Diving

Great barracudas are top of the food chain. But their populations may still be at risk

A great barracuda patrols the water above the Spiegel Grove wreck.
A great barracuda patrols the water above the Spiegel Grove wreck.

It was one of those days in the Florida Keys publicized by the visitor’s bureau. 

The temperature was in the low 80s, the wind was calm and the sea was almost flat. 

The dive boat pulled up and tied off to the mooring ball attached to the bow of the purposely sunk wreck of the USS Spiegel Grove, a 510-foot ship landing ship dock, which lies in 130-feet of water near Dixie Shoals off Key Largo. 

There was another bonus – no current! (On many days divers need to firmly grasp a line attached from the boat to the mooring ball line and then down the mooring ball line to the ship to avoid being swept  away by the prevailing current.)

I stepped off the stern of the boat and slowly sank deeper as the image of the massive ship appeared out of the haze. 

Along with the ship, several long, narrow, tubular shaped blue grey fish appeared - Great Barracuda (Sphyraena barracuda).

I realized that I had not seen many barracuda during dives the last year on the Spiegel Grove. But now, they were back –some seemed to be following me as I drifted through their territory.

Responding to concerns expressed by divers and fishermen that the number of barracuda was declining in the Keys, staff of the Florida Fish and Wildlife Commission conducted workshops and then imposed the state's first catch limits on the species effective Nov. 1, 2015. (See: http://myfwc.com/news/news-releases/2015/september/04/barracuda/)

I wondered if the catch limits were helping restore the population of barracuda or if some had decided to move back to the safety of the giant wreck of the Spiegel Grove. 

I finned to the top of the ship, went through a corridor, and then glided along a railing. A big barracuda decided to keep me company. “O.K,” I thought, “photo op.” 

I snapped off a few shots and my new buddy swam away.

Barracuda (there are 26 species worldwide) can be found from Massachusetts to Brazil. It inhabits the Gulf of Mexico, the Caribbean, the eastern Atlantic Ocean, the Indo-Pacific, and the Red Sea.

Adult great barracuda tend to live solitary lives at or near the surface in the open ocean. They have been found as deep as 325 feet. Sometimes they aggregate, like those that like to hover around the Spiegel Grove. 

The great barracuda has a large pointed mouth containing two sets of razor-sharp teeth. There is a row of small razor-sharp teeth along the outside of the jaw and with a larger set of dagger-like teeth on the inside. 

The long needlelike teeth fit into holes in the opposing jaw, allowing the great barracuda to close its mouth. Prey has little chance of escape. Small victims are swallowed whole and larger prey is bitten into pieces.

Great barracuda are big (some can grow to 6 feet) and scary looking. The barracuda’s nasty reputation goes back to the 17th century, when it was thought that the great barracuda of the Antilles had a hunger for human flesh and a poisonous bite with which to satisfy its needs. 

Great barracuda have a lifespan of at least 14 years, and reach sexual maturity at a length of about 23 inches. Males reach this size in about two years and females four. Even experts have difficulty distinguishing males from females.   

It is believed that great barracuda living in the waters of the Florida Keys breed in the spring. Eggs are released and fertilized in open waters and dispersed by the currents. 

Newly hatched larvae bear little resemblance to adults and seek safety in shallow, vegetated areas. Juveniles are recognizable as miniature versions of adults at about .5 inches in length. They move to near shore coral reefs, mangroves and sea grass beds when they reach 2 inches in length.

Barracuda are successful daytime ambush hunters that can burst in speeds up to 35 mph. Mature great barracudas feed on a variety of fish including mullet, snapper, herrings, sardines, small groupers and even small tuna. 

Inquisitive, sight-oriented fish, barracuda sometimes trail snorkelers and divers. (One following me gave me a bit of a pause as he darted around and did a few twists and turns.)

But, confirmed unprovoked attacks on humans are rare. Divers who have gotten into trouble with barracuda usually have been spearfishing and found themselves in conflict over who gets to keep the quarry. Some believe that shiny objects like jewelry may attract barracuda, but others debunk this theory. (For more on barracuda attacks see: http://www.skin-diver.com/departments/Encounters/PsychoCudas.asp?theID=271)

There are few predators large enough and fast enough to feed on adult great barracuda. Sharks, tuna, and goliath grouper have been known to feed on small adult barracuda. Juveniles likely fall prey to a variety of inshore predators.

Because barracuda are at the top of the food chain in the reef community they are reservoirs for high amounts of ciguatoxin, which can cause human ciguatera fish poisoning.

Experts recommend not eating barracuda meat because of the possible neurological, gastrointestinal and cardiac issues that may occur. In some Caribbean islands fishermen test a captured barracuda for ciguatera by seeing if flies come near it. If not, they don’t’ eat the fish. 

After capturing a few images of the barracuda I decided that I better also take a few photos of the other divers in my group for new “profile” pictures on their social media pages.

The barracuda didn’t seem to care about a new “profile” image as he swam away. 

I enjoy an opportunity to visit the Spiegel Grove. Its size and the flora and constantly changing fauna always provide something new to see. 

Now, if I can only spot that bull shark again. 

For more on great barracuda see: https://www.flmnh.ufl.edu/fish/discover/species-profiles/sphyraena-barracuda

The Florida Keys National Marine Sanctuary provides historical data, mooring buoy positions, site maps, and other information to aid divers learn about, locate and dive historical and intentionally sunk ships along a “Shipwreck Trail”. (http://floridakeys.noaa.gov/shipwrecktrail/welcome.html)

Don Rhodes, in addition to a career in government affairs, has taught scuba for 30 years. He and his wife retired to Tavernier five years ago, where he works as an instructor for Conch Republic Divers. He can be reached at donrrhodes@gmail.com.

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