According to the study the number of subspecies of fish populations in trouble has nearly doubled since 1989. The death of fish is termed as “silent extinctions” because few people notice the dramatic dwindling of certain populations deep in American lakes, rivers and streams. It is revealed that people are the chief cause of the problem by polluting and damming freshwater habitats.
Experts told that in the first massive study of freshwater fish on the continent in 19 years it is observed species, but at subspecies — physically distinct populations restricted to certain geographic areas. The smaller groups are more vulnerable and the decline is more notable. It is said that the scientists found that 700 smaller but individual fish populations are vulnerable, threatened, or endangered. That’s up from 364 subspecies nearly two decades ago.
The study found that 457 entire species are in trouble or already extinct, another 86 species are OK as a whole, but have subspecies in trouble. It is revealed that about 6 percent of fish populations that were in peril in 1989, including the Bonneville cutthroat trout, have made a comeback.
Study’s lead author Howard Jelks of the U.S. Geological Survey, said that one-third of the fish that were in trouble in 1989 are worse off now. The study includes far more species and populations than those that are on the official U.S. government endangered species list. Jelks also told that the number of species in trouble was close to double what he expected and that means people should be “considerably worried.”
According to Jelks the biggest cause is degraded freshwater habitat, both in quality and quantity of water for fish to live in. Invasive species crowding out native fish is also to blame. The number of fish species and subspecies in North America that went extinct rose from 40 to 61 since 1989.
