Winners and losers in a world where the high seas is closed to fishing

Sumaila, U. Rashid; Lam, Vicky W. Y.; Miller, Dana; Teh, Louise; Watson, Reg; Zeller, Dirk; Cheung, William W. L.; Côté, Isabelle M.; Rogers, Alex D.; Roberts, Callum M.; Sala, Enric; Pauly, Daniel

doi:10.1038/srep08481

Cited by 134 publications

(117 citation statements)

References 26 publications

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“…Finally, our theoretical results also corroborate recent empirical analyses (31,42) that suggest that the imposition of a closure of the high seas to fishing could be beneficial or at least not that costly to a collection of self-interested states exploiting a shared mobile stock. We show here that, for a large habitat, a closure might even emerge in the absence of any coordinated regulatory action (such as a treaty).…”

Section: Discussionsupporting

confidence: 78%

High-seas fish wars generate marine reserves

Herrera

Moeller

Neubert

2016

Proc. Natl. Acad. Sci. U.S.A.

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The effective management of marine fisheries is an ongoing challenge at the intersection of biology, economics, and policy. One way in which fish stocks-and their habitats-can be protected is through the establishment of marine reserves, areas that are closed to fishing. Although the potential economic benefits of such reserves have been shown for single-owner fisheries, their implementation quickly becomes complicated when more than one noncooperating harvester is involved in fishery management, which is the case on the high seas. How do multiple self-interested actors distribute their fishing effort to maximize their individual economic gains in the presence of others? Here, we use a game theoretic model to compare the effort distributions of multiple noncooperating harvesters with the effort distributions in the benchmark sole owner and open access cases. In addition to comparing aggregate rent, stock size, and fishing effort, we focus on the occurrence, size, and location of marine reserves. We show that marine reserves are a component of many noncooperative Cournot-Nash equilibria. Furthermore, as the number of harvesters increases, (i) both total unfished area and the size of binding reserves (those that actually constrain behavior) may increase, although the latter eventually asymptotically decreases; (ii) total rents and stock size both decline; and (iii) aggregate effort used (i.e., employment) can either increase or decrease, perhaps nonmonotonically.fisheries management | game theory | marine protected areas | marine reserves | spatial bioeconomic model

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Section: Discussionsupporting

confidence: 78%

High-seas fish wars generate marine reserves

Herrera

Moeller

Neubert

2016

Proc. Natl. Acad. Sci. U.S.A.

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“…Offshore effort and ecosystem-level exploitation per area also generally remains far less than in coastal regions (55,56). This is in part a reflection of the high capital cost of high-seas fishing that restricts this activity to a select subset of nations (57). Plotting the integrated catch and effort firmly places non-LME regions among the LELC outliers in Fig.…”

Section: Discussionmentioning

confidence: 98%

Reconciling fisheries catch and ocean productivity

Stock

John

Rykaczewski

et al. 2017

Proc. Natl. Acad. Sci. U.S.A.

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219

255

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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 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 phytoplankton and fish, (ii) depresses trophic transfer efficiencies in the tropics and, less critically, (iii) associates elevated trophic transfer efficiencies with benthic-predominant systems. Model catch estimates are generally within a factor of 2 of values spanning two orders of magnitude. Climate change projections show that the same macroecological patterns explaining dramatic regional catch differences in the contemporary ocean amplify catch trends, producing changes that may exceed 50% in some regions by the end of the 21st century under high-emissions scenarios. Models failing to resolve these trophodynamic patterns may significantly underestimate regional fisheries catch trends and hinder adaptation to climate change.fisheries catch | primary production | ocean productivity | climate change | food webs N early 50 years ago, John Ryther (1) published his seminal work "Photosynthesis and Fish Production in the Sea" in which he hypothesized that differences in net primary production (NPP) alone could not explain stark differences in fish catch across disparate marine ecosystems. Drawing upon "trophic dynamic" principles governing the transfer of energy through ecosystems (2), he hypothesized that synergistic interactions between NPP differences, the length of food chains connecting phytoplankton and fish, and the efficiency of trophic transfers were required to reconcile catch differences. The trophodynamic principles drawn upon by Ryther now underpin diverse models and indicators used in ecosystem-based marine resource management (3-5), yet stubborn uncertainties in the relationship between ocean productivity and fish catch persist. Official catch reports often omit globally significant discards and small-scale artisanal and subsistence catch (6). Uncertain differences in fishing effort and impacts of fishing history complicate attribution of catch differences to "bottom-up" considerations of ocean productivity or "top-down" fishing effects (7). Difficulties directly observing and estimating trophodynamic properties, including NPP (8),...

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“…Where LV% is the projected change in landed value under each catch gain scenario [11], and income and economic multipliers were taken from [20]. We used the calculated income and economic effect as an indicator of the indirect food security benefits arising from high seas closure for countries which did not benefit directly in terms of an increase in domestically consumed fish.…”

Section: Benefits From High Seas Closurementioning

confidence: 99%

“…Recent proposals to close the high seas to fishing have indicated that this may be beneficial for the rebuilding of fish biomass, increase the quantity and improve the distributional equality in global fisheries catch, and increase the resilience of fish stocks to climate change [10][11][12]. For instance, Sumaila et al [11] found that biomass spillover from closing the high seas would benefit the domestic fisheries in 120 maritime countries under a scenario in which post high seas closure catches increased by 42%. At the same time, it would result in net losses for 65 countries, particularly those which specialise in fishing the high seas, such as Japan, China, and Spain.…”

Section: Introductionmentioning

confidence: 99%

Impact of high seas closure on food security in low-income fish-dependent countries

Teh¹,

Lam²,

Cheung³

et al. 2017

Handbook on the Economics and Management of Sustainable Oceans

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We investigate how high seas closure will affect the availability of commonly consumed food fish in 46 fish reliant, and/or low income countries. Domestic consumption of straddling fish species (fish that would be affected by high seas closure) occurred in 54% of the assessed countries. The majority (70%) of countries were projected to experience net catch gains following high seas closure. However, countries with projected catch gains and that also consumed the straddling fish species domestically made up only 37% of the assessed countries. In contrast, much fewer countries (25%) were projected to incur net losses from high seas closure, and of these, straddling species were used domestically in less than half (45%) of the countries. Our findings suggest that, given the current consumption patterns of straddling species, high seas closure may only directly benefit the supply of domestically consumed food fish in a small number of fish reliant and/or low income countries. In particular, it may not have a substantial impact on improving domestic fish supply in countries with the greatest need for improved access to affordable fish, as only one third of this group used straddling fish species domestically. Also, food security in countries with projected net catch gains but where straddling fish species are not consumed domestically may still benefit indirectly via economic activities arising from the increased availability of non-domestically consumed straddling fish species following high seas closure. Consequently, this study suggests that high seas closure can potentially improve marine resource sustainability as well as contribute to human well-being in some of the poorest and most fish dependent countries worldwide. However, caution is required because high seas closure may also negatively affect fish availability in countries that are already impoverished and fish insecure.

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Winners and losers in a world where the high seas is closed to fishing

Cited by 134 publications

References 26 publications

High-seas fish wars generate marine reserves

High-seas fish wars generate marine reserves

Reconciling fisheries catch and ocean productivity

Impact of high seas closure on food security in low-income fish-dependent countries

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