HR: 1330h
AN: NB33Q-16    [Abstracts]
TI: Changes in Benthic Invertebrate Communities During the Introduction of Zebra Mussels Into an Impounded Michigan River
AU: * Luttenton, M
EM: luttentm@gvsu.edu
AF: Grand Valley State University, Biology Dept. and Annis Water Resources Institute, Allendale, MI 49401 United States
AU: Godby, N
EM:
AF: Michigan Department of Natural Resources, Northern Lake Huron Fisheries Management Unit, 1732 West M32, Gaylord, MI 49735 United States
AU: Rutherford, E
EM:
AF: University of Michigan, School of Natural Resources and Environment, Dana Building, Ann Arbor, MI 48109-1115 United States
AU: Vankampen, S
EM:
AF: Grand Valley State University, Biology Dept. and Annis Water Resources Institute, Allendale, MI 49401 United States
AB: Zebra mussels (Dreissena polymorpha, ZM) were introduced into the Croton impoundment on the Muskegon River, MI, sometime during the late 1990s, and subsequently colonized downstream. We evaluated changes in invertebrate communities in the Muskegon River during ZM colonization. ZM were not found in benthic samples collected during 1998-1999 but densities reached 12,000 m^-2 and 26,000 m^-2 in 2000 and 2001 respectively, immediately below the Croton impoundment. ZM densities remained relatively low (<70 m^-2) at sites 1.75 km and 8.75 km downstream. Total arthropod densities increased from 1998-99 to 2001. Trichoptera densities declined at all sites in 2000 but recovered in 2001. The relative abundance of Hyropsychidae varied between 1998-99 and 2001 at each sample site. Cheumatopsyche sp. increased significantly below Croton dam occupying spaces within and below ZM clumps, but declined at downstream sites following introduction of ZM. Chironomidae were uncommon in 1998-99 samples but were numerically dominant in 2000 and 2001 averaging 16525 m^-2 over both years. Data from 2003 indicated that ZM remove 32% of suspended Chl. a in the first 500 m below Croton Dam. Thus, ZM may affect benthic invertebrate communities in impounded river systems by redistributing particulate organic matter within the system.
DE: 4804 Benthic processes/benthos
SC: North American Benthological Society [NB]
MN: 2005 Joint Assembly