Posts Tagged 'fisheries'



Socioeconomic risk from ocean acidification and climate change impacts on Atlantic Canadian fisheries

Ocean acidification (OA) is an emerging consequence of anthropogenic carbon dioxide emissions. The full extent of the biological impacts are currently not well understood. However, it is expected that invertebrate species that rely on the mineral calcium carbonate will be among the first and most severely affected. Despite the limited understanding of impacts there is a need to identify potential pathways for human societies to be affected by OA. Research on these social implications is a small but developing field of literature. This thesis contributes to this field by using a risk assessment framework, informed by a biophysical model of future species distributions, to investigate Atlantic Canadian risk from changes in shellfish fisheries. New Brunswick and Nova Scotia are expected to see declines in resource accessibility. While Newfoundland and Labrador and PEI are more socially vulnerable to losses in fisheries, they are expected to experience relatively minor changes in access.

Continue reading ‘Socioeconomic risk from ocean acidification and climate change impacts on Atlantic Canadian fisheries’

Climate change impacts on fisheries and aquaculture: a global analysis

Climate Change Impacts on Fisheries and Aquaculture explores the impacts of climate change on global fisheries resources and on marine aquaculture and offers expert suggestions on possible adaptations to reduce those impacts.

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Future marine ecosystem drivers, biodiversity, and fisheries maximum catch potential in Pacific Island countries and territories under climate change

Highlights

  • Under the RCP 8.5 scenario, tropical Pacific temperature will rise by ≥ 3 °C by 2100.
  • This is accompanied by declines in dissolved oxygen, pH, and net primary production.
  • This will lead to local extinctions of up to 80% of marine species in some regions.
  • 9 of 17 Pacific Island entities experience ≥ 50% declines in maximum catch potential.
  • Impacts can be greatly reduced by mitigation measures under the RCP 2.6 scenario.


Abstract

The increase in anthropogenic CO2 emissions over the last century has modified oceanic conditions, affecting marine ecosystems and the goods and services that they provide to society. Pacific Island countries and territories are highly vulnerable to these changes because of their strong dependence on ocean resources, high level of exposure to climate effects, and low adaptive capacity. Projections of mid-to-late 21st century changes in sea surface temperature (SST), dissolved oxygen, pH, and net primary productivity (NPP) were synthesized across the tropical Western Pacific under strong climate mitigation and business-as-usual scenarios. These projections were used to model impacts on marine biodiversity and potential fisheries catches. Results were consistent across three climate models, indicating that SST will rise by ≥ 3 °C, surface dissolved oxygen will decline by ≥ 0.01 ml L−1, pH will drop by ≥ 0.3, and NPP will decrease by 0.5 g m−2 d−1 across much of the region by 2100 under the business-as-usual scenario. These changes were associated with rates of local species extinction of > 50% in many regions as fishes and invertebrates decreased in abundance or migrated to regions with conditions more suitable to their bio-climate envelope. Maximum potential catch (MCP) was projected to decrease by > 50% across many areas, with the largest impacts in the western Pacific warm pool. Climate change scenarios that included strong mitigation resulted in substantial reductions of MCP losses, with the area where MCP losses exceeded 50% reduced from 74.4% of the region under business-as-usual to 36.0% of the region under the strong mitigation scenario.

Continue reading ‘Future marine ecosystem drivers, biodiversity, and fisheries maximum catch potential in Pacific Island countries and territories under climate change’

A perspective for reducing environmental impacts of mussel culture in Algeria

Purpose

In Algeria, the Ministry of Fisheries and Halieutic Resources has designed a strategic plan for the development of marine aquaculture for the years 2015–2025, which aims at expanding the annual production of Mediterranean mussel from less than 150 metric tonnes year−1 in 2013 to 7600 metric tonnes year−1 in 2025. We used Life Cycle Assessment (LCA) for evaluating the environmental impact of suspended mussel culture in Algeria and suggest management practices which could reduce it.

Methods

In order to estimate the current and perspective impact of this industry, we (1) applied LCA to one of the few farms currently operating in Algeria and (2) investigated two management scenarios for the farms to be established in the future in the same coastal area. The first scenario (Comp_S) represents the continuity with the current situation, in which each farm is competing with the other ones and is therefore managing the production cycle independently. In the second scenario (Coop_S), mussel farms are grouped in an aquaculture management area and shared the same facilities for post-processing harvested mussels before sending them to the market. The midpoint-based CML-IA method baseline 2000 V 3.01 was employed using SimaPro software. Furthermore, we carried out a Monte Carlo simulation, in order to assess the uncertainty in the results.

Results and discussion

The analysis focused on impact categories related to acidification and global warming potential. We took into account the energy consumptions (electricity and vessel fuel), the rearing infrastructure, including longlines, and a building for stabling, grading, and packing the mussel. Electricity contributes with 38.1 and 31.8 % respectively to global warming potential (GWP) and acidification, while fuel consumption contributes with 19.5 % to GWP and 31.8 % to acidification. Results of this work are compared with other LCA studies recently carried out in France (Aubin and Fontaine 2014) and in Spain (Iribarren et al. 2010c).

Conclusions

The LCA results show that important reductions in environmental impacts could be attained if the mussel farming activity would be operated according to the cooperative scenario here proposed. In this case, the environmental benefits will be a reduction of 3150 MJ and 156 kg CO2 eq per metric tonne of mussel produced, compared with the alternative scenario. The results of this study suggest that LCA should be applied to the seafood production sector in Algeria, in order to identify best management practices.

Continue reading ‘A perspective for reducing environmental impacts of mussel culture in Algeria’

Understanding the impacts of anthropogenic stressors on species, ecosystems, and fishing communities

Anthropogenic modifications of marine environments result from a variety of activities and have effects across social and ecological dimensions. Humans inhabit linked systems, where our actions such as resource extraction, pollution and development influence species in both direct and indirect ways and feedback to influence the human communities dependent on living marine resources. In order to understand the consequences of our actions and develop strategies to plan for future environmental change, we need a diverse set of tools able to incorporate various levels of complexity. This necessitates the improvement and modification of existing tools, development of novel approaches and unique applications of methods from across fields. In this dissertation I address the ways in which we can use and improve existing tools in ecology to advance our understanding and management of marine resources. In the first Chapter I introduce a method to incorporate life stage specific responses to a stressor, ocean acidification, to gain a broader understanding of population level vulnerability. In the second Chapter I extend this work to address ecosystem level change from ocean acidification in the California Current, using an ecosystem model to determine changes in biomass and fisheries catch. In the third chapter, I work to improve our understanding of how multiple stressors acting across life history can be magnified or mitigated, based solely on biological characteristics of populations. Finally, in the fourth Chapter I introduce ecologists and natural scientists to a broader understanding of research on risk in order to improve our methods for approaching ecosystem based fisheries management. My work spans ecological scales from populations to ecosystems and links between social and ecological systems.

Continue reading ‘Understanding the impacts of anthropogenic stressors on species, ecosystems, and fishing communities’

Can shellfish adapt to ocean acidification?

Scientists peer into oyster and clam genomes to help the shellfish industry prepare for a change in ocean chemistry.

In the Pacific Northwest, oyster aficionados have likely tasted Chris Langdon’s scientific handiwork. Since 1996, his Molluscan Broodstock Program at Oregon State University has been breeding plump, fast-growing, and hardy oysters as stock for the $250 million West Coast oyster industry. But in the past several years, the program has taken on an additional goal: identifying oysters that are more resilient to ocean acidification.

In 2007, oyster hatcheries in Oregon and Washington began experiencing massive die-offs of their larvae that continued for several years. Eventually, managers and scientists realized that the larvae were dying during periods of strong upwelling, when deep waters rich in CO2 and low in pH come to the surface. These deep waters were even more acidified than in the past because of the oceans’ growing uptake of CO2 as its levels in the atmosphere increase. (…)

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Les systèmes aquacoles face au changement climatique (in French)

L’aquaculture contribue aujourd’hui pour environ 50 % à l’approvisionnement en ressources aquatiques destinées à la consommation humaine et cette part est amenée à s’accroître à l’avenir compte tenu de la stagnation des captures liées à la pêche. Si un certain nombre de travaux ont été effectués en vue d’évaluer l’impact du changement climatique sur la pêche, peu a encore été fait dans ce domaine sur l’aquaculture. Cet article de synthèse tente d’identifier les défis auxquels l’aquaculture aura à faire face dans un contexte de changement climatique et propose des voies, à la fois adaptatives et innovantes, pour répondre à ces défis. L’article se focalise particulièrement sur six composantes de l’environnement susceptibles de subir des modifications sous l’effet du changement climatique et d’avoir un impact direct sur l’aquaculture : l’augmentation du niveau des mers ; la modification de la température ; les précipitations, les crues et les sécheresses ; la disponibilité en eau ; la dégradation de la qualité des eaux et enfin l’acidification des océans. Les impacts indirects concernent quant à eux principalement l’approvisionnement en farine et huile de poissons, constituants stratégiques des aliments destinés aux élevages d’animaux aquatiques, dont la disponibilité est dépendante des débarquements des pêches minotières, elles-mêmes sensibles au changement climatique. Face au changement climatique, deux stratégies sont possibles. La première, adaptative, consiste à mettre en œuvre des solutions qui permettent de prendre en compte les modifications du milieu (espèce adaptée, sélection de site) ; la deuxième consiste à imaginer des systèmes où les facteurs du milieu sont rigoureusement maîtrisés. Réciproquement, l’impact de l’aquaculture sur le changement climatique est évoqué. Enfin, les résultats d’une enquête conduite par la FAO en 2016 sur la situation des mesures prises dans diverses parties du monde pour faire face au changement climatique en matière d’aquaculture sont exposés.

Continue reading ‘Les systèmes aquacoles face au changement climatique (in French)’


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OA-ICC HIGHLIGHTS

Ocean acidification in the IPCC AR5 WG II

OUP book