Location

Agriculture Production Theater, Oregon State University

Start Date

25-6-2013 4:50 PM

End Date

25-6-2013 5:30 PM

Description

Lamprey populations are in decline in many parts of the world and some lamprey species are of conservation concern and have legally-mandated protections. As juveniles, anadromous lampreys exhibit distinct migration behaviors that take them from larval rearing habitats in streams to the open ocean. Like out migrating salmon smolts, lamprey transformers (macrophthalmia) undergo behavioural changes associated with metamorphosis. These changes facilitate their transition from relatively sedentary ammocoetes to actively swimming macrophthalmia. Unlike salmon smolts, the timing of outmigration in lamprey is protracted and poorly documented. Lamprey emigration is often associated with periods of high flow and macrophthalmia are not strong swimmers, with maximum individual swim speeds of less than 1 m/s. They are chiefly nocturnal and appear to move along the bottom, with regular attachment to bottom substrates. At dams, macrophthalmia can become impinged on screens, suffer increased predation, and experience physical injury that may result in direct or delayed mortality. The very structures designed to protect out migrating salmonids can be harmful to macrophthalmia. Yet lampreys, which have no swim bladder, can withstand large pressure changes at turbine intakes that would kill most teleosts. In this review, we present recent research from the Columbia River drainage on downstream migration in these imperiled fish and potential structural and operational changes that may reduce lamprey injury and mortality.

Comments

Mary Moser has worked on methods to improve adult Pacific lamprey passage at Columbia River hydropower dams during the past 12 years as a NOAA fisheries biologist. More recently she has teamed up with colleagues from the Umatilla Tribe to investigate downstream passage in juvenile lamprey.

Share

COinS
 
Jun 25th, 4:50 PM Jun 25th, 5:30 PM

Concurrent Sessions B: Columbia River Passage - A Review of Downstream Migration Behavior in Juvenile Lamprey and Potential Sources of Mortality at Hydropower Dams

Agriculture Production Theater, Oregon State University

Lamprey populations are in decline in many parts of the world and some lamprey species are of conservation concern and have legally-mandated protections. As juveniles, anadromous lampreys exhibit distinct migration behaviors that take them from larval rearing habitats in streams to the open ocean. Like out migrating salmon smolts, lamprey transformers (macrophthalmia) undergo behavioural changes associated with metamorphosis. These changes facilitate their transition from relatively sedentary ammocoetes to actively swimming macrophthalmia. Unlike salmon smolts, the timing of outmigration in lamprey is protracted and poorly documented. Lamprey emigration is often associated with periods of high flow and macrophthalmia are not strong swimmers, with maximum individual swim speeds of less than 1 m/s. They are chiefly nocturnal and appear to move along the bottom, with regular attachment to bottom substrates. At dams, macrophthalmia can become impinged on screens, suffer increased predation, and experience physical injury that may result in direct or delayed mortality. The very structures designed to protect out migrating salmonids can be harmful to macrophthalmia. Yet lampreys, which have no swim bladder, can withstand large pressure changes at turbine intakes that would kill most teleosts. In this review, we present recent research from the Columbia River drainage on downstream migration in these imperiled fish and potential structural and operational changes that may reduce lamprey injury and mortality.