In Fukushima, Hokkaido, 25 large concrete boxes (4mt each) with open sides are filled with natural rocks and placed in intertidal areas. The crevices formed by the rocks provide an excellent habitat for the juveniles which are stocked in PVC pipe sections. Special tidal channels designed to increase tidal flow have also been constructed as a part of this project. These units have been very successful and tagged seedlings have experienced improved survival and growth. At Taise, Hokkaido, special juvenile stocking unitswhich are covered with plastic-coated wire to protect the seaweed food supply from sea urchins-are stocked with juvenile abalone. The abalone are raised to about 3cm at a local hatchery which uses geothermal heat to increase the growth rate of the abalone. The stocking is accomplished by divers who also monitor growth and survival. The stocking units are placed in near-shore waters 3 to 5 meters deep. Other units designed for the larger abalone are also located in this area. These units are fitted with special attachments to promote seaweed growth and thus provide both shelter and food for the abalone. Opportunities for Habitat The U.S. currently faces both a growing domestic demand for seafood and a rapidly developing export market. Popular species such as lobster, shrimp, abalone, and scallops have become increasingly expensive and scarce in recent years. Imports now account for a substantial amount of the highpriced seafood consumed in this country. Now that foreign fleets are being gradually excluded from U.S. coastal waters by the 200-mile limit, opportunities for developing coastal fisheries are expanding rapidly. Habitat improvement technology offers a means for the U.S. to increase its commercial production of high-value species for both domestic consumption and overseas export. Recreational fisheries as well could benefit from artificial reefs specifically designed and manufactured for optimum effect. Although sport fishermen-currently the major users of artificial reefs in the U.S.-do catch a substantial portion of the fish consumed in American homes, the most significant economic impact of sport fishing arises from the tourist dollars it generates. In communities near existing artificial reefs, increases in sport fishing have contributed measurably to the local economies. Despite the use of "scrap" materials for most U.S. artificial reefs, by no means are these reefs built cost-free. Preparation is becoming increasingly expensive. EPA regulations require that wrecked cars must be thoroughly steam-cleaned to eliminate oil and other potential pollutants, and their upholstery must be removed. Old tires must be perforated to reduce buoyancy, bound together, compressed, ballasted with concrete, and transported to location. Because of their potential as a chemical energy source, tires often are no longer free or available at nominal charge. Still other materials that once were used for reefs are no longer available at all-old World War II Liberty ships, for example. And none of these materials offer the advantage of optimum design. Specially designed and manufactured reefs do require a sizeable investment but it is a one-time, fixed-expense, and Americans can benefit from the extensive research and development already funded by the Japanese. If these reefs are properly engineered, sited, and placed, they represent a relatively permanent contribution to sport fisheries and commercial fisheries production. Additionally, they can be used in cost-effective combinations with other production methods. Hatcheries, for example, have the potential for increasing populations but require recurring expenditures subject to inflation; since artificial reefs significantly increase the survival and growth of stocked juveniles, they make hatchery expenditures more cost-effective. As the Japanese have demonstrated, the habitat improvement techniques made possible by specially designed and manufactured artificial reefs have enormous potential for expanding coastal resources and rehabilitating areas adversely impacted by human activities such as pollution, construction, and overfishing. Similar artificial reefs could be used in the U.S. as a fisheries management tool with great potential benefits for commercial and recreational fisheries. by John R. Twiss, Jr. Beginning in the late 1960s the plight of marine mammal populations became a matter of increasingly widespread concern. The continued exploitation of depleted great whales for various commercial purposes, the killing of newborn harp seal pups for their fur, and the high porpoise mortality associated with the commercial yellowfin tuna fishery typify the problems which caused that concern. From the Arctic to the Antarctic a sad story of over-exploitation of certain stocks of whales had been written. As one population became depleted and unprofitable to harvest, the whalers turned to other more numerous stocks to stay in business. A telling account of the effects of harvesting on whales which feed in the Southern Ocean was given in 1976 Executive Director, Marine Mammal by Richard M. Laws, Director of the "Nearly thirty years ago, I first Growing recognition among . (IWC) the intergovernmental body, including 23 member states, responsible for the regulation of whaling by its members. Beginning in 1974 with an effort to strengthen the basis for its regulations, the IWC has placed progressively heavier emphasis upon the advice of its scientific committee in setting quotas for whaling. At its meeting in July 1979, it banned factory-ship operations in all oceans and for all species except the minke whale. This decision will virtually eliminate Soviet commercial whaling in the North Pacific and will substantially reduce Soviet and Japanese whaling in the Southern Ocean. The IWC also set aside most of the Indian Ocean as a whale sanctuary for a period of ten years. These actions, coupled with prohibitions on the taking of certain species and reductions in the levels of take for other species, bespeak progress which may allow for the recovery of the great whales. The 70s also saw progress toward Manatee: reducing injury and death of porpoises incidental to the yellowfin tuna fishery. Certain species of porpoise associate with yellowfin tuna. When fishing, fishermen encircle porpoise schools in purse seine nets and thereby catch the yellowfin tuna which swim below the mammals. In the process, many porpoises drown or are otherwise killed or seriously injured. In 1972 about 300,000 porpoises were thus killed by U.S. vessels. Eventually, fishermen, environmentalists, scientists, and key Federal agency policy makers cooperatively addressed the issue. Although the problem is by no means solved, the estimated U.S. kill in 1978 was reduced to about 14,200 porpoises, less than one-twentieth of the 1972 estimate. In trying to understand improved A Hawaiian Monk Seal mother and pup; the pup is near the age of weaning from the mother. (Photo by Kenyon) regulation of whaling, lowered porpoise kills, and other advances in wildlife protection, one often discovers common contributing factors such as strong public interest in the problem, effective statutory and regulatory mechanisms, and intensified theoretical and applied scientific efforts. Public pressure has been effectively focused on a number of highly visible issues in which the adverse impacts have been clear. Such problems are those related to commercial whaling, massive numbers of marine mammals being killed or made to suffer, and flagrant habitat destruction. Statutes, such as the Marine Mammal Protection Act of 1972 and the Endangered Species Act of 1973 (as amended in 1978), and regulations emanating from them have profoundly influenced many situations. This has been accomplished either by articulating specific statutory or regulatory goals applicable to a particular problem or species or by setting forth more general conservation goals which address biologically desirable population levels and the roles of animals as significant functioning elements of an ecosystem. Both Acts make possible litigation and administrative action to protect species and/or habitats. Wildlife management theory has been evolving towards more ecosystem-oriented approaches. In speaking of living resource utilization, two leaders in the field, Sidney J. Holt and Lee M. Talbot, summarized the views of a large group of scientists as follows: The ecosystem should be maintained in a desirable state such that: a) consumptive and non-consumptive values could be maximized on a continuing basis, b) present and future options are insured, and c) risk of irreversible change or long-term adverse effects as a result of use is minimized. Management decisions should include a safety factor to allow for the fact that knowledge is limited and institutions are imperfect. Measures to conserve a wild living resource should be formulated and applied so as to avoid wasteful use of other resources. Survey or monitoring, analysis, and assessments should precede planned use and accompany actual use of wild living resources. The results should be made available promptly for critical public review. While advances in law and science offer new protection for marine mammals and their habitats, much remains to be done. In some instances where the necessary statutory provisions exist to provide protection, but governmental action, public |