Research Projects
The Course of My Career
Physical and Chemical Analysis of Coral Ingested Microplastics Across the Pacific
In progress
Coral reefs are highly complex and valuable ecosystems which are among the most threatened on Earth. An emerging threat of concern is microplastic pollution. Their small size allows them to be ingested by a variety of marine life. They pose not only a physical threat, but also a chemical threat due to their associated chemicals which negatively affect organismal health, and reproduction. Results of this study will allow for an understanding of the types of ingested microplastics, the role coral morphology plays in retention, and potential threats to coral reef ecosystems across the Pacific.
The Effects of Microplastic-Associated Chemicals on Coral Reef Reproduction
In progress
Microplastic pollution presents an emerging stressor of concern to coral reef ecosystems. The physical impact of corals ingesting microplastics has been well studied, but the chemical threat that microplastics may pose to these organisms has been understudied. Therefore, the goal of this study was to determine if a difference exists between the effects of microplastics themselves and their associated chemicals on Montipora capitata fertilization rates. Findings from this study will be the first to show that microplastic-associated chemicals are an important stressor affecting coral reproduction. Thus, microplastic pollution might pose a threat to coral replenishment and persistence within coral reef ecosystems.
The Effects of Tungsten on Coral Reef Health and Reproduction
May 2022
Among coral reef stressors in the Kwajalein Atoll, Republic of the Marshall Islands, increasing concentrations of tungsten in the water column from military ammunition are of concern. No studies to date have explored how tungsten may affect successful coral survival, health or reproduction. In our study, we exposed fragments of two common coral species, Porites lobata and Pocillopora damicornis, to five concentrations of tungsten (100 ppb, 1 ppm, 10 ppm and 100 ppm) along with a control. Each species underwent short-term (72-hour) and long-term (30-day) ecotoxicology assays followed by 30-day recovery periods. Health was monitored daily with protein expression analyzed on day 12 and day 30 of the exposures. Additionally, brooded coral planula larvae of P. damicornis and spawned gametes (eggs and sperm) of Montipora capitata were exposed to the same concentrations of tungsten for 30 days. Acute toxicity of the fragments was not observed. Reduced fertilization or subsequent recruitment were not seen either. Protein expression showed sublethal effects on metabolism with greater sensitivity in P. damicornis than P. lobata, which is consistent with other studies of stressor effects on corals. The metabolic effects of tungsten will likely result in reduced reproductive success over time by affecting lipid metabolism. Overall, the results of this study indicate that tungsten is not acutely toxic and that corals recover from associated sublethal stress over time after exposure.
Dissolved Organic Matter Effects on Daphnia ambigua
January 2020
Shifts in the composition of terrestrial plant communities could have significant effects on freshwater zooplankton due to changes in the quality of inputs of terrestrially derived dissolved organic matter (DOM). Leachate from native red maple (RM) and invasive Amur honeysuckle (AH) were used to explore the effects of DOM source on survival and growth of juvenile Daphnia ambigua. Prior research with both terrestrial and aquatic organisms indicates that AH-derived DOM has negative effects. Comparing bioassays in the presence and absence of algae with no additional DOM, RM- or AH-derived DOM, RM had stronger negative effects on both Daphnia survival and growth while AH only decreased growth. The negative effects seen in the presence and absence of algae provided evidence for both indirect and direct effects due to phytotoxicity and plant secondary compounds, respectively. DOM source may play a key role in regulating consumers in aquatic ecosystems. Read the full article here.