R/E-27-Malik

Strategic focus area:

Description:

Despite remediation attempts, the Anacostia River harbors legacy pollutants that remain a hazard to human and ecosystem health. Contaminants found in fish also biomagnify and bioaccumulate, impacting wildlife up the food chain and preventing safe fishing and recreation in the Anacostia River. Endocrine disrupting compounds are of particular concern, as detriments to reproductive success threaten the viability of native fish populations. Impacts to female reproduction are well-documented across fish taxa, but descriptions of sperm-related effects are limited. Using the mummichog (Fundulus heteroclitus), we preliminarily developed a field-adaptable method for measuring aquatic sperm quality using three metrics: 1) motility, measured by computer-assisted sperm analysis (CASA); 2) energetic capacity, measured by an adenosine triphosphate (ATP) assay; and 3) DNA damage, measured by Comet assay. These methods will be applied to field-collected F. heteroclitus from at least four sites on the Anacostia River to quantify reproductive harm from a seasonal and age-related temporal lens. Simultaneous fertilization trials will be conducted, to better understand the biological relevance of impairment observed. Finally, laboratory studies using intraperitoneal (IP) injection of F. heteroclitus with common urban contaminants will be conducted to validate field results. Preliminary results from two sites in the Anacostia suggest that male reproduction is severely impaired, thus we expect to see the same going forward, with damage increasing with age and spawning season. Ideally, fertilization trials and IP injections will reflect what is seen in field-collected organisms, giving greater weight to the results. This work will be in collaboration with Anacostia Watershed Society (AWS) to better communicate the state of the Anacostia River to residents through community engagement events like talks, boat tours, and festivals. This work will also be used to produce a policy memo supported by AWS to distribute to policymakers to appropriately address the ecological concerns the results may present.