Ever look out over the Gulf of Mexico, perhaps during a nice sunset, and wonder what kind of wild things were swimming beneath the surface of that large body of water. The near tropical waters in South West Florida are rich in many forms of sea life. Here one can skip the nature shows on TV as some of the largest, most impressive creatures live a lot closer than the sea at the end of the horizon.
Bull sharks ( Carcharhinidae leucas ) are found throughout the world's tropical and near tropical oceans, rivers, and even some freshwater lakes. In fact, they have been found 2,000 miles up the Amazon and Mississippi Rivers. Their close proximity to humans, large size, and aggressive attitude make bull sharks one of the most dangerous predators in the sea. They are the only species of shark that is frequently found in freshwater, and are very common in the waters of Lee County.
During the summer months, bull sharks mate near shore and often inshore around the mouths of rivers and inlets. Females carry the young for 10-11 months and give birth to live 29-inch pups between April and June. At about 5 or 6 years of age and 6-7 feet in length, bull sharks reach sexual maturity. They will continue to grow to lengths approaching 12 feet, and weigh more than 500 pounds! Females grow slightly larger, having a longer lifespan of about 16 years as opposed to 12 for males. Seen from above, they appear pale to dark grey, helping them disappear against the murky bottom. The bottom of the shark is white and helps disguise it's silhouette from peering eyes below.
These large ill-tempered beasts have a reputation for attacking people; however, permanent residents of the sea have much more to fear than we do. Bull sharks have been known to eat almost ALL types of fish including large tarpon. Sea turtles and birds have also fallen prey to them, as well as occasional dolphins and dogs. They are very opportunistic feeders to say the least. Once the food source is caught there is little escape. Smaller prey is eaten and swallowed whole. A bottom row of thin sharp teeth grab and hold larger meals while the wide serrated top row cut the food into manageable pieces.
Fearsome and dangerous as they might be, bull sharks are one of nature's beautiful designs that helps keep life in balance under the sea. Upper predators such as this weed out weak, sick, and old sea life, preventing disease and ensuring the strongest and most able are left to reproduce. They have coexisted closely with humans for thousands of years and with common sense, most tragedies can be avoided. Sharks typically feed in low light situations like morning, evening and nighttime. It is easier for most well evolved predators, land and sea alike, to use their advanced senses to gain an advantage over their prey under these conditions. Avoid swimming in waters adjacent to fishing piers where anglers may be throwing left overs from bait or cleaning fish. Also inlets with deep fast moving water are highly traveled areas for sharks.
If you spend enough time near the water here in South West Florida, you will have enough first hand experiences for your own series of nature shows. We have all the exciting, adrenaline pumping, man-eating creatures living right here! As a biologist and life long boater, I know caution should be used around open water for many reasons. However, I feel very fortunate to be able to share the water with such impressive animals. In fact, I can't wait until my next encounter! Maybe that next piece of mullet I throw out for bait will be the one. Interested in coming along?
Keep On Pluggin'
Capt. George Howell