Shape, size and density of daytime surface swarms of the euphausiid Meganyctiphanes norvegica in the Bay of Fundy
Daytime surface swarms of Meganyctiphanes norvegica in the Bay of Fundy were examined using a variety of techniques to provide measurements of their shapes, sizes and densities. Shapes and sizes were determined from two aerial photographs: swarms were spherical, ribbon-like or amorphous. were up to...
| Published in: | Journal of Plankton Research |
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| Main Author: | |
| Format: | Text |
| Language: | English |
| Published: |
Oxford University Press
1986
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| Subjects: | |
| Online Access: | http://plankt.oxfordjournals.org/cgi/content/short/8/1/29 https://doi.org/10.1093/plankt/8.1.29 |
| Summary: | Daytime surface swarms of Meganyctiphanes norvegica in the Bay of Fundy were examined using a variety of techniques to provide measurements of their shapes, sizes and densities. Shapes and sizes were determined from two aerial photographs: swarms were spherical, ribbon-like or amorphous. were up to 28 6 m long and ranged in area from 0.4–111 7 m2. Densities were measured by a bag-sampling device which gave figures of up to 41 000 animals m−3 by photographic methods which gave figures of up to 770 000 animals m−3 and by a plankton net which gave maximum values of six animals m−3 Using the photographic method the maximum euphausud biomass was estimated to be 154 kg m−3 within swarms and the largest swarm measured was estimated to contain up to 2 1 tonnes of M. norvegica . Mean patch biomass estimates for the two aerial photographs ranged from 77.8–778 g m−3 and 15 6–155.6 g m−3 which are similar to figures obtained by other authors using integrating sampling techniques at depth. |
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