Hurricanes are no fun! But, if there is a small silver lining to hurricanes, it’s that scientists are provided rare opportunities to gain new insights into some plant and animal species. It’s a field called disturbance ecology, and I suspect a lot of it will be taking place in the next few months to years.
Some insights from past disturbance are incredibly fascinating. For instance, in 2001, just prior to Tropical Storm Gabrielle’s landfall, 14 tagged blacktip sharks swam to deeper waters in Terra Ceia Bay. And, as Hurricane Charley approached Charlotte Harbor in 2004, six of eight tagged sharks moved to open water; the other two disappeared from the sampling array. In both cases, the timing of shark movement seemed to correspond to decreasing air and water pressure.
Another notable effect of Hurricane Charley, occurred in the Peace River and upper Charlotte Harbor, which went hypoxic (very low to no oxygen) following the storm’s passage. The hypoxia resulted in changes in fish assemblages, from our typical fish variety to only the hardiest, including the sailfin catfish and the invasive brown hoplo. The hypoxic event was short lasting, and the fish assemblages returned to normal within a month. Interestingly, the Myakka River, which did not see the eye of the storm was not affected by hypoxia or changes in fish assemblages.
March was National Seagrass Awareness Month. And although it’s now April, one could argue that we should not ONLY be aware of seagrass one month out of the year. Seagrass is important and deserves our attention throughout the year!
Seagrass are a relatively small group of flowering plants that have adapted to survive and reproduce in a marine environment. In fact, they alone are the only flowering plant that can live their entire lives completely in seawater.
Worldwide there are about 50 species of seagrass. Seven seagrass species occur in Florida, and all but one of those can be found in Charlotte Harbor. The three you are most likely to see are Turtle grass, the one with the wide flat blade (leaf), Manatee grass, a long skinny tubular grass found closer to the passes where the water is nice and salty, and Shoal grass, this one’s very fine, with thin flat blades; sometimes you see it exposed at low tides.
Each seagrass species has its own personality, things it likes, things it can tolerate. Shoal grass for instance, has a wide salinity range and can grow in low light conditions. Manatee grass however, has a narrow salinity range and needs high light conditions. And, Turtle grass has a lot of surface area on its blades, making it a favorite place for algae, tube worms, and barnacles to attach.
This is so not good! Late last month, FWC officer Michael Morrison observed a lionfish swimming off the Laishley Pier in Punta Gorda. This is the third documented lionfish sighting inside Charlotte Harbor, and it’s also the most up harbor. Laishley Pier is actually on the Peace River.
What’s not good about this beautiful fish? Well, for starters, it doesn’t belong here. Lionfish are native to the Indo-Pacific, but unfortunately they are well established throughout the Gulf of Mexico, the Atlantic to North Carolina, and the Caribbean.
The lionfish established here comprise two species, Pterois volitans, the red lionfish and P. miles, the devil firefish. The lions share, 93 percent of those established, are red lionfish. Genetic studies indicate that lionfish in the Atlantic are likely all descendants of a few individuals, which is consistent with the widely held belief that lionfish were introduced into the Atlantic as a result of accidental or deliberate release of aquarium pets. Isolated lionfish sightings were first documented in southeast Florida in the 1980s, and by the early 2000s they were established in that area. They then expanded to the Bermuda (2004), the Bahamas (2005), the Turks and Caicos (2008), the Cayman Islands and the Florida Keys (2009) and the Gulf of Mexico (2010). Today, they are a common sighting on any reef, in the listed areas — natural or manmade, including those off southwest Florida.
Sawfish are modified rays with a shark-like body. Sawfish get their name from their “saws”, which are used for defense and to locate, stun, and kill prey; mostly fish. The earliest sawfish arose about 200 million years ago. These sawfish were distant cousins of the ones we see today which appeared about 65 million years ago. At one time sawfish were abundant; however, they have experienced significant declines due to decades of unintentional overfishing, mostly the result of entanglements in fishing gear. Sawfish saws (scientifically called rostrums) have also been popular trophy items, but when they’re removed, they don’t grow back and sawfish are unable to feed normally or defend themselves. Today, all sawfish species (five) are endangered, including the smalltooth sawfish which occurs in our area. The smalltooth sawfish historically ranged from around North Carolina to central Brazil, and along the western coast of Africa. Now, smalltooth sawfish are only found in south and southwest Florida, and the Bahamas. With few remaining, it is important to learn about their life history, biology, and ecology so that conservation efforts will be successful.
In Southwest Florida, smalltooth sawfish research began in the early 2000s with most research efforts focused in the Caloosahatchee and Peace rivers; research data and angler observations indicate these areas still support juvenile sawfish. Last month I accompanied FWC-Fish and Wildlife Research Institute (FWRI) researchers on a directed sawfish trip in the Caloosahatchee River. FWRI’s sawfish research includes both random and directed sampling using a variety of net gear. We sampled in areas where anglers and shore observers had reported sawfish sightings (hence directed sampling).Sampling involved deploying a net and letting it soak for one hour. We had to check the net whenever anyone saw movement or after a half hour, whichever came first. Our first set resulted in nothing. We then cruised the shoreline looking for sawfish before setting a second net. We thought we were skunked a second time but finally at the end of our set, we got a sawfish!
Are you interested in the fisheries of Charlotte Harbor? Are you a recreational angler? A commercial fishermen? A clam farmer? Do you work at a bait and tackle shop? A marina? A fish house? Or maybe you work for some other business that relies on Charlotte Harbor fisheries? If you answered yes to any of these questions then the Charlotte Harbor Fisheries Forum wants to hear from you!
How? – The Fisheries Forum through the University of Florida has developed an online survey which may be accessed here: Charlotte Harbor Survey .
What is the Charlotte Harbor Fisheries Forum? – The fisheries forum is comprised of a group of recreational anglers, commercial fishermen, researchers, resource managers, law enforcement officers, tourism officials, and business owners who have been meeting monthly for the past year to discuss issues related to Charlotte Harbor fisheries. The forum aims to: provide a venue for long-term engagement; provide for in-depth consideration of local fisheries issues; improve links between local knowledge and science; and represent local-based perspectives to management agencies. Anyone who is interested in Charlotte Harbor fisheries can participate in the forum.
Join us at the monthly Charlotte Harbor Fisheries Forum – an independent community-based discussion geared toward informing fisheries management and science, and providing a venue for public engagement in local fisheries issues and building links between stakeholder knowledge, science, and management. The Charlotte Harbor Fisheries Forum — initiated by partnership of local Florida Sea Grant agents with the University of Florida (UF) and Mote Marine Laboratory — offers repeating, open meetings where local anglers and others interested in sustaining Charlotte Harbor’s fisheries can share their knowledge, ideas, questions and comments. The ultimate goal of the Fisheries Forum is to pinpoint the needs and status of fisheries in more detail at the local level, allowing communities to give more complete, collaborative and sustained feedback to government agencies and researchers. In this meeting (July 30), we will have 3 speakers: Judy Ott from Charlotte Harbor National Estuary Program on water quality, Melynda Brown from FDEP Charlotte Harbor Aquatic Preserves on seagrass, and Eric Milbrandt from Sanibel-Captiva Conservation Foundation on macroalgae.
Need to know: The meeting will take place from 6 – 8:30 p.m. on Thursday, July 30, at the Laishley Marina, 120 Laishley Ct, Punta Gorda.