by Rick O'Connor | Feb 28, 2018
Lionfish caught on rod and reel. Photo Credit: Alison Rogers
Since the first lionfish was spotted off Pensacola in 2010, panhandle organizations have been busy trying to control the spread of this invasive species. The story is well known to many… the lionfish is a voracious predator, consuming at least 70 different species of small reef fish, including vermillion snapper. They reproduce frequently, producing an average of 25,000 eggs/female every four days – and they breed during most of the year. The densities of these fish on our nearshore and offshore reefs are some of the highest in the South Atlantic region, and they prefer artificial reefs to natural bottom. We know they have spread across the northern Gulf to include all five Gulf states and are found in Mexican waters.
We also know that the primary method of removal is still spearfishing. The state of Florida has an open season on them and provides a program to assist local divers with selling their harvest. There are several rodeo tournaments along the Gulf coast and some traditional fishing tournaments have created a category for them. Education programs about the problem continue and some restaurants have offered them when they can get them.
So how are things going?
Are we on top of controlling the lionfish?
Lionfish at Pensacola Beach Snorkel Reef. Photo Credit: Robert Turpin
Anecdotal reports suggest we have made some impact. Local divers in the Pensacola area report that the shallower public reefs frequented by local divers and dive charters have indicated they are getting harder to find. There have been some tour trips, taking out of town residents diving for lionfish, where they have had to really search to find them. This is certainly encouraging and a numerical assessment of this is needed. However, there are also reports of charter fishing boats catching them on hook and line in deeper waters. They are not catching many, but they do occasionally grab them. When they do, it is usually on live bait and in deep water, 200 feet or so. Local divers seem to agree with this. They too find more lionfish, and some large ones, at depth – too deep to take a typical dive charter trip to remove.
Recent research has shown that lionfish are able, at least in the northern Gulf of Mexico, to swim greater distances than once thought to re-colonize reefs that have been cleaned. One study showed that selected artificial reefs, which were completely cleaned of lionfish, had restored lionfish populations, both young and old fish, within a year. This same study suggests that to keep lionfish at relatively low-density (about 5 lionfish/100 m 2) reefs would need to be cleaned every two months.
Several lionfish derbies occur along the Florida panhandle, but not at the frequency that may be needed to control re-colonization of shallower reefs by lionfish from deeper ones.
Can we increase the number of derbies?
Sure… but those who work on these derbies know the time and financial commitment required to put one on. It could happen that the number of local derbies would increase but we may have to think of other means of controlling lionfish.
One idea is to increase the number who harvest commercially. To do so a diver would need to acquire a saltwater products license from the Florida Fish and Wildlife Conservation Commission (FWC). On their website, they provide the application and a list of approved buyers for the diver to contact. http://www.myfwc.com/Lionfish.
Harvested lionfish. Photo Credit: Bryan Clark
One drawback to the commercial idea is the price. Currently divers require a high price for their catch in order to cover cost and show a profit. These high prices equate to high prices at local restaurants, higher than the public may be willing to pay. One unpublished study shows that some locals are willing to pay more for a lionfish dinner if they know it is helping the environment. Many seafood lovers understand the high cost of lobster, but have not placed lionfish in the same category and are not as willing to pay higher prices; this may have to change. Research continues on developing a lionfish trap that has low by-catch rates. If an effective trap is developed, they could be deployed from vessels, which would not require diving, and could bring prices down.
There is evidence that populations of small reef fish have significantly declined since 2010. Whether this was due to the oil spill, the lionfish invasion, or a combination is still not certain. It is known that local reefs that are cleaned of lionfish are repopulated with both large and small lionfish. We have had some success with removing but we still have work to do.
Reference
Dahl, K.A., W.F. Patterson, R.A. Snyder. 2016. Experimental Assessment of Lionfish Removals to Mitigate Reef Community Shifts on Northern Gulf of Mexico Artificial Reefs. Marine Ecology Progress Series. Vol 558. Pp: 207-221.
by Rick O'Connor | Feb 26, 2018
Invasive Torpedo Grass. Photo Credit: Rick O’Connor
The topic of invasive species has been with Floridians for decades. Stories of large pythons, exotic lizards, and crazy ants have been coming out of south Florida for years. Brazilian Pepper, Australian Pine, and Melaleuca are just three species of trees that have invaded the Everglades and other south Florida ecosystems.
Though we are having more problems with plants than animals, north Florida is not without their list of invasive problems. Cogongrass, Chinese Tallow, and Japanese Climbing Fern are well established and resource managers are constantly battling these and other invasives. In recent years Lionfish, Cuban Anoles, and a few sightings of Cuban Treefrogs have made their way onto our radar. All of these invasive species are causing either an environmental problem, an economic one, or both and need to be controlled. However, land and resource managers need to know what is out there to be able to do this; and the public can help.
So what can you do?
One of the most frequently used databases is www.EDDMaps.org. Land and resource managers, both public and private, can view this website to see which species are in the area, where they are located, and how common the species is. However, it is only as good as the data provided. Anyone can report an invasive species on EDDMaps.
Invasive lizard – the Cuban Anole. Photo Credit; Jerry Patee.
From the home page, you can find a variety of information on invasive species. To report a sighting you will need an account. On the toolbar at the top, you will see REPORT SIGHTINGS. Clicking here will take you through a series of questions. There is some information that you need to have ready. For example, how much area of the property does the invasive plant cover? Estimates are fine but try to be as close as possible. You will also need to know your location. Most phones have a compass on them where the Latitude and Longitude are provided. However, it will need to be converted to decimal point to be posted and there is a conversion tool on the website to do this for you. It is important to report your Longitude as a negative number, or else it will think you are in the eastern hemisphere. Photos are very MUCH desired and, again, your phone photo is good enough. On the home page, you will also see how to download the app “I’ve Got One” which is a quick and easy way to report an invasive species while in the field.
If you are not familiar with many of the invasive species, you can spend some time on the website to learn more. You can also contact your local extension office to discuss species that we know are in the area and those that are nearby. These are good species to be on the watch for and, with your help, we can help keep the website updated.
The extension offices in the Pensacola area will be hosting trainings on invasive species identification and EDDMaps reporting later this year. If interested contact Rick O’Connor (850) 475-5230.
by Rick O'Connor | Feb 16, 2018
As a young boy growing up here in the panhandle, I had heard of this thing called a manatee – but had never seen one. They came more into the light when I was a teenager and becoming interested in marine biology. I was the president of the high school marine biology club and one of our goals was to raise money for a trip to Crystal River to snorkel with them. The Save the Manatee Club originated in that time trying to bring more awareness to the plight of this endangered Floridian and at one point, Jimmy Buffett had led the way.
I had learned a lot about them, found out their original range was from North Carolina south to the Caribbean and the entire Gulf of Mexico, but were now down to about 1000 animals and those were found in Florida. Eventually I did get to see manatees, and have snorkeled with them many times, but still thought of them as a south Florida animal – rarely found in the panhandle.
Manatee swimming in Big Lagoon near Pensacola.
Photo: Marsha Stanton
Then the recent news report – two dead manatees in the last two weeks. One washed ashore in Okaloosa county and the other in Escambia. Probably victims of the recent cold fronts. It is not unheard of finding manatees in the panhandle in recent years. I recall since the 1990’s a manatee seen in Bayou Texar in Pensacola. In another year, one was seen near Ft. Pickens. My son worked at a local marina and saw at least one a year there. There have been so many seen in the Mobile Bay area that Dauphin Island Sea Lab now has a Manatee Watch program. There are about 40 individuals that now visit Wakulla Springs. In addition, this summer there were two separate groups living in the Pensacola area. One group was residing near Gulf Breeze and a second group of about eight animals was frequently seen near Perdido Key. These once rare animals in the panhandle are now being found each year, and sometimes in groups.
What is going on?
Why are manatees beginning to visit our area?
Your first hunch would be climate change. Manatees are marine mammals but unlike their dolphin cousins their blubber layer is not as thick and they must seek warm water refuge during the winter months. When water temperatures drop below 67°F, they locate the warm water springs found in central Florida – or move south Florida where the water remains comfortable year round. If they are remaining here, could the average water temperatures have warmed enough for them to make this move?
Along this same line, mangroves are now being found in the panhandle. Both red and black mangroves have been found growing in local estuaries. In the Apalachicola area there have been quite a few located. In the western panhandle there a few individuals here and there. Further west they are found on the islands of Mississippi and have been in the Chandeleurs for many years now. Later this spring Florida Sea Grant will be conducting surveys in each county to see where these tropical trees may be growing.
A small red mangrove growing in Big Lagoon near Pensacola FL
Photo: Rick O’Connor
And most recently are sightings of snook, a south Florida fish that have, though rare, been seen in the northern Gulf of Mexico. No doubt this Januarys hard freezes probably killed the mangroves that were here, and probably the two manatees washed ashore recently, but it will be an interesting time to see what other tropical species begin their slow migration northward. If it does happen, what will that mean? How will these changes impact local ecosystems? At this point, I am not sure if it will happen or, if it does, how fast – but it will be interesting.
by Rick O'Connor | Feb 2, 2018
Man what a winter!
Between multiple days below freezing, tough traveling, and the flu it has been a brutal winter season so far.
Dead Kemps Ridley Sea Turtle washed ashore in Little Sabine near Pensacola Beach. This turtle died of ingesting monofilament fishing line.
Photo: Betsy Walker
It is not that different for some of our marine wildlife friends. The low temperatures have driven marine water temperatures down as well, particularly in the shallow areas. There have been many reports of cold stunned sea turtles up and down the Florida panhandle – over 900 of them. There have been reports of cold stunned iguanas falling from trees and the loss of pythons in south Florida. The question sometimes comes up – “how do they deal with this apparent return from the dead?”
One has to remember we are dealing with reptiles – cold-blooded creatures. Actually, the more correct term is poikilothermic. It really does not pertain to the temperature of their blood but their core body temperature in general. Some animals, like humans, can maintain a constant body temperature, like 98.6°F, no matter what the environmental temperatures are – these are referred to as homotherms. Heterotherms can allow their body temperatures fluctuate within a range – but are in control of their body temperatures. The poikilotherms cannot control their body temperature and are thus at the mercy of the environment – the classic “cold blood”. Some of these poikilotherms have been known to actually freeze and thaw – with no observable problems, not so much for our “warm blooded” friends.
So what’s up with the cold-stunned situation?
Well… even with the “cold bloods”, extreme temperature changes can be very stressful. Some respond by changing their behavior, others their physiology, others both. They will alter their feeding – basically stop. In some, the pH and ion balance within their blood becomes unbalanced, which can trigger the feeding reduction response and increase ion exchange within the lungs. The partial pressure within the venous blood can decrease and this, along with the chemical imbalance and feeding reduction, can trigger a “lethargic” response and even a “floating” response in the marine turtles.
Locally, it seems to be the sea turtles who are having the most problems. In south Florida, scientists have noticed the American Crocodile and the invasive pythons struggle with these cold temperatures but the wider ranged American Alligator and numerous species of native snakes do not. The “locals” seem to alter their behavior to adjust for these extreme temperature drops – a method that the tropical species are not practicing. It is known that certain native freshwater turtles over winter in frozen ponds, and diamondback terrapins are known to “hunker down” in muddy bottoms of salt marsh creeks when water temperatures drop below 59°F.
With sea turtles, the larger migratory individuals offshore are still moving at 43°F but is the smaller inshore juveniles that are the subject of stunning events. The water temperatures change more rapidly in shallower water and at 43°F, these smaller sea turtles become lethargic and float – which increases their chance of predation. Data suggest that Green Sea Turtles begin to slow activity and Kemps Ridleys become more agitated when water temperatures drop below 68°F, both become dormant, reduce feeding and breathing when they drop below 59°F. It is believed the real problems from being cold stunned are from the reduction of food as much, if not more than, the actual temperature itself. The “cold bloods” bask to increase their body temperatures so that they can actually digest their food.
It is a problem frequently encountered along the American east coast but not as much in Florida. However, this year has been different. The staff and volunteers from government agencies and local aquaria have done a champion job rescuing and rehabilitating many of these animals.
References
Mazzotti, F. J., M. S. Cherkiss, M. Parry, J. Beauchamp, M. Rochford, B. Smith, K. Hart, and L. A. Brandt. 2016. Large reptiles and cold temperatures: do extreme cold spells set distributional limits for tropical reptiles in Florida? Ecosphere 7(8):e01439. 10.1002/ecs2.1439
Moon D.Y., D.S. MacKenzie, D.W. Owens. 1997. Simulated Hibernation of Sea Turtles in the Laboratory: I. Feeding, Breathing Frequency, Blood PH, and Blood Gases. The Journal of Experimental Zoology. 278: pp. 362-380.
Milton, S.A., P.L. Lutz. 2003. The Biology of Sea Turtles, Volume II. Edited P.L. Lutz, J.A. Musick, J. Wyneken. CRC Press. Pp. 510.
by Rick O'Connor | Jan 19, 2018
In the last article, we discussed what phytoplankton are, what their needs were, and their importance to marine life throughout the Gulf and coastal estuaries. In this article, we will discuss the different types of phytoplankton found in our waters.
The spherical shape of the centric diatom.
Image: Florida International University
Marine scientists interested in the diversity and abundance of phytoplankton will typically sample using a plankton net. There are a variety of different shapes and sizes of these nets, but the basic design would be funnel shaped with a sample jar attached at the small end of the funnel. The plankton net would be towed behind the research vessel at varying depths for a set period of time. All plankton collected would be analyzed via a microscope. According to the text Identifying Marine Phytoplankton (1997) there are at least 14,000 species of phytoplankton and some suggest as many as 120,000. Most of these, 12,000-100,000, are diatoms, one of five classes of marine phytoplankton. The majority of the phytoplankton fall into one of two class, the diatoms and the dinoflagellates.
Diatoms are typically single celled algae encased in a clear silica shell called a frustule. The frustule can come in a variety of shapes, with or without spines, and many resemble snowflakes – their quite beautiful. They are found in the bay and Gulf in great numbers, as many as 40,000,000 cells / cup of seawater. They are the dominate phytoplankton in colder waters and are most abundant near upwellings. These are the “grasses of the sea” and the base of many marine food webs. When diatoms die, their silica shells sink to the seafloor forming layers of diatomaceous earth, which is used in filters for aquariums and oxygen mask in hospitals.
Dinoflagellates differ from diatoms in that they produce two flagella, small hair-like projections from the algae that are used for generating water currents and movement. Their shells are not silica but layers of membranes and are called thecas. Some membranes are empty and others contain different types of polysaccharides. Dinoflagellates are more abundant than diatoms in warmer waters. There are about 2000 species of them. One type, Noctiluca, are responsible for what locals call “phosphorus” or bioluminescence. These dinoflagellates produce a blue-ish light when disturbed. Many see this when walking the beach at night. Their footprints glow for a few seconds. At night, boaters can see this as their prop wash turns the dinoflagellates in the water column. The bioluminescence is more pronounced in the warm summer months and is believed to be defense against predation. The light is referred to as “cool” light in that the majority of the energy is used in producing light, not lost as heat as with typical incandescent bulbs – hence the birth of the LED light industry.
The dinoflagellate Karenia brevis.
Photo: Smithsonian Marine Station-Ft. Pierce FL
Several dinoflagellates produce toxins as a defense. Some generate what we call red tides. In the Gulf of Mexico, Karenia brevis is the species most responsible for red tide. Red tides typical form offshore and are blown into coastal areas via wind and currents. They are common off the coast of southwest Florida but occur occasionally in the panhandle. Many local red tides are actually formed in southwest Florida and pushed northward via currents. Red tides are known to kill marine mammals and fish, as well as closing areas for shellfish harvesting.
Like true plants, phytoplankton conduct photosynthesis. Between the diatoms and dinoflagellates, 50% of the planet’s oxygen is produced. These are truly important players in the ecology of both the open Gulf and local bays.
References
Annett, A.L., D.S. Carson, X. Crosta, A. Clarke, R.S. Ganeshram. 2010. Seasonal Progression of Diatom
Assemblages in Surface Waters of Ryder Bay, Antarctica. Polar Biology vol 33. Pp. 13-29.
Hasle, G.R., E.E. Syvertsen. 1997. Identifying Marine Phytoplankton. Academic Press Harcourt Brace and
Company. San Diego CA. edited by C.R. Tomas. Pp. 858.
Steidinger, K.A., K. Tangen. 1997. Identifying Marine Phytoplankton. Academic Press Harcourt Brace and
Company. San Diego CA. edited by C.R. Tomas. Pp. 858.
