6533b7d0fe1ef96bd125a2d0
RESEARCH PRODUCT
Estimating the effects of winter-fishing: mobile echosounding under ice
Timo J. MarjomäkiRaimo RiikonenJuha Jurveliussubject
OceanographyEcho soundingEcologyHydroacousticsFishingFish <Actinopterygii>Environmental sciencePopulation managementAquatic ScienceUnderwaterPopulation densitydescription
Abstract An echosounder with a tape recorder in a propeller-driven waterproof box (an echosounder shuttle) was used under the ice to monitor the vertical distribution and density of fish in a winter seining area of a Finnish lake in April 1997. The surveyed fish were at 3.5–8 m depth, and fish density was significantly lower after seining than before. The seine catch was about 10 kg ha−1, and the echosounding results showed a decrease of 7 kg ha−1 in the hauling area. There were some difficulties due to the low temperature, and minor problems with steering and leakage of the shuttle. We conclude that it is possible to make mobile echosurveys under the ice and estimate densities of wintering fish.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 1999-01-01 | Fisheries Research |