144
R. K. DELL
and red algae of the genera Plocamium, Myriogramme and Leptosomia
in the sublittoral down to 15 m near the Chilean stations of Arturo Prat
and Bahia Paraiso on the Antarctic Peninsula.
The benthic and geographical distribution of sublittoral algae in the
Ross Sea has been studied by Zaneveld (1966, 1968). In the upper sublittoral between low water and about 10 m an abundant algal growth
even under shore-fast ice 2 or 3 m thick, was developed. The main
species were Monostroma hariotii, Hildenbrandia lecannellieri Hariot,
Phyllophora antarctica and Iridaea obovata together with Desmarestia
willii Reinsch. Between 10 and 37 m the lower sublittoral supported
these species (except for D. willii), and in addition Desmarestia menziesi,
Phyllogigas grandifolius, Plocamium coccineum, Leptosomia simplex,
and Phycodrys antarctica. Algae continued well below this down to a
depth of 668 m (Desmarestia menziesii), the lower limits for the other
forms being 478 m (Leptosomia), 312 m (Phyllogigas, Plocamium,
Phyllophora and Phycodrys) and 136 m (Hildenbrandia). The only
species confined to depths greater than 3 7 m appears to be Ballia
callitricha which reaches its lower limit at 312 m and is therefore the
only true elittoral species. Zaneveld's field observations showed that
transport by floating ice, often postulated as a mechanism for depositing algae accidentally in deeper water off shore, is not an important
mechanism in the Ross Sea. Zaneveld also demonstrated a latitudinal
distribution of the 11 species concerned along the western shores of the
Ross Sea. All the species concerned occurred at 71"s. By about 72"20'S,
Desmarestia willii, Phyllogigas, Leptosomia and Ballia had reached their
southern limits. By 76"s Desmarestia menziesii and Plocamium had
dropped out followed shortly afterwards by Phycodrys leaving Monostroma, Hildenbrandia, Phyllophora and Iridaea. Apart from the green
alga Monostroma, the red algae (Rhodophyta) seem best adapted to the
cold waters of the Ross Sea.
Off South Georgia a rich series of algal associations is found. Although Durvillea and Lessonia are absent, Macrocystis is well developed,
and foliaceous Phyaeophyceae such as Aswseira, Phyllogigas and
Desmarestia menziesii are abundant (Skottsberg, 1941). Very rich sublittoral communities of Rhodophyceae occur (Skottsberg, 1941,
pp. 62-63) with Rhodymenia palmutiformis Skottsberg abundant down
to 30 m, Picconiella plumosa (Kylin) De Toni and Plocamium secundatum well represented. Skottsberg (1941, p. 36) believed that from an
algological viewpoint South Georgia must be included in the Subantarctic
zone, while recognizing that several genera and species linked South
Georgia with the Antarctic, and that an endemic element was well
represented.
R. K. DELL
and red algae of the genera Plocamium, Myriogramme and Leptosomia
in the sublittoral down to 15 m near the Chilean stations of Arturo Prat
and Bahia Paraiso on the Antarctic Peninsula.
The benthic and geographical distribution of sublittoral algae in the
Ross Sea has been studied by Zaneveld (1966, 1968). In the upper sublittoral between low water and about 10 m an abundant algal growth
even under shore-fast ice 2 or 3 m thick, was developed. The main
species were Monostroma hariotii, Hildenbrandia lecannellieri Hariot,
Phyllophora antarctica and Iridaea obovata together with Desmarestia
willii Reinsch. Between 10 and 37 m the lower sublittoral supported
these species (except for D. willii), and in addition Desmarestia menziesi,
Phyllogigas grandifolius, Plocamium coccineum, Leptosomia simplex,
and Phycodrys antarctica. Algae continued well below this down to a
depth of 668 m (Desmarestia menziesii), the lower limits for the other
forms being 478 m (Leptosomia), 312 m (Phyllogigas, Plocamium,
Phyllophora and Phycodrys) and 136 m (Hildenbrandia). The only
species confined to depths greater than 3 7 m appears to be Ballia
callitricha which reaches its lower limit at 312 m and is therefore the
only true elittoral species. Zaneveld's field observations showed that
transport by floating ice, often postulated as a mechanism for depositing algae accidentally in deeper water off shore, is not an important
mechanism in the Ross Sea. Zaneveld also demonstrated a latitudinal
distribution of the 11 species concerned along the western shores of the
Ross Sea. All the species concerned occurred at 71"s. By about 72"20'S,
Desmarestia willii, Phyllogigas, Leptosomia and Ballia had reached their
southern limits. By 76"s Desmarestia menziesii and Plocamium had
dropped out followed shortly afterwards by Phycodrys leaving Monostroma, Hildenbrandia, Phyllophora and Iridaea. Apart from the green
alga Monostroma, the red algae (Rhodophyta) seem best adapted to the
cold waters of the Ross Sea.
Off South Georgia a rich series of algal associations is found. Although Durvillea and Lessonia are absent, Macrocystis is well developed,
and foliaceous Phyaeophyceae such as Aswseira, Phyllogigas and
Desmarestia menziesii are abundant (Skottsberg, 1941). Very rich sublittoral communities of Rhodophyceae occur (Skottsberg, 1941,
pp. 62-63) with Rhodymenia palmutiformis Skottsberg abundant down
to 30 m, Picconiella plumosa (Kylin) De Toni and Plocamium secundatum well represented. Skottsberg (1941, p. 36) believed that from an
algological viewpoint South Georgia must be included in the Subantarctic
zone, while recognizing that several genera and species linked South
Georgia with the Antarctic, and that an endemic element was well
represented.