Fish and other aquatic species
As fishing gear and boats have improved, the fishing industry has become very efficient at harvesting fish and shellfish. The industrialization of the fishing industry and the increasing world demand for seafood have people taking more fish from oceans, lakes and rivers than is sustainable. Prized fish, such as swordfish, cod and tuna, have undergone dramatic declines. In the Great Lakes over-fishing has caused whitefish, walleye, and sturgeon populations to decline. Beyond their role in the food supply, freshwater and marine fish are also trapped for the aquarium trade and fished for sport.
Birds are collected or hunted for sport, food and the cage-bird pet trade (parrots and songbirds are prized as pets). Millions of birds are traded internationally each year. Close to 30% of globally threatened birds are threatened by over-exploitation, particularly parrots, pigeons and pheasants. The Carolina parakeet was once the only species of parrot in the U.S., but it was hunted to extinction early in the last century for food, to protect crops and for its feathers (which adorned ladies’ hats).
Farmer / Rancher Shootings Ranchers may shoot wild animals on spot when they feel that they attack domestic sheep and thus destroy ranchers’ livelihoods. This happens quite often with jaguars and was the main cause of the Tasmanian tiger’s extinction. Animal Extinction and Endangerment Main Causes
Amphibians are collected and shipped all over the world for the pet trade, medicine, education (frogs are dissected in many biology classes), scientific research and for food (frog legs are a delicacy in many parts of the world). The California red-legged frog, now a federally protected endangered species, was over hunted for food and its numbers seriously depleted during the Gold Rush in the area around San Francisco.
Reptiles are harvested and traded around the world for their skins or shells, their eggs, meat, and for the pet trade. Over-harvesting of the Kemp’s ridley sea turtle’s eggs nearly led to its extinction, and today it is still an endangered species. In the U.S., box turtles are being collected at unsustainable levels for the overseas pet trade. Some reptile skins—such as crocodile, python and monitor lizard—are highly prized as exotic leathers.
Invertebrates make up at least 75% of all known animal species. Insects, oysters, octopus, crayfish, sea stars, scorpions, crabs and sponges are all kinds of invertebrates. Today, many invertebrates—particularly marine invertebrates—are at risk from over-harvesting. Chesapeake Bay oysters, once an important part of the Bay economy, are now in decline. Horseshoe crabs, whose eggs provide food for migratory birds, fish and other organisms, are being harvested as bait for eel and whelk fishing. Octopus are suffering declines world-wide due to heavy fishing pressure. Shells and corals are collected for ornaments and jewelry.
Plants are vital to our survival and are the foundation of most of the Earth’s ecosystems. People harvest plants for food, medicine, building materials, and as raw materials for making other products. But we are taking too many plants from the wild. Some plants, such as orchids, are so prized by collectors that they are now endangered and legally protected from poaching by international law. Some medicinal plants, such as American ginseng, have also been so enthusiastically collected that it is now very hard to find them in the wild. A number of tree species that are prized for their wood, such as mahogany, are under threat because of over-harvesting