NSF Postdoctoral Fellowship in Biology FY 2019: Mysticetes and baleen as bioindicators of microplastics in marine food webs

Savoca, Matthew S, Pacific Grove CA

Investigators

Abstract

This action funds an NSF Postdoctoral Research Fellowship in Biology for FY 2019, Research Using Biological Collections. The fellowship supports research and training of the fellow that will utilize biological collections in innovative ways. It is unknown to what degree baleen whales ingest microplastic, how ingestion occurs, and if there are any health effects. This research seeks answers to these questions. In whales, baleen acts as a sieve and retains prey during filter-feeding. The first objective uses a laboratory experiment to test baleen's effectiveness in trapping microplastics suspended in water. The fellow will also use baleen specimens to study pollutants derived from ingested plastic. In a live whale, baleen remains intact for two years to two decades, dependent on species, before it wears out and is replaced by growing outwards from the gum line. This process, which is similar to that of human fingernails or tree rings, allows baleen to serve as a record of variation in a whale's internal (body processes) and external (e.g., pollutants) conditions at the time that portion of the baleen grew. The second objective will establish methods to use baleen to track contaminant exposure over time. In addition, the fellow will mentor high school, undergraduate, and graduate students, fostering these young scholars' first research experiences and aiding the fellow's professional development. Baleen is a keratinized filtering structure unique to mysticete whales. Despite its iconic status, baleen remains enigmatic and understudied. For this work, baleen will be acquired from freshly deceased specimens that strand in California, and from collections stored at the Smithsonian's National Museum of Natural History. The first aim of the fellow's research is to test baleen's efficacy in retaining microplastics suspended in the water column using a laminar flow tank at the Hopkins Marine Station of Stanford University. In this experiment, the fellow will use baleen from species with divergent feeding styles and baleen morphologies to elucidate which mysticetes are more likely to ingest microplastics directly from the water column, and also how microplastic particle size and buoyancy influences their capture. For the fellow's second objective, baleen specimens will be analyzed using high resolution gas chromatography-mass spectrometry for contaminants that are indicative of synthetic material ingestion (e.g., phthalate plasticizers, chlorinated and brominated flame-retardants). Using the same analytical methods, the fellow will leverage the accreting property of baleen to create multi-year intraindividual chronologies that will clarify microplastic exposure in unprecedented geographic and phenological resolution. Taken together, these studies will provide a critical assessment of baleen whales as bellwethers for microplastic pollution and will release the untapped potential of baleen collections to assess overall marine ecosystem health. Furthermore, the fellow will develop outreach materials with the California Ocean Alliance, mentor undergraduates through Stanford's Vice Provost for Undergraduate Education (VPUE) program, and assist high school students in their Youth Engagement through Science (YES!) internship at the Smithsonian Institution. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.