SCIENCE AND THE SEA 



route. At the offshore end of the leader, lies the heart, a net enclosure 

 about 75 feet across. From the heart, fish enter the crib through the 

 gate. Cribs are usually about twice the size of the heart and are made 

 of much smaller netting. The crib section has a net bottom which, 

 when raised, permits fish to be brailed directly from net to tender. 

 Fixed and floating traps may have more than one heart and 

 crib, but are basically the same design concept. 



OYSTERS 



The oyster fishery is the oldest of all the known world fisheries. 

 Primitive peoples in the earliest days of civilization harvested this 

 food resource long before they learned to fish or hunt. Large shell 

 mounds called kitchen middens have been found scattered along the 

 coasts of Africa, Australia, Europe, and America. The size of these 

 mounds indicate the great importance oysters played in the survival 

 of these early inhabitants. Today, the oysterman is a true farmer 

 carefully tending and cultivating vast underwater tracts. The eco- 

 nomic importance is readily appreciated when we find that these sub- 

 marine farms often return higher incomes than the best land farms do. 



Oysters are a class of mollusks which have their bodies enclosed 

 in a two-valve shell. They have no head and lack the muscular loco- 

 motive foot which other members of this group, such as clams, possess. 

 Unable to see, hear or move, the oyster must lie motionless on the sea 

 floor or attached to some underwater object. To offset the lack of 

 vision and hearing, the oyster has developed a remarkable chemical 

 sense. Tiny tentacles protrude beyond the edge of the mantle when 

 the shell is open to taste the water, and detect light changes. A 

 sudden change in light, or the presence of a to.xic material in the water 

 will cause the tentacles to contract. The stimulus of this action is 

 passed through the mantle to the adductor muscle and the shell is 

 closed. A tightly closed shell is the oyster's only means of defense. 

 LOBSTER FISHERIES 



The delicacy of lobster meat and their high value per pound are 

 valid barometers of the importance of this fishery. Disregarding minor 

 specie differences, lobsters can be broadly classed as either true 

 lobsters or spiny lobsters. The key distinguishing features of the true 

 or Maine lobster are their large heavy crushing claws, stiff tail fan 

 and smooth dark green body shell. This class is concentrated along the 

 New England and Canadian coast. 



Spiny lobsters have a much broarder range of distribution being 

 found in the warmer coastal waters throughout the world. As the 

 name implies, the legs and body shell are covered with short spines. 

 Lacking the large crushing claws of the true lobster, only the tail 

 section of the spiny lobster is worth processing. 



South Africa is the world's largest spiny lobster producer. 

 Australia, New Zealand, Japan and the West Indies also harvest a 

 large crop of spiny lobsters annually, many of which are exported in 



frozen form. Commercial harvesting of all lobsters centers around 

 the use of pots or traps. Although a wide variety of sizes, shapes and 

 construction materials are to be found, the principle remains the 

 same. 



Figure 15 Lobster pot 



A typical New England trap consists of an oblong lath box 

 weighted with brick or stone and having one or two funnel-shaped 

 openings. Bait, in the form of decaying fish, is hung inside the trap 

 and acts to lure the lobsters in. While the bait last, the lobsters seem 

 content to stay, but once gone, they are often able to escape the trap. 

 For this reason, traps are hauled daily, if possible. 



Most lobsters are caught in less than 30 fathoms of water. Buoys 

 bearing the distinctive colored marking of the owner, are secured by 

 warps to the traps, making identification easy. A single lobsterman 

 can usually handle 100 traps under normal conditions. 



CONCLUSION 



It has been established that fishing is as old as man himself and 

 that the paraphernalia employed to harvest the crop is infinite. The 

 development of any commercial fishery is dependent upon a sustained 

 demand, the physical properties of the sea, an abundant resource, a 

 means of gathering, a mode of transport, and adequate storage. 

 Regardless of how primitive or how sophisticated the endeavor, it is 

 predicated on one of three basic techniques: direct attack, snaring, 

 or luring. Further, each fishery requires either special vessels, gear or 

 both to fulfill its mission. Finally, and perhaps most important, for 

 any fishery to survive at a profitable level, some form of intelligent 

 conservation program must be inaugurated. 



Armed with this basic understanding of fishery operations, 

 professional seamen can be expected to do more to make all encounters 

 with the vessels, men and gear of this industry safe. 



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