Affordable Access

Catching large herring larvae: Gear applicability and larval distribution

Authors
Publication Date
Keywords
  • A Series Of Night Hauls Were Made Both Along A Transect From The Danish Coast To The Dogger Bank And
  • The Aim Was To Evaluate The Suitability Of Two Midwater Trawls (Ikmt And Mik) For Catching Large Her
  • With Special Attention Given To The Influence Of Gear Speed On Catching Effectiveness
  • An Additional Objective Was To Investigate Larval Distributional Patterns Of Potential Importance To
  • Gear Speed Had A Pronounced Influence On The Efficiency Of The Ikmt
  • Catches Per Unit Volume Filtered Decreased To One Third When Speed Was Increased By One Knot
  • The Efficiency Of The Mik Did Not Change In The Speed Range Investigated
  • And This Gear Was In Every Case More Efficient Than The Ikmt
  • Larvae Were Found To Be Patchily Distributed At The Scale Of Sampling
  • And The Degree Of Patchiness Did Not Increase When Stations 5 Nm Apart Were Compared
  • At Night
  • Herring Larvae Are Confined To The 20-40-Metre Water Layer
  • Whereas A Migrationto Upper Water Layers At Dawn And Dusk Was Observed

Abstract

Catching large herring larvae: Gear applicability and larval distribution - DTU Orbit (16/04/14) Catching large herring larvae: Gear applicability and larval distribution - DTU Orbit (16/04/14) Catching large herring larvae: Gear applicability and larval distribution A series of night hauls were made both along a transect from the Danish coast to the Dogger Bank and at a fixed position in the southern North Sea. The aim was to evaluate the suitability of two midwater trawls (IKMT and MIK) for catching large herring larvae (20-40 mm), with special attention given to the influence of gear speed on catching effectiveness. An additional objective was to investigate larval distributional patterns of potential importance to sampling strategy. Gear speed had a pronounced influence on the efficiency of the IKMT. Catches per unit volume filtered decreased to one third when speed was increased by one knot. The efficiency of the MIK did not change in the speed range investigated, and this gear was in every case more efficient than the IKMT. Larvae were found to be patchily distributed at the scale of sampling, and the degree of patchiness did not increase when stations 5 nm apart were compared. At night, herring larvae are confined to the 20-40-metre water layer, whereas a migration to upper water layers at dawn and dusk was observed. General information State: Published Organisations: Section for Ocean Ecology and Climate, National Institute of Aquatic Resources Authors: Munk, P. (Intern) Pages: 97-104 Publication date: 1988 Main Research Area: Technical/natural sciences Publication information Journal: Journal du Conseil / Conseil International pour l'Exploration de la Mer Volume: 45 Journal number: 1 ISSN (Print): 0020-6466 Original language: English Source: orbit Source-ID: 282536 Publication: Research - peer-review › Journal article – Annual report year: 1988

There are no comments yet on this publication. Be the first to share your thoughts.