Research Story

Andy Ostrowski

Andy Ostrowski
Graduated May 2006 | Major: Biology and Marine Biology

"My honors research is focused on examining the relationship between early life history traits and survival in populations of recently settled southern flounder, Parilichthyes lethostigma. Southern flounder spawn during winter months and recently metamorphosed juveniles settle in estuarine habitats during late winter and early spring. Most individuals that have settled are between 10 - 20mm total length and experience high mortality during post-settlement months. I hope to determine whether early life history traits, specifically hatching date and early growth rate, are linked to survival to larger post-settlement sizes achieved by summer. I obtained fish from winter, spring and summer sampling collections. Taxonomic identification was completed using anal fin ray counts as well as melanophore counts and spacing to separate southern flounder from other flatfish species. Like most fishes, southern flounder deposit daily increments on their otoliths (inner ear bones) that can be used to age individuals. I extracted otoliths by soaking the fish in immersion oil. The microstructure of each otolith will be analyzed using light microscopy and computer software to count daily increments and measure the spacing between them. I will be back calculating birth dates for flounder from early and late collections by subtracting the number of daily increments counted from the date of capture. I will also estimate early growth rate for each group of fish by measuring otolith size and relating that to fish age. The distribution of hatch dates and growth rates will be compared between the fish collected just after settlement and those collected several months later that have survived the first few months of life. If differences exist (for instance the survivors are made up of fish that were hatched early and grew fast), it will give us insight as to which early life history traits may have the greatest influence on recruitment success of southern flounder.

This project has given me a tremendous opportunity to interact with numerous professionals in both the academic realm and state government field. I feel that this experience will greatly enhance my preparation for graduate school and I will forever look back on this project as my first independent research in marine fisheries."