The Spike [: or, Victoria University College Review 1957]
V.U.C.Z. Collection No. 85 Cook Strait
V.U.C.Z. Collection No. 85 Cook Strait
[The following account of Zoology Department dredging in Cook Strait is included in the symposium as a notable example of the various field studies being carried out by V.U.C. Departments."—Editor.]
Collection No. 84 had just come on board. It is impossible to count the hours spent at sea in boisterous or (rarely) calm Cook Strait to make these 84 collections. Each meant paying out wire or hempline seldom less than 500 fathoms, usually 1000 fathoms and more. This cost twenty to forty minutes. Then the long, slow patient wait of an hour, two hours, five hours, riding to the swell, and rolling broadside for as long or longer while gear was tediously brought back to the boat. Thirteen hours' rolling broadside is our record to date for one collection. On that occasion it took an hour to recover the first 60 fathoms with 1440 fathoms still to come. There can be no record now of time spent, but in each of those eighty-four collections we hoped to find in our beam-trawl, cone-net, dredge or on the set-line, the animals which proved we had reached our objective.
The objective was set some sixteen years ago when I examined the food that groper had been eating in 40 to 50 fathoms off Cape Palliser. The food proved rich in deepwater fish, prawns and other animals known elsewhere from 400 fathoms and more. The chart then available was based on soundings by H.M.S. Acheron in the middle of the last century, and gave soundings to only 100 fathoms. The food and other vague data suggested that a branch of the Great Kermadec Deep came south to the Cape and entered Palliser Bay and the Strait. It was then a fair assumption that deep water welled up near Cape Palliser bringing a rare fauna to the surface, as in the famous case of the Straits of Messina.
Not until 1952 was a boat available. Mr. J. Garrick, of the Zoology staff, who had been out often on large trawlers, led the first attempt, working gear down to some 100 fathoms from the small trawler Retina. R. Brunsdon and R. Barwick, research students, made another attempt. They showed deeper fishing was necessary. Although catches were rich in new and rare animals, none of the hoped-for animals were taken.
Then came the tedious haul after haul, each a testing out of new gear and technique. Collection 84 came on board in the early evening of Good Friday last. Eight of us had joined the skipper, A. Dickinson, and his crew of two, on the Admiral, the 48-foot Wellington commercial trawler, at 9.00 a.m. Shortly after 11.00 a.m. we had put 1350 fathoms of wire on the winch and were heading for Palliser Bay on a long but disturbing swell, trying to squeeze in a trip before a promised northerly hit the Strait.
Two six-foot cone-nets, each 18 feet long, and a three-foot cone went overboard on 1300 fathoms of wire when we crossed the 500 fathom line south-west of page 31 the Cape at about 3.00 p.m. An hour later the wire was at maximum angle, indicating greatest depth. A quiet tow for an hour, and then 80 minutes' anxious hauling before the gear came on board, with Collection 84, monotonously much as we had made before"—even though new planning had gone into the making and working of gear.
No option then but to put over the 12-foot cone-net with its 36-foot long bag of nylon net, a big investment to have on the end of a wire no stronger at its slender part than 1.1 tons and here no thicker than a good grade of clothesline. By now we were over the 1000 and more fathom plateau shown by H.M.S. Lachlan in her post-war survey. The swell was easing away, but not enough for some of the students. Setting the great net to the wire was anxious; streaming it, a problem; but it went away perfectly. Then twenty minutes to run out the wire, and a monotonous hour at idling revolutions watching the wire sink to its full angle before starting the work of the tow.
The sky cleared to brilliant starlight as we moved south with the Palliser light sinking to the horizon. An hour later, towing speed was increased; half an hour, increased again; and half an hour later, raised to near three and a half knots. This last changed the angle of the wire. The net was now working obliquely to the surface, but still deep and fishing from 600 fathoms up to 400 fathoms. Then started the long recovery with anxiety each time the train of shackles and swivel at every 250 fathoms came up to the blocks which always creaked painfully under the load.
The last hundred fathoms were, as on any of the previous 84 collections, worse than anxious. Twice gear has been lost as near the boat as this. Then came the net, a perfect set. None too sick to lend a hand to bring it in or search it. Here was Collection 85, everything hoped for since 1941, and better.
This catch contained not just midwater animals, but big midwater animals. Our objective over the years had moved from simply catching such animals, to using our unique proximity to deep water in the task of improving technique to capture these animals at their full size. The bulk of knowledge of this cosmopolitan but remote fauna is based on small young specimens. Now, where so many zoologists know the snake-like Idiacanthus from specimens only four inches or so long, our net gave us a specimen 17 1/2 inches long; Avocettina, snipe-eels, 17 to 23 inches long; a Gonostoma of 7 1/2 inches; brilliant lantern fish; a rare deepwater squid 8 inches long; and so on, for the whole catch of many species. All are animals of full size.
Away went the gear again, and in the early hours of the morning we recovered a second haul, and as good; but under the towing strain the frame of one inch steel rod had started to warp. It still held the mouth open and was sent away again as we turned to a northerly course. At 8.00 a.m. I was called to the deck. John Yaldwyn was worried. The net was towing heavy. The Admiral had been stopped. Recovery was under way at minimum winch speed. Palliser lighthouse was high on the horizon and it seemed the net had hit bottom in some 500 fathoms.
The wire came in to the final hundred fathoms. As the shackle-train passed the last deck-block, the wire jammed, then broke. Smart work by the skipper and Peter Castle secured the end and cleared the wire. Soon we saw the grotesquely twisted frame and torn bag of the net and then the gear was on board. The net page 32 had bottomed, but the mud gave Professor Fell a new and strange starfish; Miss Ralph, coral and hydroids; John Yaldwyn, a deepwater hermit crab new to us; Jack Garrick and myself, new bottom-fish. The mud goes to the Oceanographic Institute. Collection 87 is well worth while, as is any collection from this deep water wonderland at our front door.
Two in the afternoon we set unsteady feet on Queen's Wharf and transferred our activities to the more stable environment of the laboratory. All are glad to have Collections 87, 86, 85, 84 in jars; another 320 man-hours at sea behind us.
But what will Collection 88 give us, and cost us And how soon before we have it in the jars?
L. R. Richardson