MBE702 Seminar Evaluation: Lela Schlenker
Why Tag a Captive Fish? Evaluating Spawning Behavior of Mahi-Mahi Using Pop-up Satellite Archival Tags
Schlenker, LS, Stieglitz, JD, Hoenig, RH, Faillettaz, R, Babcock, EA, Lam, CH, Benetti, DD, Paris, CB, Grosell, M
Mahi-mahi (Coryphaena hippurus, “mahi” in the following) is a highly migratory ecologically and commercially important pelagic fish species. Understanding migration and habitat utilization of highly migratory fishes is paramount to understanding their ecology and concomitant with successful management. To better understand behavior in wild mahi, we used pop-up satellite archival tags (PSATs) to measure acceleration, depth, temperature, and light levels. To model acceleration patterns around spawning we tagged wild-caught captive mahi with PSATs and observed them in captivity. A boosted regression tree model was built to predict spawning events based on observed accelerometry data and time of day. We then deployed 16 PSATs on wild mahi in the Florida straits (FL; n=14) and the Gulf of Mexico (GOM; n=2). The spawning model was applied to PSAT data from wild mahi and the depths and temperatures associated with the potential spawning events were extracted. PSAT light data were modeled using Trackit, a state-space Kalman filter model, to estimate migrations. PSAT data demonstrated that mahi spawn at depth, migrate up to 100 km per day, and inhabit a wide range of temperatures and depths. These data are the first to predict spawning of a wild marine teleost from accelerometry data and a critical component of understanding the ecology of mahi.