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arXiv · 1903.01285

Autumnal deep scattering layer from moored acoustic sensing in the subtropical Canary Basin

Hans van Haren
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Abstract

An enhanced acoustic scatterer reflectance layer was observed in the bathypelagic zone around 1650 m in the subtropical NE-Atlantic Ocean for about two months during autumn. It resembles a classic pattern of diapause-resting, possibly of large zooplankton, shrimp and/or Cyclothone, at great depths well below any sunlight penetration, which is more commonly found at higher latitudes. The observed slow sink and rise of about 2-5 m per day into and out of this deep layer is considerably slower than the more than 1000 m per day of diel vertical migration (DVM). During the two-month period of deep scattering, DVM is observed to be greatly reduced.

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Hans van Haren. 2019-03-04. Autumnal deep scattering layer from moored acoustic sensing in the subtropical Canary Basin. https://doi.org/10.1007/s00227-019-3491-7

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