TIGERS OF THE SEA.

Waimate Daily Advertiser, Volume XXIII, 16 May 1922, Page 7

TIGERS OF THE SEA.

The following interesting notes on the sharks that prowl around Australian ports and inlets are. supplied by Mr Aidrich, Chief Inspector of Fisheries of West Australia.

Of the many species of sharks frequenting the waters of Australia, the more dangerous to man are undoubtedly the tiger shark (Galeocerdo rayneri), the whaler, sometimes known as river shark (Carcharias brachyurus), the blue pointer (Lamma glauca), the white pointer (Carcharodou carcharias), the wobbegong or carpet shark (Orectolobus barbatus), and the grey nurse (Odontaspis taurus).

Of these “wolves of the sea” the pointers in particular attain huge proportions, and individuals of from twelve to fifteen feet are of common occurrence, but. some of the species reach a much larger size. Generally speaking, however, they frequent the open ocean and, unlike the tiger shark, the whaler, and the grey nurse, are not often met with in the waters of our rivers, inlets, or inshore coastal beaches. The. teeth of Carcharodon are large, flat, regularly triangular, and serrated.

The sharks responsible for the now all-too-numerous bathing fatalities are, in my opinion, the tiger shark and, in a. lesser degree perhaps, the whaler. The first-mentioned powerful and dangerous creature attains a length of sixteen feet or even more, but those more commonly seen range from about nine feet to twelve feet. Even those of the lesser length are undoubtedly dangerous. This species, particularly during the summer months, roams the coastal waters and enters bays, inlets, and rivers of Eastern Australia, seeking what they may devour, even into comparatively shallow water. It is common also in our West and NorthWestern coastal. waters, but fortunately does not appear to ascend the waters of our rivers and inlets. At Shark Bay numerous individuals are to be seen and captured. It has been my lot to capture, by line.-,. a number of these sharks in tire waters of Eastern Australia, among them one which quite a few minutes previously had taken a full-gr-Avn collie dog.

A noticeable feature in the colouration of this shark is that the uniformity of the grey of the sides is broken by bands of darker grey, hence, no doubt, the name of “tiger.” The head, in this species, is much more rounded than in that of the pointer. Its teeth are serrated and oblique, have one large pointed cusp, and have a deep notch in one side.

The whaler, although perhaps not quite so formidable a creature as the tiger shark, is nevertheless . dangerous to man. Like, and frequently in company with, the tiger, it enters the waters of rivers, bays, and inlets seeking food.

fhe grey nurse, although growing to a large size and described as a very formidable shark, is not, in my opinion, so dangerous to surfers and others as the two previously mentioned. . It roves the waters of Australia in numbers, and in Eastern Australia at least enters harbours and bays. In this species the teeth are long, sharp and awl-like, with a small cusp on each side of the base.

The wobbegong or carpet shark, the latter on account of the beautiful carpet-like pattern displayed over the skin, is found in practically all parts of Australia, but, unlike the sharks previously mentioned, is not of a roving disposition. It lies quietly amongst the weeds and rocks, calmly waiting for some “food” to come by.

In this species individuals of ten or more feet in length are not uncommon. Its teeth are long, sharp and awllike. Its head and mouth are covered with peculiar' skinny weed-like appendages, and this coupled with the colouration previously referred to, gives it a most decided resemblance to its surroundings.

Press reports of recent bathing fatalities in the Eastern States indicate that the unfortunate surfers have been attacked in waters quite close to shore. If this is so, and the attacks have been made inside “broken” water, viz., inside the line of breakers usually found upon ocean beaches, the position is extremely., hard to understand, as my experience is that sharks of a species likely to attack man are not at all partial to “broken” water, although, as I have previously stated, they will traverse, comparatively speaking, shallow water where there are no breakers. I have always held the opinion. that so long as the surferremains in “broken” water inside the line of breakers he is. practically safe from the attacks of man-eating sharks. It may not be out of place ttf mention that the great majority of sharks are viviparous (that is, the young are brought forth alive), the remainder being oviparous (i.e., the young are hatched out after the deposit of the egg). Only one of the very large sharks is known to be oviparous, and that is the huge Greenland shark (Lemargus borealis), which is unique among sharks in that it produces eggs without any horny covering, these being deposited on the sea-bottom and left there to hatch. Other oviparous sharks are the small species known as dog-fishes, the- small cat-fishes, and, to us, the familiar Port Jackson shark.