The life history of Corophium salmonis in the Columbia River estuary

• Main Author: Wilson, Stephanie Lynn
• Other Authors: Holton, Robert L., School of Oceanography, Oregon State University. Graduate School
• Format: Master Thesis
• Language: English; unknown
• Published: Oregon State University
• Subjects: Amphipoda > Columbia River Estuary (Or. and Wash.); Grays Bay
• Online Access: https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/5d86p2596

The benthic amphipod Corophium salmonis was sampled seasonally from two sites (Desdemona Sands and Grays Bay) in the Columbia River estuary. Populations of C. salmonis at both sites were found to have a two generation per year life cycle, a spring generation and a fall generation. The spring generation juveniles were produced in May 1981. These juveniles then grew throughout the summer and produced the fall generation in July and August. The fall juveniles were the overwintering population which would then produce the next spring generation. Brood sizes and mature female lengths were both found to be larger for the spring broods than for the fall broods. The population of C. salmonis on Desdemona Sands disappeared from the site in September 1980 and reappeared in April 1981. These events coincided with density fluctuations at the Grays Bay site. It was also observed that salinity at the Desdemona Sands site varied more than salinities at the Grays Bay site especially during the winter. Higher salinities at the Desdemona Sands site may have been responsible for the migration of C. salmonis in and out of the Desdemona Sands habitat.