an approach which allows us to focus on species of economic (catch-value), social (number of participants in fisheries), or ecological (keystone species) importance. We parameterize the model with literature-determined ranges of sensitivity to OA and warming for different species and functional groups in the Icelandic waters. We found divergent species responses to warming and acidification levels; (mainly) planktonic groups and forage fish benefited while (mainly) benthic groups and predatory fish decreased under warming and acidification scenarios. Assuming conservative harvest rates for the largest catch-value species, Atlantic cod, we see that the population is projected to remain stable under even the harshest acidification and warming scenario. Further, for the scenarios where the model projects reductions in biomass of Atlantic cod, other species in the ecosystem increase, likely due to a reduction in competition and predation. These results highlight the interdependencies of multiple global change drivers and their cascading effects on trophic organization, and the supply of an important species from a socio-economic perspective in the Icelandic fisheries.

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Aiding ocean development planning with SDG relationships in small island developing states

Published 26 March 2021 Science Closed
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Promoting the Sustainable Development Goals (SDGs) must contend with the often siloed nature of governance institutions, making the identification of cooperative institutional networks that promote SDG targets a priority. We develop and apply a method that combines SDG interaction analysis, which helps determine prerequisites for SDG attainment, with the transition management framework, which helps align policy goals with institutional designs. Using Aruba as a case study, we show that prioritizing increased economic benefits from sustainable marine development, including those of tourism, provides the greatest amount of direct co-benefits to other SDGs. When considering indirect co-benefits, reducing marine pollution emerged as a key supporting target to achieve SDGs. The results also show that, as in many other small island states, sustainable ocean development in Aruba depends on international partnerships to address global issues—including climate change mitigation—over which it has little control. Using SDG relationships as a guide for institutional cooperation, we find that the institutions with the most potential to coordinate action for sustainable ocean development are those that address economic, social and international policy, rather than institutions specifically focused on environmental policy. Our results provide key methodologies and insights for sustainable marine development that require coordinated actions across institutions.

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Ocean and coastal indicators: understanding and coping with climate change at the land-sea interface

Published 5 January 2021 Science Closed
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The U.S. Exclusive Economic Zone (EEZ) encompasses approximately 3.4 million square nautical miles of ocean and a coastline of over 12,300 miles. Along with the Great Lakes, this vast area generates ~US 370 billion of U.S. gross domestic product, 617 billion in sales and 2.6 million jobs each year. These ocean and coastal ecosystems also provide many important non-market services including subsistence food provisioning, health benefits, shoreline protection, climate regulation, conservation of marine biodiversity, and preservation of cultural heritage. As climatic changes occur, these benefits or ecosystem services may be significantly reduced or in some cases enhanced. These services are also under an array of pressures including over-exploitation of natural resources, pollution, and land use changes that occur simultaneously in synergistic, multiplicative, or antagonistic ways. This results in direct and indirect impacts that are often unpredictable across spatial and temporal scales. Here, we discuss a set of indicators designed in close collaboration with the U.S. National Climate Indicators System. Tracking the impacts via indicators will be essential to ensure long-term health of the marine environment and sustain the benefits to stakeholders who depend on marine ecosystem services.

Continue reading ‘Ocean and coastal indicators: understanding and coping with climate change at the land-sea interface’

Chapter 2: The impact of climate change on oceans: physical, chemical and biological responses

Published 18 December 2020 Science Closed
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The rising concentrations of carbon dioxide and other greenhouse gases have caused observed physical, chemical and biological changes in the oceans, with further changes projected over coming decades. The impact of climate change on the oceans are profound, with rapid warming in ocean hotspots combined with extreme events such as marine heatwaves changing the distribution and abundance of a wide range of marine species. Further, ocean acidification, sea level rise, and deoxygenation may have important consequences for the marine ecosystems and the ecosystem services derived from the ocean. These observed and future ocean changes are irreversible on the timescale of many centuries. As a result, management of marine resources, for both extractive (for example, fishing) and non-extractive (for example, marine tourism) will need to account for the effects of climate change. For example, changes in abundance of marine species will impact harvesting levels and ecosystem structure, while changes in species’ distribution will challenge place-based management and agreements between nations. Adaptation to some of these changes will be possible; however, without substantial reduction in greenhouse gas emissions the oceans will change and not provide the same support for human activities as currently enjoyed. The changing nature of the ocean, and the impact it may have on ecosystems and communities, represents a huge challenge to future community interactions at local, national and international scales. It also raises the possibility of active intervention in the climate system to minimize the impacts of climate change which will introduce a complex set of issues to be considered before implementing any intervention.

Continue reading ‘Chapter 2: The impact of climate change on oceans: physical, chemical and biological responses’

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