Dredging-Related Mortality of Dungeness Crabs Associated with Four Dredges Operating in Grays Harbor, Washington.

Abstract

From October, 1978, to December, 1979, entrainment and mortality of Dungeness crabs (Cancer magister) was estimated for two hopper dredges (PACIFIC and SANDSUCKER), a pipeline dredge (MALAMUTE), and a clamshell dredge (VIKING) operating in Grays Harbor, Washington. Sampling on suction dredges was accomplished by straining the discharged sediment through steel baskets or nylon nets, and visual observation on the clamshell dredge. Estimates of sampling mortality, actual dredging-induced mortality, and delayed mortality were made when possible. Entrainment rates were similar among the three suction dredges, but varied greatly with location in the harbor. Based on information from dredge sampling and crab trapping, recommendations were made concerning alternations in dredges and dredge scheduling which might reduce the subsequent crab mortality.

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Document Details

Document Type
Technical Report
Publication Date
Mar 01, 1981
Accession Number
ADA100139

Entities

People

  • Bradley G. Stevens

Tags

Communities of Interest

  • Ground and Sea Platforms

DTIC Thesaurus Topics

  • Engineers
  • Fish
  • Fisheries
  • Habitats
  • Medical Personnel
  • Regression Analysis

Readers

  • Coastal and Marine Engineering/Sediment Transport/Hydraulic Engineering
  • Vector-Borne Disease and Entomology