With record catches being recorded by many international billfish tournaments, is it possible that billfish and other top big-game species could possibly be in danger of disappearing completely? For example, the recently concluded International La Guaira Billfish Shootout in Venezuela set a new record with a total of 256 blues, 46 sailfish, 13 white marlin and four spearfish released by 118 anglers fishing on 40 boats. It broke the all-time tournament record of 190 blue marlin, set a decade ago at the Club Nautico de San Juan's International Billfish Tournament in Puerto Rico.
But if you look at the big picture and consider the scientific evidence developed during the last 40 years, a far more frightening picture emerges. Decimation of the Atlantic Ocean's premiere game fish in just the last three decades has been nothing short of astounding. Although it is not as well studied and documented, the same is also occurring on a massive scale throughout the Pacific. Today's "hot spots" for big-game fish may actually be the last refuges for these species. If so, we had better think about their protection from excessive industrial-scale fishing which has been so well documented for the Atlantic.
The purpose of this article is to allow the big-game fishing community to understand the severity of the problem using the Atlantic experience as an example. It summarizes the scientific community's understanding of the population status of the most important big-game species of the Atlantic Ocean - bluefin tuna, swordfish, blue marlin, white marlin and sailfish -- and describes actions we should take. It is based on reports issued by the International Commission for the Conservation of Atlantic Tunas (ICCAT), which since its formation in 1969, has been responsible for managing all fishing for tunas and tuna-like fishes of the Atlantic Ocean. ICCAT is composed of 22 member nations with a stated management objective to produce the maximum catch on a sustainable basis, or as fishery scientists refer to it, the maximum sustainable yield (MSY).
According to ICCAT's scientific advisory committees, the stocks of most Atlantic highly migratory species that it purports to manage have declined dramatically from healthy population levels of about two times the biomass needed to produce MSY which existed before longlining was introduced in 1961, to only small percentages of MSY by the end of 1995 (the last year for which a stock assessment was conducted). Current levels are as follows:
|Stock||% Decline||% of MSY|
|Atlantic blue marlin||85||24|
|Atlantic white marlin||88||23|
|Western Atlantic sailfish||54||62|
|North Atlantic swordfish||68||58|
|Western Atlantic bluefin tuna||88||6-12|
Blue marlin and white marlin are each considered a single interbreeding stock throughout their entire Atlantic Ocean range. They are caught and retained by all industrial fishing fleets, except those of the United States where billfish are reserved exclusively for the recreational fishery and commercial vessels are required to release all billfish. However, about half to three quarters of all billfish caught on longlines are already dead on arrival at the vessel.
Atlantic-wide populations of both blue and white marlin have declined in abundance from healthy levels of nearly two times the level associated with producing MSY (1.6 for blue marlin and 2.0 for white marlin), which existed in 1960, to only a quarter of the MSY level (0.24 and 0.23, respectively) at the end of 1995. The kill caused by fishing -- called fishing mortality -- has remained high and has increased recently to two to three times the level associated with producing the MSY (2.9 for blue marlin and 2.0 for white marlin). Consequently, both blue marlin and white marlin stocks are continuing to decline. They are also rapidly approaching extinction (the zero line). Their populations are both well below the level at which there is a danger of recruitment failure (considered for these species to be at 0.5 times MSY). Passing such a threshold means there are too few adult breeders to replace the population, which can then cause the species to spiral ever faster towards extinction.
Commercial vessels (longliners) are responsible for 85 percent of the U.S. kill of blue marlin and 95 percent of the kill of white marlin. Anglers are responsible for the remainder.
In the 1960s, the western Atlantic sailfish/spearfish stock was relatively healthy. (For convenience, ICCAT lumps the rare spearfish in with sailfish.) This combined stock's abundance was then estimated to have been well above the MSY level (1.2-1.5 times MSY). By 1991, this stock had been driven to about 60 percent of its MSY biomass level. Since 1984, fishing pressure has remained well above that which would produce the MSY, ranging from 1.3 to 2.1 times the level that this stock could tolerate on a sustainable basis. However, we simply have no information on the stock's abundance or fishing pressure on it since 1991. Longlines are responsible for 98 percent of the kill caused by U.S. vessels with anglers responsible for the remainder.
At the turn of the 20th century, the average-size swordfish landed commercially was in the neighborhood of 300 to 400 pounds. That average remained as high as 266 pounds as recently as 1961, when longlines replaced harpoons as the primary commercial gear used. Today, the average commercially landed swordfish weighs only 88 pounds.
Most swordfish -- almost two of every three -- are now caught before they have a chance to spawn. On average, female swordfish do not mature until they reach age 5 and about 150 pounds, while males mature at 3 years and 72 pounds. Of the females caught commercially, 83 percent are still immature. ICCAT's minimum size limit is now 41 pounds, and U.S. longliners routinely "discard" 40 to 50 percent of the swordfish they catch because they are too small to legally sell. Due to the trauma involved in longline retrieval (e.g., jaws and gills torn apart), virtually all of these fish are either dead already or die soon thereafter. In 1995, the U.S. fleet discarded 526 metric tons of such baby swordfish.
At the end of 1995, the stock had reached a biomass of 0.58 times the MSY level or 58 percent of that needed to produce the MSY. Since fishing pressure has continued at about double the rate (2.05) that the stock can sustain (MSY), the stock has surely declined further and is now likely at or below 0.5 times MSY -- the threshold for recruitment failure.
The north Atlantic swordfish stock is declining more rapidly than any other marine species, and it has been steadily doing so at the same rate each year for the past 20 years. Destruction of this population has been meticulously documented each year for ICCAT by its scientific advisory committee, yet ICCAT has failed limit the catch of its member states in order to reverse the decline. If its population continues to decline at the same rate it has since 1978, north Atlantic swordfish will become extinct within only seven years.
The important point is that swordfish are capable of rapid recovery if given the chance. Model results based on the stock at the end of 1995 indicate that if all fishing were to cease, the stock could recover to the MSY population level in two to three years. A 10-year recovery would require a 62-percent catch reduction.
The species in the greatest danger of slipping into extinction is the bluefin tuna. Its abundance has declined by roughly 90 percent since 1975. ICCAT considers the biomass which existed in the mid-1970s to be the MSY level for the western Atlantic bluefin tuna stock. According to the National Marine Fisheries Service (NMFS), at the end of 1995, the bluefin's biomass (total weight of fish) was estimated to have declined to between 6 and 12 percent of that needed to produce the MSY. Thus, in only 20 years the population was driven from a healthy level to a level just above extinction by unrestrained industrial-scale commercial fishing sanctioned by ICCAT on this, the world's most valuable fish.
The population is being held at this precarious level by continued fishing allowed by ICCAT, ostensibly to provide scientific monitoring information. In reality, it is unnecessary to kill any remaining bluefin until they can recover since the abundance of each year class could be assessed using aircraft. There are only two relatively decent year classes left -- one just reached maturity and spawned for the first time in the spring of 1998. They should now weigh about 400 pounds. The other is younger, its members weighing about 75 pounds.
Throughout the 1960s, vast numbers of juveniles were taken (to be canned as cat food) by purse seiners operating in the bluefin's nursery areas along the U.S. Atlantic coast. Throughout the 1970s, Japanese longliners decimated the adults on their spawning grounds in the Gulf of Mexico. The western Atlantic bluefin stock has still not begun to recover from this terrible "double whammy." What makes this story all the more depressing is that purse seining was encouraged and promoted by NMFS -- the federal agency charged with the responsibility for conserving and protecting the nation's marine fishery resources. This debacle was later repeated by NMFS in the early 1980s with equally disastrous results in the case of Atlantic sharks.
The population status of most shark species of the U.S Atlantic coast (39 species) is less documented, but they appear to have declined even more severely than the billfish and in a shorter period of time. The populations of many "large coastal" sharks appear to have declined from 50 to 80 percent between the early 1970s and today. It is estimated that the large coastal shark group has declined from 9 to 11 million fish in 1974 to 1 to 2 million fish in 1998, or about 30 to 36 percent of the MSY level. (The status of the pelagic shark group is unknown.)
In 1997, NMFS cut the commercial quota and recreational bag limits in half for the large coastal group and prohibited the landing of five additional species (now totaling 21), but there is still no evidence of a recovery of any. In 1997, fishing pressure was still more than six times that which these shark populations can sustain. If all fishing were to cease, modeling results from the 1998 stock assessment indicate that there is a less than 50:50 chance that these populations could recover to the MSY level even after 30 years.
The Cause of Stock Declines
The primary cause of this destruction of the world's greatest game fish is unrestrained use of non-selective gear, in particular longlines and gillnets. Industrial-scale fishing operations conducted throughout the world's oceans employ these destructive and indiscriminate gear types primarily to catch swordfish and tunas. But longlines -- averaging over 25 miles in length and armed with hundreds or even thousands of hooks -- and drift gillnets also accidentally capture and kill much greater numbers of unmarketable juveniles, non-target fish and other wildlife including marine mammals, sea turtles and marine birds. A video detailing the destructive nature of drift longlines and gillnets in both the Atlantic and Pacific has recently been produced by the Recreational Fishing Alliance (RFA).
These two non-selective gear types are, quite simply, unmanageable. They cannot be set to avoid catching and killing large numbers of non-target animals. Excessive bykill is an unavoidable byproduct of fishing with drift longlines and with gillnets.
The situation is thoroughly examined in a 1998 report from the National Coalition for Marine Conservation (NCMC) entitled "Ocean Roulette: Conserving Swordfish, Sharks and other Threatened Pelagic Fish in Longline-Infested Waters," which presents the results of a two-year study of the longline industry. Its conclusion: "Drift, or pelagic, longlines are incompatible with effective management and our national goal of sustainable fisheries. The use of longlines must be severely curtailed."
These fisheries are public resources that must be restored and sustained at healthy levels for the benefit of all, not just those who continue to profit by their extermination. However, NMFS has failed repeatedly to provide effective stewardship for these resources. We have seen that these federal fishery managers respond only to political pressure, and until now, usually only to allow continued commercial exploitation. Accordingly, today's fisheries management situation seems a political problem that requires a political solution.
Outlaw Longlines and Gillnets
Recovery of the world's severely overfished swordfish, billfish and sharks cannot be achieved without removing the multi-mile, multi-hook longlines from the water. The RFA and NCMC are leading a national initiative to do just that. They are jointly calling on Congress to outlaw drift or pelagic longlines in all U.S. waters (Atlantic, Caribbean, Gulf of Mexico and Pacific Coasts) and then by exerting U.S. leadership abroad, to obtain international agreements to eliminate their use in the primary spawning, nursery and feeding areas of the large pelagics, worldwide.
Public education and political action will be necessary to make this happen. We all have a role to play. To be successful, we need a broad alliance of fishing and conservation interests, non-governmental organizations, clubs and business interests to endorse this goal and to participate in whatever way each can best contribute. To get involved or obtain additional information, contact RFA toll free at 888-564-9419, by mail at PO Box 308, New Gretna, NJ 08224; or e-mail email@example.com.
Already, drift gillnets longer than 1.5 miles have been banned by international agreement because of their extraordinary bycatch of marine mammals, seabirds and non-target fish. Drift gillnets have recently been banned from participating in the U.S. Atlantic swordfish fishery, primarily because of their high bycatch of protected species of marine mammals and sea turtles. However, they continue to be used without restriction in the Pacific to target swordfish as well as thresher and mako sharks. And they produce the same high bycatch, including dolphins and whales, as do the now-banned longer drift gillnets.
To successfully rebuild these stocks as required by the Sustainable Fisheries Act, we have to gain international commitments to policies adopted by the U.S., particularly eliminating these two types of non-selective commercial fishing gear from all federal waters. Essential habitats of Atlantic swordfish and billfish are actually quite small and discrete. However, initially providing protection from non-selective gear in all U.S. federal waters will have major benefits to populations of swordfish, marlin, sailfish, bluefin tuna and many species of sharks since these stocks all spend a large portion of their life cycle in our waters.
Editor's Note: More detailed information on the population declines of Atlantic swordfish, blue marlin, white marlin, sailfish, bluefin tuna and sharks can be found at www.geocities.com/Eureka/Vault/8020.