Georgia Third is a scientist studying the diet and habits of Lake Taupō's rainbow trout.
Georgia Third is a scientist studying the diet and habits of Lake Taupō's rainbow trout.
Georgia Third spent her Christmas holidays gutting and cleaning other people’s fish on boat ramps around Lake Taupō.
It might seem like a waste of the PhD student’s talents, but it was all in aid of an important research project she’s conducting into the lives and habits of trout inthe lake, in the hopes of understanding how scientists and fishers can keep their populations strong.
There’s a lot still to learn about the lake’s rainbow trout, and Third hopes her work will help improve understanding of how they choose what to eat, their growth rate, and how they migrate.
To do that, she needs samples, so has spent the festive period offering to do the undesirable task of cleaning fishers’ catches in exchange for taking a range of information and samples.
“As people come in after they’ve been fishing, I’ve been offering to clean people’s fish for them and take all the guts out.
“At the same time, I’m taking photos of the fish, taking length and weight, [and] stomach samples to see what they’ve been eating.”
Georgia Third set up a cleaning station on boat ramps around Lake Taupō to collect samples from fishers.
Third also took muscle samples for stable isotope analysis, which is a test that allows her to see what the fish has been feeding on for the previous six to 12 months, giving a better picture of the whole food web in the lake.
As well as potentially changing the way fisheries are managed for the better, Third’s research may give a scientific explanation to what generations of fishers have observed about Taupō's trout population.
“A lot of fishers will talk about there being smelt specialists or kōura specialists, and I’m interested in why.
“What makes a trout decide and how much do they switch between these prey types over time or even over a few hours? Are they feeding sometimes at the bottom and other times in the water column?”
Although originally from the rural outskirts of Auckland, Third made the long journey to collect samples from her current home in America, where she’s studying at University of California, Santa Cruz.
It might seem a long way from the Central North Island, but the Californian institute is a fitting place to look at how Lake Taupō's trout are put together, said Third, because it’s where they originally came from.
“Trout in Taupo were introduced from California and I’m studying around the area that trout came from in Santa Cruz.
“I’m studying the trout in the ancestral population and in the introduced population.
“University of California Santa Cruz have found a few different genes that are of importance to trout over there, to whether they migrate or stay resident, and how fast they grow.
“One of the things I’m doing is seeing whether those genes are relevant in the introduced population here.”
The plastic and foil lolly wrapper had formed a seal around inside of the trout's stomach, meaning it could not digest food and was slowly starving.
Although Third’s research isn’t directly concerned with pollution and litter, one catch particularly caught her attention, she said.
“There was a fish that came in through the gutting station and it looked really sickly, it was an almost green colour and it was really thin.
