New York Natural Heritage Program
Northern Brook Lamprey
Ichthyomyzon fossor Reighard and Cummins, 1916

Threats [-]
Additional research is needed on threats and their significance (Kart et al. 2005). If water levels become low, a significant numbers of larval lamprey (ammocoete) probably die (Scott and Crossman 1973). Culverts may create barriers to upstream migrations for spawning. Sedimentation reduces the quality of stream bottoms for spawning habitat (Kart et al. 2005). 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 23,394 dead lampreys shortly after treatment, comprising 0.84% of the total. It was estimated that 197 northern brook lamprey died as a result of the treatment, if the proportion held (New York Natural Heritage Program 2008; Carlson 2001).

Conservation Strategies and Management Practices [-]
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. 2005; Moen 2002; Becker 1983). 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. 2005). 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. 2005; Moen 2002; Becker 1983). 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. 2005).

Research Needs [-]
Additional information is needed on the status of the northern brook lamprey in streams in New York (Carlson 2001). 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. comm. 2009), however additional information is still needed on threats and their significance, as well as habitat changes in areas where the fish is known to be present (Kart et al. 2005; Carlson 2001).