Cobia Researchers use Transmitters as well as Tags to Gather Data on Migratory Patterns
I must admit to having very limited personal experience with Cobia, having caught one sub-legal fish to-date. However, that does not diminish my fascination with the fish, particularly since I ran across a 2019 report from the Gulf States Marine Fisheries Commission titled “Management Profile for Gulf of Mexico Cobia.” This 182-page report is definitely not a quick read and I have thus far only scratched the surface by digging into a few chapters that caught my interest. Nevertheless, it is so full of detailed life history, biology and everything else “Cobia” that it is definitely worth a look. This posting will highlight some of the fascinating aspects of Cobia and why the species is so highly prized by so many people.
Cobia (Rachycentron canadum) are the sole species in the fish family Rachycentridae. They occur worldwide in most tropical and subtropical oceans but in Florida waters, we actually have two different groups. The Atlantic stock ranges along the Eastern U.S. from Florida to New York and the Gulf stock ranges From Florida to Texas. The Florida Keys appear to be a mixing zone of sorts where Cobia from both stocks go in the winter. As waters warm in the spring, these fish head northward up the Atlantic and Gulf coasts of Florida. The Northern Gulf coast is especially important as a spawning ground for the Gulf stock. There may even be some sub-populations within the Gulf stock, as tagged fish from the Texas coast were rarely caught going eastward. There also appears to be a group that overwinters in the offshore waters of the Northern Gulf, not making the annual trip to the Keys. My brief summary here regarding seasonal movement is most assuredly an over-simplification and scientists agree more recapture data is needed to understand various Cobia stock movements and boundaries.
Worldwide, the practice of Cobia aquaculture has exploded since the early 2000’s, with China taking the lead on production. Most operations complete their grow-out to market size in ponds or pens in nearshore waters. Due to their incredible growth rate, Cobia are an exceptional candidate for aquaculture. In the wild, fish can reach weights of 17 pounds and lengths of 23 inches in their first year. Aquaculture-raised fish tend to be shorter but heavier, comparatively. The U.S. is currently exploring rules for offshore aquaculture practices and cobia is a prime candidate for establishing this industry domestically.
Spawning takes place in the Northern Gulf from April through September. Male Cobia will reach sexual maturity at an amazing 1-2 years and females within 2-3 years. At maturity, they are able to spawn every 4-6 days throughout the spawning season. This prolific nature supports an average annual commercial harvest in the Gulf and East Florida of around 160,000 pounds. This is dwarfed by the recreational fishery, with 500,000 to 1,000,000 pounds harvested annually from the same region.
One of the Cobia’s unique features is that they are strongly attracted to structure, even if it is mobile. They are known to shadow large rays, sharks, whales, tarpon, and even sea turtles. This habit also makes them vulnerable to being caught around human-made FADs (Fish Aggregating Devices). Most large Cobia tournaments have banned the use of FADs during their events to recapture a more sporting aspect of Cobia fishing.
To wrap this up I’ll briefly recount an exciting, non-fish-catching, Cobia experience. My son and I were in about 35 feet of water off the Wakulla County coastline fishing near an old wreck. Nothing much was happening when I noticed a short fin breaking the water briefly, about 20 yards behind a bobber we had cast out with a dead pinfish under it. I had not seen this before and was unaware of what was about to happen. When the fish ate that bait and came tight on the line the rod luckily hung up on something in the bottom of the boat. As the reel’s drag system screamed, a Cobia that I gauged to be 4-5 feet long jumped clear out of the water about 40 yards from us. Needless to say, by the time we gained control of the rod it was too late; a heartbreaking missed opportunity. Every time we have been fishing since then, I just can’t stop looking for that short, pointed fin slicing towards one of our baits.
Archery season for white tailed deer opens this Saturday (10/24/20) in FWC Hunting Zone D (basically the Panhandle west of Tallahassee, see figure 1). Before you go hunting be sure that you have a plan in place for logging and reporting your harvest. Last year FWC implemented a mandatory harvest reporting system. That system is still in effect this year but with some modifications.
Figure 1. FWC Hunting Zone D
The most notable change to the harvest reporting system this year is with the associated smart phone app. There is a new app this year – Fish|Hunt Florida. This new app will replace the Survey123 for ArcGIS app that was used last year.
In my opinion, the logging and reporting function on the Fish|Hunt Florida app is simpler to use than the previous app. Additionally the Fish|Hunt Florida app has many other useful features. A few highlights include; the ability to view and purchase hunting and fishing licenses/permits through the app, interactive versions of hunting and fishing regulations, and several other handy resources for sportsmen including, marine forecasts, tides, wildlife feeding times, sunrise & sunset times, boat ramp locator and a current location feature. Screenshots from the app are included below. The Fish|Hunt Florida app is available for free through the Apple App Store and the Google Play Store.
Remember, the current regulations state that your deer harvest must be logged before the animal is moved. Take a minute or two to install the app on your phone before you go hunting. Using the app allows logging and reporting to happen simultaneously. The app can be used for logging and reporting a harvest even in areas where cell service is poor. Harvest information will can be saved and the app will automatically complete the process as soon as adequate cell service is available. The alternative to using the app is a two-step process, the harvest can be logged (prior to being moved) on a paper form and then reported by calling 888-HUNT-FLORIDA (888-486-8356) or going to GoOutdoorsFlorida.com within 24 hours.
Follow the link for specific instructions for logging and reporting a harvested deer using the Fish|Hunt Florida app; don’t worry, it’s easy. Fish|Hunt Florida app instructions
For more information on the Fish|Hunt Florida app and the FWC Deer Harvest Reporting System visit myfwc.com.
Screenshot of the Boat Info tab from the Hunt|Fish Florida App. Click on the image to make it larger.
Screenshot of the Fishing Tab from the Hunt|Fish Florida App. Click on the image to make it larger.
Screenshot of the Home screen from the Hunt|Fish Florida App. Click on the image to make it larger.
Screenshot of the Hunting tab from the Hunt|Fish Florida App. Click on the image to make it larger.
“Zombie Deer” have been making headlines lately. What are “zombie deer”? They are deer with chronic wasting disease or CWD. CWD is a progressive, neurological disease that is similar to BSE or Mad Cow Disease. It is believed to be caused by a prion (an abnormal protein). CWD has not been found in Florida.
Deer infected with this disease exhibits signs such as excessive salivation and urination, weight loss, poor hair condition, head tremors and grinding of teeth. Also, odd behaviors may be observed in infected deer such as walking in circles, listlessness, staggering, standing with a wide stance, lowering of the head, and less interaction with other animals.
CWD is transmitted by deer consuming prions from infected feces, urine and saliva. Prions can survive in the soil and thus may infected deer for many years. Deer that are infected with CWD take 1.5 to 3 years to show clinical signs. This makes this disease difficult to control.
CWD has been found in the following states: Arkansas, Colorado, Illinois, Iowa, Kansas, Maryland, Michigan, Minnesota, Mississippi, Missouri, Montana, Nebraska, New Mexico, New York, North Dakota, Ohio, Oklahoma, Pennsylvania, South Dakota, Tennessee, Texas, Utah, Virginia, West Virginia, Wisconsin, and Wyoming. It has also been found in Canada, Norway, Sweden and South Korea.
Florida Fish and Wildlife Commission has a CWD Monitoring Program and has regulations to prevent the spread of CWD into Florida. How can you help protect our deer population from this devastating disease?
- Follow the regulations adopted by FWC in Executive Order 19-41 regarding the transport of carcasses and parts of animals in the deer family such as white-tail deer, elk, moose, and caribou.
- Dispose of carcasses and parts of harvested deer according to the FWC-approved Carcass Disposal Options
- Report sick or abnormal animals to FWC at 866-CWD-WATCH (293-9282)
- Take precautions when hunting in state or countries where CWD has been detected.
For more information on CWD in Florida, go to the FWC CWD website.
As the migratory birds stop off or stay in the Panhandle this winter, they need to find food, food and more food. There is a wide variety of migration activity in Florida beginning in the fall months of September, October, and November. From woodland song birds to waterfowl to the annual warbler invasion, so many different species show up in Florida. While year-to-year migration patterns and winter foraging grounds can shift for some species due to a variety of reasons, some birds stay in Florida for the winter months of December, January, and February. Some may arrive early and others may stay late.
Some North American breeding birds endure harsh winters; however, they are physically suited for cold environments in a number of ways. One, they are able to drop their metabolic rate to a near comatose state using very little energy. Two, they are able to position their feathers, or puff up, to trap heat generated by their own body. Others need to head to warmer climates.
Birds migrate for two reasons. Food and weather avoidance. North American breeding birds who nest in the northern part of the continent will migrate south for the winter. As winter approaches, insect and plant life diminishes in the snow-covered states. Migrating birds head south in search of food. Places like Florida are rich in insects, plant life, and nesting grounds.
Birds need high energy food to stay warm. Berry and seed producing plants contain proteins, sugars and lots of fats. Many native trees, shrubs and grasses can aid migratory and winter visiting birds in their relentless search for food. Gardening for birds and other wildlife enables an opportunity for people to experience animals up close, which providing an important habitat in the urban environment.
For more information on which plants are preferred by specific bird species go to: https://www.audubon.org/native-plants
For more information on landscaping for wildlife refer to: https://edis.ifas.ufl.edu/pdffiles/UW/UW17500.pdf
Over 1.8 million Monarch butterflies have been tagged and tracked over the past 27 years. This October these iconic beauties will flutter through the Florida Panhandle on their way to the Oyamel fir forests on 12 mountaintops in central Mexico. Monarch Watch volunteers and citizen scientists will be waiting to record, tag and release the butterflies in hopes of learning more about their migration and what the 2019 population count will be.
This spring, scientists from World Wildlife Fund Mexico estimated the population size of the overwintering Monarchs to be 6.05 hectacres of trees covered in orange. As the weather warmed, the butterflies headed north towards Canada (about three weeks early). It’s an impressive 2,000 mile adventure for an animal weighing less than 1 gram. Those butterflies west of the Rocky Mountains headed up California; while the eastern insects traveled over the “corn belt” and into New England. When August brought cooler days, all the Monarchs headed back south.
What the 2018 Monarch Watch data revealed was alarming. The returning eastern Monarch butterfly population had increased by 144 percent, the highest count since 2006. But, the count still represented a decline of 90% from historic levels of the 1990’s. Additionally, the western population plummeted to a record low of 30,000, down from 1.2 million two decades ago. With estimated populations around 42 million, the U.S. Fish and Wildlife Service began the process of deciding whether to list the Monarch butterfly as endangered or threatened in 2014. With the additional information, FWS set a deadline of June 2019 to decide whether to pursue the listing.
Scientists estimate that 6 hectacres is the threshold to be out of the immediate danger of migratory collapse. To put things in scale: A single winter storm in January 2002 killed an estimated 500 million Monarchs in their Mexico home. However, with recent changes on the status of the Endangered Species Act, the U.S. Fish and Wildlife Service has delayed its decision until December 2020. One more year of data may be helpful to monarch conservation efforts.
Individuals can help with the monitoring and restoring the Monarch butterflies habitat. There are two scheduled tagging events in Panhandle, possibly more. St. Mark’s National Wildlife Refuge is holding their Butterfly Festival on Saturday, October 26 from 10a.m. to 4 p.m. Henderson Beach State Park in Destin will have 200 butterflies to tag and release on Saturday, November from 9 – 11 a.m. Ask around in the local area. There may be more opportunities.
There is something more you can do to increase the success of the butterflies along their migratory path – plant more Milkweed (Asclepias spp.). It’s the only plant the Monarch caterpillar will eat. When they leave their hibernation in Mexico around February or March, the adults must find Milkweed all along the path to Canada in order to lay their eggs. Butterflies only live two to six weeks. They must mate and lay eggs along the way in order for the population to continue its flight. Each generation must have Milkweed about every 700 miles. Check with the local nurseries for plants. Though orange is the most common native species, Milkweed comes in many colors and leaf shapes.
Soon, two important ecological surveys will begin in Gulf County, concerning both diamondback terrapins and mangroves.
Florida is home to five subspecies of diamondback terrapin, three of which occur exclusively in Florida. Diamondback terrapins live in coastal marshes, tidal creeks, mangroves, and other brackish or estuarine habitats. However, the diamondback terrapin is currently listed as a Species of Greatest Conservation Need (SGCN).
Diamondback terrapin populations, unfortunately, are nationally in decline. Human activities, such as pollution, land development and crabbing without by-catch reduction devices are often reasons for the decline, but decades ago they were almost hunted to extinction for their tasty meat. The recent decline has raised concern of not only federal agencies, but also organizations and community groups on the state and local levels. Diamondback Terrapin range is thought to have once been all of coastal Florida, including the Keys.
Figure 1: Diamondback Terrapin.
Credit: Rick O’Connor, UF/IFAS Extension & Florida Sea Grant, Escambia County.
Mangroves, a shoreline plant species of south Florida, are migrating north and are now being found in the Panhandle. Both red and black mangroves have been found in St. Joseph Bay. Mangroves establishment could be an important key to a healthy bay ecosystem, as a factor in shoreline restoration and critical aquatic life habitat.
Currently there is a significant data gap for both diamondback terrapin and mangrove populations. Therefore, there is a great need to conduct assessments to learn more about their geographic distribution.
Figure 2. Black Mangrove in St. Joseph Bay.
Credit: Ray Bodrey, UF/IFAS Extension & Florida Sea Grant, Gulf County.
The Forgotten Coast Sea Turtle Center is partnering with UF/IFAS Extension & Florida Sea Grant to assist in surveying and monitoring diamondback terrapins and mangroves in St. Joseph Bay, and we need your help! UF/IFAS Extension & Florida Sea Grant Agent’s Rick O’Connor and Ray Bodrey are providing a training workshop for volunteers and coordinating surveys for St. Joseph Bay. Terrapin surveys require visiting an estuarine location where terrapin nesting sites and mangrove plants are highly probable. Volunteers will visit their assigned locations at least once a week during the months of May and June and complete data sheets for each trip. Each survey takes about two hours, and some locations may require a kayak to reach.
If you are interested in volunteering for these important projects, we will hold a training session on Monday, April 22nd at 1:00 p.m. ET at the Forgotten Coast Sea Turtle Center (located at 1001 10th Street, Port St. Joe).
For more information, please contact:
Ray Bodrey, UF/IFAS Extension Gulf County, Extension Director
UF/IFAS Extension is an Equal Opportunity Institution.