White Shark (Carcharhinus carcharias). Credit: Florida Sea Grant Stock Photo
From Fear to Fascination: White Sharks in the Florida Panhandle
UF/IFAS Extension – Florida Sea Grant
By Rick O’Connor (Escambia County) and L. Scott Jackson (Bay County)
Recently, I was walking on our local Gulf fishing pier checking fishing line recycle bins. You can’t walk on a Gulf pier without looking over to possibly catch a glimpse of a sea turtle or a shark, and I was not disappointed. It was hard to tell which species of shark but it was about 6 feet in length. It swam south along the edge of the pier and then east to make a large arching circle through the emerald water, past bathers at the surf break, and back to the pier only to swim the pattern again. Onlookers from out-of-town were giggling with delight to see the animal while a couple of local fishermen tried tossing bait at it, but most ignored it and went on with their fishing.
Bob Shipp’s book, Fishes of the Gulf of Mexico, lists 29 species of shark found locally. Most are members of the requiem shark family, such as blacktips and bulls, and hammerheads. Though these sharks are certainly capable of attacking humans, their presence usually does not interrupt water activities. Divers who encounter sharks may be startled at first but rarely do they end their dive or have problems with them. Even in 2005, remembered as the “summer of the shark attack”, few people stopped diving or surfing. Individuals have become educated regarding shark behavior and are not as startled when they see one. However, in 2015 there were several encounters with White Sharks.
Sightings in the Gulf of Mexico are rare but usually occur in the cooler months. Is the increased interaction with White Sharks unusual or something to worry about?
Burgess assured me that White Sharks do occur in the Gulf of Mexico usually during cooler months and are transients, as opposed to residents. Their movement in and out of the Gulf is temperature driven. As late spring Gulf waters continue to warm into early summer, sighting a White Shark is less likely to occur. According to Burgess, White Sharks use deep water when traveling but prefer shallow water when hunting fish, turtles, and marine mammals. So, inshore encounters especially in cooler months would not be unusual.
Why is there a sudden increase in the numbers of encounters?
One part of the answer lies with the increased number of White Sharks. Conservation of sharks has been effective. Additionally, with the passing of the Marine Mammal Protection Act, there are more marine mammals, thus an increase in their predators, White Sharks. The other part is the number of humans visiting the northern Gulf has increased. There are more more visitors to marine waters, especially since the Deepwater Horizon oil spill. Everyone has a camera. Beachgoers, Swimmers, Divers, and Anglers all have improved technology to record their adventures.
Is Northwest Florida a “hot spot” for White Sharks? Burgess indicated that the northern Gulf of Mexico is more productive than the peninsular Florida due to the number of nutrient rich rivers in the region. Seeing more White Sharks here would not be any more unusual than finding more snapper, lionfish, or other species of shark. As far as worrying, there have been no records of White Shark attacks in the northern Gulf of Mexico since they began keeping records in 1872.
Finally, what does one do if they encounter a White Shark?
The quick answer is nothing different than with any other shark. It is true that most White Shark attacks occur at the surface but there are no records of any attacks in Florida. Burgess indicated that the Bull Shark is probably a bigger threat than the White Shark. For more information about Bull Sharks and general tips to avoid a negative shark encounter read this articlehttps://nwdistrict.ifas.ufl.edu/nat/sharktips
In a recent video, recorded near Apalachicola, a diver was on an anchor line on a decompression stop when he saw a White Shark approaching from depth. What should a diver do in this situation? Should they swim for the surface and risk decompression sickness, remain still, or return to the bottom?
The answer has a lot to do with what the shark is actually doing. Is the shark interested in the diver or acting aggressively? Burgess suggests, you assess the situation and the shark’s behavior. All options are on the table and have to be weighed against the consequences given in this scenario. As a last resort, a diver may need to make a quick but graceful exit out of the water, past the shark, and depend on their diving partners to render aid as needed. The lesson is for divers to be prepared for a variety of potential issues on every dive.
Digital devices have proliferated like kudzu in July, and new user applications for these devices are as common as armadillos. Untold hours and dollars are being spent by couch potatoes to defend artificial worlds from dragons, zombies and other imaginary invaders.
Meanwhile, real exotic aliens from air potatoes to monitor lizards are invading Florida.
Don’t panic; there is some good news. A group of new applications that can help citizen scientists identify, locate and manage invasive plant and animal species in Florida is available for free.
The first line of defense is identifying and mapping new occurrences of invasive species. Many, if not most, new infestations were established before anyone noticed or cataloged them, and effective control strategies depend on knowing the extent of new infestations.
The Early Detection & Distribution Mapping System (EDDMapS) has been available at http://www.eddmaps.org since 2005. In the words of its developers, Charles Bargeron and David Moorehead of the University of Georgia’s Bugwood Network, the system was designed to: “develop more complete local, state and regional level distribution data of invasive plants, identify “leading edge” ranges of new invasive threats, provide a means of implementing early detection and response, and help corroborate threats and refine invasive plant lists and management priorities.”
“IveGot1” was developed by this same group through a cooperative agreement with the National Park Service in cooperation with the Florida Fish and Wildlife Conservation Commission and the University of Florida Center for Aquatic and Invasive Plants. The application is now available on both Apple and Android operating systems. The app includes invasive plants and animals and allows direct reporting of sightings as well as back ground information on Florida’s most common invasive species.
The impact of wild hogs on the environment is soil erosion, decreased water quality, spread of other invasive plants, damage to agricultural crops, and damage to native plants and animals. Photo by Jennifer Bearden
At least two other apps useful for invasive species management are also available. “Invasive Plants in Southern Forests” is adapted from the US Forest Service book of the same name. This publication is available for download at http://www.srs.fs.usda.gov/pubs/gtr/gtr_srs062, but it’s a big file (33MB). In addition to its ID function, the app includes appropriate control methods for the over 100 invasive trees, shrubs, vines, grasses and forbs described. As of now, this application is only available for the iPhone platform.
The second app is for Florida’s most widespread invasive animal. Although pythons may be our most infamous invasive animal, they don’t have the distribution of the wild hog. “Squeal on Pigs” combines a location app and educational information to support states’ efforts to control wild hog populations and reduce their impacts on streams and crops.
Maybe you won’t reach Destroyer level in the real battle on air potatoes and Florida’s other invasive species, but moving from Angry Birds to Squeal on Pigs will raise your power level as a Friend of Real Florida.
Florida Black Bear visiting an easy food source. Photo by Jennifer Bearden
Florida Black Bear are the largest land mammals in the state of Florida. At birth they are smaller than a soda can but they quickly grow up to 250-400 pounds for males and 125-250 pounds for females. Even though black bears are large animals, they are not fierce killers nor are they cute and cuddly. Bears are like most other wildlife; if you don’t bother them, they won’t bother you.
In 1974, bear population numbers were extremely low and the Florida Black Bear was listed as a state threatened species. Today, we have increased bear population numbers 10 fold to about 3,000 statewide.
Graphics courtesy of Florida Fish and Wildlife Conservation Commission
As urban areas have expanded into bear habitat, the number of bear/human interactions has increased. Bears are omnivorous with 80% of their diet coming from plants. Bears are fairly intelligent creatures that forage for easy food sources. Urban areas tend to attract nearby bears with food sources such as garbage containers, pet food dishes, and bird feeders. Bears become accustom to food sources near humans and lose some fear of humans and may even bluff charge humans to defend their food source. The best way to prevent this is to remove food sources.
Clean BBQ grills and store them in a secure building when not in use.
Take garbage to the curb the morning of pickup instead of the night before.
Store garbage cans in a sturdy building or other secure area.
Feed pets inside and store pet food securely.
Protect gardens and trees with electric fencing.
Hang wildlife feeders out of reach of bears and take them down if bears are in the area.
It is illegal to feed bears in Florida (Florida Administrative Code 68A-4.001(3)). In addition to being illegal, it isn’t smart. Feeding bears intentionally or unintentionally increases the likelihood of human injury, property damage and bear injury or death.
So what do you do if you encounter a bear?
Remain calm and don’t run!
Don’t approach the bear, instead give it space to retreat.
Back away slowly without looking the bear in the eyes.
Speak to the bear in a calm voice.
Bring children and pets inside.
Find a safe place then make a lot of noise to let the bear know it isn’t welcome – yell, bang pots and pans, raise your hands high and stand tall to scare the bear away.
March 8th: Tropical Soda Apple (Solanum viarum) & Alligator Weed (Alternanthera philoxeroide)
Tropical Soda Apple Photo Credit: Jeffrey Mullahey, UF, Bugwood.org
Tropical Soda Apple:Florida ranchers know Tropical Soda Apple (TSA) as the “Plant from Hell”. The plant is a native of South America. It was first noticed in south Florida, but its seeds survive in the digestive tract of animals and it spread north through the movement of hay and cattle. TSA plants are covered with thorns and can make large sections of pasture nearly useless for livestock. Concerted efforts to lessen the population of TSA since its arrival have reduced the populations in pastures but it persists in sheltered or waste locations. Cattle, birds, deer and feral hogs ingest the mature fruits and spread the plants to loafing and browsing areas that may be inaccessible to mechanical treatment with anything larger than a hoe. According to Dr. Jeff Mullahey, who has been working on TSA since its appearance in south Florida, one plant can produce 40,000-50,000 seeds with seed germination ranging from 75%-100%. The seeds remain viable for at least three years. Be on the lookout for these while engaged in outdoor activities.
In South Florida, populations of the tropical soda apple leaf beetle (Gratiana boliviana) have had some efficacy as a biological control. However in North Florida the efforts to establish populations of these beetles from TSA’s native habitat have been stymied by their inability to overwinter in our colder temperatures. Although you won’t want to pull them up barehanded, isolated plants can be controlled by mechanical means. Herbicides effective on TSA can be found at http://edis.ifas.ufl.edu/uw097, or contact your local Extension agent.
For more information contact the author Jed Dillard, Livestock & Forages Extension Agent by phone at 850-342-0187.
Alligator Weed photo by Vic Ramey courtesy of UF/IFAS Center for Aquatic and Invasive Plants, University of Florida
Alligator Weed:This highly invasive aquatic weed, which is a native of South America, was first discovered in Florida in 1894 and is believed to have been transmitted through ballast water. Alligator Weed is usually found as sprawling mats across the surface of water. Although classified aquatic, it can be found along shorelines or dry land.
This plant is a category II invasive and also an aquatic weed. The following information from the Center for Aquatic and Invasive plants, “This species is on the FL DACS Prohibited Aquatic Plant List – 5B-64.011. According to Florida Statute 369.25, No person shall import, transport, cultivate, collect, sell, or possess any noxious aquatic plant listed on the prohibited aquatic plant list established by the department without a permit issued by the Florida Department of Environmental Protection. See 5B-64.011 for more information.”
There are several biological controls of Alligator Weed, such as the Alligatorweed Flea Beetle. When they attack mats of alligatorweed, the entire mat will begin to turn yellow and eventually turn brown to die. Significant control can be achieved in 3 months once beetles are established. For more information about this biological control and others, please see the following IFAS extension publication, Alligatorweed flea beetle Agasicles hygrophilahttps://edis.ifas.ufl.edu/in831.
Chemical control is also possible with glyphosate, imazapyr and several other products. Always read the label carefully when using any herbicide. For more information please consult Efficacy of Herbicide Active Ingredients Against Aquatic Weeds (http://edis.ifas.ufl.edu/ag262).
For more information, contact the author Matt Orwat, Horticulture Extension Agent 850-638-6180.
March 7th: Eurasian Milfoil (Myriophyllum spicatum), Tiger Prawn (Penaeus monodon), The Cuban Tree Frog (Osteopilus septentrionalis)
Eurasian water-milfoil Myriophyllum spicatum photo by Alison Fox, University of Florida, Bugwood.org
Eurasian Water Milfoil:Eurasian water milfoil is a submerged aquatic plant that can be found in northwest Florida in lakes, rivers, and coastal marshes. Water milfoil forms a dense mat of vegetation that can block sunlight and habitat for native plants. These mats can increase water temperatures and interfere with boat traffic, fish habitat, and native aquatic plant species.
Eurasian milfoil was first documented in Florida in 1964. It was reportedly planted by aquarium plant dealers. It is still used today in the aquarium industry and obtained through suppliers and through internet sales. This plant is listed as a category II on the Florida Exotic Species Pest Plant Council List, which means it has the potential to overtake native submerged plant communities.
The spread of Eurasian milfoil can be caused by the breaking of stems and roots, which can be carried by boats, engines and trailers to other lakes and coastal marshes. To help prevent spread of Eurasian water milfoil to Florida’s waters, always clean off your boat, motor and trailer at the ramp to avoid transporting vegetative stems to other areas. In addition, never release or dispose of aquarium plants or animals into local waterways.
For more information, contact the author Chris Verlinde, Marine Science Agent 850-623-3868.
Giant Tiger Prawn Photo Credit: FWC photo by Michelle Sempsrott
Giant Tiger Prawn:This large shrimp, also known as the Asian Tiger Shrimp and the Black Tiger Shrimp, can reach lengths between 8-12 inches. It resembles are native edible penaid shrimp but differs in that it has distinct black and yellow stripes. It was brought to the U.S. from the Indo-Pacific region as an aquaculture product. There was an accidental release of 2,000 animals from a South Carolina farm in 1988. Reports of this shrimp in the wild have increased over time. They have been found in all Gulf coast states and there has been at least 1 record in each of the Florida panhandle counties. The impact of this shrimp to our area is still unknown but they have a high tolerance for salinity change and consume many types of benthic invertebrates. It is thought that they could become serious competition for our native penaid shrimp and could possible transmit diseases. If you think you have found one of these shrimp, record size location (GPS preferred) and email information to ExoticReports@MyFWC.com. To learn more about this species view the USGS factsheet.
For more information, contact the author Rick O’Connor, Sea Grant/Marine Sciences Agent 850-475-5230.
Image by Dr. Steve A Johnson 2005.
The Cuban Tree Frog:was introduced into Florida as a stowaway on vehicles and plants in the 1920’s. As of 2013, breeding populations have been recorded as far north as Georgia. Cuban Tree frogs have larger toepads and eyes than any of the native species. Being larger in size, the Cuban Tree frog out-competes other tree frogs for resources, to the point that they are predators of Florida’s tree frogs and inhibitors of native tadpoles. Juvenile Cuban Tree frogs can be distinguished from natives by their red eyes and hind legs with blue bones. Three-foot-long sections of 1.5 inch diameter PVC pipe can be placed in the landscape to monitor for tree frog species. Should Cubans be found, they should be reported and euthanized. For additional details visit: http://edis.ifas.ufl.edu/uw259.
For more information contact the author Sheila Dunning, Commercial Horticulture Agent 850-689-5850.
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