157 research outputs found
Climate Change-Induced Emergence of Novel Biogeochemical Provinces
No full textThe global ocean is commonly partitioned into 4 biomes subdivided into 56 biogeochemical provinces (BGCPs) following the accepted division proposed by Longhurst in 1998. Each province corresponds to a unique regional environment that shapes biodiversity and constrains ecosystem structure and functions. Biogeochemical provinces are dynamic entities that change their spatial extent and position with climate and are expected to be perturbated in the near future by global climate change. Here, we characterize the changes in spatial distribution of BGCPs from 1950 to 2100 using three earth system models under two representative concentration pathways (RCP 2.6 and 8.5). We project a reorganization of the current distribution of BGCPs driven mostly by a poleward shit in their distribution (18.4 km in average per decade). Projection of the future distribution of BGCPs also revealed the emergence of new climate that has no analog with past and current environmental conditions. These novel environmental conditions, here named No-Analog BGCPs State (NABS), will expand from 2040 to 2100 at a rate of 4.3 Mkm2 per decade (1.2% of the global ocean). We subsequently quantified the potential number of marine species and annual volume of fisheries catches that would experience such novel environmental conditions to roughly evaluate the impact of NABS on ecosystem services
Linking observed changes in pelagic catches to temperature and oxygen in the Eastern Tropical Pacific
No full textWarming increases the metabolic rates of fishes and drives their oxygen demands above environmental oxygen supply, leading to declines in fish growth and smaller population sizes. Given the wide variability in species' sensitivity to changing temperature and oxygen levels, warming and oxygen limitation may be altering the composition of fish communities and hence, that of fisheries catches. Here, we test the hypothesis that changing temperatures shape the composition of pelagic fisheries catches in the Eastern Tropical Pacific. We expect that under warmer conditions, pelagic fisheries catches will be dominated by tropical species with higher oxygen demands and less surplus oxygen for growth. To test this hypothesis, we combined an index of the physiological vulnerability of exploited large pelagic fishes (e.g. tuna and billfish) to changing ocean temperatures and oxygen levels with fisheries catch data from 1970 to 2016. We found that warming is the main driver of changes in the physiological performance and catch composition of this fishery, and that oxygen limitation may be causing a significant breakpoint in the relationship between sea surface oxygen and the index of vulnerability of pelagic catches in the Ecuador and Galapagos Exclusive Economic Zones. Warm temperature anomalies due to El Nino were projected to cause reductions in the physiological performance of large pelagic fishes, although this only led to changes in catch composition during the extremely warm events. Our results suggest that catches are vulnerable to future warming, as the increasing frequency, duration and magnitude of marine heatwaves associated with climate change impact catch composition
Rebuilding fish biomass for the world's marine ecoregions under climate change.
No full textRebuilding overexploited marine populations is an important step to achieve the United Nations' Sustainable Development Goal 14-Life Below Water. Mitigating major human pressures is required to achieve rebuilding goals. Climate change is one such key pressure, impacting fish and invertebrate populations by changing their biomass and biogeography. Here, combining projection from a dynamic bioclimate envelope model with published estimates of status of exploited populations from a catch-based analysis, we analyze the effects of different global warming and fishing levels on biomass rebuilding for the exploited species in 226 marine ecoregions of the world. Fifty three percent (121) of the marine ecoregions have significant (at 5% level) relationship between biomass and global warming level. Without climate change and under a target fishing mortality rate relative to the level required for maximum sustainable yield of 0.75, we project biomass rebuilding of 1.7-2.7 times (interquartile range) of current (average 2014-2018) levels across marine ecoregions. When global warming level is at 1.5 and 2.6°C, respectively, such biomass rebuilding drops to 1.4-2.0 and 1.1-1.5 times of current levels, with 10% and 25% of the ecoregions showing no biomass rebuilding, respectively. Marine ecoregions where biomass rebuilding is largely impacted by climate change are in West Africa, the Indo-Pacific, the central and south Pacific, and the Eastern Tropical Pacific. Coastal communities in these ecoregions are highly dependent on fisheries for livelihoods and nutrition security. Lowering the targeted fishing level and keeping global warming below 1.5°C are projected to enable more climate-sensitive ecoregions to rebuild biomass. However, our findings also underscore the need to resolve trade-offs between climate-resilient biomass rebuilding and the high near-term demand for seafood to support the well-being of coastal communities across the tropics
Harnessing the diversity of small-scale actors is key to the future of aquatic food systems
No full textSmall-scale fisheries and aquaculture (SSFA) provide livelihoods for over 100 million people and sustenance for ~1 billion people, particularly in the Global South. Aquatic foods are distributed through diverse supply chains, with the potential to be highly adaptable to stresses and shocks, but face a growing range of threats and adaptive challenges. Contemporary governance assumes homogeneity in SSFA despite the diverse nature of this sector. Here we use SSFA actor profiles to capture the key dimensions and dynamism of SSFA diversity, reviewing contemporary threats and exploring opportunities for the SSFA sector. The heuristic framework can inform adaptive governance actions supporting the diversity and vital roles of SSFA in food systems, and in the health and livelihoods of nutritionally vulnerable people—supporting their viability through appropriate policies whilst fostering equitable and sustainable food systems.Additional co-authors: Caroline E Ferguson, Nicole Franz, Christopher D. Golden, Benjamin S. Halpern, Lucie Hazen, Christina Hicks, Derek Johnson, Sangeeta Mangubhai, Rosamond L. Naylor, Melba Reantaso, U. Rashid Sumaila, Shakuntala H. Thilsted, Michelle Tigchelaar, Colette C. C. Wabnitz & Wenbo Zhan
Projecting global mariculture production and adaptation pathways under climate change
No full textThe sustainability of global seafood supply to meet increasing demand is facing several challenges, including increasing consumption levels due to a growing human population, fisheries resources over-exploitation and climate change. Whilst growth in seafood production from capture fisheries is limited, global mariculture production is expanding. However, climate change poses risks to the potential seafood production from mariculture. Here, we apply a global mariculture production model that accounts for changing ocean conditions, suitable marine area for farming, fishmeal and fish oil production, farmed species dietary demand, farmed fish price and global seafood demand to project mariculture production under two climate and socio-economic scenarios. We include 85 farmed marine fish and mollusc species, representing about 70% of all mariculture production in 2015. Results show positive global mariculture production changes by the mid and end of the 21st century relative to the 2000s under the SSP1-2.6 scenario with an increase of 17%±5 and 33%±6, respectively. However, under the SSP5-8.5 scenario, an increase of 8%±5 is projected, with production peaking by mid-century and declining by 16%±5 towards the end of the 21st century. More than 25% of mariculture-producing nations are projected to lose 40%–90% of their current mariculture production potential under SSP5-8.5 by mid-century. Projected impacts are mainly due to the direct ocean warming effects on farmed species and suitable marine areas, and the indirect impacts of changing availability of forage fishes supplies to produce aquafeed. Fishmeal replacement with alternative protein can lower climate impacts on a subset of finfish production. However, such adaptation measures do not apply to regions dominated by non-feed-based farming (i.e. molluscs) and regions losing substantial marine areas suitable for mariculture. Our study highlights the importance of strong mitigation efforts and the need for different climate adaptation options tailored to the diversity of mariculture systems, to support climate-resilient mariculture development
Marine high temperature extremes amplify the impacts of climate change on fish and fisheries.
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Creating sacred spaces: A study of storyworld building: Stairways and Ruins
No full textThis article reflects on artworks that Colette Lotz produced for the Stairways and Ruins exhibition. The article is structured along the lines of pre-production, production, and post-production as the practice-led methodological approach. The works were made using photographs of clouds and other structures taken by the artist and main author,1 and rendered digitally into symmetrical reflections. T hus, s acred s paces w ere c reated – t he w orks p redominantly show skyscapes and are therefore “celestial”. Because of this structuring of the works, the imagery becomes abstract and otherworldly, appearing like Rorschach Inkblot tests. We relate the works to sacred spaces as storyworlds. The term storyworld stresses the constructive and imaginative nature of the works
Agency through medicalization: Ghanaian children navigating illness, medicine and adult resistance
No full textMedicalization in the Global North assumes that bottom-up medicalization is driven by increasing consumer power, risk avoidance among professionals, or emancipation. Building on ethnographic work of the first author, this article aimed to explore the existence and conditions of a different and novel mechanism and found children manifesting agency through self-medicalization. We look at how Ghanaian children pragmatically deal with everyday health concerns and argue children are agents of medicalization and medicalization enables agency in children. Through interpretive and collaborative content analysis of structured ethnographic observations of 105 children from different class backgrounds (between June 2016 and December 2017) we found children in Northern Ghana framed situations of feeling ill in markedly biomedical terms and persisted in biomedical treatment even with opposition from adults. We observed that children intentionally navigated opposition from adults, mobilized support through networks, exploited power differences between adults, and organized treatment among themselves if necessary. While girls had an even harder time to muster recognition from adults, we also discovered children from a lower socioeconomic background, with more experience on the street had more leeway in navigating lack of support. So far, children's agency in health and illness has only been discussed in instances where children had already received a professional diagnosis. In our case where children had not yet received a professional diagnosis, we find that agency is enabled through bodily awareness, experience, interactions with peers, family, and the media; all working as tools for children to self-diagnose and to deal with illness in a postcolonial setting
The rapidly changing world of ocean finance
No full textA suite of recent international commitments and aspirational targets related to ocean conservation and sustainable fisheries management suggest growing consensus among states regarding the urgency of action. Yet, securing adequate financial resources to achieve these goals will be a crucial hurdle for many countries and will depend on financing mechanisms that go beyond traditional official development assistance (ODA) and philanthropy. An expanding and diversifying universe of financing mechanisms, however, risks generating confusion, incoherence, and uneven outcomes. This Special Issue on Funding for ocean conservation and sustainable fisheries was conceived to gain insights into current and emerging trends in the rapidly evolving world of 'blue' finance. While one emphasis of the Special Issue is on ODA and philanthropy, additional contributions also cover new and emerging financing mechanisms. Throughout the Special Issue, authors reflect on important gaps, future perspectives and prospects for greater impact. Two relevant topics for the Special Issue, for which dedicated manuscripts are not available, are also briefly addressed: China's growing role as a provider of development finance and a shift to overtly transactional use of aid by the current US administration.</p
Fisheries Centre research reports. Volume 20, number 2
No full textThis report summarizes the existing knowledge on three ecosystems: Hudson Bay, Canada, Kaloko-
Honokōhau, Hawai‘i, and the Antarctic Peninsula, Antarctica. Through the construction of ecosystem
models representing these three regions, research from numerous aspects of each ecosystem are pieced
together to present a holistic story. While we live in a rapidly changing world, it is important to remember
there are many regions where we are still gaining an understanding of basic knowledge.
Research on these ecosystems, from the Arctic to the tropics to the Antarctic, presents different levels of
our knowledge. For the Arctic (Hudson Bay) the focus is identifying changes known to be occurring for
certain species, and addressing the reasons for those changes in addition to the greater implications to the
rest of the ecosystem. In the tropics (Hawai‘i) the construction of a model allows insight into structure and
function of the ecosystem focusing on the role of an endangered species, the green sea turtle, and provides
a baseline to assess potential future impacts on the ecosystem from coastal development. In the Antarctic
(AntarAntarctic Peninsula) ecosystem, environmental changes are explored as they impact a key link in the food
web.
While the models presented address localized issues relating to very different regions of the world, the
ultimate goal is the same; to increase our understanding of ecosystems as a whole and the different
stressors related to each region. With this knowledge, we can formulate better questions for future
research, assist in informing managers, and hopefully gain greater insights and understanding of the likely
impact of future stressors.Science, Faculty ofOceans and Fisheries, Institute for theUnreviewedPostdoctoralGraduat
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