David Ward (Former Employee)
Science and Products
Filter Total Items: 32
Index of predation on juvenile salmonids by northern squawfish in the lower and middle Columbia River and in the lower Snake River Index of predation on juvenile salmonids by northern squawfish in the lower and middle Columbia River and in the lower Snake River
We developed a predation index to describe the relative magnitude of predation on juvenile salmonids by northern squawfish Ptychocheilus oregonensis throughout the lower and middle Columbia River and lower Snake River. The predation index was the product of an abundance index and a consumption index. We evaluated various catch indices and found that catch per unit effort best reflected...
Authors
David L. Ward, James H. Petersen, John J. Loch
Spatial and temporal variation in proportional stock density and relative weight of smallmouth bass in a reservoir Spatial and temporal variation in proportional stock density and relative weight of smallmouth bass in a reservoir
Population data for smallmouth bass Micropterus dolomieui in 20,235 ha John Day Reservoir on the Columbia River were used to (1) determine whether Proportional Stock Density (PSD) and Relative Weight (Wr) varied spatially and temporally in two areas of the reservoir with established smallmouth bass fisheries; (2) explore possible causes of any observed variation; and (3) discuss some...
Authors
Matthew G. Mesa, S.D. Duke, David L. Ward
Science and Products
Filter Total Items: 32
Index of predation on juvenile salmonids by northern squawfish in the lower and middle Columbia River and in the lower Snake River Index of predation on juvenile salmonids by northern squawfish in the lower and middle Columbia River and in the lower Snake River
We developed a predation index to describe the relative magnitude of predation on juvenile salmonids by northern squawfish Ptychocheilus oregonensis throughout the lower and middle Columbia River and lower Snake River. The predation index was the product of an abundance index and a consumption index. We evaluated various catch indices and found that catch per unit effort best reflected...
Authors
David L. Ward, James H. Petersen, John J. Loch
Spatial and temporal variation in proportional stock density and relative weight of smallmouth bass in a reservoir Spatial and temporal variation in proportional stock density and relative weight of smallmouth bass in a reservoir
Population data for smallmouth bass Micropterus dolomieui in 20,235 ha John Day Reservoir on the Columbia River were used to (1) determine whether Proportional Stock Density (PSD) and Relative Weight (Wr) varied spatially and temporally in two areas of the reservoir with established smallmouth bass fisheries; (2) explore possible causes of any observed variation; and (3) discuss some...
Authors
Matthew G. Mesa, S.D. Duke, David L. Ward