Non-native species affecting U.S. coasts, rivers, and streams.
From my personal blog:
Native fish species have evolved over time to counter threats of bacteria, fungus, disease, and other native predatory species. By adapting to the gradually changing environment, many of the species present today have became extremely robust in dealing with external pressures. Until fairly recently though, native U.S. fish species have had little reason to adapt to the habits and threats of other species half way across the globe. Now, with the addition of new species to U.S. waters, fish and plants have new challenges that they are not equipped to handle.
Recently, the Associated Press, has published information concerning the introduction of red lionfish from the Indian Ocean, into the coastal waters of Florida and the Caribbean. Though a magnificent looking marine fish, the red lionfish population is beginning to swell and create problems for smaller native reef fish. With poisonous spines and a voracious appetite, lionfish will consume any fish and crustaceans small enough to fit inside its mouth.
Not only is the lionfish a disaster for local marine life, the sting from the poison spines can be extremely painful for any person unlucky enough to get in its way. This poison is a great defense for the fish, as very few larger species are able to consume the red lion, and rarely will a predator make the mistake twice.
Fisherman and divers in areas experiencing an increase of red lionfish, are being encouraged to catch and report any sightings. These actions may help to control the outbreak, but it is very unlikely to have a profound effect on the numbers.
Since water quality and composition varies greatly around the world’s oceans, with the exception of the red lionfish, marine animals rarely become a problem that cannot be controlled by natural processes. On the other hand, fresh bodies of water are much more susceptible to damage by “out-of-town” animals.
Salmon along the Snake and Columbia rivers, are quickly declining in population due to non-native species consuming large amounts of the food sources and eggs. The spread of parasites is also of great concern.
Quite ironically, the bass and walleye causing these problems, were introduced by biologists to provide a better environment for sport fisherman. Since recreational fishing provides funding in the form of licensing and taxes, stocking these game fishes was not thought to cause harm. Now, efforts to reduce the number of these game fish, have proven unsuccessful. The rate of reproduction out numbers any progress made my biologists and anglers to decrease the numbers of bass and walleye.
These new species are very well tailored to life within new reservoirs created by hydro electric dams. While bass, shad, and walleye flourish in the large open waters, salmon prefer the swift flowing waters of rivers and streams.
While developing ways to create clean energy and new opportunities, we must be sensitive to the outcomes of any changes made to the current surrounding habitats. Though hydro power is an abundant source of power, and man made reservoirs can increase the volume of water for fish and crustaceans, not all animals are effected the same. When non-native species find local waters well suited to their survival, many native species can be lost in the transition. Proper research and a little bit of restraint will help to keep native species thriving. Most of these situations can be avoiding by following local laws and regulations governing the release of non-native species into water sources.