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Lemon Shark card by the Jupiter Dive Center dot com.

Protect and Respect Florida Sharks

In February, 40 to 50 lemon sharks were observed aggregating off the shores of Jupiter Florida. (Image above is a lemon shark education card by the Jupiter Dive Center.) Over the next week all those sharks were caught by longliners. This “incidental take” happened when longliners were fishing something else.  Shark fishery regulations that may work adequately most times, failed to work in this place at this time. This incident, the lost of these sharks, along with NOAA permitting the taking of coastal pelagics earlier in the year, indicates we must do more to protect Florida’s wonderfully diverse marine life, most especially awesome sharks.  With respect for sharks, we must slow and reverse degradations to ocean waters; we must restore unique-in-the-nation, biologically-rich, reef ecosystems.

Two Sharks to Protect and Respect

The two most prevalent species that need protection are the Sandbar Shark (Carcharhinus plumbeus) and Lemon Shark (Negaprion brevirostris), the species that were targeted in the last fishing episode. Currently the sandbar shark is listed as “vulnerable” on the IUCN red list of threatened species and the Lemon shark is listed just below it as “near threatened”. Though they live in the same habitat they are distinct creatures with different defining characteristics. The sandbar shark, also known as the thickskin shark, is 6-7.5 feet in length with blue-gray or brown to bronze coloring on the dorsal side and white on ventral side. It has a tall primary dorsal fin, smaller secondary dorsal fin, and blunt, rounded snout. The lemon shark, on the other hand, is 8-10 feet in length with yellow/brown or olive gray coloration on the dorsal surface and a lighter yellowish color on the undersides. Lemon shark can be easily identified by because its primary and secondary dorsal fins are short and nearly equivalent in length.

Both species have a long gestation period of 9-12 months, but that is one of the few facts researchers know about their reproductive and breeding behavior, especially in natural populations. It is also known that Lemon sharks that live between North Carolina and the Bahamas aggregate on the coastal shelf off Jupiter between January and April, probably for a mating period.[3] Recently Lemon sharks have come far south during the winter months.  In 2001, 12 lemon sharks were sighted there, and 60 have been sighted the two following winters. This is surprising to scientists since no one truly knows how long they stay along the Jupiter shore.[4]

Nearshore waters from Bulls Bay, South Carolina south to West Palm Beach, Florida are currently classified by the NMFS as Essential Fish Habitat for juvenile lemon sharks under the Magnusson-Stevens Fisheries Conservation and Management Act. Lemon sharks in particular warrant sanctuary and additional protection.

The population of sandbar sharks in the northwest Atlantic was reduced by 85-90% in last 10 years from over-exploitation, especially along south Atlantic coast of the US. Thanks to the implementation of fishery regulations there has been a slight rise in the population.  Lemon Sharks used to be common in the western Atlantic, from New Jersey, USA to Brazil, but lately their numbers have been dwindling, especially around Florida (S.H. Gruber pers. comm.). Though lemon shark is officially more at stake than sandbar, both shark populations need to be watched with more comprehensive protections.

These are not the only sharks that would benefit from a sanctuary in the Straits of Florida.  Bull, blacktip, spinner, scalloped hammerhead, and tiger sharks are also commonly seen seasonally, in addition to the occasional great white.  Great white sharks are now being spotted more frequently near the Jupiter inlet.

Ocean Pelagics and Other Marine Life

In addition to the many species of sharks, other pelagic species inhabit these coasts. Red grouper is Florida’s most valuable fish, with one year landing value of $16,800,000. They are bottom-dwelling fish that can live to be about 25 years old.[5] However, the most commonly caught fish in the waters around Fort Pierce, Stuart, Jupiter, and West Palm Beach are Snook. Jack crevalle, Spanish mackerel, Florida pompano, snapper, grouper, and dolphin fish also have a major presence, in addition to the vibrant sailfish.[6] A few other species that tend to stay close to shore are the amberjack, black drum, cobia, gag grouper, and king mackerel.

Goliath groupers also inhabit the waters proposed for a shark sanctuary. These gigantic fish, which can be up to 8 feet in length and weigh up to 500 pounds, frequent shipwrecks and artificial reefs. The juvenile stage of the goliath grouper is spent in shallow red mangrove tree habitat.  Reaching maturity after about 8 years, groupers leave the mangroves, move to deeper water and out onto offshore reefs. Groupers have been overfished by commercial spear fishermen.  Today, Critically endangered, goliath groupers appear to be in recovery. Groupers do not feed on or compete for fish targeted by fishermen and divers.  Groupers are an asset and not an economic burden in the sanctuary.

The area proposed for Sanctuary is also home to a range of turtles, including the loggerhead, green, and leatherback.  Thanks to ongoing local conservation work, there has recently been an increase in the number of turtle nests for all three turtles in St. Lucie and Martin Counties.

Manatees live along the shore and rely especially on seagrass beds from the Jupiter Inlet to Lake Wyman. Manta rays, crabs, and a wide range of birds that fly above and prey on the fish below coexist here as well and help make this area so special.

An Ocean Stewardship Place

These essential shark habitats are east of Boca Raton and north, past Palm Beach, to Stuart, Florida.  Here, between this Florida shore and the West End, Grand Bahama Island is the narrowest portion, 65 miles wide, of the Straits of Florida.  The Gulf Stream is compressed through here moving 30 Sverdrups of seawater or 30 million cubic meters per second.  If the water flow of all the world’s rivers were combined it would amount to about 1 Sverdrup.  Thirty times the combined flow of the world’s rivers is flowing past Palm Beach Florida and apparently sharks like it.

Limestone Reefs

Another reason why sharks and large coastal pelagic fish like this place is the bottom covering of Anastasia limestone.  Reefs of this soft stone are composed primarily of shell and coral fragments, small clam and oyster fossils, and sand.  The composite is called coquina, from the Spanish for cockleshell.

Anastasia limestone reefs are essential habitat for more fish than is any other reef formation in Florida due to the many crystal forms of calcium carbonate. An Anastasia reef is most visible and accessible from the shore at John D. MacArthur Beach State Park, the only state park in Palm Beach County. Among the many species of marine animals inhabiting the reef are parrotfish, barracuda, damselfish and loggerhead sea turtles.

Oculina Reef

Further offshore of limestone reefs is the Oculina Reef in water deeper than 200 feet. The Oculina Reef begins east of Boca Rotan stretches north 90 nautical miles along the continental shelf edge.  Here lives a single species of a branching scleractinian coral, Oculina varicosa, a type of coral not known anywhere else on earth.  Oculina corals have built pinnacles, mounds, and ridges that range from 10 to 100 feet in height. These fragile structures are very sensitive to damage by dragging, dredging or trawling.

Oculina corals grow slower than most because they lack zooxanthellae, the algal symbiont that feeds coral polyps through photosynthesis.  Elsewhere in the Atlantic deep sea coral bits hauled up by fishing vessels have been radiocarbon dated to be at least 4,500 years old. Oculina corals are pure white massive dendritic, bushy structures.  Living in clear waters, Oculina must feed by grabbing with minute tentacles scarce passing plankton and particles.

Deep Sea Reef Ecology

The biodiversity of life around Oculina corals have been found to be equivalent to shallow water tropical reefs.  Within the branches of 42 small Oculina colonies were found over 20,000 individual invertebrates including mollusks, decapods, amphipods, echinoderms, polychaetes and others.  Deep-water Oculina reefs form impressive breeding grounds for commercially important populations of gag and scamp grouper; nursery grounds for snowy grouper; feeding grounds for other fish including black sea bass, red grouper, speckled hind, Warsaw grouper, almaco jack, greater amberjack, red porgy, red snapper, gray snapper, little tunny, giant ocean sunfish, Atlantic manta ray, tiger shark and scalloped hammerhead shark.  Oculina deep reefs may also form part of the migration pathway for king mackerel, Spanish mackerel, and wahoo. The spiny tail stingrays use the area for courtship and mating, and large populations of commercially important squid have been observed spawning on the deep banks of Oculina.[1]

The Oculina deep-water reefs need protection because shrimp trawlers were caught and fined for fishing there.  While it is unlikely that trawl and dredge fishermen will work the areas of high relief Oculina pinnacles, bottom trawls with wheels along the bottom tickler chain would decimate corals.  Oculina corals took thousands of years to build to their current size and would take no less time to replace lost structures. Attention needs to be brought to this area especially since in 2010 the NOAA Fisheries Service and the Secretary of Commerce approved the establishment of a series of Deep-water Coral Habitat Areas of Particular Concern (Coral HAPCs) extending from North Carolina to the Florida Keys and encompassing more than 23,000 square miles.[2] This area we propose is within the southern most portion of these boundaries, in addition to overlapping with a critical section of the Straits of Florida.

Protect and Respect Sharks

The sharks and diverse marine life associated with the Anastasia and Oculina Reefs in the Straits of Florida deserve long-term protection.  We need to act now to stem the irreversible damage being done. You are invited to join with us in a network of many Florida groups. Together, we are engaging, educating and broadening groups fostering responsible stewardship and calling to protect and respect Florida sharks.

 

Lemon Shark card by the Jupiter Dive Center dot com.

Lemon Shark card by the Jupiter Dive Center dot com.

[1] Reed, John K. "Deep-water Oculina Coral Reefs of Florida: Biology, Impacts, and Management." Hydrobiologia 471.1-3 (2002): 43-55. Kluwer Academic Publishers, 1 Mar. 2002. Web. 8 Mar. 2015.
[2] Messing, Charles G. "Welcome to the Strait of Florida Website." The Strait of Florida. NSU Oceanographic Center, 2011. Web. 19 Mar. 2015.
[3] " Action Alert: Tell NOAA-Fisheries to Protect Florida’s Lemon Shark Aggregation." Shark Savers. N.p., 16 Sept. 2013. Web. 19 Mar. 2015.
[4]   Stearns, Walt. "Stalking the Golden Ghosts: Solving a Lemon Shark Riddle in Florida." Sport Diver July 2002: 50-53. Google Books. Web. 5 Mar. 2015.
[5] "The Economic Impact of Saltwater Fishing in Florida." Value of Saltwater Fishing in Florida. Florida Fish and Wildlife Conservation Commission, n.d. Web. 19 Mar. 2015.
[6] FWC 2013. “Where to Fish” in Fishing Lines: An Anglers’ Guide to Florida’s Marine Resources, 8th edition. Katie Williams & Heather Sneed (editors). Florida Fish and Wildlife Conservation Commission, Division of Marine Fisheries Management, p 23.

20 responses on “Protect and Respect Florida Sharks

    1. Mary DeForest

      Because the doctors and dietitians tell us to eat fish!! If we ate in moderation. Ate something renewable like beef- vegan- but in moderation. I don’t and won’t eat fish. I rant about shark finning, a school of fish happily swimming along and then being netted or running into lines of hooks. Then the ocean is the world’s sewer- I won’t eat scallops. I won’t eat shrimp. I won’t eat any fish- and my lipids are just fine.

  1. sandra hazzard

    All God’s marvelous creatures have the right to live as they were intended…..We have an obligation to protect these and all the wonderful beings any way possible…..

  2. joanne groshardt

    I doubt you will ever find compassion for these animals from our elected republicans. They’d probably like stuffed sharks and fish above their dining room table.

  3. Gina Bilwin

    There is not an animal on earth that is not threatened by human action. Every step we can take to help our fellow beings on this earth is a small, but necessary step.

  4. Joanne

    This new diet fad of eating all sorts of fish, krill, etc is totally unnecessary. It removes food from the ocean creatures who were meant to live off the fish we eat. But, it also causes further degeneration of the ecology of the oceans. Why must “humans” be so immensely selfish that they think they have the right to destroy? If they even bother to consider the horrendous harm they are visiting on Nature?

    1. Rob Moir, Ph.D. Post author

      Bravo for the students of Parker Elementary in Stuart Florida for speaking out for sharks and better stewardship by us all of the ocean waters in the Straits of Florida. What is illustrated and said for sharks will benefit all marine life, locally and ocean-wide. Thank you.

  5. Jacqui Thurlow-Lippisch

    Dear Rob,
    I really enjoyed being part of your radio show on behalf of the first grade students at JE Parker Elementary in Stuart, Florida. These students are so excited to “protect and respect” sharks along the reefs of the St Lucie Inlet. They have created 100s of drawings and even did a multi class presentation on the subject. Thank you for allowing their voices to be heard as more children become River Kidz and have the mission to “speak out, get involved, and raise awareness, as we believe kids should have a voice in the future of our rivers and oceans.”

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