AAAS: "British Trawlers Working Nearly 20 Times as Hard to Catch Fish."
Most commercial fisherfolk today don't appreciate how much harder it is to catch fish than it was for their forebears. In the 1880s, steam-powered trawlers began to compete with sail-powered fishing boats in European waters. "The practice was controversial in the United Kingdom, where some critics claimed that the new trawlers were reducing fish stocks and damaging habitats."
Marine conservation biologist Callum Roberts of the University of York in the United Kingdom decided to analyze the historical data. "To adjust the catch data for the increasingly powerful and sophisticated fishing boats, Roberts and colleagues used boat registration records to calculate the overall power of the British fleet." The researchers expressed ship 'power' in units equivalent to the catching power of one sail-powered trawler in the 1880s, calculating the Landings Per Unit of fishing Power (LPUP).
"From 1889 until 1914, LPUP dropped sharply, from more than 60 tons to less than 20 tons." The decrease in fishing during World War I allowed a recovery of fish stocks, and LPUP rebounded briefly to 30 tons in 1918. "Between WWI and the 1950s, British vessels began fishing farther from home, off the coast of West Africa and in the Arctic...[allowing] the rate of fish caught by British vessels to increase again, to about 50 tons in 1956." But with continued exploitation, LPUP nose-dived, to about 5 tons in 1980, the team reports online this week in Nature Communications.
"After 1983, the Common Fisheries Policy of the European Union set strict new limits on where and how much British vessels could fish, but stocks have not recovered."
Today it takes 17 times as much fishing power to land a fish as it did in 1889, an LPUP of 3.4.
The implications are clear, overfishing, yes, but also marine warming, loss of coral reefs as incubators, plastic + other pollution, acidification, now looming deoxygenation. Climate change + impoverishment of marine ecosystems. Pity the poor fish + the fisherfolk.
