BATON ROUGE, Louisiana — Harry Blanchet knows what cold weather does to the fish he's studied all his adult life.
Blanchet remembers the extremes, like 1989, when the memory of prolonged single-digit temperatures was burned into his psyche.
"I remember people walking on ice in the open waters of Vermilion Bay," Blanchet said from his office in the Marine Fisheries Division in Louisiana Wildlife and Fisheries headquarters in Baton Rouge.
And he, like thousands of Louisiana anglers, remembers what it did to saltwater species: Fish kills covered waters throughout the coast.
"Fortunately, we won't see anything like that this year. Even though it's been cold, there a big difference, a huge difference, between what happened in 1989 and what we've seen recently," Blanchet said. "I noticed a little ice skimming on the water's edges, and the water got cold, but one of the things that helped us was that we didn't have just one cold snap like we did then.
"The water this year was already cold and there were not a bunch of fish in the shallows," he said. "So there was a benefit in all the cold weather we had earlier in the winter."
Even though weather data shows the Baton Rouge area with more freezing and near freezing nighttime temperatures in January 2014 than any previous January, Blanchet said there were other factors that helped fish survive the procession of cold fronts.
"Water temperatures were relatively low, but what surprised me was that while (water) temperatures were in the same range (as other cold periods), the low water temperatures did not last long," Blanchet said. "That's important because even though the temperatures were in the 38-42 degree range for a few hours, they started picking back up again.
"What's important to know is that it took a while for the water to cool off especially in the big, open bays and took even longer to get cold in areas where there is deeper water," he said.
Blanchet said Louisiana's coastal waters are unique, and because the area is mostly made up of shallow bays and lakes, and winds blowing over those areas stir the water enough so that water temps are uniform throughout the water column.
That process moves fish throughout the system and pushes most species en masse into more comfortable climes.
The next questions cover any short-term and long-term effects on coastal species from this extended cold-weather run.
Blanchet said there were minimal fish kills last week.
"Our field personnel have had their radar switched on and had one or two reports of cold stunned fish last week," said Blanchet, who termed the ice, snow and air temperatures in the low 20s as a "nonevent as far as fisheries go.
"The first big cold front in January (Jan. 6-7) had water temperatures in the 60s — and that's why the trout were biting so good then — and we did have some fish kills then," Blanchet said. "We did not see any ourselves, but we had public reports, and they basically came from duck ponds where we find more fish when water was warm like that. When that strong cold front came in, the fish just didn't have a chance to get out."
He said what he expects to find in the spring is something he termed "sub-lethal effects. Fish will be in poorer shape just because it's been such a hard winter.
"But, for the fishermen, there likely won't be a population impact," Blanchet said. "Even after 1989, we still have such a good resource out there that they come back as soon as we see the results of the next year's spawn."
Blanchet said speckled trout will be the most affected species. That's because spawning stock lives and spawns in inside coastal waters.
"But there's some part of the (trout) spawning stock that live inshore. One of the things 1989 taught us was that in early 1990 we saw pretty significant numbers of trout on the beaches in the early spring. Normally we would have seen most of them up inside," Blanchet said. "And they were there to replenish the stock (of trout) that spring and summer."
Blanchet said other species like redfish, flounder, black drum and sheepshead, have offshore spawning stocks and future spawns and stocks should not be affected by the recent arctic fronts.
Information from: The Advocate, http://theadvocate.com