Cookies Policy

This site uses cookies. By continuing to browse the site you are agreeing to our use of cookies.

I accept this policy

Find out more here

A Case Study of Sampling Strategies for Estimating the Length Composition of Commercial Catches: The Sri Lankan Shrimp Trawl Fishery

No metrics data to plot.
The attempt to load metrics for this article has failed.
The attempt to plot a graph for these metrics has failed.
The full text of this article is not currently available.

Brill’s MyBook program is exclusively available on BrillOnline Books and Journals. Students and scholars affiliated with an institution that has purchased a Brill E-Book on the BrillOnline platform automatically have access to the MyBook option for the title(s) acquired by the Library. Brill MyBook is a print-on-demand paperback copy which is sold at a favorably uniform low price.

Access this article

+ Tax (if applicable)
Add to Favorites
You must be logged in to use this functionality

image of Crustaceana

Scientific surveys are expensive and often not feasible for artisanal and small-scale fisheries. Biological samples from the commercial catch are the principal source of information in monitoring these fisheries. A pilot sampling scheme of commercial craft conducted during a four-month period on the artisanal coastal shrimp trawl fishery in Sri Lanka revealed that the length compositions of two short-lived shrimp species (Metapenaeus dobsoni and Parapenaeopsis coromandelica), derived from commercial catches, showed high sampling variance and thus resulted in considerable noise in the length-frequency distributions. An analysis of variance components revealed that the total variance was mainly governed by the variance due to the number of samples. Hence, a more effective survey design was to collect samples from as many fishing craft as possible rather than increasing the sample size. The observed total variance of 0.4 based on measuring 43 109 individuals of M. dobsoni from 4 boats per sampling day (∼300 individuals/sample) in the pilot sampling was revised with the new sampling scheme, which reduced the variance to 0.2 based on measuring only 28 800 individuals from 6 boats per sampling day (∼150 individuals/sample). The length-frequency distributions constructed with the revised sampling scheme resulted in less noise in the monthly progression of modes.

Affiliations: 1: Department of Aquaculture and Fisheries, Wayamba University of Sri Lanka; Science Institute, Taeknigardur, University of Iceland, Dunhaga 5, 107 Reykjavik, Iceland; 2: Science Institute, Taeknigardur, University of Iceland, Dunhaga 5, 107 Reykjavik, Iceland


Full text loading...


Data & Media loading...

Article metrics loading...



Can't access your account?
  • Tools

  • Add to Favorites
  • Printable version
  • Email this page
  • Subscribe to ToC alert
  • Get permissions
  • Recommend to your library

    You must fill out fields marked with: *

    Librarian details
    Your details
    Why are you recommending this title?
    Select reason:
    Crustaceana — Recommend this title to your library
  • Export citations
  • Key

  • Full access
  • Open Access
  • Partial/No accessInformation