Oceanography of The New Zealand Seas
If New Zealand's field of oceanographical interests be taken to be congruent with its political boundaries which reach as far north as the mandated territory of Samoa and as far south as the coasts of the Ross Dependency, it will cover a vast expanse of ocean roughly 4,000 miles long from north to south and about
2,000 miles wide from east to west: an area bounded on the north by Latitude 13° S. and on the south by Latitude 80° S., on the west by Longitude 160° E. and on the east by Longitude 160° W. This comprises the eastern half of the Tasman Sea and an appreciable portion of the South-West Pacific Ocean.
From its geographical position, remote from the great centres of civilization, and from its small population whose economic interests are directly or indirectly concerned almost entirely with agricultural products, this Dominion's participation in oceanographical research up to the present time has been negligible, at least so far as the open seas are concerned.
As an official adviser on fisheries administration, the present writer's interest in oceanographical phenomena turns mainly upon their importance as factors affecting our fish supplies. The correlations are not likely to be simple and so far very little detailed light has been thrown upon the relationship between our fish stocks and the physico-biological character of their habitat. It may, however, be taken as an established fact that the hydrological and marine biological conditions in the seas adjacent to these islands are very largely governed by the character and origin of the ocean masses of which they form part. It thus follows that the origins of our fishery-oceanographical relationships must be sought at ocean-wide distances from our own shores.
New Zealand is placed by its geographical position in the path of three distinct major movements of ocean water-masses. Its northern extremity lies in the track of the westward-moving South Equatorial Stream, part of which goes past the North Cape to impinge on the east coast of Australia to form the East Australian Current which eddies around the Tasman Sea and flows from south to north along the western coasts of both South and North Islands. Another part of the South Equatorial Stream is diverted southward and eastward off the east coast of North Island until, in the zone lying eastward of Cook Strait, it meets the stream which, originating in the Antarctic Ocean, has washed the south-eastern and eastern coast of the South Island. There is thus to the eastward of Cook Strait and to a less extent off the south-west end of South Island an intermingling of waters which are respectively of tropical and antarctic origin. The hydrological character of these two water-masses differs not only as to temperature but also as to salinity and concentration of other mineral salts. The related differences of flora and fauna must be of appreciable degree both qualitatively and quantitatively, but so far as observations by New Zealand workers are concerned no comprehensive data have yet been collected, to elucidate such relationships.
The distribution of fish species, mainly those of commercial importance, and of inshore and littoral species of mollusca and crustacea, however, has become fairly well known, and will be further discussed later. For all oceanographical data relating to the open seas in the region above defined, we are indebted to the reports on expeditions made by ships from the Northern Hemisphere. In this paper, which is being prepared at short notice and without access to the more recent literature, one can only refer to the broad facts of the oceanography of the region as elucidated by these expeditions.
The earliest soundings in the coastal waters of New Zealand were made by Captain Cook's Endeavour in 1769. The depths shown in current Admiralty charts were obtained by H.M. ships Acheron (1849–51), Pandora (1853–55) and Pengum (1904). Special local surveys for harbour navigation have subsequently been made. In June, 1937, H.M. Admiralty Survey ship Endeavour arrived in New Zealand and commenced the task of making a re-survey of the New Zealand coastline, but her operations were discontinued on the outbreak of war in 1939. By the use of echo-sounding apparatus the collection of bottom-contour data has been greatly accelerated and extended in the last twenty years. The Bear of Oakland ran contours from Tahiti to New Zealand, from New Zealand to Easter Island, from New Zealand to the Bay of Whales and took soundings in the Ross Sea, the results of which were embodied in a report by Roos in 1937. On her Pacific cruise in 1929 the Dana took soundings with hydrological and plankton observations at stations along the following lines: Auckland to East Cape and thence southward between the meridians of 178° and 179° E. Longitude to Latitude 47° S.; thence westward towards the Otago coast to 175° E. and thence in a northerly direction to Cook Strait; thence northerly past Cape-Egmont to Cape Maria van Diemen; and thence across the Tasman Sea to
Newcastle, New South Wales. Discovery II, in her voyages between 1929 and 1939, worked lines of stations on six different courses to the Ross Sea sector of the Southern Ocean and circumnavigated these islands besides making one run off the East Coast of North Island from Auckland to Wellington on which dredge samples were taken in addition to the routine hydrological and plankton observations. The information obtained from these expeditions is of considerable interest and has thrown important light on the universal obscurity that previously prevailed, but there are many voids remaining to be filled. Dr. T. Wayland Vaughan's statement that “the South Pacific is the least known of the great oceanic areas,” made as recently as 1938, still stands as a challenge.
The general character of the sea-bottom contours in the New Zealand region may be pictured as dominated by the following broad features: to the southwest is the Tasman Basin between New Zealand and Australia, with maximum depths exceeding 5,000 meters; to the south-east is the deep area formed by the South Pacific Basin containing depths of over 6,000 meters and connecting with the Tasman Basin by a trough to the westward. To the north-west of this basin is the platform on which the islands forming New Zealand stand; this has an eastern extension from the extremity of which rise the Chatham Islands group situated 300 miles east from the South Island. On the northern side of this relatively shallow area is a trough coinciding with the deep channel of Cook Strait.
Depth data for the vicinity of the New Zealand coasts are receiving progressive additions from the work of such units as the Government steamship Matai, the lighthouse service steamer operated by the Marine Department, by the submarine-cable ships and other craft. An interesting case of an addition to our knowledge of the bottom contours is that of the discovery of the “Mernoo Bank” which was fortuitously made by s.s. Mernoo when, approaching the New coast in thick weather and therefore taking precautionary soundings, she came upon one of 32 fathoms (59 m.). According to the existing Admiralty chart, this indicated close and even dangerous proximity to land. The captain therefore ordered the anchor to be dropped and waited for daylight, but when this came it was evident that no land was in sight. Thus they came upon a previously unknown shoal surrounding by depths exceeding 200 fathoms. The locality was subsequently surveyed by s.s. Matai and, although the bank (situated between 43° 10′ and 43° 35′ S. and on both sides of Longitude 176° E.) could not be completely demarcated, it was found to cover an area of about 400 square seamiles, shoaling at one place to 21 fathoms. The discovery of most promising practical interest was that the bank apparently carried a good stock of commercially valuable fishes—a virgin fishing ground at a distance of 90 miles from the east coast of South Island. Uncharted pinnacles rising from the depths of Cook Strait have also been located by fishermen. The circum-island platform on which New Zealand stands, with the exception of the already mentioned eastern extension to the Chatham Islands, is relatively narrow and at no point is the distance from the coast to the 100-fathom line very considerable. This has a limiting effect on the area of offshore fishing-ground available.
Dynamical. The mass movements of the ocean waters surrounding New Zealand have already been indicated so far as surface streams or currents are concerned. Coastal currents are influenced to a varying extent by the effects of tidal streams and winds, and abnormal variations have occasionally involved difficulties and disasters to navigators. They also have a bearing on biological conditions. Some of the most obvious, or most appreciated, examples of this are the effects on fish propagation, to which further reference may be made later. So far as they are of interest to navigators the nature of surface movements is described in the Admiralty Pilots relating to the several portions of the region. The elucidation of the more fundamental aspects of ocean dynamics has come from the observations made on the research vessels Dana and Discovery II on their cruises in the New Zealand region, to which reference has been made. “Stations” were “worked” at intervals along their courses on a systematic plan. Data as to depth and as to temperature, salinity, phosphate concentration and pH of the water at selected depths have thus been obtained by the staff of Discovery II for all her “stations,” with determinations of oxygen and nitrate at less numerous points. In her later voyages silica and nitrite content of water samples were also determined. Similar examinations were made by the Dana's scientists.
From such data it has been possible to determine the direction of currents in different horizontal strata. These are well indicated by sectional diagrams of isotherms and isohalines given in the hydrological reports of the Discovery Committee. It is from this work that all our knowledge of the character and movement of the ocean water-masses which occur in this region has been obtained. The main features have been described in the Reports of the Discovery Committee, and such data have also been embodied in Schott's general account of the hydrology of the Pacific Ocean. The outstanding facts elucidated by the work of Discovery II relate to the character and movement of Antarctic water. More detailed information has been gathered in respect of the South Atlantic Section, the South Pacific Section of the Southern Ocean having so far provided a less complete picture. The bottom contours of the oceans are considered to have a profound effect on water movement, but there are large gaps in our knowledge of the relief of the bed of the South Pacific. It is clear, however, that the water circulation in southern latitudes has the same general character in all three ocean sectors, in all parts of the Southern Ocean. Three distinct depth strata have been shown to occur: a cold surface current of low salinity moving northward and eastward, a cold saline north-going current moving along the bottom, and a warm intermediate layer of higher salinity forming a current which moves in a southerly direction. As more northerly latitudes are reached the depth relationships between these layers undergo changes and the phenomena of sinking and upwelling, the locations of which are designated as “convergences” by the hydrologists of Discovery II, have been noted as conspicuous features in the Southern Ocean. Such convergences are demonstrated as lines of abrupt change in hydrological conditions and have been shown to act as effective barriers to the distribution of many plankton organisms. They are formed where cold surface water of low salinity flowing northward and eastward from the Antarctic meets warmer and more saline water of tropical origin from the north. An Antarctic convergence and a sub-Antarctic convergence have been roughly demarcated as a result of the work of Discovery II. It is evident that their location will be subject to seasonal and annual variation and that the seas off the coasts of New Zealand will be influenced as to both physical and biological factors by these oceanic phenomena.
Physical. It is noteworthy that New Zealand lies in the zone, or within the contours, of maximal seasonal variation in the temperature of surface water for the South Pacific, which is 6° C. The 5° contour approaches close to the southern half of the South Island and the 4° contour is not far distant on the eastern side, but is remote from the West Coast.
A general idea of surface temperature conditions and of their normal seasonal variations is obtained by considering isotherm contours. For the month of maximal warmth (February), New Zealand lies between the isotherms of 20° C. to the north and 15° C. to the south, with an appreciable degree of southward shift for the Tasman Sea waters. The 10° C. isotherm passes through the Auckland Islands.
In August, the month of minimal surface temperatures, the 15° C. isotherm passes to the northward of North Cape and the 10° C. isotherm touches the middle of the east coast of South Island, with a southward displacement on the West Coast. The 5° C. isotherm passes in proximity to the Auckland Islands.
The general trend of surface salinities for winter is shown as follows: 35.0%o–35.5%o, off east coast of North Island.
34.5%o–35.0%o, eastward of Cook Strait and of East Coast of South Island down to Banks Peninsula.
off whole West Coast from North Cape to the southerly extremity of South Island.
34.0%o–34.5%o, off east coast from Banks Peninsula southwards to Auckland and Campbell Islands and south of S.W. extremity of South Island.
The above indicates the broad aspect of the sea-surface conditions as they affect the coastal waters of New Zealand. The degree of variation to which they are liable is shown by records of the occurrence of ice which had drifted from the Antarctic as far north as the Chatham Islands, abreast of Canterbury, in the years 1855, 1883 and 1892. Such variations must have an important bearing
on the distribution of plankton organisms and the associated phenomena of whale migration and the distribution of fishes. The possibility of forecasting these conditions by long-period studies of the hydrological conditions in the southern ocean is thus a question of more than academic interest.
Up to the present the contributions of New Zealand workers to hydrological data have been made in very limited fields, and for the most part remain unpublished. Surface temperature records from the logs of certain ships are available and some of them have been collected, e.g., from some of H.M.N.Z. naval vessels and the Government steamer Matai, for the purpose of obtaining monthly means, but the readings were too irregularly distributed in space and time to give very significant results. In connection with the study of the natural history of commercially important fishes and molluscs, the marine biologist on the staff of the Marine Department has from time to time recorded water temperatures and taken water samples for estimations of salinity and other solutes in the inshore waters. As there is no hydrological specialist in New Zealand, these analyses have been made in the laboratories of the Government Analyst. For several years inspectors of fisheries have recorded surface temperatures in the vicinity of the northern rock-oyster beds. From these it is evident that the surface temperatures in shallow bays and harbours are largely influenced by atmospheric conditions.
The following examples are typical of rock-oyster habitats:—
Mean Monthly Surface Temperatures for the Ten Years 1929 to 1939.
|Bay of Islands, off Russell (East Coast).||Kaipara Harbour, Whakapirau Estuary (West Coast).|
Daily readings of surface temperatures in Otago Harbour have been recorded by the Curator of the Marine Station at Portobello.
In connection with the so-called “Cape Expeditions” [observation and communication parties stationed on the normally uninhabited Auckland Islands (166° 12′ E., 50° 32′ S.) and Campbell Islands (169° 8′ E., 52° 33′ S.) as a wartime precaution] a programme of scientific work, mainly biological, was organised under the direction of Dr. Falla, of the Canterbury Museum. Among its fruits are daily records of surface temperatures from 1941 to 1944 for the Auckland Islands and from 1941 to 1946 for the Campbell Islands. In 1944 continuous tidal observations throughout a lunar month were made at Auckland Island.
Information on our marine fauna and flora has been collected over the last hundred years or more by the work of many persons. A bibliographical list would include the following names: Forster, Gray, Quoy et Gaimard, Richardson, Günther and Regan, who described and classified collections brought back from successive exploratory expeditions including those of the Endeavour (1769–79), Astrolabe (1835), Erebus and Terror (1840), Challenger (1872–76), and Terra Nova (1910–11). Prominent among New Zealand names would be Hector, Hutton, Clarke, Waite, Griffin, and Phillips; Chilton (crustacea); Kirk, Suter, Cheeseman, Benham, Finlay, and Powell (mollusca); J. A. Thomson and Percival (brachiopods). Most of their papers have been published in Transaction of the New Zealand Institute (Royal Society of New Zealand since 1934).
Marine algology owes most to the assiduous labours of Laing, with additions in recent years by Moore and Cresswell.
Substantial additions to knowledge of littoral and sub-littoral species were made by Mortensen's Pacific Expedition, 1914–16, in which extensive collections were made in the vicinity of the coasts of New Zealand and of the Auckland and Campbell Islands, the various groups of which have been the subject of papers written by Professor Mortensen himself and by numerous specialists over the subsequent years. The most interesting general result of this expedition would appear to be the evidence for connecting the marine fauna of these so-called Sub-antarctic-island areas with the biological regions of New Zealand and Australia rather than with the littoral and sub-littoral faunas in the same latitudes to the eastward.
An outstanding effort by New Zealand naturalists was the expedition to the Auckland and Campbell Islands in 1907 under the auspices of the New Zealand Institute, the marine biological results of which were reported on by Waite (fishes), Suter (mollusca), Chilton (crustacea), Benham (annelida), Dendy (holothuria), H. B. Kirk (hydroids), and Chapman (foraminifera).
Young (1929) has described the marine fauna of the Chatham Islands.
Ecological surveys have received little attention up to the present, and much remains to be done in this field. Oliver (1923) has made local studies of littoral plant and animal communities. Powell (1937) has made a faunistic survey of the benthos of Auckland and Manukau Harbours.
The check placed by the recent war upon all research activities, except those directly connected with the production of munitions or food supplies, has been attended by one noteworthy exception in the case of the “Cape” expeditions mentioned above in connection with hydrology. Besides affording the opportunity for making daily observations of surface temperatures in the vicinity of our southern islands, the whole year's sojourn enabled one young science graduate who was stationed on Auckland Island, with the assistance of other members of the party, to make observations and collections over a twelve-month period of the land and fresh-water flora and fauna, but more particularly of the marine organisms. Shore collecting and dredging were carried on and plankton collections were made by a series of tow-nettings. The bulk of the collected material has yet to be examined. In a general interim report it is stated that the vertebrates that appeared to occur in greatest abundance were birds and Pinnipedia. Marine fishes appeared to be scarce, Nothothenia sp. (all specimens of which were found when examined to be infested by nematode parasites encysted in the muscle tissue), Tripterygium sp. and a small pilchard-like fish were the only species obtained.
Very interesting evidence on the specific feeding habits of birds and seals was obtained, and the relative scarcity of fish in the stomachs of birds—with the exception of two species of terns that fed almost exclusively on the small clupeids, and the Auckland Island shag and mutton-birds, whose stomachs were found to contain a few of these fish among other food—reflects and corroborates the paucity recorded by the observers. Squid is stated to be the most important food organism in the area for marine vertebrates, providing almost the entire dietary of the albatrosses, mollymawks, cape-hens, white-headed petrels, and part of the food of mutton birds. Squids are also eaten by sea-leopards (Hydrurga leptonyx) and for the greater part of the year form the principal food of the hair-seals (Otaria hookeri). The most important food-organisms (for vertebrates including fishes) in the Auckland Island waters are stated to be squid (species unnamed), “lobster krill” (Munida subrugosa), prawn-like decapods, amphipods and mysids, and small clupeids. Tow-nettings show that the smaller planktonic animals become fewer in numbers in autumn, are scarce in winter, and increase rapidly after the diatom outburst in spring. Littoral animal associations were studied and endoparasitic organisms (Nematodes, Trematodes, Cestodes and Acanthocephala) from birds, seals and fishes were collected.
Mr. Dawbin's own collections—excluding those that were made by other persons—contained the following phyla, orders and classes. (The figures in brackets represent the number of marine samples collected in which the group occurred):
Coelenterata: Hydrozoa (5), Scyphozoa (6), Actinozoa (6), Ctenophora (2)-
Platyhelminthes: Turbellaria—marine only (6), Trematoda (2), Cestoda (17), Acanthocephala (19).
Nematoda: Parasitic (38), free-living (2).
Polychaeta (28), Sipunculoidea (4).
Crustacea: Copepoda (45), Cirripedia (9), Leptostraca (1), Mysidacea (numerous observations), Cumacea—first record (1).
Tanaidaceae (2), Isopoda (19), Amphipoda—including developmental stages of Phronima (35), Decapoda—crabs, prawns and “lobster-krill” (27).
Arachnida: Pycnogonida (6).
Mollusca: Amphineura (specimens of several species), Gastropoda (numerous), Nudibranchiata (8), Lamellibranchiata (33), Cephalopoda (7).
Echinodermata: Asteroidea—including developmental stages of Calvasterias laevigata (36), Ophiuroidea (14), Echinoidea (9), Holothuroidea (10).
Chordata: Enteropneusta (1).
Pisces: including fresh-water Galaxiids (8).
The above catalogue-like statement has been given to indicate the amount of recent marine biological data and material that are available to amplify the results of Mortensen's investigations. It will also show that the Dominion has young potential marine biologists capable of doing good work when the opportunity offers. Records of considerable interest were also made from observations on the distribution and habits of the birds and seals of these southern islands in which various members of the island parties collaborated with Dr. Falla, who is preparing reports on these classes.
On account of their commercial importance, the marine fishes of New Zealand have been the object of the most substantial and continuously sustained collecting efforts, and they thus constitute the class of which the life histories and distribution are most fully, though by no means completely, known. As might be expected from the geographical position of New Zealand in relation to the peripheral hydrological features to which reference has been made, there is considerable variety in our marine fish fauna. It has tropical and sub-tropical forms such as the larger sharks (Cephaloscyllium, Sphyrna, Alopias, Cetorhinus, Carcharodon, Galeccerda), the marlins (Makaira), with an occasional sword-fish (Xiphias), flying-fish (Evolantia, Cypselurus), and sun-fish (Mola), besides species common to eastern Australian waters such as snapper (Pagrosomu auratus), Kahawai (Arripis trutta), garfish (Hemirhamphus intermedius) and certain dogfish and ray species; and quite distinct from these are characteristically sub-antarctic fishes including the ling (Genypterus blacodes), hake (Merluccius gayi), elephant-fish (Collorhynchus millii), apparently identical with species that occur in abundance off the coast of Chile. Similar relationships appear to be shown in respect of mollusca, crustacea and other invertebrates.
Up to the time of the trawling investigations made by the S.T. Nora Niven, chartered by the New Zealand Government with a view to assisting and stimulating commercial fishing, in 1907–8, ichthyologists had depended for their material on casually collected individual specimens. The Nora Niven's collections of fishes were examined and described by Waite, mollusca by Suter, annelida, etc., by Benham, crustacea by Chilton, and algae by Laing. Waite's reports represent the most complete and comprehensive monograph on New Zealand ichthyology yet published, adding considerably to the earlier work of Hector and Hutton. No comprehensive work on New Zealand fishes has since been published. A useful bibliography was compiled by W. J. Phillipps, of the Dominion Museum, and published by the Marine Department as Fisheries Bulletin No. 1 in 1927. Suter's Manual of the Mollusca of New Zealand is still the most comprehensive and authoritative work on this class, but requires up-to-date revision. Powell's Handbook contains an augmented list of species with revised nomenclature
together with a popular account of some of the more important families. No comprehensive monograph on crustacea has yet been written to succeed Miers' Catalogue of New Zealand Crustacea (1876).
Information regarding the fishes, molluscs and crustacea of economic importance is given in the Annual Reports of the Fisheries Branch of the Marine Department, of which the statistical statements throw light on the relative abundance and distribution of the various species. As appendices to these departmental publications are the annual reports of the Chairman of the Board of the Portobello Marine Fish Hatchery and Biological Station describing the nature of the work carried out and the observations made on the marine fauna of Otago Harbour.
Existing Agencies for Marine Biological Research.
The work done by New Zealanders, to which brief reference has been made, has been largely carried out under the auspices of the following institutions: the Dominion Museum at Wellington, the Provincial Museums at Auckland, Christchurch and Dunedin, and the Biological Departments of the four University Colleges. The staffs of all these institutions have always been handicapped in their research work by pressure of other duties and by very limited funds. The Royal Society of New Zealand, formerly the New Zealand Institute, from time to time makes small sums available as grants-in-aid to individual research workers.
The only institution in the Dominion which could be described as concerned entirely with marine biological research is the Portobello Marine Fish Hatchery and Biological Station, situated on the shore of Otago Harbour a few miles from the City of Dunedin. Unfortunately, this station was established, as one might almost say, under false pretences. Its construction was financed by a Government grant, made through the Marine Department (under a Section of the Fisheries Act which provided for the establishment of fish hatcheries), together with smaller contributions from Acclimatisation Societies and the Dunedin branch of the New Zealand Institute, on the grounds that by means of such a station it would be possible to acclimatise valuable commercial fishes from the Northern Hemisphere and to augment our indigenous food fishes by means of artificial propagation. That was at the beginning of this century when the facts of marine ecology had been little elucidated, and New Zealanders were not alone in failing to realise the impracticability of increasing the fish stocks of the open sea by artificial hatchery operations; nor did those enterprising and wishful-thinking pioneers recognise that an Atlantic species, whose propagation rate is normally exiguous on account of the high degree of mortality sustained by its pelagic embryonic and larval stages, and that is subject to a fine degree of correlation between spawning and hydrological factors in its environment, would stand a very remote chance of establishing itself in New Zealand seas. The present-day commonplace facts of marine ecology were still unknown. At the modest cost of £1,500 the station, comprising an aquarium, small laboratory, artificial ponds, and curator's cottage, was completed in 1904. During the next ten years 100 lobsters, 195 young turbots and 16 crabs were successfully shipped from England and established in the sea-water ponds at Portobello as a breeding stock. An attempt to bring out herring ova failed. It was demonstrated that turbot and lobsters could be kept and fed in captivity. Some of the lobsters grew to maturity and spawned, but, as we should expect with our present-day knowledge, nothing came of the liberations of their young progeny or of the adult turbots in the open sea. There was nothing lacking in the zeal or the resourcefulness and assiduity of the staff and the board of management in their attempts to achieve the impossible. Meanwhile, under the inspiration and with the active collaboration of the Chairman of the Board (the Hon. G. M. Thomson) and Dr. Benham, Professor of Biology in the University of Otago, good progress was made in biological work. This was mainly in faunistic studies and in the investigation of the life history and reproduction of the food fishes on the lines that had been followed by Mackintosh at St. Andrews and Cunningham at Plymouth. The results were published in G. M. Thomson's History of the Portobello Station and in papers in Transaction of the New Zealand Institute. The small aquarium, thanks to its excellent water supply from Otago Harbour (which may be more aptly described as a fiord, sound or loch), was and still is a very succesful feature of the station. Its usefulness to the public is limited by its distance from the city, involving a journey of about half an hour by railway and a crossing of the harbour by boat from Port Chalmers. The modestly
equipped laboratory has been continuously available for marine biological workers and has been utilised by zoologists from the University Colleges of Dunedin and Christchurch, but there has never been sufficient financial provision for an adequate permanent staff working under professionally qualified scientific direction. The institution was only barely saved from extinction during the financial depression in the early 'thirties; up to which time it had operated with an annual Government grant of £700. The grant was than reduced to £300 per annum —a bare maintenance allowance which reduced research possibilities to a minimum. Meanwhile a project (from an unofficial source, be it said) for establishing an aquarium and biological station at Wellington had been submitted to Government at the time when plans for the Centennial Exhibition of 1939 were being considered. Nothing has yet come of this proposal. The Minister of Marine (now Prime Minister) promised that the Portobello Station would be “kept going” until some similar but more centrally situated institution was established. During the war years the state of almost suspended animation has been inevitably prolonged. At the time of writing it may be said that a state of crisis has been reached. The adverse factors in the situation are that the working plant is old and in a condition of disrepair which calls for early renovation, that the experienced and conscientiously competent curator (Mr. W. Adams) has just retired, and the Secretary-Treasurer of the Board (Mr. G. Howes), who had managed its business affairs and supervised the station activities through many difficult years, has quite recently and suddenly died.
In earlier years claims were made for Government support for the Portobello Station on the grounds that it could serve a useful if not an essentially necessary purpose as a fishery investigation station. This was only true in a limited and local sense and at the time when the Marine Department had made no provision for the scientific investigation of any fishery problem. In the year 1927 the Fisheries Branch of the Department had acquired the services of a marine biologist in the person of Mr. M. W. Young, who had been marine biologist at Portobello and who remained stationed there for a time before transfer to departmental headquarters at Wellington. The time had arrived when it had to be recognised that a basis of biological fact was essential for the proper understanding of the problems of fishery administration. The field for the necessary investigation was not in Otago Harbour, however, but in the several areas where the fishing operations were carried on. The most urgent problems were in the Auckland province in connection with the Hauraki Gulf snapper and flounder fisheries. In the same province were the rock oyster beds and the principal toherot. (Mesodesma ventricosa) habitats which, next to the Foveaux Strait dredge oyster grounds (on which Mr. Young had charred out preliminary investigations before his transfer to Wellington), were the sources of our most valuable marketable molluses. In 1929. by the courtesy of the late Professor Johs. Schmidt, Mr. Young was enabled to make a passage on the Dana across the Tasman Sea to Australia, which afforded an opportunity for seeing the operations of a modern research vessel and also for studying the rock-oyster fisheries of New South Wales.
In 1936 Mr. Young was succeeded as Marine Biologist by Mr. A M. Rapson, who has since carried out departmental investigations mainly in connection with the distribution and life history of the toheroa and of the more important or more accessible commercial fishes. Statements on the nature and progress of these investigations are given in the departmental Annual Reports on Fisheries. At the invitation of the Discovery Committee, Mr. Rapson was enabled in the period January to June, 1938, to make a voyage in Discovery II to Antarctic waters and thus to obtain a practical training in the biological and hydrological work at sea that is of fundamental importance for fishery investigation as for whaling research.
It is well understood by every experienced investigator of fisheries that, although a complete understanding of ecological factors is ideally desirable, the questions of most urgent and immediate importance are connected with the catching of fish–with the effects of fishing operations on the fish population. Failing the possession of a research vessel equipped with suitable fishing gear, the investigator must do the best he can as a guest aboard a commercial fishing boat. This has been the usual practice for many of our departmental observations. There are. however, definite limits to what can be done when the operational initiative is not with the investigator. More especially in connection with Danish seining investigations and also for other experimental fishery operations
and for a survey of oyster grounds in Foveaux Strait, the Department has periodically chartered a commercial fishing vessel. Such arrangements provide only partial and temporary service. To keep pace with the problems, especially those involved in the task of overtaking, and if possible forestalling, exploitational enterprise and energy with effective conservational measures and guiding fishery developments along rational lines, requires the full-time employment of a fishery-research vessel. In spite of her short history as a Europeanised nation, New Zealand is in no better position than the majority of other nations in the tortoise v. hare sort of race between conservation which tends to limp and the exploitation which progressively tends to accelerate. Our main difficulty has been the prevalence of the idea, encouraged in the past by those whose opinions were regarded as authoritative, that our fisheries resources were well-nigh as limitless as the seas themselves; that they were merely being scratched; that only greater fishing enterprise and energy were necessary to win substantial wealth in providing food for the people and more commodities for export. It has been the task of twenty years to correct that notion and to obtain public and political understanding of the departmental view that New Zealand's fisheries are coastal and mainly inshore; that the stocks are depletable by continuous fishing operations on what would be regarded as a very modest scale in the fishing regions of the Northern Hemisphere.
It is now some years since Government approval for the provision of a fishery investigation vessel was given. The 65 ft. Diesel-engined vessel Ikatere was launched a few days before the outbreak of war and went immediately into service as a very useful naval auxiliary. She is now back and is being fitted out for fishery experimental and investigational work. She calls for notice in this report because she is a material factor of considerable potential importance in relation to the progress of marine biological work in New Zealand waters in the immediate future.
Marine Research for the Post-war Years.
There is no difficulty in formulating a programme for future work. There are gaps to be filled and threads to be picked up in every portion of a vast field, and some portions that are still virtually terra incognita. The problem is to prune down the programme to dimensions that are not too ambitious to be proportionate to this small country's resources and to its other scientific commitments and needs. Proposals that are, so to speak, too academically fundamental are likely to meet with little recognition on the part of the public and the people's representatives in Parliament; and these are the keys to the public purse which must provide the wherewithal for the operation of every item in the programme.
It therefore follows that the proposals that are most likely to be carried into effect are such as can be connected with economic needs, such as fisheries, and practical interests of social significance, such as education. The writer would not, however, have it inferred that he himself does not appreciate the values of every sort of biological fact on which light may be thrown by the individual worker from university or museum. The educational needs of the rising generation demand that such institutions should receive increased recognition and support, and it is considered that they can play their part in a scheme that is primarily based on a “practical” or “applied” research policy.
If one regards New Zealand's interests as covering the 4,000 by 2,000 mile area mentioned at the beginning of this memorandum, one must divide this into (a) an inner (littoral and sub-littoral New Zealand) circle, and (b) an outer (oceanic) circle in considering the geographical field of operations.
is necessarily the field for Dominion national operations:
is necessarily a field that can only be tackled by extra-Dominion-i.e., by international or at least inter-British Empire collaboration.
In regarding the whole question from the point of view of fisheries problems it follows from what has gone before that the elucidation of the more immediate and urgent practical problems must be sought in area (a). The long-term investigations likely to throw the ultimate light on our “inner circle” conditions must range into the “outer circle” of field (b).
Owing to limitations of space, Mr. Hefford's recommendations are not included.–Editor.]