Brook trout (Salvenlinus fontinalis) also known as “speckled trout,” “specks,” and “brookies,” aren’t actually trout. They are really a type of char, more closely related to the Arctic char than to true trout. However, the brook trout, true trout, char, and salmon are all in the family Salmonidae, making them all closely related. The gorgeous brook trout is New York’s state fish and is greatly prized amongst naturalists and anglers. The native brook trout can be recognized and differentiated from other types of trout by its unique colors. Brook trout have a dark green and yellow “wormlike” pattern on their backs, which fades into green sides with yellow spots and red spots surrounded by blue halos. Their stomachs range in color from white to bright orange, depending on food sources and the time of year. One of the most easily recognizable parts of the brook trout are its fins, which are a deep red with a black stripe and a white stripe underneath along the edge of each fin. In the fall, one can see why New York chose the brook trout as its state fish when spawning occurs and the fish’s colors intensify.
Brook trout live in streams with cold, clean water. They require high amounts of oxygen in the water, dissolved oxygen in order to breathe, as do many of the aquatic insects that the trout feed upon. Trout eat a variety of foods, including mayflies, caddisflies, stoneflies, scuds, smaller fish, and snails. Larger brook trout will also eat terrestrial insects such as ants or grasshoppers and have even been known to eat mice that accidentally fall into streams! Because brook trout need very clean water to survive and are highly sensitive to pollution, their presence is a good indicator of a healthy stream.
Several conservation efforts by the NYS Department of Environmental Conservation and organizations like Trout Unlimited have focused on protection of the native brook trout in New York. The brook trout is native to the eastern part of the United States from Maine to Georgia, including New York. Populations of brook trout can be found in, Allegany State Park, Bowman Lake State Park, Connetquot River State Park Preserve, Caleb Smith State Park Preserve, Chittenango Falls State Park, Harriman State Park, and many other state parks with small tributaries. Restoration work to increase brook trout habitat has been done in Allegany State Park, which boasts many wild trout streams that are readily enjoyed by anglers.
Unfortunately, due to habitat loss, pollution, climate change, and introduction of non-native species, the brook trout has less suitable places to live than it did 200 years ago. Brook trout cannot tolerate water temperatures that are too high; as the water temperature increases, the dissolved oxygen decreases. The cutting of trees along stream banks and the loss of trees due to invasive insect species can contribute to temperatures rising and can affect native brook trout populations. Trees provide needed shade over streams and keep water temperatures low, even on hot summer days. When these trees are removed or die, sunlight is able to reach streams and causes water temperatures to rise. One important tree along some stream banks is the hemlock. Hemlock trees provide more shade than hardwood trees and do an excellent job of keeping streams cool. Unfortunately, the Hemlock Woolly Adelgid (HWA), an insect that invades and kills hemlocks, is affecting hemlocks all over the east. HWA is causing thousands of these trees to die. As hemlocks die, hardwood trees will take their places. While this will still provide shade to the streams, the temperatures will still rise because hardwoods provide less shade than hemlocks.
Pollution also affects brook trout by decreasing oxygen levels and poisoning the fish. A form of pollution called “agricultural runoff,” which includes manure and fertilizers, can cause an increase of aquatic plants to grow in streams. These plants eventually die and consume dissolved oxygen when they decompose. If there are too many decomposing plants in a stream, dissolved oxygen levels can be greatly decreased and affect brook trout severely. Pollution also decreases pH in water, making it more acidic, which allows more metals to be dissolved into the water. These metals can interfere with the brook trout’s body functions and cause developing eggs and fry to die.
Another major cause of habitat loss for the native brook trout is the past introduction of the brown trout (Salmo trutta) as a sport fish, which is native to Europe. Brown trout were brought to the United States due to their popularity with anglers. This is because they are aggressive fighters and can grow quite large. Brown trout can withstand higher water temperatures than the brook trout and are less sensitive to changing conditions. Because the brown trout is more aggressive, it can find food and shelter more easily than the brook trout. Brown trout will sometimes prey on the brook trout’s young. Streams in which brown trout have been introduced almost always have a noted decrease in native brook trout populations.
The introduction of rainbow trout (Oncorhynchus mykiss) has also contributed to decreased brook trout populations, but to a lesser extent. Both the introduction of brown and rainbow trout create competition for resources that the brook trout did not have to contend with before.
Fortunately, New York no longer stocks browns or rainbows in waters where populations of native brook trout are found in order to preserve the species. Many of these populations prevail in high mountain elevations in the Adirondack Park, as the brook trout is particularly talented at jumping up waterfalls. In fact, a brook trout can jump up to four times its body length if the pool they jump from is deep enough! This unique ability has allowed native populations to thrive in areas with many small waterfalls and pools. Today, dam removal and the installation of fish ladders also help to conserve brook trout habitat. Fish ladders provide a series of pools on an incline that allow fish to jump up over barriers. These installations allow waters to remain passable, even in dammed waters. Populations of brook trout exist in several places throughout New York, and the determined angler or observer can find many of these beautiful fish. Hopefully, with continued efforts of conservationists across New York state the brook trout population will continue to thrive and one day, increase.
Post by Mikey Bard, avid fly fisher and SCA/Americorps Member serving as Assistant Environmental Educator at Clay Pit Ponds State Park Preserve.