Home About Browse Search
Svenska


Nyquist, Nils, 2019. Trapping efficiency and retention ability of four pontoon trap entrance types for use in coastal cod fishing, a fishing gear development field trial in the Baltic sea. First cycle, G2E. Uppsala: SLU, Dept. Of Aquatic Resources

[img] PDF
785kB

Abstract

As the Baltic Sea cod gets smaller both in number and size, and the grey seal population continues to increase, the need for alternative fishing methods in coastal fisheries increases. In this project one commercially used and three experimental pontoon trap entrances are tested with the objective to investigate if there are differences in trapping efficiency and retention ability when fishing for cod. The four entrance types were installed in fish pots together with video cameras and lights. From the recorded video material the number of Enter, Exit, Approach and Turn events were logged and
used to calculate trapping efficiency (Enter/Approach ratio) and retention ability (Exit/Enter ratio). There was a statistically significant difference trapping efficiency between Narrow-Short and Narrow-Long, both indicating that Narrow has a lower trapping efficiency. Due to limitations in analyses of the recorded observations, clear conclusions may not be drawn from the study's results. There is a need for further research focusing on entrance types for pontoon traps in order to develop seal safe gear with increased catch efficiency.

Main title:Trapping efficiency and retention ability of four pontoon trap entrance types for use in coastal cod fishing, a fishing gear development field trial in the Baltic sea
Authors:Nyquist, Nils
Supervisor:Ljungberg, Peter and Öhman, Kristin
Examiner:Bryhn, Andreas
Series:UNSPECIFIED
Volume/Sequential designation:UNSPECIFIED
Year of Publication:2019
Level and depth descriptor:First cycle, G2E
Student's programme affiliation:Other
Supervising department:(NL, NJ) > Dept. Of Aquatic Resources
Keywords:cod, pontoon trap, entrance type, coastal fisheries, video analysis, BORIS
URN:NBN:urn:nbn:se:slu:epsilon-s-10868
Permanent URL:
http://urn.kb.se/resolve?urn=urn:nbn:se:slu:epsilon-s-10868
Subjects:Fisheries and aquaculture - General aspects
Fisheries production
Language:English
Deposited On:11 Sep 2019 13:12
Metadata Last Modified:04 Jun 2020 12:50

Repository Staff Only: item control page

Downloads

Downloads per year (since September 2012)

View more statistics

Downloads
Hits