The Atlantic Ocean is a really big fishing hole.

Besides the enormity and variety of gamefish populations the Atlantic hosts, the ocean borders several countries, each, no matter how large or small, vying for its fair slice of the pie, plus a few other nations who wet a line in the pond that want to crash the dessert table.

Because of shared resources spread across such a large body of water, monitoring the status of fish populations that inhabit these waters is tough, to say the least. Just from the United States' standpoint, a host of acronym agencies that make alphabet soup look bland are involved with management.

The fish don't recognize borders or territorial waters either. Some migrate all over the place while others, such as some bottomfish, are happy to camp out on a piece of live bottom right off of the Palmetto State.

Nonetheless, South Carolina Sportsman magazine is here to breakdown the information and tell you what is happening offshore.

As you may recall from the 2007 Saltwater Inshore Preview in the February issue, monitoring fish species revolves around sampling. There are two types of sampling that fisheries biologists utilize, fishery-dependent and fishery-independent.

Fishery-dependent sampling entails collecting data from fishermen, commercial and recreational. An example might be total landings of yellowfin tuna reported or sold in the U.S. or size, sex and age of king mackerel weighed at fishing tournaments. Each one of these pieces of information provides evidence for stock assessment.

Fishery-independent sampling is collection of data that doesn't rely upon fishermen. It might involve fishing gear but is independent of someone fishing. For example, fisheries biologists might set a length of long-line gear in a structured manner that meets certain statistical rigor to monitor a particular species.

When fishery-dependent and independent data are combined, fisheries biologists are able to converge on the status of gamefish populations.

However, the absence of data, be it fishery-dependent or independent, can make the task much more difficult.

For evaluation of offshore species, fish could be divided into two groups, sedentary species such as bottomfish that are slightly easier to sample than the highly-migratory species, such as billfish and tunas that swim all over the place.

The highly-migratory species are regulated by the International Commission for the Conservation of Atlantic Tunas. Fish with more localized movements are regulated by one of eight regional fishery management councils in the United States, such as the South Atlantic Fishery Management Council.

The SAFMC is responsible for the conservation and management of fish stocks within the federal 200-mile limit off the coasts of North Carolina, South Carolina, Georgia, and eastern Florida to Key West.

With an idea of how fisheries populations are monitored, here's a look at several popular offshore gamefish that are found off the South Carolina coast.

"Let's start with the great news," said Dr. John Dean, Professor and Senior Fellow of Science and Ocean Policy at the University of South Carolina and, until recently, chairman of the U.S. Advisory Committee for ICCAT and Chairman of the Highly Migratory Species Committee of the SAFMC.

"Swordfish are back, and back big time," he said. "These fish have ,responded to the management actions that were started in the mid 1990s."

Dean is referring to the drastic cuts placed on the fishery starting in 1995.

"In the early 1990s we had to come to grips with the fact this fishery was near total collapse from overfishing," Dean said. "There were terrific cuts in total allowable catch, which was primarily in the commercial fishery since recreational fishing accounts for very little harvest, minimum sizes implemented and time and area closures, such as the closure of the Charleston Bump.

"Through ICCAT, the United States took the biggest hit, but the swordfish population has recovered at or above maximum sustained yield."

Maximum Sustainable Yield (MSY), a term scientists use, is the highest amount of allowable harvest from a population without causing a decline in that population.

Swordfish populations were assessed by ICCAT in 2002 and again in 2006. The 2006 assessment indicated the North Atlantic population had improved because of strong recruitment during the late 1990s, combined with the reductions in total catch, especially compared to the peak catches of 1987.

Given that the swordfish population is nearly rebuilt and operating near MSY, ICCAT believes - if the current management strategy is maintained - swordfish stocks are likely to remain near levels that would produce MSY under existing environmental and fishery conditions.

This means recreational anglers who head offshore in the late summer for night-time swordfish trips should continue to find good success.

"With a decline in long-lining effort following the restrictive swordfish regulations, one of the beneficiaries was billfish," Dean said. "Although the recreational effort for blue marlin has increased, the fishery is nearly all catch and release. It also is a fishery that features high minimum sizes and there is virtually no commercial value for blue marlin, outside of the value of the fishery as a recreational fish, which is tremendous."

ICCAT assessed blue marlin populations in 2000 and 2006. Data is scant, but it appears that the long-term decline in the abundance of blue marlin may have slowed or halted. Blue marlin officially are classified as overfished and overfishing is occurring.

The suggestion that several abundance indicators show blue marlin populations could be recovering requires the confirmation of at least four or five years of data. As such, current management recommendations already in place should continue. It was suggested that should ICCAT wish to increase the likelihood of success of current management measures, further reductions in mortality would be needed, for example by expanding the use of circle hooks.

"I don't get what the thinking is with white marlin," Dean said. "This is a fishery that functions very similar to blue marlin. Recreational fishermen value it, and there is little interest in from the commercial fleet.

"The reduction in effort from the long-lining fleet has helped the species, yet fishermen continue to kill white marlins along the East Coast. I don't know why we haven't turned the corner yet from a conservation ethic standpoint with white marlins. There is incredible commercial value from the recreational fishery.

"The recreational fishermen have the responsibility for the future fate of white marlins."

Two groups filed a petition with the National Marine Fisheries Service in September 2001 to list Atlantic white marlin as either a threatened or endangered species, based on the sharp decline the population had been undergoing since the 1960s.

NFMS announced in late 2002 that listing white marlin under the Endangered Species Act wasn't warranted. ICCAT conducted an assessment of white marlin in 2006, and found white marlin populations are depressed but declines in abundance may have reversed. Like blue marlins, white marlins have the potential to rebuild under current management. Verification still will be needed from longer data sets and improved data collection.

The result of the subsequent litigation and settlement agreement over the white marlins' listing has prompted NFMS to initiate a status review of white marlin. This isn't a formal assessment of the species like that conducted by ICCAT but rather a request for new information on the status of and threats to white marlins. Examples might include life-history information, such as growth rates, findings from post-release mortality studies, and habitat destruction.

Although South Carolina offshore anglers are more likely to hook blue marlins and sailfish, any future regulation changes for white marlins would probably affect anglers here.

There has been no new assessment of sailfish populations by ICCAT since 2001. Because of this, no relative estimates of abundance are available. ICCAT reports that it is unknown whether sailfish stocks are undergoing overfishing or if stocks are overfished.

Dean has a much more positive take on the status of sailfish.

"Despite no new assessment, I believe sailfish populations are doing fine," he said. "The fish matures at an earlier age; it is primarily a release-fishery by recreational anglers; and the fish is largely not captured in the long-line fishery. These factors work in favor of maintaining an abundant sailfish population.

"Since sailfish occur much closer to the coast than other billfish, coastal water quality, for example, is probably a bigger threat than something related to the fishery itself."

The last assessment by ICCAT of yellowfin tunas was conducted in 2003. Catch and effort data through 2001 was rigorously evaluated in that assessment but the latest data provides further insight into yellowfin populations.

"Yellowfin tunas are currently classified as not overfished but overfishing may be occurring," Dean said. "The stock assessment indicated that yellowfin populations are at MSY or slightly above it."

Dean said any changes in yellowfin regulations probably wouldn't affect the United States because it's a small player in the yellowfin tunas fishery.

"The U.S. accounts for only about 3 percent of total landings of yellowfin tunas," he said. "The fish are active spawners in the Gulf of Guinea off of West Africa and off of Venezuela and, to a lesser extent, in the Gulf of Mexico.

"The fish that South Carolina anglers encounter are mostly fish spawned in the Gulf of Guinea. They ride the ocean currents from there, and pass off of our coast as older juvenile fish moving towards sexual maturity. It is rare to see a sexually-active yellowfin off of South Carolina. From here, tunas move with the currents back to the Gulf of Guinea to spawn."

Dean said the majority of harvest of yellowfin tunas occurs in the Gulf of Guinea for the canned-tuna industry. He said while the fish have annual variations in abundance he has not heard of any rumblings to date about any efforts to reduce the harvest of yellowfin tunas.

"God designed dolphin for all of us," Dean said.

The species matures at a young age and at a size that's not worth keeping by fishermen. In addition, dolphins are prolific spawners and fast growers.

"There is year-to-year variation in dolphin populations, as with any fish," Dean said. "However, the dolphins' traits and the conservative management plan is in place for the species favors its current abundance. Anglers should continue to see good dolphin populations."

King and Spanish mackerel populations are regulated by the SAFMC, and Dean said, like swordfish, these two species are success stories of effective regulations.

"Kings and Spanish show year-to-year variations, but they are doing great overall," Dean said. "Harvest by both commercial and recreational fishermen in the 1970s and early 1980s exceeded the reproductive capacity of the populations. Beginning in 1983, quotas, trip limits, gear restrictions and bag limits helped rebuild king and Spanish mackerel stocks."

SAFMC reports landings for king and Spanish mackerel have remained below total allowable catch. Despite this fact, the SAFMC remains concerned that a shift in effort towards the mackerels could lead to overfishing of both species.

"What you see currently happening with mackerel regulations is adaptive management," Dean said. "Because several vessels in the snapper/grouper fishery also participate in the mackerel fishery, the stricter regulations recently enacted for the snapper/grouper complex could lead to a shift and increased effort towards kings and Spanish, which could lead to overfishing and a closure situation.

"To avoid a season closure, SAFMC is proposing to reduce the total allowable catch for mackerels. This shouldn't affect the recreational fishing experience for either species,"

Many bottomfish species that S.C. anglers will find offshore are regulated by SAFMC, but a program within the South Carolina Department of Natural Resources provides a snapshot of populations off of the state's coast.

"Several species of bottomfish are a favorite target of recreational fishermen and anglers on headboats," said Pat Harris, DNR associate marine scientist and coordinator of the Marine Resources Monitoring, Assessment and Prediction program.

"The MARMAP program provides an index of abundance for species," Harris said. "Some people have been critical of the program because they say we aren't sampling where the fish are located.

"MARMAP is a fishery-independent sampling procedure that samples the same areas at the same time of the year. We can annually look at the changes in fish populations at those areas. Any change in fish populations should be consistent between all areas where the fish occur, whether they are the best or marginal areas. Therefore, no matter where you are sampling, you should detect some sort of change if one has occurred."

New regulations were put into effect in October 2006 for several species in the snapper/grouper complex, and many of the changes in these fish populations have been captured by MARMAP.

"Prior to 2003, we were seeing an increase in vermilion snapper," Harris said. "We had a cold snap in 2003, and since then we haven't seen a rebound. In fact, catches remain below the 17-year average.

"Recreational catches have trended downward since 1982 but have shown an increase since 2002. The 2005 catch estimate was about twice the 14-year average for the recreational fishery."

Vermilion snapper are classified as not overfished but undergoing overfishing. This means the proportion of stock taken by the fishery is too high but the biomass of the stock is not too low.

If overfishing is allowed to continue, the stock would decrease. As such, regulations have been changed (the minimum size was increased from 11 to 12 inches).

"Black sea bass are classified as overfished and undergoing overfishing," Harris said. "Both the commercial and recreational landings have shown a downward trend since 1991. Most recent MARMAP samples are near the 18-year average.

"The biomass of black sea bass has been stable since about 1990, but it appears to be about 25 percent of what it would be if the population was unfished. It is nowhere near the biomass of fish that occurred in the 1960s and 1970s."

The recent assessment of black sea bass led to regulation changes for commercial and recreational fishermen. For recreational anglers, the minimum size was initially increased from 10 to 11 inches, and will increase to 12 inches beginning June 1, 2007. Further, the bag limit was reduced from 20 to 15 fish per person per day.

"Red porgy are showing signs of improvement," Harris said. "The commercial and recreational landings of red porgy have remained low in recent years because of restrictive catch limits.

"MARMAP data has indicated an increasing trend in abundance of red porgy and rebuilding of those stocks. The 2005 estimate was above the 18-year average and close to the peak of 1992.

"Red porgy supported a substantial fishery in the 1970s and 1980s. By the mid 1990s, the fishery had become severely depleted. Regulations were enacted that have helped recover the species.

"With this recovery, the bag limit for recreational anglers was recently increased from one to three red porgy per person per day."

Declines in snowy grouper lead to a reduction in bag limit for recreational anglers. Anglers are now limited to one snowy grouper in the five-grouper-aggregate bag limit.

Despite the mixed news for offshore species, Dean and Harris recommended anglers keep things in perspective.

"We've learned a lot in recent years through research that has allowed us to better manage these stocks," Dean said. "The research funds are very limited, and in some cases drying up, yet we've discovered a lot of information that has improved our understanding for many of these species. This comes at a time when there are more fishermen vying for these resources.

"I think it's great that we currently have success stories, such as swordfish. It shows that with the correct resources, the process works."

Harris cautioned anglers about shifting baselines.

"Many of today's anglers have been fishing for 20 years or less," he said. "As a result, a lot of them don't recall what fishing was like back in the 1950s and 1960s. That should be a benchmark. What fishing is like now doesn't compare, in some cases, to what it was like back then.

"Everything is relative to what you saw yesterday. The time scale to provide a baseline for populations has to go back further."

Offshore populations are going to ebb and flow some as the fish move in relation to bait and environmental conditions.

As time moves forward, the data should become stronger and bumps in population size will be smaller, and hopefully, begin to trend only upward for all offshore species.