ANTARUTIC BENTHOS
147
biomass figures were between 1 245 and 1 347 g/m2, while between 200
and 600 m, the average ranged between 239 and 319 g/ma. Andriashev,
himself stressed that the highest indices of biomass depend on the
presence of sponges, ascidians and bryozoans which may make up to
between 60 and 90% of the total weight.
Dearborn (1967) gave a general account of the invertebrate studies
carried out in the Ross Sea, and particularly McMurdo Sound between
1958 and 1961. Material was collected using the usual sampling techniques, from ice-breakers and other vessels as opportunity offered. The
major programme was maintained through adventitious, or man-made
holes in the ice a t McMurdo Sound throughout the year. Grabs and
wire traps were the main collecting devices used for the benthos,
although trawls were used in cracks, or between neighbouring holes.
Accounts of the first years’ endeavours sound very similar to the account
given by Hodgson (1907) on methods he used for collecting on the
National Antarctic Expedition of 1901 to 1904. However, the modern
collecting methods were more sophisticated and became more so. Huts
which could be heated were erected over the main collecting holes, and
gradually the collection of material became more of a routine and less
of an heroic adventure.
Tressler (1964) gave a good account of the hydrographic and biological operations at the later stages (1960-61). The main collecting
holes were not static in relation to the bottom since the ice shelf was
gradually and regularly moving.
Peckham (1964) recorded the general results of a diving programme
throughout a year at McMurdo Sound. His description of the bottom
is so graphic that it is worth quoting in full :
The benthos of the Antarctic is reputed to be one of the richest areas
for sponges in the world. In the shallow waters of McMurdo Sound
sponges, along with sea anemones, soft corals, many alcyonarians, and a
few stalked tunicates are attached to a volcanic gravel or rock substratum.
As the depth increases the biotype changes, with a thick encrusting sponge
mat forming the base for other animal attachments. Larger anemones
replace the ubiquitous alcyonarians found in shallow water; pterobranches
are found and there are other sponges growing on this mat which are
nearly 3 feet high and as large in diameter. On the horizontal surface of
these large sponges, communities of hydroids and serpulid worms form
separate sponge-top biocoenoses.
Living in association with this base of sessile fauna are the grazers and
scavengers. Sea spiders, some larger than 8 in in diameter, are found on
the sponge mat or feeding on coelenterates. The foot-long nemertean worm
Lineua corrugatus and the asteroids Odontaster spp. are the major predators
147
biomass figures were between 1 245 and 1 347 g/m2, while between 200
and 600 m, the average ranged between 239 and 319 g/ma. Andriashev,
himself stressed that the highest indices of biomass depend on the
presence of sponges, ascidians and bryozoans which may make up to
between 60 and 90% of the total weight.
Dearborn (1967) gave a general account of the invertebrate studies
carried out in the Ross Sea, and particularly McMurdo Sound between
1958 and 1961. Material was collected using the usual sampling techniques, from ice-breakers and other vessels as opportunity offered. The
major programme was maintained through adventitious, or man-made
holes in the ice a t McMurdo Sound throughout the year. Grabs and
wire traps were the main collecting devices used for the benthos,
although trawls were used in cracks, or between neighbouring holes.
Accounts of the first years’ endeavours sound very similar to the account
given by Hodgson (1907) on methods he used for collecting on the
National Antarctic Expedition of 1901 to 1904. However, the modern
collecting methods were more sophisticated and became more so. Huts
which could be heated were erected over the main collecting holes, and
gradually the collection of material became more of a routine and less
of an heroic adventure.
Tressler (1964) gave a good account of the hydrographic and biological operations at the later stages (1960-61). The main collecting
holes were not static in relation to the bottom since the ice shelf was
gradually and regularly moving.
Peckham (1964) recorded the general results of a diving programme
throughout a year at McMurdo Sound. His description of the bottom
is so graphic that it is worth quoting in full :
The benthos of the Antarctic is reputed to be one of the richest areas
for sponges in the world. In the shallow waters of McMurdo Sound
sponges, along with sea anemones, soft corals, many alcyonarians, and a
few stalked tunicates are attached to a volcanic gravel or rock substratum.
As the depth increases the biotype changes, with a thick encrusting sponge
mat forming the base for other animal attachments. Larger anemones
replace the ubiquitous alcyonarians found in shallow water; pterobranches
are found and there are other sponges growing on this mat which are
nearly 3 feet high and as large in diameter. On the horizontal surface of
these large sponges, communities of hydroids and serpulid worms form
separate sponge-top biocoenoses.
Living in association with this base of sessile fauna are the grazers and
scavengers. Sea spiders, some larger than 8 in in diameter, are found on
the sponge mat or feeding on coelenterates. The foot-long nemertean worm
Lineua corrugatus and the asteroids Odontaster spp. are the major predators