Salmon embryo success
For the past 15 years, aquacultural salmon farmers in Maine have struggled with plummeting embryo survival rates, forcing them to drastically increase the number of eggs they produce — which comes with a hefty price tag. LeeAnne Thayer, Ph.D. candidate in marine sciences at the University of Maine, is determined to find out what is causing the declines. Working with Heather Hamlin, assistant professor of aquaculture and marine biology, the researchers are studying the embryonic development of salmon in order to increase their survival rates, save farmers money and keep Maine’s aquaculture industry afloat.
All the farmers had this one problem, and it was that their salmon egg survival was decreasing. It had been decreasing for about 10 to 15 years. All of them are like, “Why is this happening? What’s going on?”
Farmers used to be able to rely on 90 percent, maybe 80 percent or above in embryo survival. Today average embryo survival is around 50 percent. It’s significantly less than it used to be.
If we have egg short fall at any given year, you can’t really plan for that. Maybe, instead of growing 30 million eggs, we might have to plan for 50 million eggs. You’re really spending a lot more money than you actually need to.
For a whole year we’re going to raise Atlantic salmon, and once a month we’re going to take their blood samples and see, “Are they going through their cycle?”
I’m looking at the eyes because this is a significant milestone in their development. When the eyes appear, I know that there’s actually an embryo inside here and that the embryo is going to survive until hatch.
I’m working on a capstone with Heather looking at the histology and development of larval Atlantic salmon to get good pictures of their development to track their cartilage and bone.
My project helps them determine whether or not these female respond at the right time. Also, it helps to determine whether or not their hormones have anything to do with how the eggs are developing.
Once the two data sets are put together, we can figure out if there’s a correlation between certain hormones and certain egg developmental processes.
If we were able to bring back their survival back to 80–90 percent consistently, that would allow us to carry fewer brood stock on a given year, and that would be a huge saving for a company like this.
One of the great missions of the university is to help industry. It’s to help the economy of Maine. Our edict in our lab and many labs at the university is to basically try and help farmers.
It’s very refreshing to see a researcher come to you and say, “What’s your problem? What can I help with?”