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Atlantic Blue Marlin Management and Recovery
Mark E. Steiner
04.28.02-St. Louis, MO

Part I: Introduction
Ernest Hemingway’s ode to the blue marlin, The Old Man and the Sea, is a fitting tribute to this magnificent game fish. It is the most sought after recreational fish species in the world. Anglers travel thousands of miles to reach a destination that gives them a better chance to capture a blue marlin, the pinnacle of angling achievement. Hemingway’s novel also points out a problem with such ardent pursuit. Santiago finally lands the giant fish, and kills it to sell back on his home island. For the longest time, blue marlin were killed every time one was caught. It was not uncommon for a boat to bring several back to the dock, often only to take a picture and make a taxidermy mount. This wanton taking, combined with indiscriminate commercial takings, has wreaked havoc on the population of blue marlin, especially in the Atlantic Ocean.

More recently, recreational fisherman turned to catch-and-release fishing, rather than kill fishing. This practice sprung from the widespread belief that fishing was in decline, and that conservation through catch-and-release would put less pressure on the marlin population. Legislation followed suit, and soon blue marlin from the Atlantic Ocean were outlawed from sale in the United States. The legislation in place has not been sufficient to curb the decline of the species. The management of this species is an international concern, and the regulating body in charge of blue marlin has fallen on the shoulders of ICCAT, the International Commission for the Conservation of Atlantic Tunas.

In this paper, I will identify the major problems that plague the management of Atlantic blue marlin. These include commercial overfishing, insufficient scientific knowledge, and a lack of economic perspective. After assessing the difficulties, I will present several options in each category that could help to provide a solution to these problems, and to aid in successful management with the aim of full recovery of Atlantic blue marlin.
Part II: Biological Overview
Atlantic blue marlin (Makaira nigricans) is among the largest of the billfish species. The females are the larger animals, and they grow to well over 1000 pounds. Though the sport fishing world record is 1492 pounds, caught off of Brazil, there have been reports of fish weighing in excess of 2000 pounds from most parts of the Atlantic Ocean. Blue marlin are distinguishable from black marlin (Makaira indica), morphologically their closest relative, by the pectoral fins, which on a blue marlin are free moving, as opposed to fixed on a black marlin. However, this distinction is unnecessary in the Atlantic, since black marlin are exclusively Indo-Pacific in range.

Blue marlin are apex predators, and they feed on smaller pelagic fish species including tunas, mahi mahi, and mackerel. When feeding, blue marlin strike their prey with their bill, stunning them, and then return to eat them.

Atlantic and Pacific blue marlin are a single species, though they are separate breeding stocks, with no demonstrable crossover. In the Atlantic, blue marlin have been landed from as far north as New England to as far south as Argentina. In the eastern Atlantic they range from southern Africa north to Spain and the Mediterranean Sea. Seasonal migrations bring large concentrations of marlin to South America in the fall months, and to the Caribbean in the summer. Peak seasons in North America are also the summer months. That being said, the entire Atlantic population is a single breeding stock, and these fish have proven worthy of the label "highly migratory." In a post-catch survival study, Graves found that two marlin that were tagged with 30-day satellite pop-up tags traveled 750 miles east and 1500 miles northeast, respectively, in the monitored period (Graves). This evidence shows that a marlin released in Ghana could feasibly be recaptured in the U.S. Virgin Islands several months later. These facts underscore the necessity of treating the entire Atlantic blue marlin population as a single group for management under an international infrastructure. The predator-prey relationship between blue marlin and tuna is very important to consider when thinking about management scenarios. Since tunas are the primary food for blue marlin, they are often found in close proximity to each other, and they have similar ranges. This relationship is made even more important because of the prevalence of commercial tuna fishing. This fishery is responsible for most of the blue marlin mortality, as bycatch. Bycatch is defined as fish that is caught unintentionally, or is not the target species of a hook set, and is taken rather than released alive.
Part III: Decline in species health: 1960s Present
Commercial Fishing
Commercial longline fishing began in earnest in the Atlantic in 1956, when the Japanese started targeting yellowfin tuna in the tropical parts of the ocean. The fishery expanded rapidly, and by the mid-1960’s several other countries, notably Taiwan, Korea, and Cuba, joined the effort. This was the time period when the fishery reached its height, with nearly 100 million hooks set annually. Not coincidentally, this was also the height of blue marlin bycatch mortality. In the decades following the 1960’s, blue marlin takings fell dramatically, though they remained higher than pre-1960 levels. This reduction of blue marlin mortality is associated with the migration of fishing effort to the more temperate regions of the Atlantic to the north and south (Beardsley, 1989). The United States also participated in the tuna longlining industry, but since there is no commercial incentive for killing marlin in the U.S., most of those captured incidentally are released alive.

The optimal blue marlin population is that which equals the maximum sustainable yield (MSY). At this point, blue marlin replace their population naturally, though not too much as to become overabundant. Their general lack of predators creates a situation where overabundance can also become a problem. Therefore, population stabilizing at the replacement level is optimal, and is therefore the goal of fisheries managers.

Whereas blue marlin abundance was about two times the maximum sustainable yield in 1960, today it stands at two-fifths of MSY. Maximum sustainable yield is the biomass abundance level at which species replacement over generations can be guaranteed. Obviously, then, any management plan must target MSY levels to be effective, and this already requires rebuilding of the stocks. Currently, commercial longline fishing takes incidental blue marlin at a rate of four times (The Billfish Foundation) the sustainable yield, meaning that fishing is being carried to excess and driving marlin populations to extinction. (see Chart 1 and 2)

NOAA (1999) estimated the economic impact of foregone revenue by U.S. commercial fishermen due to blue marlin discards during 1989-1996, it "ranged from $239,989 to $433, 207…with an eight year cumulative gross revenue of $2.5 million" (2-14). Compared to revenue from the tuna and swordfish industries, and indeed from recreational billfishing in the U.S. alone, this is a relatively paltry sum. However, in Japan, "The various species of billfish now have established markets…that can be distinguished from tuna markets" (King: 1989, 90-91). In addition, King reports that on the international market, billfish prices are on the rise:

Billfish prices are rising faster than the price of most other kinds of finfish, and in recent years have been rising faster than the major components of fishing costs. As long as such market trends continue, interest in commercial billfishing will continue even if billfish become scarcer. (91)

The market is strongest in Japan, where most commercially caught blue marlin eventually ends up. Blue marlin still makes up only a small percentage of the approximately $1.1 billion billfish industry there.
Recreational Fishing
The recreational blue marlin fishery has grown immensely over the past thirty years. At the same time, it has evolved from a kill fishery to a mostly catch-and-release, or tag-and-release fishery. Recreational blue marlin takings are now a minimal part of overall harvests, and "most recreational anglers consider themselves to be strong advocates for conservation of Atlantic billfish resources" (NOAA: 1999, p. 2-13). The economic benefits, however, are tremendous. The recreational billfisherman often has a relatively high income. He enjoys myriad benefits from recreational billfishing. Meyer (1989) notes, "Catch-and-release fishing will generate enjoyment and will create spending in the economy. It may also create lifestyle benefits depending on the characteristics of the billfisherman" (104). In the Atlantic Billfish Fisheries Management Plan Amendment of 1999, NOAA cites research that reports that an angler spends and average of $2,147 total per trip, and makes an average of 13 trips each year.

The plan notes, "Ditton (1996) reported that the annual net economic benefits for the group surveyed was over $2 million" (2-13). These expenditures on trips in the United States are only a small part of the economic impact of billfishing.

Tourism industries of several nations depend on recreational fishing for blue marlin and other billfish. When the landslides in Venezuela devastated that nation, almost all tourism ceased, except for billfishing. Recreational billfishing has expanded into nations rife with political unrest, including Guatemala and Panama, and created a strong and reliable industry that employs native peoples, and generates income associated with tourism throughout the nation. A newly discovered fishery for truly large Atlantic blue marlin has opened in the West African nation of Ghana, and has already accounted for two charter fishing operations and numerous recreational fishing trips.

The impact of the recreational blue marlin industry has several levels. The "Direct Impact" is "the initial purchases by the recreational fishermen" (Rockland: 1989, 256). This would include equipment like rods and reels, plane tickets to fishing destinations, hotel accommodations, boat and gas expenditures, etc. These purchases have an indirect impact on industries that produce the raw materials for fishing products. Further, there is a third level of impact, and that is the impact of the people who are employed by these industries, and their own spending. One can also consider indirect uses of the blue marlin resource. For example, even if a fisherman does not go on a trip, he may purchase an issue of Marlin magazine, or watch a Discovery channel special about blue marlin. These industries also take obvious benefits from the blue marlin fishery.

With such a large and varied economic impact, the recreational blue marlin fishery is quite obviously worth protecting. Revenues from recreational billfishing in the United States dwarf those generated by commercial landings of blue marlin. The United States’ participation in foreign recreational billfishing also accounts for very large revenues in the respective host nations. It would be imprudent to lose such a profitable industry due to poor resource management.
Determining Species Health
The only way to gather information on the species health is to release fish with tags attached. A tag is attached by impaling the tag’s anchor into the fish’s dorsal musculature, in the flesh just below the dorsal fin. Tagging programs have been around since the 1970’s, but in the 1990’s their use became more widespread. Today, free tags are available from a number of organizations, and almost everywhere blue marlin are caught, they are tagged and released. Upon recapture, information including growth statistics and migration routes and distance traveled are revealed, and this contributes to the knowledge of stock health.
Of course, gaining this information requires the recovery of the tags, and many problems exist. Often, tags go unrecognized in recaptured fish, or are not reported even if they are noticed. The possibility of the fish dying (either due to the capture or by natural causes) is also very real. However, Ellen Peel, President of The Billfish Foundation (the largest private tagging program in the world), reports that conventional tag recoveries are as frequent as recovery rates for other animal tagging programs. Others disagree, citing the mere 2% recovery rate as far below normal.

The more reliable tag in terms of getting information and performing studies are pop-up satellite tags (PSATs). These tags contain computer hardware in them, are positively buoyant, and detach after a predetermined amount of time (usually five or thirty days). They are able to withstand depths of about 650 meters, but are sufficiently compact as to not create a major nuisance for a blue marlin. They record water temperature and degree of horizontality. A fish that is actively swimming (and thus alive), will experience changes in temperature depending on the depth at which they swim, and also will keep the tag at most 30 degrees above horizontal, due to water drag at the speed at which it swims (Graves, 2002: 135).

Small studies have been conducted on samples of both commercially and recreationally caught blue marlin. In each study, satellite tags were implanted into the live released fish, and each time almost all of the tags reported back at the end of their tenure results indicating the fish had survived. The caveat to this data is the fact that small sample sizes create a situation where the data is not statistically significant, though they do suggest positive results given a larger sample.

John Graves et al. (2002) deployed nine such tags (PSATs) on recreationally caught blue marlin in Bermuda. After the five-day at-large period, eight of the nine tags popped up and sent data indicating live fish, and the ninth did not report at all. Graves points to several possibilities to explain the non-reporting tag. It is impossible to distinguish between a post-release mortality and an incident of mechanical failure. In any case, the results indicate an 89 percent survival rate even if the non-reporting tag is considered to have died.

Kerstetter et al. (2002) performed a similar study on longline caught blue marlin on the United States Atlantic coast. They released eight blue marlin with five-day tags, and two with 30-day tags. Six of eight five-day tags reported back positively, as did both of the tags with longer soak times. This demonstrates at least an 80 % post-release survival rate.
Part IV: Governing Authorities
The International Commission for the Conservation of Atlantic Tunas (ICCAT)
The government authority on the management of blue marlin in the Atlantic Ocean is the International Commission for the Conservation of Atlantic Tunas (ICCAT). It manages tunas and tuna-like species, including billfish (one of which is blue marlin). ICCAT is an international intergovernmental organization, with the goal of maintaining a sustainable fishery in its target species for both commercial and recreational purposes. The organization is recognized as the only authority with the resources to pursue statistical information and recommend policy changes regarding management of the species it regulates, namely highly migratory pelagic species including tunas and billfish. ICCAT conducts studies to analyze the conditions and trends of stocks of marlin, including ecological, biometric, and oceanographic studies, with a special emphasis on the effects of fishing pressures on these stocks. ICCAT’s major problem is its derivation of authority, "International management, alone, has failed to gain the support of the majority of the countries of the world. It has failed to be supported because the perception has been - I emphasize "perception" - that coastal State interests have not been adequately dealt with or have been ignored" (Blondin: 1989, 323). This lack of confidence has the potential to nullify any efforts the Commission makes towards regulation, if major nations refuse to comply. In order to overcome this difficulty, input from all interested parties must be considered, and a democratically designed policy should be put in place.

Recently ICCAT made its first binding resolution on the subject of blue marlin fisheries. It resolved to reduce blue marlin mortality and landings to 50% of 1999 levels in the years of 2001 and 2002 (see BUM Table 1). It also encourages better monitoring of catch data by member nations. This quota system is to work in conjunction with legal limits in place in the various member countries. For example, the United States maintains a 99-inch fork length requirement for any killed blue marlin, and also a limit of one fish per vessel per day. It is illegal in the United States to sell or purchase blue marlin from the Atlantic Ocean. These limits have been quite effective in reducing recreational harvest of blue marlin, as Atlantic-wide recreational mortality now represents only one percent of total mortality. However, the effect on commercial landings is less impressive. Blue marlin remain a common bycatch on vessels targeting other species, and are often dead upon landing. The recommendation of technological adjustments made by ICCAT serves to try to reduce bycatch mortality. The use of circle hooks, designed to catch in non-vital mouth tissue rather that gut-hooking common with conventional style hooks, is one such gear limitation.
National Marine Fisheries Service
Another group with interests in placing restrictions on blue marlin catches is the National Marine Fisheries Service of the United States (NMFS). NMFS first identified blue marlin as over fished in 1997. Recently, they set forth their management plan in the United States, to work in conjunction with ICCAT standards. They proposed aggressive rebuilding goals, and also management tools including increased size limits, lower bag limits, and increased monitoring and enforcement. They also require release of all marlin bycatch still alive on longline hooks. One would expect that as stocks decrease, fishing pressure would also decrease due to the higher marginal cost of fishing per marlin landed. However, since blue marlin is largely caught as bycatch in the tuna longlining industry, this is not the case. The tuna stock is somewhat healthier than the blue marlin population, and so incidental bycatch is likely to continue at least in the near future. Since the United States accounts for only about five percent of the international fishing pressure on blue marlin, NMFS really has little independent influence on the international problem. Its main contribution to this arena is as the U.S. envoy to ICCAT, where they exert strong influence on ICCAT’s policy directions.

One possible way for the United States to virtually eliminate blue marlin mortality is to give it threatened or endangered species status. Such a distinction would essentially ban takings in U.S. waters, and also provide for a recovery plan, and possible designations of protected habitat areas. However, there are several reasons that this would be mostly ineffective. First is simply that they are so often caught incidentally. Secondly, protective habitat designation would likely eliminate more than just blue marlin fishing, but also eliminate areas that are productive fishing grounds for other species, which would be intolerable for recreational and commercial fishermen alike. Finally, as discussed earlier, such a designation in the U.S. would account for only a small percentage of the blue marlin takings in the Atlantic, meaning that the overall effect of adding them to the Endangered Species list would be minimal.
Relation to Tuna IndustryThe blue marlin fishery is inextricably tied to the tuna longlining industry. It remains a fact that over ninety percent of overall fishing-related blue marlin mortality is due to bycatch in the tuna and swordfish industries. Further complicating the issue is the fact that blue marlin have a rising value in foreign, especially Japanese, food markets. It is difficult to impose restrictions on blue marlin mortality without similarly affecting the tuna and swordfish fisheries. The only way to reduce marlin mortality without negatively effecting the tuna industry (and to a lesser extent the swordfish industry), is to require live release of blue marlin whenever possible.
Part V: Economic FactorsThe economic problem with fishing lies in property rights. The ocean is not owned by anyone, so fish are not the property of any particular country. The fish are considered to be a “capture resource,” which is a good that is not produced or harvested. The lack of property rights creates the problem of open access. Open access is a situation where there is no restriction on who may enter, what equipment they use, and how many fish they catch. Open access is similar to that of the “tragedy of the commons,” where each commercial fisherman has the incentive to try to catch as many fish as he/she can as quickly as possible, even though it may reduce the fish stock’s ability to maintain its population. The end result is overfishing.

The catch rate plays a very important role in sustaining fish populations, especially in the situation of pelagic fish, such as the blue marlin, where there exists the problem of open access. Catch rate refers to the amount of fish taken in a given year. It can be calculated by simply total catch, which was 3155 million tons in 2000. Additionally, it can be tallied by a formula of catch per unit effort (CPUE), where effort can be a unit such as fishermen, hooks in the water, fishing hours, or vessel days. Before WWII the technology of the fishing industry did not allow commercial fishermen to catch more fish than the fish population needed to sustain its size. Coastal vessels, cotton nets, and hand lines limited the number of fish fishermen could catch but as technology has improved over the years, the balance between fish population and the catch rate has tipped the balance to the fisherman’s favor. Though mortality from commercial fishermen’s landings takes an exceedingly large role, the blue marlin’s stock size is also dependent on environmental factors as well as its population growth rate. As the blue marlin population declines, commercial fishermen are going to spend more money increasing the technology they employ in trying to catch more fish, bringing the population of blue marlin to even lower levels. Ideally, the population of the blue marlin should not fall below the point at which the “reproductive potential of the fish population can replace what is taken” (Iudicello et al: 1999, 38).

The open access problem and the lack of property rights create the need for some sort of regulation on the commercial fishing industry. The three main options of regulation would be to control inputs, control outputs, and taxation. By controlling inputs, regulatory bodies can restrict the number of fishermen working in fisheries, the amount of gear or size of the vessel, or limit the amount of time fisherman are allowed to fish.

By restricting the number of fishermen, one is creating “limited entry.” Creating a licensing program will allow regulatory officials to monitor and limit how many commercial fishermen there are. Limiting fishermen will similarly limit catches. This will allow the blue marlin population to increase its stock size. As the population size increases, the effort to catch blue marlin will become easier, since there are more of them out there. The commercial fishermen will expect to gain a higher profit. But this situation does not occur in practice. After a while, those people possessing the license will invest in better technology to increase their fishing effort. They will buy bigger and faster boats and stronger and bigger nets, thus enabling them to catch more fish. Since the only input control is on the number of fisherman, they will increase inputs that are not being restricted, otherwise known as “capital stuffing.” If regulatory agencies placed more restrictions on the inputs, fishermen will find other means to increase capacity, and a cycle of regulation and evasion will begin.

Another way to try to reduce over fishing is through reducing the amount of time commercial fishermen are allowed to fish. If one assumes that a fisherman can catch a certain number of fish in one day, one can calculate how long the fishing period should be based on maintaining the optimal level of catches a year. In practice, this is very difficult to calculate. When there are seasonal restrictions, commercial fishermen are going to increase their efforts during the season they are allowed to fish. Through the use of technology, they will be able to increase the amount of fish they catch for a given period of time, so that they will be about to catch the same amount of fish, but in a shorter period of time (DeAlessi: 1998, 32). This leads to overcapitalization, excessive level of catching power to catch the amount of fish available, which creates inefficiency in the market.

Another input limitation is restricting the technology being used otherwise known as placing technical restrictions. But prohibiting commercial fishermen from increasing their technology will also prevent them from decreasing the marginal cost of fishing. Therefore, since their marginal cost is not decreasing, they will not be able to increase the number of catches that they make. The idea of capital stuffing will occur in this situation as well.

Output controls seem to be a more direct way of reducing the number of catches. Placing an overall quota, or total allowable catch (TAC) on the number of fish being caught is a direct way of controlling the over fishing problem. The difficulty lies in how to distribute the catch limit. The easiest way is to announce the quota at the beginning of the season and then stop the season when the quota has been met. The problem with this situation is that it works similarly to that of the seasonal approach. Commercial fishermen will increase the technology that they are employing so that they can catch as many fish as they can in the shortest amount of time. Another approach to a quota is to place individual quotas (IQs) on each commercial fisherman so that the total amount of IQs will equal TAC. From experience, quotas will only work if they are high enough to allow commercial fishermen to work within them. Otherwise the incentives of illegal fishing will defeat the purpose of the quotas (Gray: 1998, 79).

One can also place a tax on the fish landings. This will be similar to increasing the marginal cost of fishing. By making each catch more expensive, commercial fishermen will not catch as many because depending on the amount of tax, fishermen are not going to catch more than the optimal catch level. The main problem with this situation is that political factions will not allow it to happen.
Part VI: Policy Recommendations
Regulatory Recommendations
There are several areas where policy can decrease overall blue marlin mortality. One good place to start is by imposing gear restrictions on tackle and materials. One of the easiest changes that could be made is by requiring the use of circle hooks, as opposed to J-hooks. Circle hooks are designed to catch in the corner of a fish’s mouth, thereby minimizing the harm done to the fish. J-hooks can be swallowed deep and cause the fish to become gut-hooked, creating substantially more internal damage that would likely decrease chances of post-release survival.

Longlines pose an interesting regulatory problem. The major question is how to design them to discourage marlin bycatch, without diminishing their capacity to catch target species (tuna or swordfish). One possible method is setting the lines deeper, where marlin are less frequent but tuna still roam. Another method that would reduce bycatch is the placement of a length cap on the line, perhaps 6 to 8 miles per set. By lowering the number of hooks in the water, you decrease the amount of bycatch. Obviously, though this method would also reduce the ability to catch the target species for exactly the same reason.

The other method that should be put in place that would certainly create positive benefits is a live release requirement. Any fish that is alive upon landing must be released, preferably with a tag to facilitate research. This is absolutely essential. A marlin that is dead when brought boatside may still be landed.

Commercial netting should be altogether eliminated or otherwise severely restricted. Nets are indiscriminate in their catch, and the fish that are caught cannot be released due to damage caused by the nets. Because of this, netting must be minimized in order to avoid incidental catches of blue marlin. Each of these gear restrictions must be spearheaded by ICCAT, as the governing body. They cannot be effective if only a few countries use them, especially if the major fishing nations of Japan, Korea, and Taipei do not comply.
Scientific Recommendations
It is a mantra of the scientific world that we always need more information. In that vein, more scientific studies, with greater sample sizes (and budgets), would help us to better define both species health, as well as migratory information. This information would certainly allow us to make better decisions as far as quotas, seasonal closures, and other policy directives. Additionally, more reliable post-release survival studies must be done to prove conclusively that a live-release requirement is a productive policy to protect blue marlin species health.

Catch statistics taken today commonly include information on catch location, amount, and effort. However, it is difficult to determine how much effort actually goes to blue marlin, since they are mostly bycatch. The problem lies in the fact that species health is best determined by finding catch-per-effort rates, and "It is therefore difficult to determine which part of the fishing effort is being applied to billfish stocks…The competition between the different species of billfish for longline hooks compounds the problem, further confounding the interpretation of catch-per-effort statistics" (Farman: 1989, 218). Because of these difficulties, tagging studies are more helpful in determining species health.
Economic Recommendations
In order to make effective policy for conservation, the economic issues must be addressed. Effective methods include strategic time and area closures, especially in well-known spawning areas and seasons. Closing an area to all fishing is a surefire way to prevent overfishing. Again, ICCAT must take the lead in declaring places off limits to fishermen. Due to the international nature, of the problem, the closures must be internationally recognized and enforced.

Another policy that could prove effective is the United States’ plan to contract to longlining industry, and buy back some of the equipment to subsidize the industry’s losses. In conjunction with the Atlantic Highly Migratory Species Act (1999), the U.S. closed fishing grounds for certain months of each year totaling 160,000 square miles of the Atlantic Ocean and Gulf of Mexico that were designated as breeding grounds and designated for the rebuilding of fish stocks including marlin. In the introduction of this bill, the sponsor states, "Recognizing the economic impact on commercial fishermen, the legislation provides a fair and equitable program for longline vessel owners who are adversely impacted by the [fishing] prohibition. Funding of the permit buyback program would come through a partnership of the recreational and commercial [fishing] industries and federal funds" (AHMS: 1999, Par. 5). Equipment buyback is an economic incentive for commercial fishermen to relinquish their activities, and take up another line of work, presumably less destructive for the marlin population. This program is well designed, and if it were adapted on an international scale, it could seriously reduce the level of marlin mortality, as well as aid the recovery of the species.

It seems that the most concrete method of economic management is the use of output quotas. ICCAT has instituted successively more restrictive quotas over the last several years. The organization first recommending 50% cuts from 1996 catch levels in the succeeding years. When it was demonstrated that blue marlin were still overfished, the quota was reduced to 40% of 1999 levels by 2002. This was an important cut, because it was determined that mortality needed to be reduced by 60% simply to prevent further species decline. Dr. Goodyear’s (2000) estimate of the need for a 90% cut to guarantee the recovery of the species is still not a feasible policy.

Another adaptation of quotas that would make them easier to accept politically is customizing them to each nation. Quotas could be assigned based on several factors particular to a nation, including previous catch levels and national demand. For example, because it is already illegal to sell or purchase Atlantic blue marlin in the United States, there is virtually no demand. Therefore, the United States could be assigned a quota that caps landings at a small percentage of previous years. Conversely, since Japan accounts for such a high percentage of blue marlin mortality, and there remains a high demand among consumers there, they would take a quota that makes comparatively smaller, though still significant cuts in landings. It is important to note that all fishing nations will have to accept more restrictive quotas if the goal of blue marlin recovery is to be reached.

Blue marlin quotas are feasible because they are still not the target species. This means that the pressure from illegal fishing would probably be minimal. But illegal fishing pressure is not the biggest concern; that is still bycatch. Quotas could be easily met, however, with a live release requirement for all marlins that do not die before being landed.
Enforcement Recommendations
This point brings to the fore one of the biggest problems in any management system, monitoring and enforcement. Currently nations report catches with logbooks for the most part, with a voluntary observer system used infrequently. The methods of the Commonwealth of the Northern Mariana Islands Division of Fish and Wildlife (DFW) for collecting landing statistics, the "trip-ticket" system, seems to be applicable and effective:

The DFW provides numbered two-part invoices to all purchasers of fresh fishery products, including hotels, restaurants, stores, fish markets, and roadside vendors. Dealers complete an invoice each time they purchase fish directly from fishermen. They keep one copy for their records and provide one copy to DFW. Some advantages of this method of data collection are that it is relatively inexpensive to implement and maintain, nearly complete coverage of the commercial fisheries is fairly easy to accomplish, and DFW can provide feedback to dealers and fishermen to ensure data accuracy and continued cooperation. (CNMI, Par. 1)

In addition to a trip-ticket system, observers need to be used more regularly to make independent reports of blue marlin bycatch landings. Observers should be placed on at least half of the boats in each fleet to monitor catches and release practices, where applicable (as in the live release requirement). The observers need to be sponsored and provided by ICCAT, so that there is some force behind its position of government.
Part VII. Conclusion
All of the research conducted regarding the status of Atlantic blue marlin stocks indicates that the population is not healthy. In fact, overfishing is occurring, and at rates that severely imperil the continued existence of the species. Several studies conducted by ICCAT as well as independent organizations like the Billfish Foundation find that marlin fishing is going on at a rate of four times the MSY, and that stocks are currently at a level that stands at only 40% of the biomass associated with MSY. Chambers and Associates, an independent conservation oriented consulting firm, concludes that if current catch rates continue, Atlantic blue marlin will be extinct in perhaps as few as 10 years!

Dr. Phillip Goodyear predicts that catch reductions of 60% are necessary simply to prevent further stock decline, and that recovery will require cuts of at least 80%. Such drastic cuts in catches will be difficult to achieve across international boundaries, and yet this is the task for ICCAT. The Commission must impose regulations that will be effective and yet strict. The biggest test will be whether the member nations can unite in the face of stronger restrictions that are necessary for species recovery, because the recovery of blue marlin cannot happen without unanimous support. The level of international compliance in the face of such restrictive measures will demonstrate whether or not ICCAT really has the strong governmental authority it needs to affect the necessary changes.

The methods that will be most effective in managing blue marlin in the coming decades are a combination of economic restrictions and incentives, and legal regulatory measures. The economic restrictions should include seasonal and yearly national quotas, area closures in spawning grounds and other critical habitats, and possibly even longline industry contraction. Legal regulatory policy should include measures for gear requirements that decrease incidents of bycatch mortality, like circle hooks instead of J-hooks, recreational size and bag limits (like those in place in the United States), and the elimination of netting practices for highly migratory species like tuna. A combination of these policy directives will make a positive impact on the recovery of blue marlin from their currently overfished state.

Finally, the importance of increased scientific studies on population and stock assessment cannot be overstated. Better knowledge about the fish itself will make the decisions about what is necessary for recovery more clear. There is a need for better knowledge on postrelease mortality in both commercial and recreational fishing settings, and also for better stock assessment overall. Better reporting and monitoring are also needed to get a better picture of what is being taken. Better science is the third and final piece of the puzzle in blue marlin management.

There are many variables in the management of blue marlin in the foreseeable future. However, one thing is clear: Atlantic blue marlin are worth saving. The myriad benefits include recreation, food, and economic stimulation. Ernest Hemingway’s famous words in the Old Man and the Sea are an apt tribute to this great game fish, "Thank God, they are not as intelligent as we who kill them; although they are more noble and more able" (63).
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