During the meeting in January, 1904, of the Australasian Association for the Advancement of Science, at Dunedin, a party of the assembled zoologists proposed to attempt some deep-sea dredging. The project received the cordial sympathy of the President, Professor T.W.E. David, F.R.S., who referred to it in his presidential address.
To Professor Benham, Messrs. A. Hamilton, G. M. Thomson, and the writer, the use of a steamer was generously granted by the Dunedin Harbour Board. We gratefully acknowledge also the assistance of the Union Steamship Company of New Zealand, who provided us with deep-sea sounding apparatus, and the services of two of their officers to operate it.
I had brought with me from Sydney several hundred fathoms of wire rope and a dredging-bucket of my own design which had done good service on similar occasions. The latter may be briefly described as a conical bucket, the aperture of which was choked by a movable inverted truncated metal cone, like that fitted to the mouth of a rain-gauge.
The day appointed for the excursion was unfortunately spoilt by rough weather. We spent twelve hours of the 14th January in great discomfort, sounding and dredging about twelve to twenty miles outside Port Chalmers, in from 100 to 300 fathoms. As a result we lost considerable gear, and obtained only a cupful of bottom from 100 fathoms. The bucket dredge appeared to fill properly, and was raised to within a few fathoms of the surface when the line parted. It seemed to be twisted off. This accident I attribute to the want of a swivel link.
A second expedition was later organized in Auckland, where Professor Park, Rev. W. H. Webster, Messrs. H. Suter, R. Murdoch, and C. Cooper joined the writer. The bucket lost off Port Chalmers was replaced by one built by a local tradesman. A serviceable vessel, the “Awarua,” fitted with steam winding-gear, was engaged for the trip.
On passing out to the open sea from the Hauraki Gulf we encountered a heavy swell, and found that the gale which had proved so disastrous to the Dunedin excursion had followed us up the coast. The success ultimately achieved was largely due to a happy suggestion of Mr. Cooper. By his advice we packed a sack with cotton-waste and poured therein a couple of bottles of machine-oil. Trailing this over the ship's side as we drifted, a zone of calm water afforded us protection while we dredged.
The spot selected for operations was in the vicinity of Cuvier Island, east of Great Barrier Island, in S. lat. 36° 8′, E. long. 175° 55′; depth, 110 fathoms. The time, sunrise on the 22nd January, 1904.
At or about the 100-fathom zone the submarine slope here, as elsewhere in New Zealand or East Austraili, suddenly changes to a steeper descent. I have met with no explanation of this phenomenon, and now venture to suggest that this alteration marks the lowest point at which currents have transported material.*
After twenty minutes' winding, the bucket came up full to overflowing with soft, sticky, green mud. A second haul produced similar results. A few echini were entangled in frayed rope-yarn attached to the small end of the bucket.
We returned to Auckland with about a third of a ton of sea-bottom. Mr. Cooper hospitably gave the party the use of his premises. After reserving samples for geological examination, the mud was placed in fine sieves, on which was played the garden-hose. On preliminary examination the mud, which was perhaps coloured by glauconite, showed but few shells; washing yielded about a spoonful of shells to a gallon of mud. An interesting feature is the occurrence of several species, such as Poroleda lanceolata and Loripes concinna, previously only known as Tertiary fossils.
It was resolved by the company that Mr. Suter take charge of the collections and distribute different groups to specialists who might undertake their study, and that types of new species should be ultimately placed in the Colonial Museum.
Under this arrangement the examination of the following Mollusca has been assigned to me. My labours have been much lightened by the kindness of Messrs. Suter and Murdoch, who sorted out the species and assisted me with preliminary determinations.
[Footnote] * Since writing the above I find that Admiral Wharton has already advanced this explanation—“Nature,” 25th February, 1897, p. 392.