Study is like finding a needle in a haystack

While following a bunch of radio transmitter-outfitted fish around all day might seem like an attempt at herding cats, Ole Miss graduate student Dylan Williams, who handled much of the legwork of the study, said it’s all in a day’s work.

“We try to get tags on them in March, maybe late February,” Williams said. “We were interested in tracking them through the spawn.

“After the tagged fish are released, we tried to monitor them at least once a week. We tried to go out every week, but you can\’t always go out there when you\’ve got (bad) weather.”

It\’s hard to imagine a piece of technology that will attach to something the size of a crappie and record data of the fish\’s movements and provide a homing beacon for it\’s location, but that\’s exactly the sort of equipment the research team had.

“We used archival tags, a device that stores data on the tag itself,” said Williams. “We\’re using those tags to record depth and temperature. It takes a data point every four minutes. It\’ll record for 70 days, so we end up with 35,000 data points on one tag.”

The weekly process was to locate — or at least try to locate — every tag in the lake once a week to double-track the fish\’s movements in case a tag with stored data was not recovered.

That\’s where the rubber hits the road, Williams said.

“You have to get on the boat and run transects of the entire lake — the entirety of Sardis and the entirety of Enid,” he said. “Basically, we have on earphones, we have our antennae out, and we drive back and forth across the reservoir.”

That\’s easier said than done.

“The study requires us to find all the fish, but it\’s rare that we find all the fish in a particular week,” Williams admitted. “On average we\’d have about 25 or 30 fish out there, and we\’ll find all but four or five of them, typically.”

Williams explained that, in order to locate an individual fish, you practically have to be right on top of it, and you have to be tuned in to its specific radio frequency. The process is the best means of locating that needle in a haystack on a regular basis.

“We key all the frequencies into the receiver,” he said. “We put all 24 frequencies into the receiver, and it scans through each one. In other words, it\’ll scan 064 then 094 then 102 then 144. And it\’ll hold it for two seconds, and as it goes through those you\’re listening for a beep on any one of those particular frequencies.

“If you hear one, you stop the scan and you go right to that frequency and you try to pinpoint where that fish is.”

And you thought it was easy to catch a crappie.