THE EEL

Manawatu Herald, Volume XLVIII, Issue 3009, 11 March 1926, Page 4

THE EEL

ITS MIGRATION TO THE SEA,

['By W. 8., Otorohanga, New Zealand Herald.]

The visit of the Danish scientist, Dr. Schmidt, to the Western Pacific to investigate the habits of the eel reminds me —a layman —of my own study of that tish. As is well known, v it formed an important flesh food for the Maori, who, aware of its migration seasons, built permanent extensive weirs to capture it.

It was the principal flesh food of the Moriori on the Chatham Islands, who also knew of its migratory habits and watched for them. The centre of the main island is covered by a lake of brackish water with only one outlet to the sea ; said outlet is subject to a sand-bar barrage which if not artificially opened may remain closed for several years. When an opening was scoured, the high tide flowed in till lake and tide were level. While the barrage remained, and at the migratory season (March-April), an easterly gale sent an over-wash across it; the eels, awaiting that over-wash, leapt into it by that means to attain a floatage to the sea. This, the observant Moriori, when “K’ye” (food) lay in the scale, utilised by stretching a net across the barrage, which permitted the passing of the over-wash, but retained any eels which might essay to cross.

This right of capture belonged only to the elan who owned that section of the island, or to such persons as those owners might permit. As firewood was scarce, and a kind of heath abundant, and thus cooking became a matter of inventive search, the Moriori availed himself of partial decay in eels, fish, cray, etc., to soften these foods, and steeped his captures in fresh water —stagnant, if possible —till they acquired the ammoniacal odour so fragrant to his taste; and, if eels, held by the head, and slid through the other closed hand the skin stripped off, and left the earcase clean and white, he heated the same over a heath or grass blaze, and thus prepared a meal to his ineffable content. Eels so steeped, air desiccated, and peatsmoulder cooked, wood-hard, and stored; but soaked for use, provided a staple ration for the winter months. But this is by the way. X MAORI CLASSIFICATION. The Maori, on his arrival there, disregarding the, to him, unpronouncable Moriori names, classified the eels into five varieties and a nomenclature of his own: “Kokopu,” the largest and rarest weighing up to JO-401b.; the “whaka-ahu,” the most common, light-brown with dir-ty-yellow undersides; the “ngehu,” bluish-brown, a mud burrower, the “tuna-whenua,” denizen of the brackish lake, light-brown with dir-ty-white underside; the “tuna Morion,” also of that lake, goldenbrown with silver-white underside, the smallest of the larger eels, 1820ins. —rather rare, confined to only certain parts of the lake, small, nandsome, almost transparent head, delicate of flavour, always reserved by the Moriori as a delicatessen pie„e for the chief or honoured visitor.

Besides these a very small eel i'rora 8-12 ins., dark-brown, inhabiting peat-stained inland waterholes, distant and absolutely abcised from .lie sea by means of streams, had no distinctive name, but simply “tuna”; considered “kawa” (unsavoury), and the primordial ancestor of eels spontaneously generated from the mud —as were all eels —but as these never exceeded their puny size they were given the primacy. They had also the “piharau” (hundred-gilled —lamprey) of the streams, migrating to and from the sea; also the “tchur” (Maori, translated to “luere” —sea-lamprey, colloqually “blind eel”), the only fish name to my knowledge that the Maori adopted from the Moriori. In those meridians also flourished the “Ivoiro” (conger eel), but though commonly called eels, the latter two confined solely to the sea, of course, have a biologic definition of their own. THEORY AND OBSERVATION. The Danish scientist’s theory that eels travel thousands of miles to a prevised destination, there to spawn and die, and that this migration there is impelled by some virtue of those regions to fertilise the ova or spawn; and further, that the tender elvers return over the same route and distance back to their parents’ home, seems, fr.om my own observation, somewhat doubtful for acceptance, for these reasons: — ’ I have known our brackish lake to be barraged from access to the sea for eight years. That lake is cov creel, some quarter of a mile wide, with a belt of lake grass between which and the shore a space of uncovered clear water shows a sandy bottom, perhaps 10ft. wide. Riding along the lake margin one day before the end of the eight years’ lake closure to the sea, 1 saw a moving object like a monster eel, some 12ft long, which, on alighting, inspection and scooping up a handful, 1 found to be a ribbon of closely packed, in aligned formation, travelling elvers, from a horsehair thickness to a darning needle size and length. If now, eels must reach the sea to spawn fertilised ova, and nowhere else, where were these elvers born? Were they eight years old? Could in any case, these tender fragile creatures live through a never-ceasing heavy churn of thrashing surf which beats high tide and low, calm and storm upon that shore, including the lake outlet to the sea, on their return from where they were born? THE PROBLEM. So far the general conclusion ar-

rived at by investigators seems to be that sea water is necessary that eel spawn be fertilised, or, at any rate, conduces thereto. As already mentioned that the eel endeavoured for some reason unknown to them, to reach the sea, was evident to such unscientific observers as the Maori and Moriori. If, then, a fertilising purpose was the eels urged to the sea, where were the eels fertilised whose elvers I saw absolutely barraged there from eight years. Is brackish water sufficiently salt, does it contain the virtues necessary to attain the .desired result? This aspect of the research is of coterminous importance. The Chatham Island brackish lake eel tenancy, despite a many centuries’ depletion, was inexhaustible. Tradition avers that log canoes dotted those lakegrass boarders: “mete taunga pokai parera!” (like alighted coveys of wild duck), in thundery or foggy weather, when the eels rose to feed on the small kidney-bean shapped mussel that grew on the lake-grass haulms, and the fisher hooked them in with his bone-barbed gaff, up to his “fingers and toes twice told” in numbers—that was the furthest he could count

Tradition further avers that the closure of the outlet was frequent, of long duration and much desired, for then the eel could only migrate to be caught in his retaining net while he stood by to gather in. . If, again the lake contained all fertilis'ing virtues, what did the eels desire to reach the sea for? And, if Doctor Schmidt’s researches have definitely established, as a fact that eels must reach a select meridian or remain infertile, the fecundity of ccitain Chatham Island eels—absolutely debarred by distance and other obstacles from contact with the sea forces the conviction that sea-watet fertilisation must apply to certain species only, and .cannot be for all. Also, further, that the Pacific Ocean too has somewhere an eel-fertilising spot which it is apparently the doctor's purpose to locate. Reviewing all the pros and eons., this matter is an unclosed question still 0 Moriori biologist, almost persuadest thou me that eels are spontaneously generated from some property of mud!