SEMINAR: MBF602 10/7/11 S/A 103 1:00pm Sean Bignami: Resistance to ocean acidification in larvae of a subtropical fish

["Maxine Williams" <mwilliams@rsmas.miami.edu>]

MBF602 10/7/11 S/A 103, 1:00pm Student Speaker Sean Bignami

 

Resistance to ocean acidification in larvae of a subtropical fish

Compared to our knowledge of the effects of ocean acidification (OA) on marine invertebrates, our understanding of how acidification impacts larval fishes is rudimentary at best, with only a handful of published studies focused mostly on demersal, benthic-spawning tropical reef species. Rachycentron canadum (cobia) is a useful comparative study species with physiological traits and a life history contrasting those species studied to date. In this study, the effects of OA on larval cobia were investigated during the first three weeks post-hatch, utilizing multiple assays of growth, development, swimming ability, and behavior. Additional trials were also conducted with OA treatments paired with increased temperature and starvation stress, to identify synergistic interactions. Results indicate that when raised under extreme OA conditions (6,500ppm to 13,000ppm atmospheric CO₂ equivalent), cobia demonstrate reduced size-at-age and delayed development, while under more realistic predicted future scenarios (700ppm and 2,000ppm CO₂), cobia exhibit resistance to impacts on growth, swimming capability, and behavior. Despite this apparently robust nature under predicted future conditions, preliminary analyses also indicate an increased starvation mortality rate and altered otolith development under OA conditions. Further comparative trials with coastal Trachinotus carolinus (Florida pompano, Carangidae) and pelagic Coryphaena hippurrus (mahi mahi, Coryphaenidae) will contribute to a broad understanding of the effects of OA on marine fishes.

 

 

Sean Bignami

University of California, Santa Barbara, B.S. Aquatic Biology 2006

Entered Ph.D. program, Fall of 2008

Advisors: Su Sponaugle & Robert Cowen