Research Center provides a wealth of information about speckled trout
Good fishermen are always eager to learn.
Recently my buddy and fellow speckled trout enthusiast, Don Balius, and I went to the Gulf Coast Research Laboratory of the University of Southern Mississippi in Ocean Springs, Miss., to see what else we could learn about speckled trout.
At the lab, we met Hatchery Manager Angelos Apeitos, a fisheries biologist who can divulge speckled trout knowledge like water from a firehose. Angelos is also an avid speckled trout angler, so he was uniquely positioned to expand our knowledge about Louisiana’s favorite fish.
The GCRL is a modern facility not uncommon in appearance to many industrial facilities. Its buildings are filled with dozens of large tanks, which are roughly the size and shape of above ground swimming pools. Standing like sentinels alongside each tank are engineered systems which regulate the water quality and guard the fish from sickness and death. These GCRL developed systems recirculate the tank water through devices to remove oils, ammonia, nitrates, and toxic compounds, add oxygen, kill harmful micro-organisms and regulate water temperature.
In these ideal waters, they can breed, incubate and grow out fish and other aquatic organism, including spotted sea trout, red drum, tripletail, flounder and blue crabs. At another campus on Davis Bayou, we toured their oyster hatchery, where they breed oysters and sell the larva when it is ready to attach itself to hard surfaces like reefs. These pediveliger stage oysters are sold to the DNR for coastal restoration and to private oyster farms.
This facility is not an aquarium. It is a laboratory for developing mechanical, chemical and biological processes. This knowledge is transferred to private aquaculture companies so that the fish species we like to catch and consume can be farm raised and bought in the supermarket, thus protecting the wild fish. In a perfect world, this type of high quality aquaculture would take commercial harvest pressure off of the wild fish stocks and leave more fish for anglers to catch. In the case of Louisiana, this seemed particularly obvious to me as I interacted with a very friendly red snapper living in the lobby’s demonstration tank.
If you are wondering how healthy a trout or redfish would be having been raised in a swimming pool, let me assure you that we saw some impressive specimens gliding around in the tanks. At the bull redfish tank, we were warned away from getting our hands near the surface of the water, and a few pieces of cut bait thrown in left me and my camera gear drenched with saltwater. The tank for the oversized speckled trout held fish larger than 99% of us will ever pull over a gunnel. Angelos estimated that one of them could be 16 pounds, thus raising my only real criticism of the tour. Angelos did not let us fish in the trout tank.
The GCRL also serves as a hatchery for restocking programs along the Gulf Coast. They can take brood trout from anywhere, breed them, and in 25 days can produce half a million 1 inch fry from a tank of 20 brood fish. The restocking programs typically release trout that are 1 inch in length, so the hatchery could produce millions of stockers in one summer from just one tank.
Speckled trout spawning
The people at GCRL are experts in breeding speckled trout, so they have knowledge that could not be reasonably captured by observers of wild trout. One of the topics Angelos talked about was the spawning patterns of speckled trout.
“Sea trout spawn at dusk, or one hour after dusk,” he said. “In the GCRL tanks, the lights are shut off at night and if we have a good spawning tank, and you come in at 9 p.m., you can hear the males drumming, especially the males that are 18 inches to 20 inches. It sounds like a pump that is drawing in air. In the wild they do the same thing.”
It is helpful for anglers to understand speckled trout spawning behaviors. For instance, they feed aggressively before spawning and will school up in a particular area. Angelos explained that in the GCRL tanks, “the trout spawning tank water temperature is kept in the 80’s. If they don’t start spawning after being added to the spawning tank, we can get a spawning response by upping the intensity of the artificial lights in the tanks, upping the water temperature, and then dropping both conditions. This can cause the trout to start spawning.”
In regard to the spawning capability of various sizes of trout, Angelos explained a trout of 15.5 inches to 18 inches can output 200,000 to 300,000 eggs per day of spawning, and so can produce 600,000 or more eggs in 60 days. A 10-pound trout is capable of giving 2 million eggs, but there is no predictability to when the big trout spawn.
For the big gator trout, who typically lives a solitary life, producing a lot of eggs is not the same as producing a lot of offspring, as Angelos explained.
“If you have a big trout that is 10 pounds, the first thing that trout wants to do is feed that 10 pound body,” he said. “She has no concern about reproducing. If a male even gets close to her that is half her size, she will eat it. Plus, the older a fish gets the more the quality of the eggs it produces degrades. Only two drops of sperm will fertilize a huge batch of eggs, but it only has 10 seconds to fertilize an egg once it hits the water. Not all eggs get fertilized in the wild or in our tanks. We come in the morning and pull out 1.5 million eggs, and maybe only 80% are fertilized. So if I am a male trout, I am more effective swimming around in a school of 200 trout than swimming around a big solitary fish.”
Angelos said that in the wild spawning happens from May to September in a bell shaped curve. There are a few spawners at the start and at the end of the curve, but peak spawning occurs at the top of the curve. In Mississippi, August is the peak of the speckled trout spawn.
Salinity and specks
I had to ask Angelos about water salinity and speckled trout behavior, because in my opinion, success in Louisiana is tied strongly to salinity.
“Sea trout have a broad tolerance for salinity,” he said. “In Texas they live in 30 ppt but in the Pascagoula River, Graveline Bayou area you find them in 5 ppt to 6 ppt. Trout have little tolerance for completely fresh water, especially if it is a sudden burst of fresh water, with salinity going from 8 ppt to 0 ppt. That is not good for them. Too much shock, and they get stressed. If they can, they will run away from that. If we change the salinity rapidly in our tanks, the trout will go belly up with too much cortisol built up in their muscles and they can’t ever recover.”
Angelos said that they keep the salinity in their spawning tanks at greater than 20 ppt, so the eggs float and enter into the tank’s recirculation system, where the eggs are concentrated in an area where they can be collected. But he also said that in the wild, he wouldn’t be surprised if they spawn in 5 ppt to 6 ppt, because of the broad range of salinity that sea trout tolerate.
I was very interested in Angelos’ conservation perspectives, because he is both an avid angler and an expert in speckled trout biology and reproduction.
This is what he told us. “I don’t take females larger than 17 inches, males up to 18 inches, because males grow slower and reach a smaller maximum size. If you are catching a 5 to 6 pound trout and putting it back strictly for conservation, great, but biologically that trout is going to spawn likely less frequently than the trout that are smaller. So, if you are letting go of the 15 inch, 16 inch, or 17 inch fish, those are your kick ass spawners. For me, I take two or three fish home and they’re all 3 to 4 pounds.” (Keep in mind that the legal length for Mississippi speckled trout is 15 inches and the daily creel limit is 15.)
“My advice if you want to help the fishery recover, don’t keep everything you catch, target the larger fish and let more of the smaller fish go, then over time you have more fish recruiting into the larger sized fish,” he said. “Understand the consequences of harvesting certain fish. If you don’t understand, then you can’t make good choices for yourself and for the next generation of anglers.”
I was very impressed with the high degree of science and engineering that GCRL has developed to make aquaculture economical, sustainable, and environmentally friendly, while expanding the choice of species for consumers beyond catfish, tilapia, and rainbow trout.
“Here we develop technology to try and culture sea trout so you don’t have to commercially fish them in the wild anymore,” Angelos said. “When you have a stabilized harvest in the ocean and decreasing fish stocks, there is a huge deficit formed. With the push for healthier protein, especially seafood protein, there has to be a mechanism to accommodate that deficit created in the wild fish harvest. At GCRL we produce enough protein per unit of water that economical aquaculture is possible, and we are just waiting for the next person who is going to come in with an investment.
“Louisiana and Mississippi are aquaculture friendly states, so they not only promote the culture of anything, they also incentivize it. We just need the people to start tuning in.”