EAGER: New molecular methods for studying copepod nauplii in the field
This research is funded under NSF grant OCE-1255697.
Investigators: Erica Goetze (PI), Petra Lenz (co-PI), and Karen Selph (co-PI).
The most abundant metazoans in the open sea are often the earliest developmental stages of copepods, their nauplii. Nauplii remain under-studied due to the limitations of conventional techniques and an historical emphasis on studying the larger mesozooplankton. However, there is increasing recognition that nauplii play important roles in food web dynamics, and considerable evidence suggests that nauplii may be important trophic intermediaries between microbial and classical food webs, due to their high abundance, high weight-specific ingestion rates, and ability to feed on relatively small particles. This team of investigators is developing a novel molecular approach to studying diverse populations of nauplii in mixed field samples based on quantitative PCR (qPCR). Here we propose to complete development and validation of this qPCR-based technique for enumeration of nauplii, and demonstrate its utility in the field. The specific objectives of this research are to identify and reduce technical and biological sources of error, determine the accuracy of the method across a range of environmental conditions, and complete one paired field experiment that compares the grazing impact of naupliar and protozoan micro-grazers in a model subtropical coastal ecosystem, in order to demonstrate the utility of this new method.
The qPCR-based method we are developing could yield transformative insights on the importance and trophodynamic role of copepod nauplii in planktonic marine food webs. Using this new qPCR approach, we plan to conduct detailed studies that compare the trophic ecology and grazing impact of naupliar and protozoan micro-grazers, in order to assess their relative importance in food web dynamics in subtropical ecosystems. If nauplii are found to contribute substantially to the grazing impact of microzooplankton, this would demand significant re-appraisal of pelagic food-web dynamics and have important implications for marine biogeochemical cycling. This research is also high risk in that the final accuracy, and ultimate utility, of this qPCR-based method is unknown. Detailed laboratory studies are required to develop the method to the highest possible level of accuracy.
Broader impacts will include training of graduate and undergraduate students, inclusion of research results in graduate and undergraduate courses at UH Manoa, and public outreach through the web, talks in public venues, and in the SOEST Open House. These PIs have a strong track record of engaging under-represented students in research, and particular emphasis will be placed on recruiting and training students from under-represented backgrounds.