Evolution of Global Marine Fishing Fleets and the Response of Fished Resources

Y. Rousseau, R. A. Watson , J. Blanchard, E. Fulton, (2019). PNAS,

fishing capacity; effort; cpue; artisanal; industrial

10.1073/pnas.1820344116, http://www.ecomarres.com/downloads/Yannick1.pdf

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 since 1950, showing the increasing pressure of fisheries on ocean resources. The effective CPUE of most countries in 2015 was a fifth of its 1950s value,which was compared with a global decline in abundance. There are signs, however, of stabilization and more effective management in recent years, with a reduction in fleet sizes in developed countries. Based on historical patterns and allowing for the slowing rate of expansion, 1 million more motorized vessels could join the global fleet by midcentury as developing countries continue to transition away from subsistence fisheries, challenging sustainable use of fisheries’ resources.

Defining Global Artisanal Fisheries

Y. Rousseau, R. A. Watson , J. Blanchard, B. Fulton, (2019). Marine Policy 108, 103634.

artisanal; small-scale; global Fisheries

10.1016/j.marpol.2019.103634, http://www.ecomarres.com/downloads/Artisanal.pdf

While small-scale and artisanal fisheries are undeniably important globally, there is no global consensus on how to define the sectors, hindering comparative studies and international agreements. We focused on the usage of the words in both the scientific literature and legal documents and show that the confusion stems from a misuse of the terms artisanal, small-scale, coastal and subsistence, and is further propagated by language barriers. Accepting the complexity and subtleties of each term, we developed a simple method based on rhetoric and within a transdisciplinary background, which allows the ‘level’ of artisanal fisheries between nations to be parameterised and compared

Sixty Endangered Marine Species Are Legally Caught in Industrial Fisheries

L. Roberson, R. A. Watson, C. Klein, (2020). Nature communications 11, 4764.

endangered; global fisheries, sustainability

10.1038/s41467-020-18505-6, http://www.ecomarres.com/downloads/Endangered.pdf

Industrial-scale harvest of species at risk of extinction is controversial and usually highly regulated on land and for charismatic marine animals (e.g. whales). In contrast, threatened marine fish species can be legally caught in industrial fisheries. To determine the magnitude and extent of this problem, we analyze global fisheries catch and import data and find reported catch records of 91 globally threatened species. Thirteen of the species are traded internationally and predominantly consumed in European nations. Targeted industrial fishing for 73 of the threatened species accounts for nearly all (99%) of the threatened species catch volume and value. Our results are a conservative estimate of threatened species catch and trade because we only consider species-level data, excluding group records such as ‘sharks and rays.’ Given the development of new fisheries monitoring technologies and the current push for stronger international mechanisms for biodiversity management, industrial fishing of threatened fish and invertebrates should no longer be neglected in conservation and sustainability commitments.

Rethinking Spatial Costs and Benefits of Fisheries in Marine Conservation

M. Baker-Médard, T. F. Allnutt, M. L. Baskett, R. A. Watson, E. Lagabrielle, C. Kremen, (2019). Ocean and Coastal Management 178, 104824.

Marine conservation, Fisheries, Marxan, Spatial planning, Marine reserves, Madagascar

10.1016/j.ocecoaman.2019.104824, http://www.ecomarres.com/downloads/Spatial2.pdf

Fishing catch is often used as a cost in marine conservation planning to avoid areas of high fishing activity when identifying potential marine reserve locations. However, the theory of marine reserves indicates that reserves are more likely to benefit fisheries in areas of heavy fishing activity that would otherwise be overfished. Whether or not fishing catch is calculated as a cost depends on the balance of conservation and fisheries goals for a reserve, and thus is critical for policymakers to consider when designing marine reserve networks. This research shows the utility of running an inverted cost model of fishery catches during marine reserve spatial prioritization as a first step in a marine planning process oriented towards stabilizing local fisheries. This technique serves as a heuristic tool that may help conservation planners explore regions that would otherwise be overlooked if fisheries data were absent or integrated purely as a cost in the planning process. Drawing on data from Madagascar to illustrate our approach, this research demonstrates that the regions most frequently selected using the inverted cost model not only meet conservation targets, but are also those most accessible to community-based resource managers, the dominant management paradigm in Madagascar as well as in many developing countries.

Global Ecosystem Overfishing: Clear Delineation within Real Limits to Production

J. S. Link, R. A. Watson, (2019). Science Advances 5, eaav0474.

ecological indicators, ecosystem, overfishing

10.1126/sciadv.aav0474, http://www.ecomarres.com/downloads/LinkandWatson.pdf

The well-documented value of marine fisheries is threatened by overfishing. Management typically focuses on target populations but lacks effective tools to document or restrain overexploitation of marine ecosystems. Here, we present three indices and accompanying thresholds to detect and delineate ecosystem overfishing (EOF): the Fogarty, Friedland, and Ryther indices. These are based on widely available and readily interpreted catch and satellite data that link fisheries landings to primary production using known limits of trophic transfer efficiency. We propose theoretically and empirically based thresholds for each of those indices; with these criteria, several ecosystems are fished sustainably, but nearly 40 to 50% of tropical and temperate ecosystems exceed even extreme thresholds. Applying these criteria to global fisheries data results in strong evidence for two specific instances of EOF, increases in both pressure on tropical fish and a climate-mediated polar shift. Here, we show that these two patterns represent evidence for global EOF.

Naturalness as a Basis for Incorporating Marine Biodiversity into Life Cycle Assessment of Seafood

A. K. Farmery, S. Jennings, C. Gardner, R. A. Watson, B. Green, (In Press). The International Journal of Life Cycle Assessment, 3.

Biodiversity, Hemeroby, Land use, Life cycle assessment, Naturalness, Sea floor, Seafood, Seawater column  Continue reading →