OCE-RIG: Novel approaches to better understanding the trophic role of small pelagic fishes and their critical link between the plankton and higher trophic levels
Overview: Small, schooling pelagic fishes often represents a critical link in how planktonic production reaches the upper trophic levels of ocean food webs. Despite their ecological and economic importance, distinct gaps exist in our understanding of the role these fishes play as consumers of zooplankton. This study takes a multifaceted approach, employing four types of analyses in order to better understand the feeding dynamics of six species of small pelagic fishes in the Large Marine Ecosystem of the Northeast U.S. continental shelf. Analytical techniques include detailed visual inspection of gut contents, bulk and compound-specific (amino acid) stable isotope analyses, and DNA barcoding techniques for identifying the otherwise unidentifiable prey. Intellectual Merit: Because of their economic importance, small pelagic fishes have received substantial interest and research attention from fisheries agencies such as NOAA. This work, however, has largely focused on either monitoring population sizes or examining the nature of small pelagic fishes as prey for other important natural resources. But, being consumers themselves, small pelagic fishes play a major role in determining when, where, and how much planktonic production flows either towards fish and upper trophic levels or is available for other processes, including export due to sinking. In this project, the investigator will use novel approaches to study small pelagic fishes not as a fishery resource, but as major consumers within planktonic food webs. By gathering trophic-related data using techniques that will be applied to each specimen, a larger picture of the top-down impact that small pelagic fishes have on all or particular zooplankton taxa should emerge. The use of compound-specific stable isotope analyses is of particular note, as this powerful technique will afford the ability to examine variability at the base of the food web, thereby providing insight into the bottom-up forces that influence these important species. Broader Impacts: This project is heavily geared toward involving many young and future scientists from underrepresented groups in research activities. At least eight undergraduates will participate on research cruises, to assist with sampling efforts. Two undergraduate summer student fellows will assist in laboratory-based data collection efforts, and will spend the summer in Woods Hole gaining research experience and a sense of what a career in oceanography might entail. An early-career lab assistant will gain valuable research experience by leading the sample processing activities in the laboratory. Travel support to a national meeting will allow one of the summer students or lab assistant to share results from this study with the scientific community. In an effort to foster scientific curiosity in local schools, the investigator will host students from East Boston High School as they spend a day in Woods Hole visiting various labs, facilities and attend presentations by the investigator and other scientists on careers in oceanography. The students' teacher will also participate on one of the research cruises, enabling her to share her experience with many other students.