1063-0740/02/2805- $27.00 © 2002
Russian Journal of Marine Biology, Vol. 28, No. 5, 2002, pp. 298–307.
Original Russian Text Copyright © 2002 by Biologiya Morya, Bazhin.
Three species of sea urchins of the genus
inhabit the shelf of eastern Kamchatka and
differ in their ecology and distribution patterns .
was found everywhere on sublittoral
rocky bottoms from Cape Lopatka up to the Kamchatka
Peninsula [5, 31]. The largest and most stable popula-
tions of this species were recorded in Avachinskaya
Guba and in the southern and northern parts of the Kro-
notsky Gulf and in the southern part of the Kamchatka
is the most abundant in the bays
of Avachinsky, Kronotsky and Karaginsky gulfs:
Avachinskaya, Morzhovaya, Vilyuchinckaya, Saran-
naya and Ossora bays .
promising as ﬁshery objects, because they were picked
up by SCUBA divers using a technique traditional for
sea urchin ﬁshery.
is not of commercial
interest because of its fragile shell and its unusual taste
for Japanese consumers; also, adequate instruments for
ﬁshing at depths of 30–150 m also do not exist.
Assessment of the sea urchins reserves based on
long-term scientiﬁc ﬁshery studies showed that the
density and size structure of their populations in a num-
ber of regions of Avachinsky and Kronotsky bays and
in adjacent water areas could allow ﬁshing for these
species. However, to develop a scientiﬁcally based ﬁsh-
ing strategy for this potentially commercially important
species of sea urchins, it is necessary to have informa-
tion concerning their ecology. Accordingly, we have
tried to reveal the distribution patterns of three sea
urchin species of the genus
ing the coast of eastern Kamchatka relative to physical
factors such as the depth of inhabitation, type of sub-
strate, intensity of surf action, and some hydrological
MATERIAL AND METHODS
The sampling of sea urchins was conducted using
SCUBA gear along the coast of eastern Kamchatka
from Cape Africa to Cape Lopatka from May to
November during the period 1984–1996. The location
of the stations was determined during a preliminary
survey. The distance between the stations ranged from
100 to 500 m depending on bottom relief, ground, and
the shoreline pattern. The sampling method comprised
a total inventory of each species of sea urchins in each
depth range collected in a metal frame that was ran-
domly thrown onto the bottom. The frames were low-
ered three to 25 times per sample for each depth range,
so the total number of sea urchins in a sample was no
less than 80 specimens. Altogether, samples were col-
lected from 166 stations.
The average relative abundance ( ) of the
cies was estimated for each locality and depth range
using the equation
is the total number of samples from all locali-
ties and depth ranges and
is the relative abundance
(%) of specimens of the
th species in the sample. This
was calculated using the following equation:
Distribution Patterns of
along the Coast of Eastern Kamchatka
A. G. Bazhin
Kamchatka Research Institute of Fisheries and Oceanography, Petropavlovsk-Kamchatsky, 683902 Russia
Received January 29, 2002
—The distribution patterns of three sea urchin species of the genus
in relation to
depth, type of substrate, surf action, and to some hydrological parameters were studied along the coast of east-
ern Kamchatka and in adjacent waters in 1984–1996. The sea urchin
nated the open coast on rocky subintertidal sites with increased surf action and standard oceanic salinity.
prevailed in shoals with lower salinity, higher water temperature and lower turbulence (enclosed
and semienclosed bays).
dominated at depths corresponding to the position of the cold intermediate
layer deeper than 30–50 m with normal oceanic salinity and lower temperature.