Shrimp fishery

The shrimp fishery is a major global industry, with more than 3.4 million tons caught per year, chiefly in Asia. Rates of bycatch are unusually high for shrimp fishing, with the capture of sea turtles being especially contentious. The shrimp fishery is a major global industry, with more than 3.4 million tons caught per year, chiefly in Asia. Rates of bycatch are unusually high for shrimp fishing, with the capture of sea turtles being especially contentious. A shrimper is a fishing vessel rigged for shrimp fishing. The term shrimp, as used by the Food and Agriculture Organization (FAO), covers all shrimp (Caridea) and prawns (Dendrobranchiata, comprising Penaeoidea and Sergestoidea) – a group formerly known as 'Natantia'. This nomenclature often differs from local use, in which the same species may be known by different names, or where different species may be known by the same name. Small-scale local fishery for shrimp and prawns has existed for centuries and continues to form a large proportion of the world's shrimp fisheries. Trawling increased in scale with the introduction of otter boards, which use the flow of water to hold the trawling net open, and the introduction of steam-powered vessels, replacing the earlier sail-powered boats. Both of these developments took off in the 1880s, and were soon applied to shrimp fisheries, especially following the research effort of the Norwegian marine biologist Johan Hjort. Over time, the original open skiffs, 5–8 metres (16–26 ft) long, were replaced by decked boats, to which diesel engines were added, allowing the boats to reach an average of 18 m (59 ft). In the United States, shrimp and prawn fisheries are second only to crab fishing in terms of importance. In the northern parts of the country, cold-water shrimp are targeted, while warm-water species are targeted along the south-eastern Atlantic coast, and in the Gulf of Mexico. Most of the production is of warm-water species, but this is dwarfed by the imports of shrimp, mostly from aquaculture. This has led to international controversies, with some United States fishermen accusing countries such as Brazil, China, Ecuador, India, Thailand and Vietnam of dumping shrimp on the US market, while some of the producing nations protested to the World Trade Organization about duties levied by the US in response to the inferred dumping. Shrimp fisheries produce unusually high levels of bycatch. Before the introduction of bycatch reduction devices in the 1980s, shrimp fishery had a bycatch ratio (ratio of the amount of non-target species caught to the amount of the target species caught) of 4.5–5.3:1. Since BRDs were introduced, the bycatch ratios may have been reduced by as much as 30%. Shrimp fisheries tend to 'capture more sea turtles than any other commercial fishery'. Shrimps are from all different types of bodies of water in the world. Fewer than 300 species of shrimp and prawns are of commercial importance, out of a total of 3000 species. The catch is dominated by six 'species items', which collectively account for 82% of the global catch. These are given in the table below: Shrimp and prawn fisheries can be divided into cold-water, warm-water and paste shrimp fisheries, broadly corresponding to the three taxonomic categories Penaeoidea, Caridea and Sergestoidea, respectively. Although the various species of the genus Acetes are not always distinguished by fishermen, collectively they form the world's largest shrimp fishery. There are fisheries for Acetes in Korea, Japan and Southeast Asia, but the vast majority of the catch is in China. The total catch is likely to be grossly under-recorded, but was estimated at 664,716 t in 2005. Within the Asia–Pacific region, the Acetes fishery is the fourth largest fishery by weight, after hairtails, anchovies and scads.