Page:Popular Science Monthly Volume 78.djvu/256

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Professor C. A. Kofoid, of the University of California, has designed a small, surface tow net, made of fine bolting silk, to collect the swarms of minute animals—salpæ, medusæ, arthropoda and the metamorphic forms of other groups—which are always found at the surface of the open sea or a few feet below it. While making a bottom haul, this small net is usually towed from the ship's side for half an hour, and the contents are washed out into a jar as a gelatinous, unrecognizable mass to be sorted over in the laboratory at Washington later.

Much of the collecting work of the Albatross has been done along clear beaches and in rivers with seines drawn by a crew of six or eight men. The boat used on these expeditions is a round-bottomed, keel-less shell of Norwegian model, called a "praam," a craft which is easily held against currents, but which drifts readily with the wind, and which shows on the whole a more unmanageable disposition than any other of the ship's small boats, until one has learned how to trim the boat and to pull it with even oar. Then one realizes how well suited this boat is for knocking about in swamps and rivers and on the beaches.

But more sweeping than any of these other methods of collecting is dynamiting the fish which congregate in great numbers on the coral reefs. Peering through a water glass, or glass-bottomed bucket, over the stern of a small boat, one plants a shot which is exploded by an electric fuse. The fish are either stunned or killed by the explosion and rise to the surface, dotting it with flecks of red, green, yellow, or chocolate brown. Many more fish sink to the bottom, the degree of the congestion of the internal organs due to the explosion and the bursting of the swim-bladder apparently causing the fish to sink. Amid more or less excitement the fish on the surface are speedily gathered in and the boat devotes itself to the more prosaic work of picking up the fish on the bottom with the aid of the water glass and an unweildy bamboo spear. Although one can not but regret the waste of many fish killed by dynamite for every specimen sent to the museum, this method is justified because it is the only means by which many species can possibly be taken, which must otherwise remain unknown.

There is, however, one small wrasse fish (Labroides paradiseus Bleeker) about as long as one's finger, which fearlessly flaunts its dark blue tail among the coral branches as the dynamite shot is being placed, and which even more saucily hovers near the jagged and broken coral after the shot has been fired. One's pride in his catch is humbled still further on meeting a silent, half-naked native poling his flimsy bamboo raft homeward with his basket filled with fish similar to those in the dynamite boat. The native has taken his fish in the early morning, before the breeze has ruffled the surface of the bay, without the help of dynamite or of water glass, and with only a slender, iron-tipped spear of his own rude contriving with which he has speared his fish alive.