Lamprey are eel-shaped fish with a skeleton made of cartilage and they belong to a relic primitive group of jawless fishes called Agnathans. The sea lamprey has smooth, scaleless skin and two fins on its back dorsal fins. The sea lamprey is parasitic; it feeds on other fish, using a suction disk mouth filled with small sharp, rasping teeth and a file-like tongue.
These are used by the sea lamprey to attach to a fish, puncture its skin, and drain its body fluids. Sea lamprey have a complex life cycle. The first four years of their life are spent as ammocoetes [am-mah-seats] — a blind worm-like larval stage — in the soft bottom and banks of waters that flow into Lake Champlain. They then transform into the parasitic adult stage and enter the lake to feed on landlocked Atlantic salmon salmon , lake trout and many other fish species; which they prefer due to their small scales and thin skin.
After twelve 12 to twenty 20 months in the lake the adults migrate back into the streams flowing into the lake to spawn, after which the adults die. Moderate numbers of sea lampreys were first noted in Lake Champlain in Recent genetic studies indicate that the sea lamprey may be native to Lake Champlain. Three other lamprey species are found in the Lake Champlain Basin. Two species are non-parasitic, and while the third species is parasitic, it does not have a significant impact on the Lake Champlain fish community.
Whether the sea lamprey is native to Lake Champlain or not, it is having detrimental impacts on the Lake Champlain fisheries, ecosystem, and human residents that are very significant. Sea lamprey have a major detrimental impact on the Lake Champlain fish community, the Lake Champlain Basin ecosystem, the anglers that fish Lake Champlain, and the many people throughout the watershed whose livelihood is directly or indirectly supported by the fishing and tourist industry.
Portable traps are rigid box traps with a cone-shaped fyke net entrance. Sea lamprey that enter the trap are unable to find an exit and are removed at regular intervals.
Sea lamprey traps are particularly useful in conjunction with sea lamprey barrier structures and in constricted stream channels where adults concentrate. Trapping at barriers limits the adult sea lamprey from moving to alternative streams where they may successfully spawn. Trapping is labor-intensive, and traps must be maintained for the duration of the spawning run.
Trapping is used as a supplemental control method except where the physical stream conditions make trapping an effective primary technique or where other control techniques are not feasible.
Upstream escape of a small number of adults could repopulate available nursery habitat resulting in little or no reduction of the sea lamprey produced in the stream. The smallest sea lamprey spawning streams with small numbers of spawning sea lamprey and high trap efficiency provide the most potential for control by adult trapping alone. Traps are operated during the spring spawning season, usually from shortly after ice out to late June. Traps are operated on the following waters:.
The most significant and effective form of control has been the treatment of streams and deltas with lampricides - TFM in tributaries and Bayluscide on deltas. The lampricides target the larval sea lamprey, killing them before they can transform into their parasitic adult form. Since the larval sea lamprey typically reside in streams or deltas for 4 years, lampricide treatments need only occur every 4 years in a specific water.
The chemical compound 3-trifluoromethylnitrophenol, better known as TFM, is remarkably effective for controlling sea lampreys without significantly impacting other species. TFM was developed as a lampricide in the 's following evaluations of over 6, chemicals for this purpose. TFM has been successfully used in the Great Lakes since to control sea lamprey and is considered one of the most target specific pesticides in use today. It is relatively non-toxic to fish other than lamprey at the levels used in control treatments.
Some non-targeted fish and other aquatic organisms may be killed in TFM treatments, but numerous studies have shown that the effects on non-targeted species are minor and do not have long term effects on the populations of non-targeted species. The treatment procedures used in Lake Champlain are consistent with the use described on the label and with Great Lakes Fishery Commission standard operating procedures.
Decades of laboratory tests and experience from thousands of stream treatments have demonstrated that at the dose needed to control sea lampreys, TFM is nontoxic or has minimal effects on aquatic plants, other fish, and wildlife.
Studies have also shown TFM to be nontoxic to humans and other mammals. TFM does not accumulate in the tissue of aquatic organisms and it breaks down in a matter of days. In the Great Lakes, long term studies have shown no traces of TFM in fish, even in cases where several treatments had been made in tributaries to the lakes in which the fish were caught. During the treatment of a stream or river TFM is applied in closely monitored and precisely measured amounts to target larval sea lamprey.
The amount of TFM applied is based on the chemical and physical characteristics of the stream - such as flows, pH, alkalinity, etc.
The application of the TFM is monitored constantly throughout the treatment period, and adjusted as needed based on the chemical and physical characteristics of the water and the concentrations of TFM in the water which are also monitored. A great deal of effort is undertaken before, during and after a TFM treatment to ensure that the treatment is effective, to prevent effects on human health and to minimize environmental impacts.
Bayluscide is the product name of a lampricide that is used to treat the deltas where larval lamprey reside. The stewards are college students helping to educate water users and shoreline property owners about how they can help slow the spread of aquatic invasive species.
Learn more online at www. If you have issues, please right-click and copy any of the links, and open it in an RSS reader of your choice. Follow Us:. Web Pages Research. If water levels become low, a significant numbers of larval lamprey ammocoete probably die Scott and Crossman Culverts may create barriers to upstream migrations for spawning.
Sedimentation reduces the quality of stream bottoms for spawning habitat Kart et al. The application of lampricides to control parasitic sea lamprey populations in Lake Champlain may be a threat, although numbers of northern brook lampreys captured before and after lampricide treatments in the Great Chazy River, a tributary of Lake Champlain, showed no permanent effects. There were 8 dead northern brook lamprey present in a sample of 23, dead lampreys shortly after treatment, comprising 0.
It was estimated that northern brook lamprey died as a result of the treatment, if the proportion held New York Natural Heritage Program ; Carlson Habitat protection is important for the northern brook lamprey. The fish is senstitive to environmental degradation, and seems to prefer undisturbed habitat and clear water.
Watershed management practices that reduce erosion and pollution, and thus maintain high water quality, are beneficial Kart et al. Barriers to movement such as culverts and dams should be addressed to ensure adult fish can migrate upstream to spawn and to ensure habitat connectivity Kart et al.
Lampricides, which are intended to control parasitic sea lamprey populations, usually do not affect most fish populations but are toxic to all lampreys. The distribution of northern brook lampreys and parasitic sea lampreys overlap in some areas, but northern brook lampreys can also be found in upstream areas that are not suitable for sea lampreys.
Consequently, lampricides should be applied with discretion and, whenever possible, should not be applied in northern brook lamprey habitat Kart et al. In Vermont, traps are being used instead of lampricides to control parasitic sea lampreys in streams in which northern brook lampreys are also known to be present Kart et al. Additional information is needed on the status of the northern brook lamprey in streams in New York Carlson Information about the fish has been gained from studies conducted during sea lamprey control efforts in Vermont and other areas of the Great Lakes basin Doug Carlson, pers.
In New York State, northern brook lampreys inhabit streams and small rivers mostly in transition or middle reaches Doug Carlson, pers. They have somewhat specific habitat requirements. They seem to prefer clear, permanent, medium-sized streams with moderately warm temperatures Becker For spawning, adults require clean, clear stream sections with alternating riffles and pools, where the substrate is usually gravel and stone Pflieger Larvae ammocoetes drift downstream to quiet, clear water areas such as the slower parts of streams, pools, and the banks, where they dig U-shaped burrows in the sand or muddy sand bottom Pflieger ; Smith ; Scott and Crossman The developing ammocoetes need these low-gradient, permanent waters with sand or silt substrate and organic debris as a place to reside while filter feeding Pflieger ; Smith Transforming larvae and adults use burrows as a place to hide as well Scott and Crossman Northern brook lampreys are known from 3 creeks in western New York and 7 brooks, creeks, and small rivers in northern New York.
The western creeks are located in Erie County and are part of the Lake Erie watershed. The northern waterbodies are located in Clinton, Franklin, and St. Lawrence Counties and are part of the Lake Champlain and St. Populations of northern brook lampreys are found from the St. Populations are localized in the Ohio River basin of northwestern Pennsylvania, western West Virginia, eastern Kentucky, northern and south-central Ohio, and northern Indiana. It is locally common Page and Burr Within its range, New York is peripheral and disjunct Carlson One population is known in Vermont, in the Lake Champlain basin Kert et al.
Recently the species was found in Iowa Gelwicks et al. The northern brook lamprey is a small fish that resembles an eel. It reaches a maximum length of 7 inches 17 cm. It has an elongate body, 7 pairs of gill openings, no scales, a single nostril in front of the eyes, and a single dorsal back fin that is connected to the caudal tail fin.
The body coloration is dark slate gray or brown on the back, silver below the gill region, and pale gray tinted with orange along the rest of the underside. There is often a pale line along the back. The fin is gray, yellow, or tan, with a light tan, bluish base. The lateral line organs are unpigmented. The fish is nonparasitic, and it has a small, round, sucker-like mouth that is usually narrower than the gill region.
The mouth disc has weak, blunt teeth, all of which have only one point cusp. The teeth are obvious only near the side of the mouth.
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