MAWSON EXPEDITION.

New Zealand Herald, Volume LXVII, Issue 20622, 22 July 1930, Page 9

MAWSON EXPEDITION.

BACK TO AUSTRALIA

VALUABLE INVESTIGATIONS

REPORT OF CHIEF BIOLOGIST:

BY Sin, DOUGLAS MAWSON

(All rights reserved.) No. IV.

One heavy gale was encountered- in lh« neighbourhood of 63deg. south latitude but otherwise the run north was under favourable conditions.

Royal Sound, Kerguelen Island, was reached on abounds in teal duck and rabbits which were shot in great numbers, providing a much appreciated change in our diet. Coaling operations were executed by the crew, allowing the scientific staff further opportunity for investigating that extremely interesting locality. Corrections were made and further details were added to the existing chart. The aviators. Campbell and Douglas, made several flights. In association " with Hurley a series of aerial photographs were taken, which illustrate in the best possible fashion the remarkable topography of the island.

The coaling was not completed until February 20, when the weather broke. Thereafter a succession of high winds with falling snow continued until March 2, when an improvement took ' place. Hardly had we got out to sea before a. gale of wind descended once more. Jt was evident that summer was over. A course was set for the south-west corner of the Australian continent. A number of marine stations distributed at regular intervals along that route were successfully occupied. Thus our programme came to an end on arrival of!: Albany ori March 21. Summary of Objectives Achieved. .Summarising the principal objectives achieved, the following deserve special mention : Reports upon anchorages and dangers to shipping are in course of preparation. Exhaustive bdvrological data have been secured. These deal with the ocean currents and the chemical nature of tho sea water in the various areas visited from the surface to the greatest depths. In this work special regard has been, had to such conditioning factors as determine the existence of valuable fisheries. The data have been so collected that with further observations to be made on the next cruise there will be available matter for a full exposition of the marine conditions over the wide ocean to the south of Australia and the adjacent Indian Ocean.

The distribution of the southern packice and its movements have been fully recorded as a guide to navigators prosecuting commercial operations in that area. Balloons for Upper Air Records.

The northward movement of the cold surface water has been a subject of note in regard to probable influence upon Australian climate. In this latter connection also meteorological observations, have been as thorough as possible, including upper-air records oblained by th« use of exploring balloons which operated to an extreme height of 50,000 it. Biological studies were continued throughout the whole of the cruise on an extensive and intensive scale. Thus regular observations relating to the whale, and bird life were made, and the ship was frequently stopped for station work where both qualitative and quantitative investigations were made concerning the Plankton, Xekton and Benthos. From this data it will he possible to indicate quantitatively the fisheries possibilities of the region visited and its relative richness in economically valuabl® products. Plant Lile on the Islands. The following are extracts from the report of Professor T. Ilarvey Johnston, professor of zoology, University of Adelaide, and chief biologist to the expedition :—•

Short, visits made to the principal subAntarctic islands of I lie Indian Ocean gave some opportunity for investigating the nature and amount of tlie land vegetation. Such information was obtained for Possession Island of the Crozet Group, for Kerguelen Island, and for Heard Island. riant life was more abundant and varied at the Crozets than at Kerguelen, but was scantiest in regard to species as well as individuals at Heard Island. Grasses were well represented at the first-named, where, in conjunction with other low-growing plants, they formed practically a meadow. Such a condition was much less marked at Kerguelen,. and did not exist at Heard Island, though one species formed large tussocks in a swampy area near Atlas Cove, where the seaelephants were fairly abundant at the time of our visit.

Kerguelen cabbage, known for its antiscorbutic properties, occurred on all three groups, especially Kerguelen, where it grew abundantly in damp situations which were free from rabbits and sheltered from the violent winds. Wild burnet, or Acaena, was found on the Crozets,. and was extremely common on where it was the dominant plant at medium and low elevations, such a condition being due, at least 111 part, to the influence of the introduced rabbit, which has upset the natural plant balance so as to favour the hardy, less palatable burnet. The latter has practically taken possession of large areas, though a species of ranunculus and a few other plants grow under the shelter it affords. Characteristic of these sub-Antarctic island? arc the absence, of trees and shrubs, and the tendency of many, plants to form dense cushions or mats as a response to Ihe influence of high winds. Tho most striking in this respect are azorella and certain rather large mosses, in tho shelter of which a few other species are able to maintain themselves. Australian and African Sectors. Mosses were abundant on the three groups, while liverworts or hepatics wero common in very damp situations, except on Heard Island. A small, hardy fern occurred on all three groups, while a second more delicate species'was found on the Crozets and Kerguelen. Fungi were uncommon, while lichens, mostly of the encrusting type, were very abundant on rocks 011 all the islands, and ranged in distribution from sea level to the highest elevations visited. Some of them were brightly coloured, orange, creamy, pinkish, etc. 'lulled lichens occurred in quantity on windswept rocks in the bleakest situations. Tho bogs and streams were found to contain abundant Jowly plants, many of them microscopic algae and diatoms. Peaty formations were common. Sixty degrees south is generally taken as the northern limit of the Antarctic. Two flowering plants, several hepatics and a fungus, together with many mosses and lichens, are known from the American sector, which includes the South Orkneys as well as Graham's Land. In the Aus- . Lralian sector only lichens and a few mosses have been found, their number being less in the more westerly portion, which was investigated by the German South Polar (Gauss) Expedition and by tho former Australasian Expedition. . The only rocky land surface in the: African sector which we had an opportunity to examine was found to bo destitute of land plants, except a microscopic '-j snecics of aiqa which occurred under damp rocks and gave a greenish tinge t<> ihe small amount- of soil which was afue to \ cpiicct in such situations.