GULFPORT, Miss. (AP) — During the winter months, the Mississippi Sound appears dead with little movement of fish other than the species, such as speckled trout, redfish and black drum, that call the body of water home.
The summer months, however, are a different story as the Sound turns into a nursery for many different species.
The Sound, which includes the waters north of the Mississippi barrier islands to the beachfront, attracts minnows, crabs and shrimp from the spring to the late fall.
The reason for such diversity of marine life is the nutrients that dump into the Sound on a daily basis.
"The Mississippi Sound is nutrient-rich water in which our marine fisheries thrive," said Kerwin Cuevas of the Department of Marine Resources in Biloxi. "The Sound gets its nutrients from the several rivers that churn and dump water across the state of Mississippi.
"The Mississippi River, Pearl River, Jourdan River, Tchoutacabouffa River and the Pascagoula River all play a vital role in this valuable eco system. The nutrients are food for marine invertebrates, which are food for small fish such as the Gulf menhaden. Then other, larger marine fish feed on menhaden and other filter feeding species. It's a giant food web," he said.
One of the larger species cruising the Mississippi Sound during the spring and summer is the shark, an apex predator that has been around for more than 400 million years.
The shark also controls the food chain.
"Sharks are here," said Jill Hendon of the Gulf Coast Research Lab in Ocean Springs. "We see a seasonal shift in the numbers present in the Mississippi Sound, and right now we are in the middle of 'shark season.'"
Sharks are present in Mississippi's coastal waters during the spring through fall and then they move offshore in the winter months.
"Our shark lab at USM's Gulf Coast Research Laboratory samples for sharks during the spring, summer and fall months to assess the species diversity and population numbers in our region," Hendon said.
"Currently we are finding that our catch numbers are very similar to those of previous years, and to date we have seen nothing out of the ordinary."
Despite its shallow water, the Mississippi Sound has attracted aggressive sharks such as the Tiger, one of the animals considered to be man-eaters by biologists, on a yearly basis.
The more common sharks in the Sound are Atlantic sharpnose, blacktip, finetooth, bonnethead and bull.
Some of the species spawn in the Sound while others invade the area looking to feed on baitfish, including menhaden, that have already spawned.
Although feared by some anglers and swimmers, the shark plays a major role in keeping the ecosystem in check throughout the Mississippi Sound by eating dead or dying fish.
"We are very lucky because the Sound is a great nursery area for many shark species," Hendon said. "The protection that the shallow waters and sloughs provide, as well as the nutrient-rich inflow of riverine water, make it a great place for shark pups to grow and develop.
"Adults seem to prefer the higher salinity waters (25-to-30 parts per thousand) and are typically found out by the islands. The presence of sharks in our waters allows for a great ecosystem dynamic and can actually aid in keeping populations of other coastal fish at a healthy level.
"By far the most abundant shark in our area is the Atlantic sharpnose shark (often noted by the white spots present on its body). We also see many blacktip, spinner, bull, finetooth and bonnethead sharks. Out near the islands we also encounter blacknose, tiger and occasionally a hammerhead."
In all, there are more than 360 shark species worldwide. Of that number, 10-to-12 species can be found in the Mississippi Sound and an additional 15-to-18 in the offshore waters of the Gulf of Mexico. Some species can reach weights of more than 1,000 pounds.
Hendon said there is a lot left to be learned about sharks.
To help learn more about the shark, the Research Lab has established a tag-and-release program.
If a tagged shark is caught, call the Lab at 872-4257.
"We would also like to make anyone out there fishing aware of our tagging program," Hendon said. "During our sampling we tag and release the sharks we catch in hopes that someone else will catch our tagged fish in the future.
"Our tags are yellow or red and can be found attached to or at the base of the dorsal fin. If you catch one of our tagged sharks, please make note of the tag number, species of shark (if known), a total length for the animal, and the GPS location where it was caught.
"By calling us with these details we can obtain growth and movement data for this animal, which in turn will give us a better idea of the health the shark populations in our area. You will also receive a tag report for the animal so you can see what we learned from the shark you caught. Only with the help of our local anglers can we obtain this valuable information," Hendon said.
Information from: The Sun Herald, http://www.sunherald.com