There may be trouble on the horizon for North American fish species: Scientists at the United States Geological Survey have found that fish species in North America will be going extinct at twice the rate at which they are now. The study, which will be published this September in BioScience, reveals that one fish species goes extinct every 3 million years, but in North America that rate is far higher.
A preview of the study at the USGS states:
In the fossil record, one freshwater fish species goes extinct every 3 million years, but North America lost 39 species and 18 subspecies between 1898 and 2006. Based on current trends in threatened and endangered fish species, researchers estimate that an additional 53-86 species of freshwater fish may be extinct by the year 2050. Since the first assessment of extinct North American freshwater fishes in 1989, the number of extinct fishes increased by 25 percent.
This hike in extinction rate bears the question — what has caused the increase in extinction? According to the study, there are variety of factors at play, including: Natural causes (“transitions in landforms and continental watercourses over time”), water drying up, human-induced causes (dams, channelization of rivers, water pollution), and alterations in the fish food chain. Essentially, the study points at human activity as the major reason as to why there has been a significant increase in the rate of extinction of the fish and it predicts that the rate will increase as we continue to pollute the environment the fish live in.
And this phenomenon hasn’t only been seen in North America: Last year The New York Times reported that more than 40 species of Mediterranean fish (including bluefin tuna, sea bass and hake) are at risk of extinction due to overfishing and pollution, according to a report by the International Union for Conservation of Nature. Also facing extinction, according to the same report, are almost half of the Mediterranean sharks and rays.
Unfortunately, bad news seems to be following the tails of fish around the world since a recent report compiled by British scientists has found that freshwater fish are the most endangered group of animals on the planet with more than a third facing extinction. Dr William Darwall, manager of the freshwater unit at the IUCN in Cambridge, told The Telegraph:
“There are still some big gaps in our knowledge, but of the 5,685 species that have been assessed, 36 per cent of them are threatened. Compared to mammals, where 21 per cent are threatened, and birds, where 12 per cent are threatened, it is clear that fresh water ecosystems are among the most threatened in the world. Sadly, it is also not going to get any better as human need for fresh water, power and food continues to grown and we exploit freshwater environments for these resources.”
The problem with unnatural fish extinction is that it messes with the ecosystem and the ripple-effect could be potentially devastating for the environment and for other underwater species.