Many new visitors are quick to express their concern about swimming in the ocean, fearing they may be attacked by sharks. Talk with a local and you will quickly find out that most of us consider it a lot safer to swim with the sharks than to drive on U.S. 1 every day.

One of the most common sharks you are likely to encounter in the Keys is the Nurse Shark. These affable creatures are much more interested in eating crustaceans and small fish than dining on an alcohol saturated tourist. While most sharks must remain in constant motion to keep water flowing through their gills so they can breathe and survive, Nurse Sharks are one of the few that can stop and remain motionless for extended periods of time. Many first encounters with Nurse Sharks occur when an inexperienced diver pursues a lobster under a coral head and comes face to face with a "sleeping" Nurse Shark. Startled, both diver and Nurse Shark usually end up "running away bravely," and as a result both are no worse off for the brief encounter.

The truth is, sharks are in a lot more danger from humans than we will ever be from their formidable jaws. As a result the shark population has ultimately suffered tragically from its interaction with humans. Fortunately, there are a few dedicated marine scientists in the Keys who are working countless hours studying these predators, hoping to ultimately protect them and their environment. One of these dedicated researchers is Wes Pratt. He worked as a researcher with the Fisheries Service in Narragansett, R.I., and is now working with Mote Marine on Summerland Key. He has spent more than 42 years studying and tagging sharks.

When you talk with Wes, it is easy to see that he is enamored with these marvelous creatures, especially Nurse Sharks who spend the majority of their life span living in our shallow tropical waters. In fact, this is the 19th consecutive year that Wes has studied the migration and mating behaviors of Nurse Sharks in the Dry Tortugas.

On one excursion, Wes was so intent on video taping the amorous behaviors of these usually docile animals that he got a little too close and ended up being entwined in their mating roll. Luckily they didn't turn their mating behaviors on Wes, but his brief and bizarre ménage a' trios did result in a cracked underwater housing and a ruined camera.

In the studies at the Dry Tortugas, Wes has observed that the Nurse Shark lives in a kind of "soap opera" of mating, rejection, multiple partners, hot males and controlling females; wanting to get pregnant but not with just any fellow. Female nurse sharks mate and more often avoid mating by getting into water so shallow that their big dorsal fins are high in the air. Adult females seven to nine feet in length "refuge" against shorelines to help them avoid the many amorous males. Unlike most other fishes, all mom sharks (and cousins skates and rays) make little ones by internal fertilization. Males have pairs of "claspers," penis-like organs, on the inner edge of the pelvic fins. To "romance" a female, the male must grasp her pectoral fin in his mouth, all the way up to her gills. He then arches and rolls her into a mating position. A female spends over a year developing big glossy tennis ball sized eggs in her uterus. In June, many males are in attendance, drawn by female reproductive perfumes. Males can even cooperate to herd and block the females.

Wes, his wife Theo and his colleagues are working together to unlock the wealth of information held by these easy-going beautiful animals. They have learned that Nurse Sharks, and by extension other sharks, are a valuable, exciting, but vulnerable part of Keys marine life. Live sharks help protect our reefs, draw visitors to our islands and make our local waters a rich and enchanting sea. We need all of our sharks alive and healthy.

Many adult and juvenile sharks have been tagged by the team. We get visits every year from sharks that were tagged in the early 1990s. They are like old friends returning. Each visit is a valuable data point. Though a local shark, some of the Tortugas males have wandered as far as Key Largo. Tags help to understand seasonal movements and distribution. If you catch a shark of any species, please look for a tag on the dorsal fin and note the number, tag color and location of capture. Some tags have phone numbers and addresses but most are mossy and hard to read. Please write it down immediately and phone the number on the tag or the Mote Lab at 305-745-2729. Or, e-mail wpratt@mote.org. Either cut off the tag or leave it in place as you release the shark. Many thanks in advance.

As vital members of the marine community, sharks need to be accurately understood and, as it turns out, conserved. They are both vulnerable and valuable right where they are. A good shark is not a dead shark. As top predators, sharks keep the web of marine life healthy from the top down. As sharks die out, so do the reef fish and, interestingly, coral also die, corrupted by a failure of a trophic cascade, an energy flow down through living reef communities.

Like I tell visitors to the Keys, if you happen to be out snorkeling and you run into a shark, you should really consider yourself lucky. Just remain calm (you can't out-swim them anyway) and simply take a moment to admire their stealth and beauty.

I would like to personally thank all of the researchers in the Keys who have dedicated their lives to saving the Keys ecosystem. If you don't think their environmental work is vital, consider the fact that our Conch population was decimated due to over-harvesting to the point that we are no longer able to legally take Conch. This is a sad reflection on a location that prides itself on its conch heritage.

Capt. Pete Peterson welcomes comments and suggestions sent to petersonventures@aol.com.