Episode 31: What Fish Populations Are Telling Us About the IRL’s Health

Dan Kolodny:

Hi there everyone and welcome to One Lagoon One Voice the podcast of the Indian River Lagoon National Estuary Program where we talk all things Lagoon with smart people doing great work to restore the Indian River Lagoon. I’m Dan Kolodny, Chief Operating Officer for the IRLNEP, and this episode’s host.

Do you ever wonder where all of the regulations around fishing come from? You may not know that today’s regulations are based on a wide variety of data collected by Fish and Wildlife biologists who monitor fish populations – both game fish and nongame species. The folks provide the data that allows regulators to effectively manage Florida’s marine and estuarine species and, hopefully, keep the catching good for everybody.

Today we’ll discuss fisheries monitoring and how the data collected impacts management decisions. If you like to fish on the lagoon like I do, you’re definitely gonna want to stay tuned for this next episode.

Dan Kolodny:

All right. To help discuss the health of the IRL fisheries and some of the trends we’ve seen over the years, we are joined by Derek Tremain from the Florida Fish and Wildlife Conservation Commission. Derek’s a fisheries biologist and the research administrator for the Fisheries-Independent Monitoring Program at the Indian River Field Lab in Melbourne, Florida. Welcome, Derek.

Derek Tremain:

Yeah. Thank you, Dan. Appreciate being here.

Dan Kolodny:

Yeah. Tell us a little bit about, um, your background and some of the work that you do there at the, uh, the fisheries lab.

Derek Tremain:

Yeah. I always enjoy getting a chance to, to spread the word on what we’re up to these days. I actually grew up here on the lagoon back in the 1960s as a boy. Um, I remember running around behind the house. We lived in Merritt Island, running around in the flats catching or chasing at least the blowfish, as we called them back in the day.

We moved away growing up. I came back here to Melbourne, uh, in the early 1980s to complete my schooling at FIT, and after working on several different grant-funded projects first with Harbor Branch and then with the IFS Lab down in Vero Beach, I ended up back here in Melbourne and joined the, FWC’s Indian River Field Lab when they opened here in 1990. So I’ve been around the area for a while.

Um, I’ve been mucking around in the lagoon for some 40+ years now. I’ve spent the last 36 years here at the FWC as a research biologist with the Fisheries-Independent Monitoring program. And the most recently, creeping up there in years have kind of shifted me over. I’m now, uh, as you mentioned, the moving on to more administrative roles around here, but I still enjoy the chance to get out and, and haul some of the nets when I can. And, and, uh, you know, that’s what we got into the field for, so, you know, that’s the, that’s the fun part of the job.

Dan Kolodny:

For sure. And it’s funny you mentioned that because, um, you know, you said FIT and, and how we first met was actually-

When I was at FIT in the late ’90s, early 2000s and, I forget if it was Jon Shenker or Ralph Turingan told me to go, you know, volunteer at the field lab and, and see what they do at the fisheries there for FWC. And so, I went over and met Rich, who was your predecessor.

Dan Kolodny:

And we went out in the field and yeah, I remember that was the first time I met you. We were dragging big hall seine nets and, and so that’s really cool stuff. I was really impressed with everything that we got to do and, you know, that kind of leads me into, you know, what you do at the field lab, which is Fisheries-Independent Monitoring. can you tell us a little bit about the, how that’s performed, some of those nets and, and the work?

Derek Tremain:

Yeah. So first of all, Fisheries-Independent Monitoring really just means that, we’re collecting data using standard, standardized gears and, and scientific methods. our program, if you’re interested in the background of the program, we got started back in the, in the late 1980s as a response to some, declines in populations of red drum on the west coast of Florida. And so, there was a need to kind of understand estuarine habitat use by the juveniles in the early life history of, red drum over in, over on the West Coast. so that program as they were collecting red drum in some of these backwater areas and parts of the lagoon, they also found, you know, they’re collecting a lot of other animals too, a lot of other species and including a bunch of sportfish species. And so, they expanded the program to not just be specific to red rum, but to include, more of everything.

And, eventually it expanded through Tampa Bay. It moved to Charlotte Harbor and, and eventually in 1990 we started the lab here in the Indian River. I think now we have six, estuarine systems that we’re sampling with a long-term presence. We go into a lot more areas than that throughout the state, but the goal of the whole program is to, to provide sort of current data and analyses to fisheries managers then they can use to make informed decisions to protect fisheries.

The way that we monitor fisheries over here and throughout our program is using a stratified random sampling approach. basically that’s pretty simple to break down. The stratified just simply means that we’re, our sampling universe is divided into various regions based on some sort of a strata as it were. It could be something like salinity or physical barrier, , but our sampling effort then is, is allocated proportionally within those strata.

The random nature of it means that we’re sampling sites that we don’t select, uh, with any bias the sites and the gears that we use in each site that, that we go to are selected for us by a computer. what that does is it sort of ensures that there’s this unbiased coverage throughout the lagoon of our sampling efforts and that, the data that we get back from those efforts is representative of the, of the lagoon as a whole.

In the Indian River here, we are the area that we’re responsible for is samples from basically from Ponce Inlet up in Volusia County all the way down to Lake Worth Lagoon in Palm Beach County, which is a massive area.

Derek Tremain:

But our core monthly sampling now is focused more, basically from Titusville down to Jupiter Inlet down near Tequesta. As I say, it’s a big area to cover it. We do get help from a, a group out of the fish biology lab down in Tequesta that works, is also a FWC lab, so they help us in the southern part of the lagoon. It’s a lot of effort that goes into it and we’ve been doing this, like I said, for 36 years.

Dan Kolodny:

That’s awesome. How often do you, would you say you kind of go back to, like, the same area, on average? I mean, I know it’s random, but on average, is it, like, once a year, once every other year, more than that?

Derek Tremain:

Well, it, yeah, it’s, it is. It’s really variable. usually not too often. There are some, the way we have our system designed or allocated, but we divide the whole area up into these nautical mile by nautical mile grids-

Dan Kolodny:

Yeah, I remember seeing them. Mm-hmm.

Derek Tremain:

But it’s rare that we go back continually to the same site. We do hit some areas more than once in a year maybe but pretty rare. It’s a pretty good spread across. If you look at our shotgun pattern of where our sampling occurs in any given year, it’s a broad coverage with very little overlap in a, within a year.

Dan Kolodny:

Very interesting. And so, you know, based on that differences in different habitats and bathymetry of those sites, you know, what kind of gear are you using to collect your data out there?

Derek Tremain:

So nowadays, we’ve limited it down to two, but we’ve started with many gears when we were developing the program. In the early years, we did a lot of extensive gear testing and we did it, used a variety of seines, trawls, gillnets, traps, even hook and line stuff. but following that, the, net amendment, the Net Limitation Amendment-

Dan Kolodny:

Sure.

Derek Tremain:

… back in 1997 where they removed entangling gears, we also switched some of our gears and now we use basically two different seine types to collect our data. These are actively set so we can, we’re not relying as a gillnet. We’re not relying on, some fish behavior, patterns and movement patterns to come in contact with the net. These are actively set gears, so we’re actually collecting the animals, um, actively.

But the two that we use are, uh, first is a small mesh seine. It’s 70-foot long and it’s designed to capture these smaller forage species and also the juveniles of some of the larger species that we see in the lagoon. it samples an area along the shorelines and the shallow flats of the lagoon and it samples an area of about, say half the size or the size of half of a tennis court, um, or maybe nowadays it’s more common to say, almost the size of a pickleball court.

But we also use a second gear, that’s designed to capture these larger, more mobile adult species or adults of species that are able to escape the smaller gear. this is a large mesh seine 600-foot long and it is limited to shoreline habitats, because of the way we set it, it’s set off the stern of a boat. but each of these nets sample’s a little over an acre of habitat, about the size of an American football field. So it’s a large gear. Both these gears are hauled in by hand. They’re tough work on, on a good day,

Dan Kolodny:

For sure. I, I remember that, that boat, that was a pretty neat boat, you know, where the, the motor’s actually center mounted in the hull. It’s a kind of a neat, structure where instead of, you think of a typical boat where you have the outboard on the outside, it’s actually right in the center, like right behind your wheel where you’re driving. So it’s a pretty cool vessel.

Derek Tremain:

Yeah. These are old, they call them Bird Dog Boats. They’re old mullets skiffs that have been used throughout the, in the old days throughout with Florida fishermen, sampling for mullet and shallow waters and that, that bow-mounted engine allows you to run in shallow flats on a plane that allows you to peel your net off the back of the boat without getting tangled in the, in the motor.

Dan Kolodny:

Tangled out, mm-hmm.

Derek Tremain:

So it’s, yeah, it’s pretty effective. And I think, you know, there’s very few people that still use them. You can still find them over with actively being used with fishermen over on the west coast of Florida, but there’s very few around other than people who are doing scientific research.

Dan Kolodny:

So now you’ve, you know, gone out, you’ve collected all your, your samples, you know, your juvenile fish and everything. What kind of data are you collecting from these fish to kind of help in this, this monitoring effort?

Derek Tremain:

Yeah, it’s a great question. We collect a lot of data. that’s one of the, one of the big value points of our program. But some of the data that we do collect when we get onsite, we obviously collect biological data. We’re collecting, species identity. We’re looking at, you know, what species are in our gears. We’re taking length measurements. We’re also counting everything that we catch. at the same time, we’re recording environmental conditions, things like salinity and temperature, dissolved oxygen, Secchi depth, which is an instrument, instrument that gives us some measure of water clarity.

We’re also collecting a lot of habitat information we’re characterizing and we’re recording the vegetation onsite if there’s SAV species present, what percent cover they have, we’re characterizing the bottom habitats we’re characterizing the shoreline habitats, you know, salt marsh, mangrove,

Dan Kolodny:

Wow.

Derek Tremain:

… hardened shorelines. And then we’re also taking, measuring the, what the weather is and the tide stage. We’re writing all that down as well.

Dan Kolodny:

So there’s a lot of ancillary data than just the actual fish themselves. That’s pretty cool.

Derek Tremain:

Exactly. A ton of data in the field. And then back at the lab, we actually bring, bring some of those species back. I don’t know if we, when you were along, I don’t recall if we brought anything back to work at the lab, but, but back at the lab we do return some species that will look we’ll collect tissues to analyze things like fish age or their reproductive status or the, you know, the fish health aspects, um, if there’s tumors or things like that that we see or we even back at the lab do a lot of mercury testing on fish here in the lab. So it’s a very comprehensive data set. Um, we collected a lot of data over the years for sure.

Dan Kolodny:

Yeah. And that actually, I think brings back some memory onto how I got in- into that program was, uh, my undergrad research project was looking at, um, the morphology of sea trout, Cynoscion nebulosus. And so, I think it was Turingan who had got all those samples and they came from your lab, so that’s when he said, you know, “You’re doing all this work on these fish. Why don’t you go see how they collect them?” So, yeah.

Derek Tremain:

Yeah, we, we appreciate that too when we, when we’re (laughs), when we do a lot of, when we give people fish to work on in their programs, it’s really helpful to have them come out and, and see how we work and, and, you know, lend a hand and take some of the strain off of us for a day or two. So yeah, that, your, your participation back in the day was certainly appreciated, I know. (laughs)

Dan Kolodny:

Yeah. And I was amazed at how much work it was, you know, I mean, just going out in the waters are great for us even now, but-

Derek Tremain:

Yeah.

Dan Kolodny:

I mean, you guys are hauling, getting in the water, dragging fishing. And then I remember, I don’t know if it was you or somebody else who was like, “We gotta measure these fast because we’re trying to get most of them back in the water and, and stay alive.”

Derek Tremain:

Right.

Dan Kolodny:

And it was a lot, these little teeny, you know, juvenile redfish or, you know, those, um, those little ribbons that are either tarpon or bonefish-

Derek Tremain:

Right.

Dan Kolodny:

… or ladyfish-

Derek Tremain:

Yep.

Dan Kolodny:

… just little clear things.

Derek Tremain:

Yeah.

Dan Kolodny:

Like we gotta get them back.

Derek Tremain:

Yeah.

Dan Kolodny:

We gotta get them back. So-

Derek Tremain:

Yeah, we really try to, we really try to get the important fish back in, in a hurry. some of the anchovies might not make it. I can’t swear to that. You know, they all probably go back alive, but there might be a couple that don’t make it back in there. But we can collect a net that’s you know, a six by six by six bag full, of completely full of anchovies, you know, a school of anchovies, which is on the order of, can be, you know, 40 to 50,000 maybe-

Dan Kolodny:

Wow.

Derek Tremain:

… net at one time. There’s a lot can be in there. So most of those go back, we take a sub sample on things like that and, and we work up the sub sample, sub sample and then extrapolate it with some math equations and get back to where we estimate of what the, the original sample was. Uh, but yeah, it’s a lot of work in the, in the field for sure.

Dan Kolodny:

Yeah. So before we move on to kind of some of the data analytics and that kind of stuff, you know, for our listeners, you know, you’re doing Fisheries-Independent Monitoring, but there’s also Fisheries Dependent Monitoring. Can you explain what the difference is between those two?

Derek Tremain:

Sure. Yeah. The, the difference in those two is basically who gets to do the fun part of the work, you know?

Dan Kolodny:

(Laughs).

Derek Tremain:

You know, we always enjoy the fish collecting and, and Fisheries Dependent Data the fishermen are doing the hard work or the fun work of-

Dan Kolodny:

Ah.

Derek Tremain:

… collecting the, collecting the samples. And so the scientists get involved when the fish come back to the dock and at the, when they return to the dock, then the scientists meet them at the dock and take their measurements and do the identifications and collect the parts that they really need to get.

Dan Kolodny:

Interesting that it’s basically who does the collecting part. So that’s kind of cool.

Derek Tremain:

It is, but there’s a difference in the two, um, methods, one of the problems with the fisheries dependent data is that as you, as you’re aware, fishermen are subject to a lot of regulations. We may have bag limits or size limits-

Dan Kolodny:

Sure.

Derek Tremain:

… or area closures, season closures and things like that. And the problem with that is that regulations can change. So what the fishermen bring back to the dock is limited to begin with. They’re only allowed to be within certain restrictions and then those restrictions may shift over time. So it can lead to biases in the data and then it can make it create these challenges when you’re trying to analyze long- term data trends. You know, was that shift that we saw part of an actual shift in the population or was it something that happened, you know, on the management side that, that shifted that? With fisheries independent sampling, the scientists go out and collect the, the data themselves.

Dan Kolodny:

Yeah.

Derek Tremain:

And they do that using, you know scientific survey using standardized and quantifiable methods and the difference being that you can use those methods consistently over long periods of time, which gives you, allows you to sort of have a higher level of confidence in any trends that you do see, you have confidence that those trends are real.

Dan Kolodny:

It’s interesting to think about, you know, how the fishermen are the only ones who catch the adults. They don’t get to see those, you know, juvenile aspects in the juvenile phase and, and how that can recruit in. I think you were gonna talk about a little bit about recruitment into these areas and, um, I think that, that helps us understand why looking at juveniles is so important because it can help, with that fisheries management. Can you tell me a little bit about how collecting this data will lead into rulemaking and fisheries management?

Derek Tremain:

Sure. Yeah. So you, you mentioned that we, you know, are looking at recruitment timing, really, we can look at recruitment habitats by collecting these data collecting these individuals, particularly at the juvenile sizes and, and knowing where we caught them, what time of year we caught them, what were the habitat conditions surrounding their capture or the time of year that they were captured.

That can tell us a lot about the habitats that are important to them. it can tell us about, from year to year, we can look at the abundance trends and see if there are, you know, cycles of positive and high quality recruitment years or bad recruitment years. Sometimes that can be used by the managers to proactively manage for a future say decline in a fishery. If we know the recruitment year, we’ve had several years of poor recruitment, we can guess that there’s gonna be a poor year class of, of adults some, some few years down the road-

Dan Kolodny:

Mm-hmm.

Derek Tremain:

… different for each species. So they can do some proactive management. They may change regulations proactively to protect those recruitment years that were bad so that the adults aren’t fished out of those before they can recover. and we do look at a lot of, with the adult data, we can look at long-term trends in abundance, we can look at changes in age structure. All those metrics go into, or given to the stock assessment biologists. And stock assessment is basically just a way to as the name implies, characterize the quality of that stock, the health of that stock at any given time.

And so, these stock assessment biologists use our data to tune their indexes, which allow them to see whether populations are increasing or decreasing. and then they can use that data then to help manage the stocks and set these regulations, you know, potentially and ideally before some crash occurs. We try to act, you know, act proactively rather than reactively. And so, this data helps a lot, a lot in that regard.

Dan Kolodny:

You know, talking about trends we’ve had some, some pretty bad trends over the past decade or so. have you seen those, like, was there any warning signs in the data, you know, that we were about to hit, you know, a, a critical point before maybe we saw a massive drop? Did you see anything in the juvenile data that said, you know, “This is not good. What’s going on here?”

Derek Tremain:

The thing about these, these abundance data and the thing about nature in general is it’s really messy. And so, we see a lot of ups and downs in, in our data and so it’s sometimes hard to pinpoint what those ups and downs are. But if you look at this over the long term trend, we can start to pick out what’s abnormal. You see the broad general trend of decline, but you see a lot of wobble within that general decline. we started to see, we didn’t notice it at the time, but we started to see some of these declines in these sportfish species back in early 2000s. But I think we saw something that was interesting that we may have not considered or thought about completely at the time.

And we s- one of the early, early warning signs that we might’ve noticed that took place was this puffer fish toxicity outbreak back in the early 2000s. And I don’t know if people recall that or are familiar with it, but basically-

Dan Kolodny:

Yeah.

Derek Tremain:

… there was a puffer fish, uh, fishery, a lot of it centered up in Titusville.

Dan Kolodny:

Mm-hmm.

Derek Tremain:

And, uh, these fishermen all of a sudden, they’ve been doing it for years. All of a sudden, fishermen started feeling dizzy after eating the puffer fish or getting tingling, in their, mouth, getting muscle weakness, some of them feeling nausea, some other more serious sort of neurological effects and, and that was unusual. And so, they did a lot of work went into figuring out what that was and they initially assumed it was one of these sort of tetrodotoxin, which is a toxin that, that puffer fish can have. You may be familiar with the Japanese-

Dan Kolodny:

Mm-hmm.

Derek Tremain:

… sushi, the fugu.

Dan Kolodny:

Fugu, yeah. Oh, yeah.

Derek Tremain:

You know, you’ve-

Dan Kolodny:

I’m not brave enough for that. (laughs)

Derek Tremain:

Nor, nor am I, nor am I

Derek Tremain:

But these, um, puffers were producing what actually was a saxitoxin and saxitoxin is-

Dan Kolodny:

Pyridinium.

Derek Tremain:

Yep, it’s more, more often associated with shellfish poisoning and it came from those blooms of, of pyridinium, which was, you know, one of the first signs they were, you know, they would become one of these important, um, um, harmful algal blooms in the system that have, you know, caused problems for years since then. But that may have been one of the early signs that, um, you know, some of this was on the horizon. But we did see back to those sportfish species, we did see declines in several of those species, um, steadily through the mid 2000, mid 2010s. some of those have recovered now quite nice, the sea trout and the snook, but like the sheep’s head, which I know sportfish species, but it’s one that we track pretty, it’s a important commercial fishery or-

Derek Tremain:

… fishery species in the lagoon. those have still, those for some reason have not ever recovered fully and we don’t, at all, really. Um, they declined and they have never started showing any signs of return yet. So that’s something that we’re, um, this long-term data can, can show us these trends and give us, give us a sense of where these fish are and is this recovery happening and, or give us an opportunity to start to notice these is, something’s not right, you know, why are the other fish recovering and this isn’t what’s going on with that, you know, with that species in, specifically that’s causing it problems. So…

Dan Kolodny:

You have, um, sheepshead, have you seen, I guess this is, and I’ve heard this at the symposium, have you seen increases in sea bream?

Derek Tremain:

Yeah, so sea bream is a, is a species that’s closely related to sheepshead and, um, it’s interesting, it’s a more tropically oriented species. It’s, it’s-

Dan Kolodny:

Mm-hmm.

Derek Tremain:

It’s, we see it more often in, in systems like down in Lake Worth Lagoon, and we started to see it in the southern part, part of the lagoon, but really not often in the early years the northern part of the system up here around Melbourne, um, until recently. And this kind of coincided with the increase in sea bream populations coincided with a decline in these sheepshead populations. And we don’t think that there was any antagonistic or effective from one fish on the other directly, but in the Indian River Lagoon, sheepshead are an interesting, uh, character. They, in the lagoon, which is somewhat different, they have a different bit of life history than many other places. Typically, they’re considered to be molluscum feeders and you know, bivalves and, and barnacles and such.

Dan Kolodny:

Yeah.

Derek Tremain:

Um, in the lagoon, they also feed pretty consistently on seagrasses, similar to what pinfish and sea bream feed on. pinfish being another similar species-

Dan Kolodny:

Sure.

Derek Tremain:

… relative to sea-

Derek Tremain:

Yeah. And so, uh, what we think is going on is maybe that, that these sea bream as they moved into the northern part of the lagoon are maybe interacting with these, with the same habitats and competing for some of the same resources that sheepshead are using. And so, there may be this competitive depression, in the sheepshead that doesn’t, is not allowing them to recover as well as fast or as quickly as they may normally because they have additional competition that they weren’t exposed to before. it’s just a theory we don’t know for sure, any of that. But, we have seen this increase in sea bream populations in the northern part of the lagoon in the last six, eight years or so.

Dan Kolodny:

Really interesting. Yeah, that kind of I guess leads into my next kind of question was, you know, have you see, has there been anything that’s really surprised you, over your tenure and, and especially in the last four or five years as seagrass is starting to recover in many, many areas, you know, is there anything really kind of stood out like, “Wow, I did not expect that to happen?”

Derek Tremain:

Uh, well, I don’t know if I’d say I, I wouldn’t expect something to happen. It’s more of what didn’t happen that I would have expected.

Dan Kolodny:

Ah.

Derek Tremain:

(Laughs) Um-

Dan Kolodny:

All right.

Derek Tremain:

You know, we’ve had this seagrass recovery and we lost a lot of species or the, you know, the, the abundance of a lot of species-

Dan Kolodny:

Sure.

Derek Tremain:

… went way down when we lost seagrass. and with this recovery, what we haven’t seen that I would have expected is of, is a more rapid recovery of some of these seagrass associated foraged species like, uh, you know, pinfish and, and pipefish. Our data still show those to be fairly depressed. in general, when you have a disturbance to a system, the, you know, fish are pretty resilient creatures and, um, they can recover fairly quickly in open systems when we, when habitats and, and water quality and such return.

So it’s kind of, uh, concerning or at least it’s a, it’s interesting maybe why we haven’t seen a more quick recovery like the, the pinfish and the, and these, these pipefish, where these pipefishes are, you know, an indicator species for seagrass health. And so, with these grasses coming back, we’d expect to see more, but, but it’s been slow. And so, it kind of re- raises other questions, you know, are there other factors that are affecting the recovery? Are there, is there a sufficient larval supply or is there competitive interactions with other species that, you know, they now have to compete with and, and deal with? it opens questions and, and I guess the overall lesson is that, despite what you know, there’s always something different that could happen, but, but the lesson is kind of recovery is gonna take some time regardless.

Dan Kolodny:

Yeah, for sure. And I think that is a perfect lead into, you know, the importance, my next topic, the importance of long-term data, you know, why is it so important to have a large and long data set?

Derek Tremain:

Yeah, I mentioned before that, uh, you know, nature is messy. Um, ecosystems are, are complex, it’s full of all sorts of natural variability, you know, at any given site, at any given time, there can be a, a hundred or a thousand different sources of variability and so, and so short term sampling can miss out on that variability and this long-term monitoring can allow us to look for patterns within that variability, that wobble that we were talking about before.

Dan Kolodny:

Mm-hmm.

Derek Tremain:

And within that, then we can begin to understand some annual and seasonal cycles. we can identify wind disruptions occur, like we had a, big freeze event back in 2010. We saw, you know, big decreases in, some of the fish populations around that time. We’ve seen recoveries after that, but if you hadn’t been sampling in there, you wouldn’t have known what caused, you know, that blip. You wouldn’t have known maybe that it was a blip if that was the only year that you had sampled. So we can start to, by, by collecting long-term data, we can see how these trends are affected by, uh, other factors and we can start to look at, um, different things that are potentially harmful or causing problems for these species in the long run.

Dan Kolodny:

Interesting. You know, we, you mentioned the freeze, you know, we just had one this past, uh, February. Any similarities in the data?

Derek Tremain:

We did see dead fish, which was similar.

Dan Kolodny:

Yeah.

Derek Tremain:

But, way fewer than before. I think the 2010 freeze was, it was acute. This one was very acute here. It was a quick drop in temperatures.

Dan Kolodny:

Sure.

Derek Tremain:

A lot of fish events are slow declines, you know, temperatures are getting slower gradually. Fish move to these, you know, thermal refugia for them.

Dan Kolodny:

Mm-hmm.

Derek Tremain:

Wherever that may be. It may be up in the Tidal Creeks, it may be out to the inlets or deeper holes in the system. Uh, when you have these rapid, uh, declines in temperature, water temperature and air temperature a lot of times they don’t have a place to go.

This last episode this year seemed to let, to be quick. It, it came on quickly, but it didn’t last as long.

Dan Kolodny:

Mm-hmm.

Derek Tremain:

I think the, the freeze in 2010 was more long-lived. And so, I think-

Dan Kolodny:

Yeah.

Derek Tremain:

… we saw fewer dead fish and more, um, what we call more abund fish. They were stunned. They were still swimming around, but sometimes upside down, you know, sideways, whatever it may be. But many of those fish were able to recover once the temperatures increased. Had it stayed cold for another week, probably most of those would have died as well. So, um, I think this year’s was, was less, less harmful overall throughout the state than, than the one in 2010, which was, was pretty dramatic.

Dan Kolodny:

I think you already touched on the statewide nature and consistency across, well you can talk about that a little bit, tell us kind of a little bit about how this is important statewide and how when you have this consistency across all seven labs, you know, we’re not just looking at, okay, well, the, you know, you’re doing something different here in Indian River or we saw something different here, you know, then you’re getting like the whole regional approach and for that management. Tell me a little bit about, about that part.

Derek Tremain:

Yeah, absolutely. This is, this is one of the, the things that make our program so strong is that we’re, we’re using the same gears, the same methodologies, the same standards across the state and, and six or seven of these different labs. and the, the benefit is that, that we can see, um, multiple trends across some of these estuaries. There’s a difference between Melbourne or for the Indian River Field Lab and, you know, Apalachicola or even up in the St. Johns River up in Northeast Florida, but a lot of what we see in the Indian River in the central part of the state is similar to what we may see over in Tampa Bay or in Charlotte Harbor.

Dan Kolodny:

Right.

Derek Tremain:

And we talked about that freeze event, back in 2010, that had a, a really big effect on, on all the estuaries in the state. that kicked a lot of, um, of these fish species in the teeth, but we saw a different response to that in, in the Indian river than we did in, uh, Charlotte Harbor. And there was a good paper put out in, I think it was 2016 by Phil Stevens that talks about this, so by having long-term data in a lot of, in different places, we can, we can see these differences in, in the response to some of these disturbance events or whatever it may be and that can give us a clue as to, you know, where do we look for what caused that? why do they respond differently in one place than the other?

And it can give us a clue, um, to sort of the, the health of these systems or the, or the biology of the fish that are different in some places

So we didn’t see the same response to that fish kill or that mortality event in, 2010 here in the Indian River as we did in other systems. And so by having data coming from different places through the same events, we can, we can use that to kind of tease out why there’s a difference response in the fishes. It tells us something else about the fish that we didn’t know before.

Dan Kolodny:

So just really, really interesting stuff. I’m sure a lot of our listeners, may be fishermen themselves and they are thinking, okay, this is so cool, you know, now I, I kind of get a little bit why, you know, some of these rules are made, how they are and why this is so important, you know, um, what can our listeners do to really, help out in this aspect? You know, first thing I would think of is, you know, stay informed about, you know, fisheries health and what’s happening in your estuary.

Derek Tremain:

Yeah.

Dan Kolodny:

But, you know, what else can, can they do?

Derek Tremain:

If you’re a fisherman yourself, there’s a couple of different groups you can talk to about this, but if you’re a fisherman, one of the most direct things you can do to help out is to practice ethical angling, right?

Dan Kolodny:

Sure.

Derek Tremain:

Basically, gives the chance of fish that are not being harvested to, to survive when they’re put back in the, in the system, you know, practice catch and release, use gear that allows you to reduce the fight time, use heavier tackle, particularly in the summertime when the waters are warm, try not to fight fish to exhaustion, use single hooks versus treble hooks, handle the fish safely when you get them on, on deck, you know, use gloves or something to keep, try to-

Dan Kolodny:

Wet hands, yeah.

Derek Tremain:

… protect that slime coat.

Dan Kolodny:

Mm- hmm.

Derek Tremain:

You know, recycle fishing line. There’s a lot of different little things that, that fishermen can do to, help or maintain or improve the condition of the fisheries, you know, that they’re relying on.

So for the, for the general public, I think it’s really important, as you mentioned, to, to stay informed, to stay informed on, on regulations, um, to stay informed on what’s happening in the, just in your system, you know, subscribe to, you know, IRLNEP, sites, subscribe to the FWC social media sites, IRLNEP social media sites, get informed on that, you know, any news that’s up, you know, being updated, alerts that have come out, things of that nature. And then probably maybe the most important is to stay involved at the local level. There’s a lot of opportunities for volunteers with, in, in the area and with nonprofit groups and others that are working on the lagoon, you know, day in and day out.

Dan Kolodny:

Yeah.

Derek Tremain:

So there’s a lot of, lot of things you can do to, to, you know, help out.

Dan Kolodny:

For sure. I know one thing I did recently was, um, you know, sat in on some work groups. Uh, FWC holds workshops for, you know, potential rule changes and stuff. And so being able to, you know, talk with some of the biologists and hear a presentation about the fisheries, you know, kind of what things they’re thinking about proposing and the things that they would like to hear from us as fishermen, uh, I think is really important, um, to be part of that process.

Dan Kolodny:

Well, you know, I, I think this has been fantastic. I, I love talking fish because I’m a fisherman and, you know, love being out in the water. you know, and it really opened my eyes a little bit too about the whole regional aspects. That, that was something that really surprised me. You know, I wanna thank you, Derek, for taking the time to come on and talk to me about, all these different aspects of fisheries monitoring and independent fisheries.

Derek Tremain:

So there’s a lot of, lot of things you can do to, to, you know, help out.Well, first of all, thanks for having me on. I appreciate getting the chance to talk about what we do. I think it’s been way too long since we’ve had you on a boat with us, so- (laughs)

Dan Kolodny:

Anytime.

Derek Tremain:

Get back, we need to get you back out there. We say 1990s? Yeah, it’s way too long, Daniel. (laughs).

Dan Kolodny:

Yeah. And late 90s, early 2000s. So yeah, it’s been 20+ years doing that kind of work. So yeah, I’d love to go out again, for sure.

Derek Tremain:

Yeah. But, you know, closing thoughts, I think in terms of fisheries, you know, in the last 100 years there’s, we’ve lost tens of thousands of acres of habitat in the system, right? These declines in salt marsh and natural shoreline habitat and, the seagrass habitat obviously has had a dramatic impact on the fisheries that are in the lagoon. Um, and despite the best efforts, I think there’s, you know, we’ve seen limited recovery. But I think, the thing that we know about fish are that they are resilient and they will respond, to improvements in the system. Um, it may take time, um-

Dan Kolodny:

Sure.

Derek Tremain:

… for sure. But I think the bottom line is that if we continue to you know, use, find these innovative management, you know, techniques, create strong private partnerships or private public partnerships withcuser groupscand get everybody involved together think there’s really an opportunity to be hopeful and potentially even optimistic about the recovery of fisheries in the system. You know, there’s been success stories in other estuaries in Florida that have really focused on trying to improve their habitats and their, uh, water quality and, um, I think that same holds true for here in the Indian River with as we move down the road. So-

Dan Kolodny:

Yeah.

Derek Tremain:

… leave it there.

Dan Kolodny:

I would totally agree with you there. You know, it’s, there’s so many places where there’s declines and this is one of the few lately where we’ve seen some in- some, uh, success. So, you know, just gotta keep pushing forward.

Derek Tremain:

Yeah, yeah.

Dan Kolodny:

So yeah, I appreciate that.

Derek Tremain:

100%.

Dan Kolodny:

Well, thank you, Derek. I really appreciate your time and, uh, look forward to getting on the water again with you.

Derek Tremain:

Come on, Daniel. This is an open invitation. (laughs)

Dan Kolodny:

All right. We’ll make it happen.

Derek Tremain:

All right. (Laughs). All right, good deal. Thank you guys.

Dan Kolodny:

Thank you. If you enjoy these discussions about the IRL, please like, subscribe, and follow this podcast wherever you get your podcasts. To learn more about the Indian River Lagoon National Estuary Program, how you can get involved, and tips on living lagoon friendly, visit us at onelagoon.org. Hit the shop tab at the top of the page to check out our branded One Lagoon merchandise or hit the license plate tab to find out how you can support our work by buying a Lagoon license plate. To stay informed about Lagoon news and upcoming events like our monthly What’s Up in the Watershed webinar, follow us on Facebook, Instagram, and YouTube @onelagoon.