- I work as a professor, researcher and analyst to map global fisheries, and their interactions with marine ecosystems.... moreI work as a professor, researcher and analyst to map global fisheries, and their interactions with marine ecosystems. With over 40 years of experience with international fisheries - both hands-on and computer modelling, I collaborate in global studies of marine biodiversity, economics of fishing, and impacts on birds and mammals; and desire to develop better ways to assess the health of exploited marine systems, the impacts of climate change, and the social consequences of mismanagement. see my pages http://ecomarres.com/?page_id=92edit
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Humanity has never benefited more from the ocean as a source of food, livelihoods, and well-being, yet on a global scale this has been accompanied by trajectories of degradation and persistent inequity. Awareness of this has spurred... more
Humanity has never benefited more from the ocean as a source of food, livelihoods, and well-being, yet on a global scale this has been accompanied by trajectories of degradation and persistent inequity. Awareness of this has spurred policymakers to develop an expanding network of ocean governance instruments, catalyzed civil society pressure on the public and private sector, and motivated engagement by the general public as consumers and constituents. Among local communities, diverse examples of stewardship have rested on the foundation of care, knowledge and agency. But does an analog for stewardship exist in the context of globally active multinational corporations? Here, we consider the seafood industry and its efforts to navigate this new reality through private governance. We examine paradigmatic events in the history of the sustainable seafood movement, from seafood boycotts in the 1970s through to the emergence of certification measures, benchmarks, and diverse voluntary envi...
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Previous reconstructions of marine fishing fleets have aggregated data without regard to the artisanal and industrial sectors. Engine power has often been estimated from subsets of the developed world, leading to inflated results. We... more
Previous reconstructions of marine fishing fleets have aggregated data without regard to the artisanal and industrial sectors. Engine power has often been estimated from subsets of the developed world, leading to inflated results. We disaggregated data into three sectors, artisanal (unpowered/powered) and industrial, and reconstructed the evolution of the fleet and its fishing effort. We found that the global fishing fleet doubled between 1950 and 2015—from 1.7 to 3.7 million vessels. This has been driven by substantial expansion of the motorized fleet, particularly, of the powered-artisanal fleet. By 2015, 68% of the global fishing fleet was motorized. Although the global fleet is dominated by small powered vessels under 50 kW, they contribute only 27% of the global engine power, which has increased from 25 to 145 GW (combined powered-artisanal and industrial fleets). Alongside an expansion of the fleets, the effective catch per unit of effort (CPUE) has consistently decreased sinc...
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Concepts underpinning the planetary boundaries framework are being incorporated into multilateral discussions on sustainability, influencing international environmental policy development. Research underlying the boundaries has primarily... more
Concepts underpinning the planetary boundaries framework are being incorporated into multilateral discussions on sustainability, influencing international environmental policy development. Research underlying the boundaries has primarily focused on terrestrial systems, despite the fundamental role of marine biomes for Earth system function and societal wellbeing, seriously hindering the efficacy of the boundary approach. We explore boundaries from a marine perspective. For each boundary, we show how improved integration of marine systems influences our understanding of the risk of crossing these limits. Better integration of marine systems is essential if planetary boundaries are to inform Earth system governance.
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Large teleost (bony) fish are a dominant group of predators in the oceans and constitute a major source of food and livelihood for humans. These species differ markedly in morphology and feeding habits across oceanic regions; large... more
Large teleost (bony) fish are a dominant group of predators in the oceans and constitute a major source of food and livelihood for humans. These species differ markedly in morphology and feeding habits across oceanic regions; large pelagic species such as tunas and billfish typically occur in the tropics, whereas demersal species of gadoids and flatfish dominate boreal and temperate regions. Despite their importance for fisheries and the structuring of marine ecosystems, the underlying factors determining the global distribution and productivity of these two groups of teleost predators are poorly known. Here, we show how latitudinal differences in predatory fish can essentially be explained by the inflow of energy at the base of the pelagic and benthic food chain. A low productive benthic energy pathway favours large pelagic species, whereas equal productivities support large demersal generalists that outcompete the pelagic specialists. Our findings demonstrate the vulnerability of ...
Fisheries and aquaculture make a crucial contribution to global food security, nutrition and livelihoods. However, the UN Sustainable Development Goals separate marine and terrestrial food production sectors and ecosystems. To sustainably... more
Fisheries and aquaculture make a crucial contribution to global food security, nutrition and livelihoods. However, the UN Sustainable Development Goals separate marine and terrestrial food production sectors and ecosystems. To sustainably meet increasing global demands for fish, the interlinkages among goals within and across fisheries, aquaculture and agriculture sectors must be recognized and addressed along with their changing nature. Here, we assess and highlight development challenges for fisheries-dependent countries based on analyses of interactions and trade-offs between goals focusing on food, biodiversity and climate change. We demonstrate that some countries are likely to face double jeopardies in both fisheries and agriculture sectors under climate change. The strategies to mitigate these risks will be context-dependent, and will need to directly address the trade-offs among Sustainable Development Goals, such as halting biodiversity loss and reducing poverty. Countries ...
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Information about the global structure of agriculture and nutrient production and its diversity is essential to improve present understanding of national food production patterns, agricultural livelihoods, and food chains, and their... more
Information about the global structure of agriculture and nutrient production and its diversity is essential to improve present understanding of national food production patterns, agricultural livelihoods, and food chains, and their linkages to land use and their associated ecosystems services. Here we provide a plausible breakdown of global agricultural and nutrient production by farm size, and also study the associations between farm size, agricultural diversity, and nutrient production. This analysis is crucial to design interventions that might be appropriately targeted to promote healthy diets and ecosystems in the face of population growth, urbanisation, and climate change. We used existing spatially-explicit global datasets to estimate the production levels of 41 major crops, seven livestock, and 14 aquaculture and fish products. From overall production estimates, we estimated the production of vitamin A, vitamin B12, folate, iron, zinc, calcium, calories, and protein. We als...
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Fuel consumption is a leading cost to fishers and the primary source of greenhouse gas emissions from the global fishing industry. Fuel performance varies substantially between and within fisheries, but the drivers behind this variation... more
Fuel consumption is a leading cost to fishers and the primary source of greenhouse gas emissions from the global fishing industry. Fuel performance varies substantially between and within fisheries, but the drivers behind this variation are unclear and inconsistent across studies. We surveyed rock lobster fishers in Australia and New Zealand to measure rates of fuel use and assess the influence of technological (e.g. vessel size, engine power), behavioural (e.g. distance travelled, speed), and managerial (e.g. catch per unit effort, fishery capacity) factors. Weighted fuel use intensity across the region was 1,890 l/t. Managerial factors were the most influential drivers of fuel use in single day trips while technological factors heavily influenced multi-day trips. Catch per unit effort was the only significant driver present across both types of fishing trips. The vast majority of surveyed fishers identified fuel use as an important aspect of fishing operations, and nearly half had...
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Photosynthesis fuels marine food webs, yet differences in fish catch across globally distributed marine ecosystems far exceed differences in net primary production (NPP). We consider the hypothesis that ecosystem-level variations in... more
Photosynthesis fuels marine food webs, yet differences in fish catch across globally distributed marine ecosystems far exceed differences in net primary production (NPP). We consider the hypothesis that ecosystem-level variations in pelagic and benthic energy flows from phytoplankton to fish, trophic transfer efficiencies, and fishing effort can quantitatively reconcile this contrast in an energetically consistent manner. To test this hypothesis, we enlist global fish catch data that include previously neglected contributions from small-scale fisheries, a synthesis of global fishing effort, and plankton food web energy flux estimates from a prototype high-resolution global earth system model (ESM). After removing a small number of lightly fished ecosystems, stark interregional differences in fish catch per unit area can be explained (r = 0.79) with an energy-based model that (i) considers dynamic interregional differences in benthic and pelagic energy pathways connecting phytoplankt...
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... 498 18.6.1 Competition between User GroupsEquity and Access Rights 18.6.2 Effectiveness of International Instruments in Managing Shared Stocks ... species, especially larger high-value fish and those caught incidentally (the... more
... 498 18.6.1 Competition between User GroupsEquity and Access Rights 18.6.2 Effectiveness of International Instruments in Managing Shared Stocks ... species, especially larger high-value fish and those caught incidentally (the ''bycatch''), has been reduced to one tenth or less ...
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... Jackson e colegas mostraram que o declínio massivo das populações de mamíferos marinhos, tartarugas, pássaros e grandes peixes, ocorreram em todas as linhas costeiras onde as pessoas vivem desde muito antes do período examinados por... more
... Jackson e colegas mostraram que o declínio massivo das populações de mamíferos marinhos, tartarugas, pássaros e grandes peixes, ocorreram em todas as linhas costeiras onde as pessoas vivem desde muito antes do período examinados por nós. ...
Formal analyses of long-term global marine fisheries prospects have yet to be performed because fisheries research focuses on local, species-specific management issues. Extrapolation of present trends implies expansion of bottom fisheriesinto deeper waters, serious impact on biodiversity, and dec...more
RASHT, IRAN—In a cavernous hall packed with navalgray steel tanks, a precious commodity is being enriched and multiplied. No, this is not a hitherto undeclared uranium facility in Iran's nuclear program: It'sa breeding facility... more
RASHT, IRAN—In a cavernous hall packed with navalgray steel tanks, a precious commodity is being enriched and multiplied. No, this is not a hitherto undeclared uranium facility in Iran's nuclear program: It'sa breeding facility for Caspian sturgeons. Each tank is filled with fish of various ages, from fingerlings, a few centimeters long with crocodilian snouts, to meter-long juveniles. Here at the International Sturgeon Research Institute (ISRI) in the northern town of Rasht, scientists are refining techniques for rearing fingerlings that ...
La pêche industrielle épuise les mers. A l'échelle de la planète, les prises diminuent parce que les populations ne se renouvellent plus. Face à cette évolution préoccupante, une idée gagne du terrain: constituer de véritables... more
La pêche industrielle épuise les mers. A l'échelle de la planète, les prises diminuent parce que les populations ne se renouvellent plus. Face à cette évolution préoccupante, une idée gagne du terrain: constituer de véritables réserves marines dans des zones de plusieurs dizaines de milliers de kiomètres carrés.
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Georges Bank--the patch of relatively shallow ocean just off the coast of Nova Scotia, Canada--used to teem with fish. Writings from the 17th century record that boats were often surrounded by huge schools of cod, salmon, striped bass and... more
Georges Bank--the patch of relatively shallow ocean just off the coast of Nova Scotia, Canada--used to teem with fish. Writings from the 17th century record that boats were often surrounded by huge schools of cod, salmon, striped bass and sturgeon. Today it is a very different story. Trawlers trailing dredges the size of football fields have literally scraped the bottom clean, harvesting an entire ecosystem--including supporting substrates such as sponges--along with the catch of the day. Farther up the water column, longlines and drift nets are snagging the last sharks, ...
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Research Interests: Zoology, Marine Ecology, Ecology, Marine Mammals, Ecological Niche Modeling, and 12 moreEcological Modelling, Sea surface temperature, Global Information Systems, Habitat Suitability, Environmental Conditions, Minke whale, Marine Environment, Tiger Habitat Suitability model, Expert knowledge, Humpback whale, Marine Mammal, and Large Scale
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The growing human population must be fed, but historic land-based systems struggle to meet expanding demand. Marine production supports some of the world's poorest people but increasingly provides for the needs of the affluent, either... more
The growing human population must be fed, but historic land-based systems struggle to meet expanding demand. Marine production supports some of the world's poorest people but increasingly provides for the needs of the affluent, either directly by fishing or via fodder-based feeds for marine and terrestrial farming. Here we show the expanding footprint of humans to utilize global ocean productivity to feed themselves. Our results illustrate how incrementally each year, marine foods are sourced farther from where they are consumed and moreover, require an increasing proportion of the ocean's primary productivity that underpins all marine life. Though mariculture supports increased consumption of seafood, it continues to require feeds based on fully exploited wild stocks. Here we examine the ocean's ability to meet our future demands to 2100 and find that even with mariculture supplementing near-static wild catches our growing needs are unlikely to be met without significan...