Taking a biochemical snapshot of sea turtle health

New research from Griffith uses biochemical profiles from sea turtles’ blood as a tool to monitor the health of populations in the wild.

In work published in Comparative Biochemistry and Physiology Part D: Genomics and Proteomicsthe researchers used metabolomics, which measures the byproducts of physiological processes, to determine whether environmental conditions or the way they are trapped can affect their health.

“As an iconic yet endangered species, there is a lot of interest in adapting advanced analytical techniques to evaluate the health of wild populations of sea turtles,” said Dr. Steve Melvin, a research associate at the Australian Rivers Institute.

“Nuclear magnetic resonance spectroscopy is a powerful technique that can provide a metabolic fingerprint of the physiological processes taking place in an animal. It provides a direct indication of an organism’s health and how external conditions affect an animal’s physiological response.”

“Because they are not lethal, metabolomics provides an attractive method to compare populations of endangered species such as sea turtles and to understand how the environment they live in affects their health. However, few studies have used this method to wild populations of sea turtles.”

This study is the first of its kind to compare the biochemical profiles of both resting and active turtles from coastal and reef sites, sampled over multiple seasons in South East Queensland.

“Our results show marked differences in the chemical fingerprints of turtles living in different locations, which can be attributed to varying food or feed quality and possibly different levels of exposure to stressors such as chemical contaminants between coastal and reef sites,” said Dr. Melvin.

“We also observed clear markers of physical exertion in animals captured while active, using a method called the ‘rodeo’ technique, which was absent in turtles sampled while resting.”

Turtles sampled at one site over an 8-month period showed only modest differences in metabolome over time, suggesting that the technique is flexible and not prone to confounding factors.

“When evaluating the health of sea turtles or other marine wildlife, locational characteristics such as the quality of an animal’s food source, the amount of pollution, and whether they are resting or active appear to have a much greater influence on turtle physiology than the effect of seasonal changes,” said Dr. Melvin.

“Our study provides a realistic example of how an untargeted metabolomic technique, providing a non-invasive snapshot of physiological health, can contribute to the monitoring and management of sea turtle populations and serve as an example for the monitoring of other marine megafauna species over large areas. areas and timescales in the wild.”