A study due to be published soon will further establish Bermuda's large international role in the scientific study of blue marlins, The Royal Gazette has learned.

The Bermuda Department of Fisheries - in cooperation with the Virginia Institute of Marine Science and the US National Marine Fisheries Service as well as several of Bermuda's charter captains - have been conducting a catch-and-release programme with satellite tags on blue marlins of different sizes.

Their efforts featured prominently in Marlin sportfishing magazine's March, 2003 issue in an article entitled "Grander Blues of the Atlantic".

"Granders" (blue marlins weighing over 1,000 pounds) were unheard of until 1931 when one was caught off Tahiti. They have become increasingly common in recent years and scientists were eager to find out why.

Better fishing technology and communication between fishermen was one reason put forward. However the suggestion that the increase in larger marlins signals the end of the species with all the mid-size marlins fished out (similar to the dilemma facing the Atlantic bluefin tuna population in the 1970s) was also put forward.

The theory was dismissed - for now - but scientists have warned that populations are decreasing so severely that they may be facing a crisis within the next two decades. With that in mind, studies such as the ones conducted by the Department of Fisheries are driven to provide essential data that could save the marlin population.

The pop-up satellite tags the study used, as Dr. Brian Luckhurst of the Department of Fisheries noted in an article in April's Envirotalk Environmental bulletin, allowed scientists for the first time to obtain detailed information about the movements and behaviour of blue marlins after release.

The first study in the Atlantic using these tags (which were programmed to release after only five days) was conducted out of Bermuda in 1999 by Dr. Luckhurst along with Dr. John Graves from the Virginia Institute and Dr. Eric Prince from the National Marine Fisheries. The data from the tags demonstrated the marlin not only survived the catch-and-release, but swam up and down the water column and travelled significant distances.

Dr. Luckhurst and his team conducted a follow-up study in 2000-01, deploying pop-up satellite tags from commercial longliners. Those survival results appeared comparable to their first study. One of the marlin in the second study travelled just over 600 miles and another more than 1,200 miles in 30 days.

In the summer of 2002, the team tagged fish off the Bahamas, where blue marlin are said to spawn. Two of those released last summer went away wearing 30-day tags. The satellite recorded up and down movements, travel distances and water temperatures for four weeks, providing the team with the best long-term look at Atlantic blue marlin survivability to date.

In the autumn, they tagged off the US Virgin Islands (St. Thomas). The data from these 2002 studies are due to be published in scientific papers later this year.

"The main reason for us doing this is to try to better understand their biology and movements, so we can try to find some way to increase survivorship," Dr. Luckhurst said.

"The basic equation is, if you don't have any blue marlin to catch you don't have any sportfishing" - a sport which brings in hundreds of millions of dollars in revenue each year over the Atlantic.

"This year we are planning to deploy a bunch more tags in the Bahamas and also here in Bermuda," Dr. Luckhurst continued. Each year, he explained, the team builds upon the results from previous years, creating a long-term follow up from the initial study in 1999.

Marlin magazine noted that the trio expect to tag a grander blue marlin within the next year (or two) and follow its movements with a satellite receiver over the course of a month.