Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Autumnal deep scattering layer from moored acoustic sensing in the
  subtropical Canary Basin   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.

31
The categories of this paper are: ao-sci
29
The categories of this paper are: funct-an
15
The categories of this paper are: nucl-ex
25
The categories of this paper are: patt-sol
13
The categories of this paper are: quant-ph
21
The categories of this paper are: adap-org
24
The categories of this paper are: dg-ga
10
The categories of this paper are: q-bio
19
The categories of this paper are: eess
0
The categories of this paper are: hep-ph
12
The categories of this paper are: nucl-th
11
The categories of this paper are: hep-lat
18
The categories of this paper are: econ
26
The categories of this paper are: bayes-an
37
The categories of this paper are: supr-con
33
The categories of this paper are: plasm-ph