Fróðskaparrit - 01.01.1998, Side 88

94
DECAPODA NATANTIA (CRUSTACEA) IN THE FAROE AREA
in the Faroe area may be important for zoo-
geographical analyses. In the area there are,
according to Westerberg (1990), three main
categories of water mass which differ with
respect to formation area and general flow
direction: Atlantic Water (AW), bottom wa-
ter of the Norwegian Sea (NW), and Arctic
Intermediate Water (AI).
The Atlantic Water (AW) forms the in-
flow of water in the upper layers to the Nor-
wegian Sea. The salinity is > 35.1. The
temperature is above 7 °C, except in de-
pressions on the Faroe plateau where win-
ter-cooled water might be trapped.
The bottom water of the Norwegian Sea
(NW) forms the coldest component of the
water overflowing the thresholds around
the Faroes to the Atlantic. The temperature
is below 0 °C.
The Arctic Intermediate Water (AI) is
present between the warmer AW and the
colder NW. AI, of which several types can
be distinguished, is formed north of the
Arctic (or Polar) front in the Iceland and
Greenland Seas. From the areas of genera-
tion AI sinks and spreads to the northern
slope of the Faroe-Iceland Ridge which it
follows towards the Faroe plateau and into
the Faroe-Shetland Channel. In the Faroe
area this water usually has a temperature
between 1.5 and 3.5 °C.
Water with temperatures between 3.5
and 7.0 °C is a mixture of AW and AI.
Colder water with temperatures between 0
and 1.5 °C found north of both the Faroe-
Iceland Ridge and of the Faroe plateau, and
in the Faroe-Shetland Channel is a mixture
of AI and NW. Water of the same tempera-
ture range south of the Faroe-Iceland Ridge
is a mixture of AW, AI and NW.
Parts of the material of Decapoda Natan-
tia collected during BIOFAR was used by
Erik Ibsen Rømer in his cand. scient. thesis
(Rømer, 1991) (Zoological Museum, Uni-
versity of Copenhagen). The theme for the
thesis was geographical distribution and
depth distribution of bottom-related
shrimps and prawns of the Faroe area in re-
lation to hydrography, especially tempera-
ture. The sorting of the material collected in
the years 1987-90 was not completed at the
time Rømer wrote his thesis. Additional
specimens from unsorted and incompletely
sorted BIOFAR material have been added
in this paper as well as material from some
BIOFAR 2 stations. Under each species
specimens from deployments indicated
with normal letters were studied by both
authors, boldface indicate specimens stud
ied by E.I.R., and italics indicate specimens
studied by T.B.
For each species in the systematic list be
low the following information is given: the
valid name with author and publication
year; synonyms when relevant; reference to
a good description of the species; previous
Faroese records; the BIOFAR and BIOFAR
2 stations where it was found; area descrip-
tions (Fig. 1); the depth range; measured
temperature range or estimated tempera-
ture range of the near-bottom water (based
on data from a database created by H. West-
erberg, in Nørrevang etal., 1994); breeding
or notes on ovigerous females; the type of
water mass in which the specimens were
caught (identified by H. Westerberg, in
Nørrevang et al., 1994); and short notes on
the distribution and the depth range of the