Measuring Mucus for Biomarkers of Farmed Salmon Reproductive Fitness

Erin Legacki, NIST

31 January 2020

Advancements in measurement science create the ability to completely visualize fish reproductive endocrinology which can increase aquaculture production through the improvement of brood stock selection. As the fastest growing form of food production in the world, marine aquaculture in the United States contributes to seafood supply, supports commercial fisheries, and has great job growth potential. However, the major marine aquaculture product in the United States, Atlantic salmon, has had a drop in embryo survival rates of more than 35% since 2000. Reduced embryo survival can be influenced by the endocrine status of adult salmon. Currently, only a few steroid hormones of the Atlantic salmon endocrine profile have been measured. This is due to several limitations in the measurement of fish steroids, which are mainly based on time consuming, costly, and invasive blood or tissue sampling that immediately affects the fish endocrine profile. Utilizing skin mucus can provide a non-lethal and relatively non-invasive matrix to monitor fish reproductive status.  Second, steroid hormones are measured using immunoassays, which are indirect measurement methods designed to only detect a single hormone. The complexity of endocrine pathways requires a more in-depth analysis to impart a complete understanding of fish fertility. Advancement of -omics technologies which explore the roles, relationships, and actions of various molecules that make up the cells of an organism, can provide a detailed picture of both endocrine and metabolic pathways unique to reproductively fit salmon. Using a combination of untargeted metabolomics and more targeted steroidomics to define biomarkers of superior fertility in Atlantic salmon can be used to increase aquacultural yield along with increasing the understanding of fish reproduction as a whole.