Ecology of nonnative Siberian prawn (Palaemon modestus) in the lower Snake River, Washington, USA

Aquatic Ecology
By:  and 

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Abstract

We assessed the abundance, distribution, and ecology of the nonnative Siberian prawn Palaemon modestus in the lower Snake River, Washington, USA. Analysis of prawn passage abundance at three Snake River dams showed that populations are growing at exponential rates, especially at Little Goose Dam where over 464,000 prawns were collected in 2015. Monthly beam trawling during 2011–2013 provided information on prawn abundance and distribution in Lower Granite and Little Goose Reservoirs. Zero-inflated regression predicted that the probability of prawn presence increased with decreasing water velocity and increasing depth. Negative binomial models predicted higher catch rates of prawns in deeper water and in closer proximity to dams. Temporally, prawn densities decreased slightly in the summer, likely due to the mortality of older individuals, and then increased in autumn and winter with the emergence and recruitment of young of the year. Seasonal length frequencies showed that distinct juvenile and adult size classes exist throughout the year, suggesting prawns live from 1 to 2 years and may be able to reproduce multiple times during their life. Most juvenile prawns become reproductive adults in 1 year, and peak reproduction occurs from late July through October. Mean fecundity (189 eggs) and reproductive output (11.9 %) are similar to that in their native range. The current use of deep habitats by prawns likely makes them unavailable to most predators in the reservoirs. The distribution and role of Siberian prawns in the lower Snake River food web will probably continue to change as the population grows and warrants continued monitoring and investigation.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Ecology of nonnative Siberian prawn (Palaemon modestus) in the lower Snake River, Washington, USA
Series title Aquatic Ecology
DOI 10.1007/s10452-016-9581-4
Volume 50
Issue 4
Year Published 2016
Language English
Publisher Springer
Contributing office(s) Western Fisheries Research Center
Description 15 p.
First page 607
Last page 621
Country United States
State Washington
Other Geospatial Snake River
Online Only (Y/N) N
Additional Online Files (Y/N) N