Knowledge for better food systems

Showing results for: Fish stocks/overfishing

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.

Photo: natalienicolecrane, fishing at lake victoria, Flickr, Creative Commons License 2.0 generic.
8 May 2017

A common hypothesis used to link declining human health to environmental outcomes predicts that illness will reduce human populations or harvest effort, thus benefitting the environment. When investigating the behaviour of fishers around Lake Victoria in Kenya, this research found little evidence that illness reduced fishing effort to indirectly benefit the environment. Instead, ill fishers shifted their fishing methods – using more illegal methods concentrated in inshore areas, that are less physically demanding but environmentally destructive.

Photo: fklv, two fishing boats, Flickr, Creative Commons License 2.0 generic.
19 April 2017

This paper models human and natural influences on the global capture of wild marine fish. The researchers show that wild fish harvest increases during the 20th century were most likely explained by improvements in fishing technology. Their simulated future projections, that assume ongoing technological progress and open access (i.e. no policy constraints), suggest a long-term decrease in harvest due to over-fishing.

Photo credit: Gideon, Flickr, Creative Commons License 2.0
15 December 2016

The European Environment Agency has published a report on food systems approaches for the seafood industry in Europe, with the explicit aim of making ‘a first contribution to the collective endeavour of rethinking Europe's food system for sustainability goals’.

Credit: thebarrowboy - trawling, Flickr, Creative Commons Licence 2.0
11 October 2016

The authors used a species distribution model and applied this to the 887 marine fish (which represents 60% of global average annual catch in the 2000s) and invertebrate species in the world oceans under high and low emissions scenarios. The authors find that global maximum catch potential (MCP) is projected to decrease globally by 7.7% between 2010 and 2050, under the business as usual scenario, and the global revenue from this is predicted to decrease by 10.4% compared to 2010. Under the low emissions scenario, MCP is projected to decrease globally by 4.1% and revenue by 7.1%​

Photo: Susanne Nilsson, Flickr, Tropical Fish, Creative Commons License 2.0
31 August 2016

Researchers from Conservation International have found a small island near Timor-Leste with staggering species richness. Atauro Island, home to about 8,000 people sits in the middle of the so-called Coral Triangle, known for its biodiverse marine environments.

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