Last updated March 8, 2018 at 9:48 am
A global study reveals data showing how more than half the world’s oceans are commercially fished.
Maps of total fishing effort. Credit: Global Fishing Watch
This is the first time a study has looked at such a large global scale. More than 70,000 industrial fishing vessels were tracked with automatic identification system (AIS) technology that records position, speed, and turning angles from January 2012 to December 2016. That culminated in 22 billion AIS messages to analyse.
The results from the study by David Kroodsma and colleagues showed that industrial fishing takes place in over 55 per cent of the world’s oceans – equivalent to four times more than the area used for land agriculture.
The fishing hot spots were mostly condensed around the northeast Atlantic and northwest Pacific oceans.
The top five countries for fishing activity were China, Spain, Taiwan, Japan, and South Korea, accounting for 85 per cent of the world’s fishing activity.
The video above shows activity tracks for different types of fishing vessels over one calendar year. AIS tracks, recorded by satellites, of a trawler (blue), a purse seiner (green), and longliner (red). Credit: Global Fishing Watch
The unprecedented detail allows researchers to track fishing patterns beyond numbers of ships and gives insight into the type of fishing by countries.
In this example, the trawler covered approximately 48,000 kilometres, the purse seiner 72,000 km, and the longliner 94,000 km in one year.
Purse seiners target mainly schooling species from small sardines to ocean-going tuna. Longliners target mainly ocean-going species such as tuna, shark and billfish. Trawlers target mainly species that live close to the sea floor such as flatfish, crab and rays.
China is by far the world’s most prolific industrial fishing country so much so it skews global patterns of fishing activity.
Globally, fishing activity significantly drops in in the last week of December and over the first week of January, which corresponds with the Christmas and New Year holidays.
However, in China, they tend to a longer drop in activity during the entire months of June and July where their government has imposed strict fishing bans in the South China Sea.
In 2017, after the data from the study was collected, China extended the fishing ban by a month to span May to July.
This graph shows the number of fishing hours by flag state in 2016 according to AIS and Kroodsma et al. 2018. Credit: Global Fishing Watch
Along with the publication of the paper, an interactive website has been launched allowing people to see an interactive time series of fishing effort by flag state: http://globalfishingwatch.io/time-series.
You can track and compare fishing hours and numbers of vessels by country.
The research is published in Science.
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