Tracking native species

According to the Federal Endangered Species Act of 1973, two categories of declining species of plants and animals need protection: endangered species and threatened species. Endangered species are defined as “any species that is in danger of extinction throughout all or a significant portion of its range”, while a threatened species is defined as “any species that is likely to become an endangered species within the foreseeable future throughout all or a significant portion of its range”. Simply put, endangered species are at the edge of extinction now, and threatened species are likely to be at the edge of extinction in the near future. Declining species not yet characterized as threatened or endangered can show significant decreases in population, and will benefit from monitoring information to help understand population levels.

Species we’re tracking

Declining New York native species

Deep water cisco, also called Lake Herring (Coregonus artedii)

Ciscoes are freshwater schooling fish that are predominantly found in waters below 18°C (~65°F). These cold-water fish breed once a year, spawning in shallow coastal waters in the winter and returning to deeper waters during the spring.  Cisco eggs develop slowly, hatching in the spring as the ice starts to thaw. Juveniles usually live in shallow bays for their first month, and mature within 1 to 4 years.

Ciscoes play an important role in the ecosystem. They feed predominantly on zooplankton and insect larvae and are a primary food for other economically important fish species like lake trout, yellow perch, walleye, and northern pike. In the 1940s, ciscoes were one of the most commercially important fish in the Great Lakes, where fisheries produced an average of 19 million pounds annually. However, the combined pressures of over-fishing, competition by invasive species like rainbow trout and alewives, and pollution have caused a significantly declining population.

Once abundant in all five Great Lakes, ciscoes are now common only in Lake Superior. Currently one of the greatest risks to ciscoes in the Great Lakes is the increasing level of nutrients being added to the lakes each year, which results in a decrease in the amount of oxygen in the water. Ciscoes are sensitive to changes in temperature and levels of dissolved oxygen.  Being forced to move into shallower, warmer parts of the water column where higher temperatures during the summer months can cause large die-offs in cisco populations.

In New York, ciscoes are native to ten watersheds in Great Lakes drainage, including the Finger Lakes, lower elevations of the Adirondacks, and Chautauqua Lake. However, populations have declined in the westernmost watersheds and in lower elevation lakes, including Lake Erie. Re-establishing Cisco in the lower Great Lakes would help improve connections in the food web. Additional information on location and abundance of native populations will aid efforts to protect and restore this important native species.

Map of cisco range in New York pre/post 1976-1977

American eel (Anguilla rostrate)

American eels are the only freshwater eel native to North America. American eels hatch in the Sargasso Sea in North Atlantic. Larvae drift with the Gulf Stream, reaching the US Atlantic coast about a year later. American eels undergo several distinct morphological stages as they mature. Depending on the environment, they can take up to 40 years to reach sexual maturity, at which time they return to the Sargasso Sea where each female lays 20 -30 million eggs.

Although the American eel remains widely distributed throughout much of its historical range, the population has decreased significantly over the last several decades, a result of the combined effects of habitat destruction, dam construction, water pollution, parasites, and overfishing, along with a huge increase in demand by Asian food markets following large decreases in the native Asian eel populations.  Although the U.S. Fish and Wildlife Service has not yet provided endangered species protection to the American eel, populations are declining, and according to the International Union for Conservation of Nature (IUCN), the American eel is at very high risk of extinction.

Conservation of the American eel is important for many reasons. American eels are an ecologically important species, playing various roles as prey, predator, and host species that help maintain ecosystem balance. In New York, the American eel is native to 17 of 18 watersheds. It was introduced to Lake Erie but the population was not sustained.  American eel  numbers have been greatly reduced throughout the watersheds of the Great Lakes. It has been completely eliminated from the Allegheny, and has declined to levels below detection in the Chemung and Susquehanna.

Although conservation efforts are now underway, much more will need to be done to restore this important species to healthy, sustainable levels. Efforts to protect and restore this important native species will benefit from additional information on current locations and abundance of native populations.

Map of American eel range in New York pre/post 1976

Brook trout (Salvelinus fontinalis)

Brook trout are popular small game fish generally weighing two pounds or less and seldom living more than five years. They require clean high-quality cold water (below 72 degrees Fahrenheit) to survive and depend on clean gravel areas for spawning. Once widely distributed, brook trout are now most commonly found in small streams and the headwaters of larger streams in mountainous areas. Brook trout are so sensitive to environmental conditions that they are considered an environmental indicator species. A large number of brook trout generally indicates a relatively healthy aquatic environment while a decline in the brook trout population often indicates a deteriorating habitat and decreased water quality. Brook trout are native to all 18 New York watersheds and have been introduced to additional areas throughout the state where they are not native. However, intact stream populations of brook trout now exist in only 5% of sub-watersheds, and the vast majority of large rivers that were historically home to thriving brook trout populations no longer support self-reproducing populations.

Although not listed under the Endangered Species Act, the brook trout have suffered decline due to a combination of factors.  Brook trout evolved in waters where there were few other fish species competing for resources. Brook trout do not compete well when non-native fish like yellow perch, bass, golden shiner, and various baitfish (small fish used as bait to attract larger fish, often game fish) are introduced into their waters. In the presence of non-native fish, brook trout populations generally experience a serious decline. As a result, the use of baitfish is prohibited in many brook trout ponds and it is illegal in New York to introduce any fish into waters they did not come from. Brook trout are also particularly sensitive to the effects of acid rain, especially in areas low in limestone that cannot naturally buffer increases in acidity. As a result of acid rain coupled with illegal fishing, in some areas of the Adirondacks, only ~3% of the waters that previously supported brook trout still maintain a viable population. To help counter this problem, New York State has stringent acid rain control requirements and is working to support reductions in power plant emissions outside the state.

An active brook trout restoration program has been established in the Adirondack Park. To secure the survival of the species in this area, ponds are selectively treated with lime each winter to decrease acidity levels, and competitive non-native fish populations are eliminated. When acidity levels suitable for fish survival are reached and competing fish species have been eradicated, ponds are restocked with brook trout.

Map of brook trout range in NY pre/post 1976

Threatened and endangered New York native species

Sturgeon