Ling of the Florida Panhandle – or Should I Say Cobia of the Florida Panhandle

Ling of the Florida Panhandle – or Should I Say Cobia of the Florida Panhandle

This fish is a classic example of why scientists use scientific names.  There are numerous common names for this species and multiple ones even in the Gulf region.  Ling, Cabio, Lemonfish, Cubby Yew, Black kingfish, Black salmon, Crabeater, and Sergeant fish to name a few.  The Cajun name for the fish is Limon – possibly where the name Lemonfish came from.  Based on the references, Cobia seems to be the most accepted name, but Ling is often used here along the Florida panhandle.  Again, this is a great example of why scientists use scientific names when writing or speaking about species.  There is less chance for confusion.  I say less because at times the scientific names change as well, and some confusion can still occur.       

The Cobia Photo: NOAA

The scientific name for this fish is Rachycentron canadum.  The genus name refers to the sharp spines of the first dorsal fin, which are sharp.  The species name may refer to Canada.  It is a common practice to give a species the name of the area/location in which it was first described.  But it seems that Carlos Linnaeus, the biologist who first described it, used a specimen from the Carolinas to do so.  So, not sure why the name was given4.  It is the only North American fish in the family Rachycentridae and its closest relative are the remoras of the shark sucker family.  

Some state that cobia have only one dorsal fin, but in fact they have two.  The first is a series of 7-9 spines spaced with no membrane connecting.  They are small, sharp, and somewhat embedded into the body.  This is very similar to how the remoras and shark suckers first dorsal spines work, albeit remora’s first dorsal is softer.  Cobia have a low depressed head that gives them the appearance of a shark when viewed from the side.  It is often confused with sharks because they can get quite large – an average of five feet in length and up to 100 pounds in weight.  The small juveniles resemble remora quite a bit.  They are darker in color with pronounced lighter colored lateral stripes and their caudal fin (tail) is more lancelet and less lunate than the adults. 

Biogeographically they are listed as worldwide, albeit tropical to subtropical – they do not like cold water.  In the United States they are found all along the east and Gulf coast, but are absent from the west coast – again, a dislike for cold water.  The literature states that there are two population stocks of cobia here.  The Atlantic group and the Gulf of Mexico group all head south towards the Florida Keys for winter.  However, breeding appears to take place in the northern parts of their range and so no genetics are exchanged while the two groups co-exist in the Keys.  If this is the case, and it seems to be, there is a reproductive barrier, or behavioral barrier, that could, over time, isolate these two groups long enough that the gene pools could become different enough that attempts to breed between the groups would not produce viable offspring.  If this were the case then they could be listed as subspecies, possibly the Atlantic and Gulf Cobia.  But this has not happened.  There are also studies that suggest in the Gulf there may be isolated groups.  One comment is that there are cobia along Florida’s Gulf coast that migrate inshore and offshore but do not make the run to the Keys and back4.  There are also studies that show a similar behavior with a group over near Texas.  Obviously, there is a lot of work to be done on the movement and genetics of these possible subgroups to completely understand the biogeography of this animal.  And don’t forget, there are cobia along the European/African coast of the Atlantic as well as the Indian and western Pacific.   

Cobia resemble both shark suckers and sharks. Photo: University of Florida

But migrate they do.  The “Ling Run”, as it known in the Pensacola area, is something many anglers wait for early in the year.  We even have some local bait and tackle shops monitoring water temperature to announce when the run will begin.  When water temperatures warm to 67°F it is time.  Local anglers flock the Gulf side piers and head out on their boats with high ling towers to search for them.  At the beginning of the ling run I have seen the inshore Gulf of Mexico littered with hundreds of boats covering the surface like small dots as far as you can see.  One boat I remember was about 20 feet long and had precariously placed a large step ladder in the center as a “ling tower”.  The angler was perched at the top of the ladder, holding on in the chop, searching the waters for his target. 

Cobia will travel alone or in groups of up to 100 and are often attracted to objects in the water.  Flotsam like Sargassum weed, or marine debris are places that anglers focus on.  They are known to shadow sharks, manta rays, and sea turtles.  I know anglers when they see a sea turtle begin throwing bait in that direction in hopes that a cobia is nearby.  To the west of us in Alabama they seem to visit the offshore gas rigs and are attracted to the fishing piers many communities have extending into the Gulf – hence the large crowds of non-boating anglers visiting them during the run.  Many anglers are known to drop FADs (Fish Attracting Devices) into the water to attract cobia, though these are not allowed during cobia/ling tournaments – which also pop up across the panhandle during the run. 

Despite this apparent heavy fishing pressure, it is considered a sustainable fishery.  Cobia mature at an early age, 2 years for males and 3 for females – and they live for about 12 years.  They mass spawn in the northern waters.  A typical season will find females breeding 15-20 times and producing 400,000 – 2,000,000 per spawn event.  There is no evidence that this fishery is overfished, and there is commercial fishery for them as well.  Due to their quick growth rates, large size, and high-quality flesh, there is interest in offshore aquaculture of this species.  

It is an amazing fish.  One of the best fish sandwiches I have ever had was a fresh ling sandwich.  It is also a very interesting species from a biographical point.  Enjoy the next “Ling Run” along the panhandle – or “cobia run”, or “lemonfish run”, which ever you wish to call it. 

References

1 Bester, C. 2017. Discover Fishes; Rachycentron canadum. Florida Museum of Natural History. https://www.floridamuseum.ufl.edu/discover-fish/species-profiles/rachycentron-canadum/.

2 Lovestrand, E. 2021. Cobia: An Amazing Fish and Fishery for North Florida. University of Florida IFAS Blogs. https://nwdistrict.ifas.ufl.edu/nat/2021/03/11/cobia-an-amazing-fish-and-fishery-for-north-florida/.

3 NOAA Fisheries. 2020. Cobia; Species Directory. https://www.fisheries.noaa.gov/species/cobia.

4 Staugler, B. 2016. Cobia Stripes. University of Florida IFAS Blogs. https://blogs.ifas.ufl.edu/charlotteco/2016/05/21/cobia-stripes/.

Bluefish of the Florida Panhandle

Bluefish of the Florida Panhandle

“Bluefish!” … “It’s just a school of bluefish!”  So yelled the lifeguard in Jaws II when Chief Brody had mistaken a school of bluefish for the rogue great white shark that was plaguing the town.  He would not have been the first to mistake these large schools for a larger fish, particularly a predatory shark, but as some know, bluefish are quite predatory themselves.

Bluefish
Image: University of South Florida

Growing up along the Florida panhandle we heard little about this species.  We had heard stories of large bluefish schooling along the Atlantic coast killing prey with their razor-sharp teeth and, at times, biting humans.  But not much was mentioned about them swimming along our shores.  But they do, and I have caught some.

Bluefish are one of several in a group Hoese and Moore refer to as “mackerel-like fish” in Fishes of the Gulf of Mexico. They differ in that they lack the finlets found along the dorsal and ventral sides of the mackerel body and mackerels lack scales having a smoother skin.  Bluefish are the only members of the family Pomatomidae.  They can reach three feet in length and up to 30 pounds.  They travel in large schools viciously feeding on just about anything they can catch and seem to really like menhaden.  They move inshore for feeding and protection from larger ocean predators but do move offshore for breeding.

Bluefish landed from the Gulf of Mexico are much smaller than their Atlantic cousins, rarely weighing in more than three pounds.  They do have a deep blue-green color to them and thin caudal peduncle and forked tail giving them the resemblance of a mackerel or jack.  Some say they are bit too oily to eat while others enjoy them quite a bit.  There is a commercial fishery for them in Florida and, as you would expect, it is a larger fishery along the east coast.  Most of the panhandle counties have had commercial landings, albeit small ones.

Biogeographically, the blue fish are found all along the Atlantic seaboard and into the Gulf of Mexico.  It is listed as worldwide but seems to be absent from the Caribbean and other tropical seas.  This could be due to a distaste of warmer waters, or the lack of their prey targets.

They are an interesting and less known fish in our region.  Swimming in a school of them should be done with caution, there are reports of nips and bites from these voracious predators.

The Recent Fish Kill Near Pensacola Was Due to Stratification… Say What?

The Recent Fish Kill Near Pensacola Was Due to Stratification… Say What?

This began with a call from one of my volunteers who was checking salinity at Shoreline Park.  She reported the salinity, but also reported to smell of dead fish – though she could not see them.  I visited Shoreline Park the following day on another project and could smell it as well.  There was a large amount of dead seagrass washed ashore from a recent storm and I thought this may be the cause of the smell because I did not see the dead fish either.

 

When I got home, I checked the FWC fish kill database.  It reported a redfish kill in Pensacola Bay.  It is unusual to see a kill of only one species.  Many times, these are releases from fishing activity, particularly bait, and thought this must be the case – FWC did not mention the cause.  I let the volunteer know and asked to keep an eye out.

 

I reported this to the Escambia County Division of Marine Resources to (a) let them know, and (b) to find out if they had any idea of cause.  They replied that the location was incorrect.  The kill was actually near Galvez Landing on Innerarity Point.  He (Robert Turpin) had visited the site and did find any dead fish.  I have a lot of volunteers over that way so asked each to take a look.  They did not see any dead fish.  I asked them to keep an eye out and collect a dead fish if they saw one for testing.  Often when a large fish kill occurs, and it is only one species, the suspect cause is disease.  Tissue samples could confirm this.

 

And then came another call.

This time it was from one of our Master Naturalist who lives on the eastern shore of Mobile Bay.  He wanted to know what was up with all of the dead redfish along the shore of the bay.  He sent photos and his beach was littered with them.  I reached out to Mississippi/Alabama Sea Grant to see if they knew what was going on.  They had heard about the situation and knew the Alabama Department of Natural Resources was collecting samples.  The Gulf Islands National Seashore then reported large numbers of dead redfish along the National Shores property in Mississippi, something was up.

Dead redfish on the eastern shore of Mobile Bay.
Photo: Jimbo Meador

I eventually got word from Dr. Marcus Drymon at the Dauphin Island Sea Lab.  They had a team working on this.  Their team reported that stratification of the Gulf had created a hypoxic (low dissolved oxygen) layer on the bottom and the male “bull redfish” had gathered for breeding and died.

 

So, we are back to our title – what is stratification and how did this cause the fish kill?

 

Stratification is the layering of the water.  Less dense water will sit atop the more dense.  Water temperature or salinity can cause this density difference and layering.  Colder and/or saltier water is denser and will form the bottom layer.  If you have high winds, it will mix the water and the stratification disappears.  Tides and currents can affect this as well.

 

What they believe happened recently was excessive amounts of rainfall created a large layer of freshwater to move from Mobile Bay into the open Gulf.  The combination of tides and wind allowed a stratified layer to form.  The oxygen that marine life uses is dissolved into the water at the surface and referred to as dissolved oxygen (DO).  If the system is stratified, then the oxygen dissolved at the surface will not reach the bottom and hypoxia (low DO) can happen.  They this is what happen.  It just so happens that the large male redfish (bull reds) had congregated just offshore for breeding.  They are more sensitive to low DO than the smaller females and any juveniles.  So, the males died.  To answer the question as to why other fish did not die (what you typically see in a DO related fish kill) – the numbers were not mentioned by there was one reference to 4.0 ppm.  This is the high threshold of hypoxia.  Many fish can tolerate at this concentration, but the male redfish could not.

 

So, that is what we think happened.  The perfect storm of the demise of a group of male redfish just off of Mobile, and the carcasses drifted to other locations.

Tilefish of the Florida Panhandle

Tilefish of the Florida Panhandle

I am going to be honest and say that I know very little about this fish.  I did not know they even existed until I attended college.  Shortly afterwards, my father-in-law asked “hey, have you ever heard of a tilefish?” – to which I responded yes… He was having lunch at a restaurant in Apalachicola, and it was on the menu.  My father-in-law was an avid fisherman and knew most of the edible species, but he had not heard of this one.  The rumor was that it was pretty good, though my father-in-law chose not to eat it that day.

Tilefish
Photo: NOAA

I have never seen it on a menu, and only a few times in the local seafood markets, but according to Hoese and Moore1 by the late 1970s there was a small commercial fishery for this fish emerging in Louisiana, as was a small recreational fishery.  In Florida, since 2000, there have been 15,435 commercial trips for this fish with an average of 321 each year.  The value of this fishery over that time is $33,118,554 with an average of $689,969.90 each year.  The average price for the fishermen was $2.62 per pound with the highest being $5.14/lb. on the east coast and that in 2022; the Gulf fishermen are getting $4.16/lb. right now.

 

The highest number of landings per county since 2000 was 340 in Palm Beach County in 2000.  Only eight times has there been more than 200 landings in a single year over the last 22 years.  Five of those were in Monroe County (Florida Keys) and three were again in Palm Beach County.  The vast majority were less than 100 landings in a single year, this is not a large fishery in Florida either.

 

Are they harvested here in the Florida panhandle?

Yes… Bay, Escambia, Franklin, Okaloosa, Wakulla, and Gulf Counties all reported landings.  Bay County seems to be the hot spot for panhandle with landings between 50-100 each year since 2000.  Most of the other counties report less than 10 a year and several only reported one.  Again, this is not a large fishery, but it was sold at a restaurant in Apalachicola and is said to be good.  Hence, I decided to include in this series.

 

Hoese and Moore report four species of tilefish in the Gulf of Mexico.  The sand tilefish (Malacanthus plumeri) is a more tropical species.  The tilefish (Lopholatilus cheamaeleonticeps) and the gray tilefish (Caulalatilus microps) seem to be the target ones for fishermen.  Both are reported from deep cold water near the edge of the continental shelf.  FWC reports them from 250 – 1500 feet of water where the temperatures are between 50 – 60°F.  Because of their tolerance to cold water, their geographic range is quite large; extending across the Gulf, up the east coast to Labrador.  They live in burrows on hard sandy bottoms and feed on crustaceans.  The National Oceanic and Atmospheric Administration2 reports this as a slow growing – long lived fish, up to 50 years of age.  In their cold environment, this makes sense.

 

This is not a well-known fish along the Florida Panhandle but maybe one day you will see it on the menu, remember this article, and take a chance to see if you like it.

 

References

 

1 Hoese, H.D., Moore, R.H. 1977. Fishes of the Gulf of Mexico; Texas, Louisiana and Adjacent Waters.  Texas A&M Press.  College Station TX. Pp. 327.

 

2 Golden Tilefish. 2020. Species Directory. NOAA Fisheries. https://www.fisheries.noaa.gov/species/golden-tilefish.

Sea Bass and Grouper of the Florida Panhandle

Sea Bass and Grouper of the Florida Panhandle

When you look over the species of sea basses and groupers from the Gulf of Mexico it is a very confusing group.  Hoese and Moore1 mention the connections to other families and how several species have gone through multiple taxonomic name changes over the years – its just a confusing group.

Gag grouper.
Photo: National Oceanic and Atmospheric Administration

But when you say “grouper” everyone knows what you are talking about, and everyone wants a grouper sandwich.  This became a problem because what people were serving as “grouper” may not have been “grouper”.  And as we just mentioned what is a grouper anyway?  The families and genera have changed frequently.  Well, this will probably get more technical than we want, but to sort it out – at least using the method Hoese and Moore did in 1977 – we will have to get a bit technical.

 

“Groupers” are in the family Serranidae.  This family includes 34 species of “sea bass” type fish.  Serranids differ from snappers in that they lack teeth on the vomer (roof of their mouths) and they differ from “temperate basses” (Family Percichthyidae) in that their dorsal fin is continuous, not separated into two fins.  These are two fish that groupers have been confused with.

Banked Sea Bass.
Photo: National Oceanic and Atmospheric Administration.

We can subdivide the serranids into two additional groups.  The “sea basses” have fewer than 10 spines in their dorsal fin.  There are 10 genera and 18 species of them.  They have common names like “bass”, “flags”, “barbiers”, “hamlets”, “perch”, and “tattlers”.  They are small and range in size from 2 – 18 inches in length.  Most are bottom reef fish with little commercial value for fishermen.  Most are restricted to the tropical parts of the Atlantic basin but two are only found in the northwestern Gulf, one is only found in the eastern Gulf, and one has been found in both the Atlantic and Pacific.  The biogeography of this group is very interesting.  The same species found in both the Atlantic and Pacific suggest an ancient origin.  The variety of serranid sea bass suggest a lot of isolation between groups and a lot of speciation.

 

The ”groupers” have 10 or more spines in their dorsal fin.  There are two genera in this group.  Those in the genus Epinephelus have 8-10 spines in their anal fin and have some canine teeth.  Those in the genus Mycteroperca have 10-12 spines in their anal fin and lack canine teeth.  Within these two genera there are 15 species of grouper, though the common names of “hind”, “gag”, “scamp” are also used.  Most of these are found along the eastern United States and Gulf of Mexico.  Five species are only found in the tropical parts of the south Atlantic region, five are also found across the Atlantic along the coast of Africa and Europe, and – like the “sea bass” two have been found in both the Atlantic and the Pacific.  They range in size from six inches to seven feet in length.  The Goliath Grouper can obtain weights of 700 pounds!  Like the sea bass, groupers prefer structure and can live a great depths.  Unlike sea bass they are heavily sought by commercial and recreational anglers and are one of the more economically important groups of fish in the Gulf of Mexico.

The massive size of a goliath grouper. Photo: Bryan Fluech Florida Sea Grant

One interesting note on this family of fish is that most are hermaphroditic.  The means they have both ovaries (to produce eggs) and testes (to produce sperm).  Sequential hermaphrodism is when a species is born one sex but becomes the other later in life.  This is the case with most groupers, who are born female and become male later in life.  However, the belted sand bass (Serranus subligarius) is a true hermaphrodite being able to produce sperm and egg at the same time – even being able to self-fertilize.

 

For many along the Florida panhandle, their biogeographic distribution and sex do not matter.  It is a great tasting fish and very popular with anglers.  For those with a little more interest in natural history of fish in our area, the biology and diversity of this group is one of the more interesting ones.

 

Reference

 

1 Hoese, H.D., Moore, R.H. 1977.  Fishes of the Gulf of Mexico; Texas, Louisiana, and Adjacent Waters.  Texas A&M Press.  College Station TX.  Pp. 327.

Celebrating the Okaloosa Darter

Celebrating the Okaloosa Darter

World Wildlife Day was celebrated on March 3, 2022.  This year’s theme is “Recovering key species for ecosystem restoration.” We celebrate this day to bring attention and awareness to many of the plants and animals that are considered threatened and endangered species and highlight efforts to conserve them. It is estimated that over a million species are currently threatened with extinction.

Turkey Creek Niceville, FL (credit E. Zambello)

Florida is considered a very biodiverse state having a great variety ecosystems and unique plants and animals that inhabit these areas.  This makes Florida an attractive place to live but can result in increased pollution and land use changes that can be threats to this biodiversity. One local species that experienced this type of pressure is the Okaloosa darter. This tiny 1 to 2 inch fish dwindled to as few as 1,500 individuals surviving when it was declared endangered in 1973.  Factors such as its small range, competition from other species, and historical land use practices including artificial impoundments, erosion, and siltation, contributed to its demise.

The Okaloosa darter prefers to live in small, clear, lightly vegetated streams fed by ground water seepage from sand hill areas.  This highly specialized habitat is found in only six streams in Okaloosa and Walton Counties and almost exclusively within Eglin Air Force Base’s boundaries.  Environmental managers from Eglin Air Force Base partnered with U.S. Fish and Wildlife Service and other agencies and worked diligently to reduce land use impacts and rehab the impaired streams over the past several decades. They reclaimed clay pits near stream headwaters, improved road crossings to reduce sedimentation and enhanced the habitat for the darter.

Okaloosa darter photo credit: FWS.gov

Due to these efforts, the population of Okaloosa Darters has increased to more than 600,000 and the species has now been down listed from endangered to threatened.  In fact, the projects have been so successful that the darter is now being considered for delisting as a threatened and endangered species under the Endangered Species Act. This is something to celebrate on this World Wildlife Day as an example of how we can recover key species for ecosystem restoration.  The best news is that Eglin Air Force Base’s Jackson Guard Unit is continuing to make on-base conservation a priority, not only for the Okaloosa Darter, but for other plants and animals under their purview.