If countries live up to their current pledges to reduce greenhouse gases, the planet’s average temperature is set to rise by about 3.5 degrees Celsius above pre-industrial levels by 2100 – well beyond the point at which climate change produces significantly more dangerous weather conditions.
After considering the effects on 892 different species eaten by humans, they concluded that each degree of warming could potentially result in a 3.4 million ton fall in the weight of fish caught every year, they reported in the journal Science.
The global fish catch is currently about 109 million metric tons.
World seafood production neared 160 million tons in 2006, the last year for which there are data. The growth over the previous year was entirely due to increased fish farming, or aquaculture, which increased by more than 3 million tons, an annual addition that has been fairly consistent over the last 10 years. In contrast, fish caught in the wild declined for the second year in a row and dropped to almost 4 million tons below the peak catch in 2000
Prior to 2016, commonly cited statistics have understated the size of the global seafood catch by about 30%, a new tally finds. The estimate, drawn in part from a painstaking effort to gather statistics on poorly documented subsistence, recreational, and illegal fisheries, suggests that the world catch has also declined more steeply since the 1990s than official figures indicate.
Overall, fishers caught an estimated 109 million metric tons (mt) of fish in 2010, researchers report today in Nature Communications. That’s well above the 77 million mt that nations reported to the Food and Agriculture Organization (FAO) of the United Nations, which keeps global catch statistics.
The reconstructed 2010 catch was 15% below peak landings of 130 million mt in 1996, estimate the researchers, who are based at the University of British Columbia (UBC), Vancouver in Canada. In contrast, FAO figures for the same 14-year period showed an 11% decline, from 86 million mt to 77 million mt.
The FAO report on fishing and aquaculture is here
Fish farming and aquaculture produced 73.8 million tons in 2014 and is growing by about 3 million tons each year. 2016 likely had 80 million tons of fish farming production.
Almost all of the cows, sheep and chickens are on farms now.
In the future it is clear that farmed fish will go from about 40% to 90% in 2100.
The amount of wild fish would also be enhanced by fertilizing the ocean with iron.
In 2012 the Haida Salmon Restoration Corporation conducted a massive ocean fertilisation test, fertilizing around 100 tonnes of iron sulphate off Canada's coast Satellite images confirmed the claim by Californian Russ George that the iron has spawned an artificial plankton bloom as large as 10,000 square kilometres. Now it appears that the fish catch in the area was boosted by over 100,000 tons.
Pink salmon mature in two years. Salmon can add a pound a month if they are well fed in the ocean. 2013 had the largest pink salmon run in 50 years.
The Alaska Department of Fish and Game (ADF&G) has completed compilation of preliminary values for the 2013 commercial salmon fishery. Powered by a record pink salmon harvest of 219 million fish, this year’s harvest ranks as the second most valuable on record. At $691.1 million, 2013 is only exceeded by the 1988 harvest value of $724 million. In addition to setting a record for pink salmon, the total number of salmon harvested also set a new record at 272 million fish.