Knowledge for better food systems

Showing results for: Fish stocks/overfishing

24 April 2019

This report from the US-based campaigning organisation Changing Markets Foundation examines the impacts of catching wild fish to feed to farmed fish in aquaculture operations, i.e. reduction fisheries.

Image: Romaniamissions, Fishing boats Spain, Pixabay, Pixabay Licence
12 March 2019

This paper retrospectively models the impacts of ocean warming on the productivity of 235 fish populations around the world representing around one third of reported global catch. It uses a temperature-dependent population model to estimate that the overall maximum sustainable yield of the fish populations dropped by 4.1% between 1930 and 2010.

Image: Phil Manker, Swirling fish schools, Wikimedia Commons, Creative Commons Attribution 2.0 Generic
12 March 2019

This paper models the impacts that the Paris Agreement on climate change would have on seafood production. It finds that three quarters of maritime countries would benefit from the Agreement’s implementation.

Image: Narek75, Recirculating Aquaculture System, Wikimedia Commons, Creative Commons Attribution-Share Alike 4.0 International
18 February 2019

Aquaculture generally supplements wild fisheries rather than replacing them, according to this paper, which used models based on historical data.

11 February 2019

This report, part of the UK Food Research Collaboration’s Food Brexit Briefings series, argues that the UK’s exit from the European Union will not solve the fishing industry’s problems - rather, that international fishing rules, overfishing and the UK’s own policies have contributed to those problems.

Image: Maia Valenzuela, translucent squid, Flickr, Creative Commons Attribution 2.0 Generic
12 November 2018

This paper assesses the possibility that cephalopods, such as squid, octopus and cuttlefish, could become a more important source of food in the future. In contrast to many fish population, cephalopod populations have been rising over the last few decades, possibly due to warmer ocean temperatures. The paper gives an overviews of the nutrients provided by cephalopods and the ways that they can be used as food. The authors also note that some cephalopods, including the octopus, are intelligent and possibly sentient, raising ethical issues over their use as food.

16 October 2018

This book, by Simon R. Bush and Peter Oosterveer, examines the sustainability, governance and future of seafood.

Image: skagman, Modern trawler, Skagen harbour, Denmark, Wikimedia Commons, Creative Commons Attribution 2.0 Generic
18 September 2018

The vast majority of industrial fishing (defined as fishing vessels of over 24 metres) is done by vessels that are registered to relatively wealthy countries, according to a recent paper. Vessels registered to high income and upper middle income countries (according to World Bank classifications) accounted for 97% of industrial fishing effort in international waters and 78% of industrial fishing effort in the national waters of poorer countries. China, Taiwan, Japan, South Korea, and Spain together account for most of the fishing effort.

Image: David Stanley, Net full of fish, Flickr, Creative Commons Attribution 2.0 Generic
12 September 2018

Fishers increase their fishing activity prior to the establishment of a new marine reserve, a new paper claims. The study used satellite data to study one particular marine reserve, the Phoenix Islands Protected Area (PIPA). While fishing effort dropped to almost zero after the marine reserve was established, fishing effort prior to the reserve’s establishment was 130% higher than in a control region (where no reserve was planned).

Image: TonyCastro, Guanay Cormorant, Wikimedia Commons, Creative Commons Attribution-Share Alike 4.0 International
12 September 2018

Attaching green light emitting diodes (LEDs) to gillnets (vertical fishing nets that catch fish behind the gills) reduces the number of guanay cormorants accidentally caught by 85% relative to control nets with no lights, reports a recent paper. A previous study of the same fishery has shown that illuminating nets can reduce bycatch of green turtles by 64% without reducing catch rates of the target species (the current paper did not specify catch rates of the target species). The authors hypothesise that it may be possible to tailor the wavelength of light to attract or repel specific species, according to a fishery’s needs.

Image: Cliff, Swirling schools of Anchovies, Wikimedia Commons, Creative Commons Attribution 2.0 Generic
4 September 2018

Farmed fish are often fed on forage fish (such as anchovies and sardines) caught from the wild. A new paper points out that demand for forage fish to support aquaculture production is forecast to grow beyond the maximum sustainable supply level. The authors calculate that demand for forage fish could be reduced to below the maximum supply limit by combining a number of measures: reducing use of forage fish in land-based agriculture, replacing some forage fish with fish trimmings from processing, and reducing the proportion of forage fish in the diets of non-carnivorous farmed fish.

Image: Chaos07, Recife coral reef mar, Pixabay, CC0 Creative Commons
20 August 2018

The first systematic analysis of marine wilderness around the world finds that only 13% of the ocean can still be classed as wilderness, i.e. having experienced low impacts from human-caused stressors such as fertilizer runoff, fishing and climate change. Only 4.9% of that wilderness (covering 0.6% of total ocean area) falls within official marine protected areas.

24 July 2018

The FAO has released its 2018 report on world fishery and aquaculture statistics. Key findings include that fisheries output peaked in 2016, having remained approximately static since the late 1980s, while aquaculture production is rising, as shown in the figure below. In 2015, fish accounted for around 17% of global animal protein consumption. One third of fish stocks are currently overfished, although progress has been made in the United States and Australia in increasing the proportion of fish stocks that are sustainably fished.

Image: Brocken Inaglory, Total internal reflection of Chelonia mydas, Wikimedia Commons, Creative Commons Attribution-Share Alike 4.0 International
9 May 2018

Many important marine species, including marine mammals, sea turtles and seabirds, are threatened by bycatch - i.e. being accidentally caught by fishers who are targeting other species. A new paper finds that around half of the populations threatened by bycatch could be protected by managing fish stocks to maximise fishery profits, which would reduce bycatch as a side-effect of reducing overfishing.

30 April 2018

Building UK fish stocks up to their maximum sustainable yields could increase fish catches by 27%, create 5,100 new jobs and add £319 million to the UK’s GDP, NGO Oceana reports. Oceana points out that Brexit may provide a window of opportunity to change the UK’s fishing practices for the better.

Image: John Wallace, A mountain of dogfish (Squalus acanthias) caught during a trawl survey. California, Southern California Bight, Wikimedia Commons, public domain.
6 March 2018

This paper presents the findings of a large-scale study which used global tracking data on sea-going vessels to characterise the scale, distribution and drivers of the global fishing effort.

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