Chapter 13 Harvesting Living Marine Resources Most of the world ocean is intensively exploited for fishing, recreation, military purposes, commercial shipping, dumping of waste materials, and extraction of gas, oil, and other mineral resources. Copyright © 2004 Jones and Bartlett Publishers

A Brief Survey of Marine Food Species The raw material of the fishing industry includes: The raw material of the fishing industry includes: –bony and cartilaginous finfish –shellfish –a variety of other aquatic organisms Chapter 13

A Brief Survey of Marine Food Species Chapter 13

A Brief Survey of Marine Food Species Clupeoid fishes account for about one third of the world’s total commercial catch. Clupeoid fishes are found in shallow coastal waters and in upwelling regions. Clupeoid fishes account for about one third of the world’s total commercial catch. Clupeoid fishes are found in shallow coastal waters and in upwelling regions. Cod, pollack, hake, and other gadoid fishes, redfish, bass, sea perch, and other miscellaneous coastal rockfishes, and tuna are also important commercial targets. Cod, pollack, hake, and other gadoid fishes, redfish, bass, sea perch, and other miscellaneous coastal rockfishes, and tuna are also important commercial targets. Bottom fishes and benthic invertebrates account for 10–15% of the total global catch. Bottom fishes and benthic invertebrates account for 10–15% of the total global catch. Chapter 13

Major Fishing Areas of the World Ocean About 90% of the marine catch is taken from continental shelves. About 90% of the marine catch is taken from continental shelves. Several major fishing areas are centered in regions of upwelling, such as those along the west coasts of Africa and North and South America. Several major fishing areas are centered in regions of upwelling, such as those along the west coasts of Africa and North and South America. Chapter 13

A Perspective on Sources of Seafoods Most of the seafood harvested are animals three or four trophic levels above the primary producers. Most of the seafood harvested are animals three or four trophic levels above the primary producers. In contrast to land, more animals than plants are harvested on land. In contrast to land, more animals than plants are harvested on land. Chapter 13

A Perspective on Sources of Seafoods The fish meal fraction had increased to about 40% of the world catch. The fish meal fraction had increased to about 40% of the world catch. We are currently overharvesting most commercially important fish populations. We are currently overharvesting most commercially important fish populations. As a result, only 1–2% of the food consumed by the world human population came from the sea. As a result, only 1–2% of the food consumed by the world human population came from the sea. Chapter 13

Fishing Down the Food Chain By fishing one trophic level down, a 5- to 10- fold increase could be harvested because one trophic level (and its associated energy loss) would be eliminated. By fishing one trophic level down, a 5- to 10- fold increase could be harvested because one trophic level (and its associated energy loss) would be eliminated. However, harvesting near the base of a food web often deny larger predators adequate prey, and their populations suffer even though they are not directly targeted by commercial fisheries. However, harvesting near the base of a food web often deny larger predators adequate prey, and their populations suffer even though they are not directly targeted by commercial fisheries. Chapter 13

Mariculture Mariculture is the practice of using agricultural techniques to raise marine animals and plants Mariculture is the practice of using agricultural techniques to raise marine animals and plants Mariculture presently contributes less than 20% of our total marine food production. Mariculture presently contributes less than 20% of our total marine food production. Chapter 13

Mariculture Estuaries, salt marshes, and other productive coastal habitats are preferred for cultivating marine species, yet for each fish pond installed, a portion of the native populations are displaced or denied access to these productive coastal waters, which often serve as essential nursery areas. Estuaries, salt marshes, and other productive coastal habitats are preferred for cultivating marine species, yet for each fish pond installed, a portion of the native populations are displaced or denied access to these productive coastal waters, which often serve as essential nursery areas. Chapter 13

The Problems of Overexploitation Numerous examples of overfished stocks can be found in most segments of the fishing industry: Numerous examples of overfished stocks can be found in most segments of the fishing industry: –Cod of the N. Atlantic Ocean –Anchoveta of the S. Pacific Ocean Chapter 13

The Problems of Overexploitation North Atlantic Cod North Atlantic Cod –Among the first to be taken by factory trawlers (rather than by hand-lines for individual fish). –When the population diminished and catches declined, U.S. and Canadian regulatory agencies closed nearly all cod fisheries in their waters in Chapter 13

The Problems of Overexploitation North Atlantic Cod North Atlantic Cod Chapter 13 Fig The dramatic decline in Northwestern Atlantic cod harvests, Data complied from UNFAO statistics.

The Problems of Overexploitation Peruvian Anchoveta Peruvian Anchoveta –The Peruvian anchoveta has become a classic example of the consequences of intense overfishing. Chapter 13

The Problems of Overexploitation Peruvian Anchoveta Peruvian Anchoveta Chapter 13 Fig Changes in the anchoveta catch and the guano bird populations along the northwest coast of South America. Adapted from Muck 1989 and UNFAO statistics.

The Tragedy of the Commons Fishing is too often considered a right without attendant responsibilities. Fishing is too often considered a right without attendant responsibilities. Oceanic species exist outside the jurisdictional limits of all nations and therefore are open to access by any nation. Oceanic species exist outside the jurisdictional limits of all nations and therefore are open to access by any nation. Chapter 13

The Tragedy of the Commons Unrestricted fishing activities remove a valuable commodity from a common resource pool, and all people share the cost of losing the fish, the great whales, and the other marine animals that have nearly disappeared because of overfishing. Unrestricted fishing activities remove a valuable commodity from a common resource pool, and all people share the cost of losing the fish, the great whales, and the other marine animals that have nearly disappeared because of overfishing. Yet the short-term profits derived from overfishing are not similarly shared. Yet the short-term profits derived from overfishing are not similarly shared. This is Hardin’s concept of the “tragedy of the commons.” This is Hardin’s concept of the “tragedy of the commons.” Chapter 13

International Regulation of Fisheries Concerned nations have created a variety of multinational and international regulatory commissions for the purpose of governing the management and harvest of regional fish populations. Concerned nations have created a variety of multinational and international regulatory commissions for the purpose of governing the management and harvest of regional fish populations. Chapter 13

International Regulation of Fisheries Common strategies for management include: Common strategies for management include: –setting quotas on the amount of fish harvested –establishing seasons and minimum size limits –defining acceptable gear such as net mesh sizes –limiting the number of boats that are allowed to participate in a fishery. Chapter 13

International Regulation of Fisheries In 1976, the United States passed the Fisheries Conservation and Management Act, which claimed exclusive jurisdiction over natural resources (including fishing), scientific research, and environmental preservation in an EEZ extending from shore 200 miles to sea. In 1976, the United States passed the Fisheries Conservation and Management Act, which claimed exclusive jurisdiction over natural resources (including fishing), scientific research, and environmental preservation in an EEZ extending from shore 200 miles to sea. Other nations followed suit with the UN Law of the Sea Treaty. Other nations followed suit with the UN Law of the Sea Treaty. This has dramatically changed the concept of open access for most of the world’s continental shelves, coastal upwelling areas, and major fisheries. This has dramatically changed the concept of open access for most of the world’s continental shelves, coastal upwelling areas, and major fisheries. Chapter 13

International Regulation of Fisheries Chapter 13 Fig Worldwide extent of the 200-mile Exclusive Economic Zones sanctioned by the United Nations LOS Treaty.

Marine Ornamentals Keeping personal marine aquaria supports a trade that may be worth as much as $330 million annually. Keeping personal marine aquaria supports a trade that may be worth as much as $330 million annually. Unfortunately, destructive collection techniques, overexploitation of some species, and careless handling and transport all undermine potential benefits of the trade. Unfortunately, destructive collection techniques, overexploitation of some species, and careless handling and transport all undermine potential benefits of the trade. Chapter 13

Marine Ornamentals Fisheries for marine ornamentals need to be managed to ensure sustainable use and application of proper regulations to decrease conflict with other user groups (such as sport divers). Fisheries for marine ornamentals need to be managed to ensure sustainable use and application of proper regulations to decrease conflict with other user groups (such as sport divers). Chapter 13

Sealing and Whaling Pinnipeds and whales have long been targets of commercial harvesting for their meat, oil, and skins with dense insulating fur. Pinnipeds and whales have long been targets of commercial harvesting for their meat, oil, and skins with dense insulating fur. Chapter 13

Sealing and Whaling Pinnipeds Pinnipeds –The gregarious nature and relatively poor terrestrial locomotion of pinnipeds make them easy targets for sealers. –As predators near the tops of their food webs, the reduction of the their prey species by human fishers can have a large negative effect on their survival. Chapter 13

Sealing and Whaling Pinnipeds Pinnipeds Chapter 13 Fig Steller sea lion rookery beach photographed on the same day of the year in (a) 1969 and (b) (a)(b)

Sealing and Whaling Baleen Whales Baleen Whales –In the 18th and 19th centuries, whales became major items of commerce as demand for their oil grew and whaling as an industry grew into a profitable commercial enterprise. Chapter 13

Sealing and Whaling Baleen Whales Baleen Whales – Aided by cannon-fired harpoons equipped with explosive heads and pelagic factory ships fitted with stern ramps to haul whale carcasses aboard for processing, the kill of large rorquals rose dramatically, and several species were pushed to the edge of extinction. Chapter 13

Sealing and Whaling Baleen Whales Baleen Whales Chapter 13 Fig Harvests of blue, fin, sei, and minke whales in the Antarctic, Data complied from UNFAO statistics.

Sealing and Whaling Baleen Whales Baleen Whales –In 1948, 20 whaling nations established the IWC to oversee the utilization and conservation of the world’s whale resources. Unfortunately, the IWC has neither inspection nor enforcement powers. Chapter 13

Concluding Thoughts: Developing a Sense of Stewardship The world ocean provides food, transportation, and recreation while absorbing the effluvia of human societies. The world ocean provides food, transportation, and recreation while absorbing the effluvia of human societies. Our continued wise use of the seas for these purposes depends on a better understanding of the consequences of our intrusion on the workings of marine ecosystems. Our continued wise use of the seas for these purposes depends on a better understanding of the consequences of our intrusion on the workings of marine ecosystems. Chapter 13

I am only one, but I am one I cannot do everything, but I can do something I will not let what I cannot do interfere with what I can