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Joel Fodrie’s quest to think like a fish has only just started and has a long, long way to go. Already it’s been a round trip.

 

by David E. Brown ’75

 On a clear day, Joel Fodrie ’99 could have seen his future from his backyard. In that fantastic playground out there in the shallows of North River, amid the electric greens of Middle Marsh, on the finicky ocean beyond the banks. On long days of clamming, shrimping, floundering, surfing, of bare back and feet, of weaving around shoals and bars in places non-native helmsmen seldom go.

The boy, whatever he thought about what he wanted to be, had no idea that this right here was his office, his laboratory. There was basketball — he made it as far as the Carolina JV — maybe medical school, maybe something with history.

Today, if you know what you’re looking for, you can see on a Google aerial the oyster reefs Fodrie helped build when he was an undergraduate and that today he watches like a hawk for subtle signs of success and failure and to try to divine the reasons.

Then there is what he cannot see. The fish.

The difficuly of trying to think like a fish reminds Fodrie of a story. Two black drum were caught in the New River near Camp Lejeune and tagged. About a year later (amazingly on the same day), one of them was caught a stone’s throw from where it had been tagged. The other was caught 30 miles from Philadelphia.

Playtime is over. Being a marine ecologist is hard. And the backdrop is dramatic declines in some fisheries along the Atlantic states — of which the eclectic North Carolina coast is at the center — and the loss of livelihoods, of whole ways of life and profound damage to the seafood economy. The culprits are overfishing, pollution, loss of sea grass and salt marsh and oyster reefs. Somebody needs to understand what often seems impossible: what fish want.

“How they allocate their time in different habitats. Are they there to feed, are they there to avoid being food,” he said. “Some are homebodies, some travel all over. Some like a reef right against a salt marsh; some like a reef next to sea grass. There’s no shortage of questions.”

Fish are not, Fodrie said, “like cows.” You have to get to know them without being able to watch them.

Fodrie and members of his lab

Fodrie and members of his lab check the progress of artificial oyster reefs in Middle Marsh at low tide. The reefs are placed at slightly different elevations so that the tides’ impact is different. More time in the open air limits the oysters’ exposure to predators. (Photo by Steve Exum ’92)

The natural laboratory

The last thing Fodrie wanted to study was oysters.

“Oysters are sharp, they cut you, they’re smelly.” But you don’t last long in marine ecosystems by picking your critters and ignoring others. So it was, not long after he arrived at UNC’s Institute of Marine Sciences in Morehead City in 2009: “They converted me. Even though I didn’t want to do oysters, I wanted to know how fish use oyster reefs.”

So as he points the skiff at the east end of Beaufort’s Taylor Creek, oysters as well as swimming things are on the day’s agenda. Less than a minute beyond the creek, Fodrie slows to idle in front of a high bluff on Carrot Island. The bluff indicates high erosion, which means wave action — one of the things he wanted to study when his lab built an artificial reef, 150 meters long, by dumping oyster shells to attract live ones. Between the reef and the beach, he’d planted salt marsh; how well would it grow behind the reef?

He says he’s impressed by the way the marsh has grown. Sure enough, the waves have deepened the water in front of the reef. Depth matters.

Suddenly the boat does a 180 and blasts off across the short distance to Middle Marsh. (One of Fodrie’s longtime mentors figured out a long time ago that he’d just as soon not have to ride with him. Fodrie likes to go fast, and because of advanced local knowledge honed over almost all of his 38 years — uncharted nautical data wired into his brain through experience — he can.)

This area, Carrot Island, Bird Shoal and the triangular marsh of some two square kilometers, surrounded by navigable water, is part of the Rachel Carson Estuarine Reserve, named for the environmentalist who studied there. Open to fishing and recreation but not to development, and with tides and currents that keep its waters amply flushed, it’s the kind of place a marine scientist would dream about.

“We don’t do a ton of lab experiments,” Fodrie said, “because we have this out here.”

Inside the marsh, the boat glides over thousands of oysters clustered on a reef built in 1997. Two hundred yards to the north is another, built exactly the same way, and there are oysters there, too, but not nearly as many. The main difference — probably — is the amount of time each reef spends submerged and in the open air; they’re placed at slightly different elevations so that the tides’ impact is different. On the reef that spends more time out of the water, the oysters’ predators and pests do not venture upward — they can’t handle the exposure.

This would seem to be an elementary lesson in where to place artificial reefs, as fishers strive to revive a harvest that peaked, by weight, in 1902 and has declined over the past 50 years to less than 10 percent of that peak.

Fodrie tries to explain why it’s not. There are so many different things to study and so many different ways to study them — so many more questions than answers — that, he says, marine ecologists “forget” things over time as they move from question to question and have to rediscover what they’ve temporarily set aside.

“People that worked in the 1800s and early 1900s — these were smart men and women — they were interested in many of the same questions we’re interested in today. They would like to know, when locally the abundance of fish or crabs is up or down, what causes that. And they’re not fundamentally new things — it’s the same things — the temperature or habitat or [over]fishing.” As oyster habitat declined dramatically, everything was up for re-examination.

“As a person who’s interested in history, I have no problem acknowledging that some of these things were known and got lost. Things cycle through. We have tagging and so much better technology now.”

Joel Fodrie

Fodrie inspects an oyster bed at Middle Marsh near Morehead City. (Photo by Steve Exum ’92)

Scientists, fishers, marine management specialists (and politicians) all want to turn the decline around — a healthy oyster population is a huge factor in natural filtration of the undesirable elements in estuarine waters, exceeding even their value on the dining table.

But oysters are not the main reason we’re in the marsh on this July day.

Max Tice-Lewis ’14, a technician in the lab, and Shelby Ziegler, a graduate student who started in the lab this fall, feed a long blue net into the water, followed by carefully positioned and awkward trawl doors. Speed, three knots. Length of trawl, precisely two minutes. At first it looks like the catch is just dead eel grass, but at the end of the net: oyster, toadfish, grouper, tonguefish, summer flounder, gulf flounder, pinfish, blenny, pigfish and blue crab.

This is done once a month in 24 places in the Morehead area. All these juveniles are counted, weighed, measured — sometimes taken back to the lab to see what they’ve been eating. There are some 300,000 fishes in the Fodrie lab’s records — “a ginormous data set.”

These are the fish that will move out to the ocean and become part of the commercial catch. Why are they here? The oyster reefs? Which variations do they like? (Why are they not here?) The sea grass? What’s up with their predators?

What if a major storm or an oil spill changed the area dramatically? A baseline like this would be needed to determine the impact.

The reefs also help measure change over time.

“The way most research is funded, only having one or two years at a time, it’s not uncommon to only study something for one or two years and then move on to the next topic. So the ability to look at these things over decadal scales I think’s really powerful,” Fodrie said.

“The other things we’ve learned about these reefs is they do a number of different things. They do provide habitat for fishes and shrimp and crabs; they do remove excess nitrogen from the system. They do capture carbon. They do change sedimentation rates along a marsh shoreline and increase deposition.”

A remarkable summer

Fodrie grew up near the wide mouth of North River, which empties into Back Sound between the historic port of Beaufort and Harkers Island, home to traditional boat builders and once to a thriving fishing community. He still has the boat he got when he was 14.

He comes from teachers and principals and librarians — dad, mom, grandmother, aunt, niece, sister and others.

He comes, too, from the water. “Everything and everybody you were around was the water — town festivals were about the water, the people making a living off it.”

Valedictorian of East Carteret High, he was a good science student, on the biology track. But he’d spent much of his summers working on his basketball. He played two years on the junior varsity team at Carolina, and then “they kind of told me, ‘OK, you’re done.’ I had to figure out what to do the next summer.”

He got to his junior year at Carolina before he figured out he could live off this — and make a difference. Walking through old Venable Hall, he noticed posters on the wall about the study of marine science. “I was like, oh my God — people do this for a living. That was the light bulb going off. I wanted to do it for a summer. Something did speak to me. By the end of that summer, I knew.”

It was one remarkable summer. Fodrie had read up on some veteran faculty in Morehead City and started a dialogue with Hans Paerl and Charles “Pete” Peterson.

Peterson was interested in a noticeable increase in the population of cownose rays in the area. He tapped into Fodrie’s inquisitive nature.

Net

(Photo by Steve Exum ’92)

Fodrie started doing experiments with the rays in the ponds at the institute’s compound, ponds fed by Bogue Sound. What was the relationship between them and their prey, the bay scallop? He decided to take off on an honors thesis under Peterson.

Fodrie built “stockades” out of sticks, so that all the scallops’ predators could get in except the rays. Then he went out and replicated these tests at Oscar Shoal near Middle Marsh. He studied the ray presence off Harkers Island, where bay scallops had thrived. About mid-August, the scallops began to decline outside the stockades — inside there was no change. By Sept. 3, there were none outside the stockades. It had to be the rays — only they have the ability to grind the shells to sand.

“In a month’s time, the rays completely eliminated the scallop population,” Peterson said. But that’s not what got Peterson published.

What appeared in the March 2007 issue of Science was this: The bay scallop industry was devastated — and the recovery of scallop, oyster and clam populations along the Atlantic Coast was inhibited — by overfishing that led to a decline in big sharks. The sharks are the cownose ray’s only enemy. His hypothesis: With fewer sharks, there were more rays to eat the scallops. In other words, we have a scallop problem and a shark problem.

“All of which was made possible by Joel’s careful research,” Peterson said. “It was so stimulating to him that he could go to an area where he enjoyed the bounty of the waters as a teenager and do scientific research and reach a conclusion nobody had reached before.”

It was a pretty good entree to graduate school. Fodrie applied to Duke and to West Coast schools and wound up at the prestigious Scripps Institution of Oceanography at San Diego for six years.

Postdoc work would be either at Rutgers, with access to the Atlantic, or South Alabama and the Gulf of Mexico. Rutgers, just too cold. Thus began a secondary fascination with the Gulf that continues today.

Fodrie arrived back home in Morehead in July 2009: “They value the fact I came from here.” He submitted his tenure package last spring.

Flounder trouble — again

As last summer gave way to autumn in the sounds and river mouths along the North Carolina coast, the flounder was the subject of bickering among fishers, dealers and fisheries management officials.

The Marine Fisheries Commission wanted everybody to consider a reduction in the harvest — numbers from the previous year pointed to a decline in young flounder. Recreational anglers argued the catch limits favored the commercial side and were too harsh on the grand tradition of fishing for the satisfaction of it. Commercial fishers were divided over whether it was better to limit the catch or to let them pursue their livelihood with abandon.

It was nothing new, really. But this time, members of the N.C. General Assembly got involved, trying to block any regulation of the harvest. All was at stalemate near the November end of the flounder season.

North Carolina boats brought $8.2 million worth of summer flounder to the docks last year and $4.8 million worth of Southern flounder.

Politics has been known to drown out science, but for anybody who’s listening, Joel Fodrie wants his research to be getting better all the time.

Speaking of fisheries in general, he said: “In North Carolina, I think there’s examples of good and bad. In a general sense historically, we certainly seem to have fished at too high a rate to maintain healthy populations at the community level. That doesn’t mean that every species is as susceptible — things like shrimp, blue crabs tend to be more resilient than things like, perhaps, red drum or striped bass. Right now, the health of the Southern flounder stock is being debated and contested and thought about.

“People depend on these fisheries to pay their bills, and so the default position that had to be for a long time was, ‘There may be a problem on the horizon, but I’ve got to feed my family today.’ And so that led to overfishing of many stocks.”

A decision by fisheries officials to close an area to give stocks time to replenish can be a livelihood decision for a fisher — and more often than not, it’s made just on the theory it will help; you don’t know whether that was the problem until you close it for a time and watch. That puts the learned advice of a scientist on a very hot seat.

“Today I can’t tell you if we lose X acres of sea grass, we’re gonna lose X number of fish,” Fodrie explained. “I can’t tell you that, if we restore X acres of sea grass, we’re gonna have X number of new fish that make it to be adults, and that’s just a general pattern in our field. So we attack [it with] a number of different questions and tools — the acoustics, the surveying, the experiments, the restoration ecology, working summer-fall-winter-spring.

“All that’s kind of chipping away at this issue of what is that fundamental numerical relationship between X amount of habitat, X amount of fish — because if we know that, then we’re going to have a lot more power to make decisions to manage our coastal resources. It’s not for me to decide if we need to remove a grass bed to make something else or to allow a yacht basin or boating. I don’t have that wisdom. But I do want to provide the information so that stakeholders can get together and say, ‘If we do this, here’s the result; if we do that, here’s the other result — what do we want?’ ”

Here again, local knowledge is a strong leg up.

Fodrie knows the fishers he grew up around. He is of their community. It was their idea, for instance, to employ derelict crab pots — the thousands each year that become lost to their owners — as new oyster reefs. The scientists modified the structures, but this is an idea that came much easier to people who fish.

“We have a good relationship with some fishermen because of a shared background,” Fodrie said. “They give a little more of the benefit of the doubt. What I hope makes me a better scientist in service to this state is relationship with fishermen.

“There are some fishermen who would catch the last fish. There are some very bright fishermen, and there are some knuckleheads. I can tell them as friends, ‘I love you guys, and I think you’re wrong.’ And we see when they have better ideas than we do.”

“He has the relationships,” Pete Peterson said. “That is a huge issue because fishermen’s experience on the water is invaluable. Joel is already there. His knowledge base is the knowledge base of a commercial fisherman.”

Fodrie pays a visit to the Caudill Labs on the Chapel Hill campus

Fodrie pays a visit to the Caudill Labs on the Chapel Hill campus, where a mass spectrometer helps him analyze the chemical makeup of the otoliths — the “flight data recorders” of 350 summer flounder. (Photo by Steve Exum ’92)

The wondrous otolith

Sept. 2 was a long day, a long way from his boats and the water. Fodrie spent the hours from seven in the morning to 11 that night on the ground floor of the Caudill chemistry labs in Chapel Hill, recording the comings and goings of some 350 summer flounder caught in various places from New Jersey to South Carolina.

He used a mass spectrometer to identify the chemicals in the fishes’ otoliths — the rough human equivalent would be the inner ear. The otolith keeps a fish upright rather than spinning aimlessly, and it’s also what Fodrie calls the fish’s flight data recorder: It grows rings that can be sliced and read like the rings of a tree to determine age but also much more. These fish are 20 to 30 days old, and at this age the otolith has an observable ring for every day of life — a discovery from within Fodrie’s lifetime. The rings reveal the chemistry that tells the scientist where the fish has been in terms of salinity, temperature and what kind of sediment they lie in.

He knows where each fish was caught — what’s important is, were all the fish larvae that reach the coast from here to New York spawned in the same place or in different environments? “Where animals go is very important,” Fodrie said. “This offers us a world of information about where the fish went.”

It’s also possible, as always, that he’ll find this experiment was of limited value, but that in itself would be another small piece to the puzzle of how to advise fisheries managers to maximize the harvest.

Fishers, Fodrie says, “may listen and not be particularly impressed by what I have to say. I am kind of bound by the uncertainty that I am aware of. People have a really hard time dealing with uncertainty. Like, if I tell people that I’m 50 percent sure, that may be a fair scientific interpretation, but for someone that’s trying to run a charter or someone that’s a commercial fisherman, like, what do they do with that? … They’re 100 percent sure that they want their kids to have clothes and a meal and a roof over their heads.

“I do think we’re getting better at measuring things in the ocean. I do think we’re getting better at setting tipping points where, if we go beyond that, we do temporarily close a fishery, so I think managers in the general sense are getting better at turning the crank of this machine that is sort of the fisheries management. We’re getting better at data. We have a ways to go.

“I’m not the one who believes that we’re on the brink and that we’re getting ready to collapse. I do think that we’ve got to get the pulse of the system, and I do think there are species that we’re doing a good job of showing that, if you put the right management rules in, you can actually recover.

“That doesn’t mean everybody agrees with all your management rules. Some people think the red drum will be fine if we hadn’t changed management, and some people think that they’re worse off because of the management. I think the consensus of this is that management and the data that come in from science has helped shift the system back toward something that is going to be healthier.”

Still, he is nagged by what he doesn’t know.

How has the dramatic loss of oyster habitat, and the losses of 30 percent of the sea grass and 30 percent of the salt-marsh habitat, affected the fish habitat?

“The state has a need and a directive to spend X amount of dollars on habitat restoration. But the how, the why, the where are not perfectly understood by a long shot.

“The only thing I care about is the data should lead us. If the data says stop fishing tomorrow, so be it. If the data says fish all you want, so be it.

“These are questions people would have liked to have been able to answer a hundred years ago.”

In six years, Fodrie’s lab has trained undergraduate technicians who have gone off to graduate programs like California-Davis, Northeastern, Duke and the Chesapeake Biological Laboratory. It has graduated two master’s students and currently supports seven doctoral students among a total of 12 people.

The lab has collected five years’ worth of trawl surveys of juvenile fish that swim among the sea grass and salt-marsh habitats in Back Sound and Core Sound — the first ones along the central N.C. coast since at least the 1970s, Fodrie says, to systematically sample these habitats.

Fodrie is home now, but not so much the homebody — he’s studied mangroves as a nursery habitat in Galapagos, where UNC has a research center. Recently named a National Academy of Sciences Gulf Research fellow, he could be spending a significant amount of time in the next two to three years back in the Gulf of Mexico.

When he’s not at work, he might be taking his boys, Rafe, 9, and Luke, 4, fishing near his home in Smyrna, one of a string of small towns on and off U.S. 70 between Beaufort and Cedar Island. He considers himself a “decent” flounder fisher, and this is why it’s one of his favorite water pastimes: It’s a nighttime thing, in shallow water, the boat rigged with lights. Whether looking for food, for sport or for answers, he likes to turn on those lights and get a rare chance to see the fish move.

David E. Brown ’75 is senior associate editor of the Review.

Watch videos of members of Joel Fodrie’s lab tagging fish and running a shark survey and see Middle Marsh from Google’s satellite view.
In North Carolina’s summer of the shark, in which an abnormally high eight bites on humans were reported in the surf this year between June 1 and July 4, Joel Fodrie was the reluctant point man when the media called UNC’s Institute of Marine Sciences.
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