Faced with dwindling stocks and rising demand for seafood, fishers are employing new technologies that leave no safe haven for fish, including the application of military technologies, spotter planes, and round the clock exploitation. “New technologies and fishing effort have peeled the lid off the oceans,” says University of York scientist, Callum Roberts. “If we want to keep seafood on our plates we need to put back refuges so some fish survive long enough to reproduce.” For most of human history, fish and other marine species had naturally protected areas. These were places inaccessible to fishing because they were too remote, too deep, or too dangerous to fish.
The ‘peace dividend’ from the end of the cold war has led to civilian applications for military technologies developed for submarine warfare and espionage. These transferred technologies include sonar mapping systems that reveal every crack and contour of the seabed in exquisite detail. Today the U.S. Geological Survey is publishing maps that are enabling fishers to penetrate deep into regions once considered too difficult to fish. Private companies are also weighing in, selling the secrets of the seabed for short-term profit. Guided by precision satellite navigation systems, fishers can now drop nets into previously unseen canyons, or land hooks on formerly uncharted seamounts. “Such places may be the last refuges of vulnerable species like skates or rockfish,” says Roberts.
Fishers are also looking to the skies for better catches. Off the U.S. East coast, the Atlantic swordfish fleet receives daily faxes from the National Oceanic and Atmospheric Administration, showing satellite images of sea-surface temperatures on the fishing grounds. These maps, and temperature and depth sensors carried by boats, allow the fleet to target the places where swordfish are most vulnerable. The same technology guides the bluefin tuna fleet to the best fishing areas, and spotter planes help boats pursue schools to the last fish.
“The modern fishing armory has vastly expanded,” says Yvonne Sadovy of the University of Hong Kong. “The boats of today are larger, faster, stronger and can fish in conditions that would have been impossibly dangerous 100 years ago.” They fish deeper, for longer and employ nets that can penetrate areas of rough seabed, moving rocks up to 3m in diameter and weighing up to 16 tonnes.
“Not all new fishing technologies are hi-tech; modern improvements can be just as devastating to fish stocks,” says University of Hawaii researcher Charles Birkeland. In islands throughout the Pacific, fishers have long valued the huge and docile bumphead parrotfish. By day, these wary fish would keep their distance from spearfishers, so the take was never very high. In recent years, spearfishers equipped with SCUBA have begun targeting the parrotfish at night when they sleep in shoals in shallow reef lagoons. “Spearguns and nightlights are as lethal to bumphead parrotfish today as rifles and railroads were for American Plains bison in the 19th Century,” says Birkeland.
The unsustainable pursuit of larger and more desirable coral reef species is also being fueled by the growth of international markets. “Greater prosperity and demand for live food fish in South-East Asia has driven prices so high that it is profitable to pursue fish to the farthest corners of the world,” says Sadovy. “Because so many species are targeted, fishing operations can remain economically viable far beyond the point where the most vulnerable species have been eliminated.”
As fishers expand their reach, the importance of creating natural refuges for sustaining breeding stocks increases. “When there is no place for fish to hide, we can devastate entire populations. There is evidence that severely overexploited species may not recover, even decades after depletion,” says University of Dalhousie scientist Jeff Hutchings. For example, over a hundred tons of black-lipped pearl oyster were taken from Pearl and Hermes Reefs in the Northwest Hawaiian Islands in 1927. Only six individuals were found during an intensive survey late in the year 2000, 63 years after the harvest. In Canada, northern cod were depleted to a few percent of their former abundance in the early 1990s, and there is still little sign of recovery. “We are realizing, too late in some cases, that severe depletion can undermine population resilience by impairing reproduction, reducing recruitment of young animals, degrading habitat integrity, and altering behavior and interactions with other species,” says Howard Choat of James Cook University. This further points to the need to be proactive so that populations don’t reach this point of no return.
“We are pushing fisheries off the edge of viability, and species to the edge of extinction,” says Birkeland. “We must recreate the refuges of old by establishing networks of marine reserves.”
New evidence indicates that fully protected refuges can help protect stocks from reaching the point of no return by providing safe havens, protecting habitats and by exporting fish and their offspring to surrounding fishing grounds. “Without such marine reserves, the ocean’s future looks bleak,” says Roberts.
The Symposium New Fishing Technologies Make Marine Reserves Imperative takes place from 9 am to 12 noon on Sunday, February 17th, 2002 at the Annual Meeting of the American Association for the Advancement of Science.
Panelists will also debate fishers and fishing industry representatives at the American Museum of Natural History, New York, in a Coastal Fisheries Panel Discussion on Tuesday, February 19th at 7pm.
For assistance contacting speakers at AAAS please call Jessica Brown at #202-497-8375 or #831-212-5948.
Dr. Charles Birkeland, University of Hawaii, USA charlesbirkeland@hotmail.com
Dr. Callum Roberts, University of York, UK cr10@york.ac.uk
Dr. Yvonne Sadovy, University of Hong Kong yjsadovy@hkusua.hku.hk
Dr. Jeffrey Hutchings, Dalhousie University, Canada jhutch@mscs.dal.ca
Dr. Howard Choat, James Cook University, Australia John.Choat@jcu.edu.au