Welcome to our blog series, Research Highlights! On the second Monday of each month, we debut newly published fisheries research by our women of fisheries colleagues. If you have research you would like to highlight and share with our readers, submit a nomination form!

Our February’s Research Highlight:
Vecchio, J.L., J.L. Ostroff, and E.B. Peebles. 2021. Isotopic characterization of lifetime movement by two demersal fishes from the northeastern Gulf of Mexico. Marine Ecology Progress Series 657:161-172.

There is just something about the eye. It is the subject of literally dozens of idioms, from “apple of your eye” to “beauty is in the eye of the beholder.” According to Merriam-Webster, an idiom is an expression in the usage of a language that is peculiar to itself either in having a meaning that cannot be derived from the conjoined meanings of its elements or in its grammatically atypical use of words. But what if “keep an eye peeled” isn’t just an idiom, but actually science? Because sometimes science really is “more than meets the eye.”

That brings us to this month’s research highlight. Dr. Julie Vecchio, currently a research scientist at the Florida Fish and Wildlife Research Institute, recently published her doctoral research on fish eye lenses. She and her colleagues used carbon and nitrogen stable isotope values in fish eye lenses to determine if they can be used to detect ontogenetic habitat shifts of fish. This approach is part of an exciting new frontier in fisheries science.

Isotopic carbon and nitrogen analysis is used in fisheries, because patterns of carbon and nitrogen in the aquatic environment are stable over time but can vary by location. Fish eye lenses are made almost entirely of protein and proteins are made, in large part, of carbon and nitrogen. Because fish keep these eye lenses their whole lives, their incorporation of carbon and nitrogen isotopes from their environment into their eye lenses can act as a kind of diary. “This means,” according to Dr. Vecchio, “ that with a tissue that is stable over time, providing a lifetime record, we can interpret this record to reveal spatial patterns and movements over the whole lifetime via a “natural tag.””

In their study, they chose two species with different life histories. The Great Northern Tilefish Lopholatilus chamaeleonticeps lives its whole life in one place on the outer continental shelf, whereas the Red Grouper Epinephelus morio moves across the continental shelf. The isotopic patterns exhibited the same pattern, revealing that the Great Northern Tilefish were not moving during their lives, whereas the Red Grouper were. Therefore, their work confirmed that fish eye lens stable isotopes can be used to interpret the movement pattern of fishes. “I think that this is the most exciting thing. This technique has the chance to be applied to any number of species with sparse life history information. By examining the patterns of stable isotopes in the eye lenses, we can get full lifetime records using far fewer specimens and much less time than what has previously been invested to get movement and general diet information,” states Dr. Vecchio.

We agree; Dr. Vecchio sure has an “eye” for exciting, cutting edge science!

The full manuscript can be found and downloaded here:
https://doi.org/10.3354/meps13525