By: Jonathan Rodemann, FIU PhD candidate
I was a bass fisherman as a kid. Fishing the lakes up in New Jersey was all I knew. Then I moved to Florida to attend University of Miami as an undergraduate student and was introduced to the wonders of coastal saltwater fishing. I heard stories about snook, tarpon, jacks, snapper, and other incredible sport species. However, one species caught my attention and has been an obsession ever since. Red drum (Sciaenops ocellatus), also known as redfish or just reds, is a coastal fish species ranging from the Gulf of Mexico all the way up to New Jersey (who knew I had them in my neck of the woods?!), but are most common in the southern portion of their range. In Florida, they are one of the most sought after sportfish, known for their “bullish” fights and delicious taste.
These traits ramped up interest in red drum fishing in Florida Bay through the mid-20th century. Fishing was good back then, with healthy populations and no regulations. By the early 1980’s, 40% of the recreational fishermen in Florida Bay were targeting red drum and there was a strong commercial harvest as well. It felt like the unlimited supply of reds would never end.
Then catches began to drop off. In a fashion that is too common nowadays, overfishing led to a large decline of red drum in Florida Bay. It got so bad that emergency seasonal closures of the fishery, as well as size and bag limits, were enacted in the late 1980’s. Redfish populations started to recover due to these regulations all around Florida, except for Florida Bay. The altered freshwater flow input into Florida Bay from the canalization of the Everglades has changed the salinity regime, reducing habitat quality throughout Florida Bay and causing widespread seagrass die-offs. With all these detrimental alterations to the habitat, the already low populations of red drum could not recover.
Coming to FIU, I knew I wanted to study the ecology of recreationally important fish species. So I jumped at the opportunity when a project opened up in the coastal fisheries lab run by Dr. Jennifer Rehage looking at how the 2015 seagrass die-off in Florida Bay has affected the movement and trophic ecology of grey snapper (Lutjanus griseus), spotted seatrout (Cynoscion nebulosus), and red drum. However, when describing my project to people who have fished Florida Bay, all I heard was “Good luck! You won’t find any redfish there!”. Worried about the project, I started to look at other species as options. But then I started to hear whisperings. Trickling down through the grapevine was information on an abundance of “puppy drum,” red drums under the size limit, in Florida Bay. Excitement built and then curiosity set in. What caused this huge recruitment pulse? I came to the only logical conclusion: Hurricane Irma.
Hurricane Irma passed directly over Florida Bay in early September of 2017, the first hurricane to do so since the mid 1900’s. While devastating for human populations in South Florida, Irma was a godsend for many fish species, including red drum. The category 4 hurricane dumped a tremendous amount of freshwater into the entire Everglades system, drastically reducing the normally high salinities in Florida Bay. This input of freshwater along with the timing (breeding season for redfish is August to December) created a perfect storm (pun intended!) for red drum recruitment.
Now in early 2019, we are seeing tons of 12-15 inch redfish, whose size is indicative of hatching right after Hurricane Irma. So what does this teach us about the red drum population of Florida Bay? It seems that high freshwater input will increase the number of spawning events and the survival rates of the offspring. Therefore, restoring freshwater flow into Florida Bay through programs such as CERP (Comprehensive Everglades Restoration Plan) has the potential to bring back red drum populations! I am very excited to start tracking these “Irma reds” to learn more about what makes them tick, hopefully leading to information that will help redfish thrive once again in Florida Bay.