Every species of sea turtle on our planet is currently endangered. Sea turtles face countless threats to their existence in the modern world. All these threats can be traced back to human actions, either intentional or unintentional.
In the area of intentional human acts, many coastal communities of humans use sea turtles as a food source. This can be done by digging up sea turtle nests and eating the eggs. In many countries this is illegal, but it happens anyway because hungry people often care little about the law and expect they will not be caught. In Mexico, turtle eggs have long been considered a food that improves male sexual prowess. This inaccurate idea has been bad news for turtle populations.
Adult sea turtles, because of their solid shells, have few predators besides man. Traditional coastal cultures in Central and South America, however, will sometimes capture a turtle and store it on its back, (a position from which it cannot escape,) until it is time to kill it for food.
Along with intentional human predation on sea turtles, there is the added population pressure exerted by unintentional killing. The seafood industry has a problem that is called “by-catch,” the accidental capture of other species by a fishing vessel that is only bringing home one species. For example, a shrimp boat goes out and hauls in a net. In the net is a dead turtle. Why is the turtle dead? The turtle is dead because turtles breathe air, and the net kept the turtle underwater far too long so that it died. Many thousands of large adult turtles die this way in the Gulf of Mexico and other areas of tropical seas where fishing is intense. Bottom Longline fishing is especially damaging to turtles because they may be hooked and drowned accidentally by fishermen trying to catch Grouper.
“Turtle excluder devices” have been suggested as a possible answer to the unintentional killing of sea turtles in fishing nets. These devices, however, are somewhat expensive and some fishermen have resisted using them. This is a shame, because shrimp boats that use these devices kill 97% fewer turtles.
Lastly, turtles are sometimes killed by pollution. Old, leftover fishing nets that are drifting in the ocean uselessly can still drown turtles. Leatherback turtles may also sometimes die from mistaking pieces of plastic in their environment as a prey species. Plastic bags drifting in the sea resemble jellyfish, something Leatherbacks like to eat. The plastic bags can be fatal by clogging the turtle’s digestive system.
The recent strategies of protecting nests on beaches and reducing mortality at sea from fishing nets have shown promise in the US, but many other nations with greater poverty and less governmental authority have so far been unwilling or unable to undertake such measures. Even in US waters, populations continue to decline. Because of the many intentional and unintentional ways in which people take the lives of these creatures, it is not certain that sea turtles, which have been around for a hundred million years, are going to survive their encounter with the human race. Time will tell.
Sources:
http://en.wikipedia.org/wiki/Sea_turtles
http://www.fws.gov/northflorida/seaturtles/turtle-facts-index.htm
http://earthjustice.org/features/sea-turtles-rescued-from-longliners?gclid=CNrx0q6MzaYCFcbc4AodYxYOIg
