Publications
Publications
October 2025
Coral reef ecosystems face numerous anthropogenic threats, including plastic pollution which poses a significant threat to coral health and reproduction through both the physical and chemical properties of polymers. To date, most studies have focused on how physical characteristics (size and shape mostly) affect coral health, with very few considering the associated chemicals or impacts on coral reproduction. Chemicals are added during manufacturing (additives) while also being absorbed from the surrounding environment (sorbed) under different environmental parameters. There is currently limited information on the occurrence of microplastics and their associated chemicals within corals, making it difficult to conduct environmentally relevant studies. Additionally, existing studies vary widely in their methods, making comparisons difficult. Therefore, my dissertation research tested the direct effects of microplastic-associated chemicals, through creation of microplastic leachate, on coral fertilization (Chapter 2) and settlement (Chapter 3) and investigated methods to effectively extract, isolate, visualize, and analyze microplastics from coral environmental samples through a literature review of current methods and testing of existing protocols (Chapter 4)...
July 2025
Coral reef ecosystems, especially those in Hawai`i, are increasingly threatened by marine plastic pollution, which may impair coral reproduction. Microplastics contain toxic, persistent, and endocrine-disrupting chemicals. While negative effects of microplastic ingestion have been observed on adult coral viability and health, very few studies have explored impacts on reproduction. Recent studies found that microplastic leachate negatively affects coral fertilization likely due to plastic additives incorporated into products during manufacturing. This study explored the effects of microplastic leachate on coral planula larvae settlement and survival. Planula larvae of the broadcast spawning species, Montipora capitata, and the brooding species, Harbor Porites, were exposed to microplastic leachate from four plastic types [nylon, polypropylene (PP), high-density polyethylene (HDPE), or low-density polyethylene (LDPE)] at three concentrations (50, 100, or 200 particles/L) for 7 days. Settlement and survival were affected by leachate concentration and polymer type strongly on Days 5 and 7 indicating delayed and/or potentially cumulative effects. The most pronounced negative effects on survival were observed with HDPE—100 and LDPE—200 treatments. One treatment unexpectedly promoted settlement (HDPE—200) likely due to attractive chemical cues released by the leachates. This is particularly concerning, as it suggests that planula larvae may be drawn to settle on degraded or suboptimal substrates affecting reef recruitment and replenishment. Species-specific responses were also found, with Harbor Porites exhibiting higher survival and variable settlement. Overall, microplastic leachate significantly impacted survival and settlement of both Montipora capitata and Harbor Porites planula larvae with complex temporal, species-specific, polymer-type, and concentration-dependent effects. Microplastic leachate presents an additional stressor to already threatened coral species making addressing both local and global stressors critical for the protection of coral reef ecosystems.
November 2024
Corals provide immense cultural, economic, and ecological resources to humans and marine life. These organisms are under threat from many stressors including plastic pollution which is ubiquitous in our oceans. The term “plastic” describes a diverse group of polymers with unique physical, chemical, and biological characteristics that contribute to complex effects on corals. Most current data focus on the effects of the physical characteristics of plastics (i.e. size, shape, color) on corals, with only a few studies considering the effects of the chemical (i.e. manufacturing additives and absorbed contaminants) and biological characteristics (i.e. hitchhiking organisms and biofilms), making interventions difficult. Many policies to protect corals do not include regulations for plastic pollution threats. However, initiatives towards addressing the removal of current plastic pollution in the ocean and the prevention of more plastics entering the environment are vital to protecting these organisms.
August 2024
Microplastic pollution is an emerging stressor of concern to coral reef ecosystems, which are already threatened by additional global and local level anthropogenic stressors. The effects of ingesting microplastics alone on corals have been well studied, but the effects of the chemical composition of these particles have been understudied. Many microplastic-associated chemicals are endocrine disrupters potentially posing a threat to organismal reproduction. Therefore, the goal of this study was to determine if differences exist between the effects of microplastics themselves and microplastic leachate on Montipora capitata fertilization due to changes in fatty acid quantity and composition. Assays were conducted two years in a row which exposed M. capitata gamete bundles to either one of four types of recently manufactured, virgin microspheres (nylon, polypropylene, high-density polyethylene, or low-density polyethylene) at three concentrations (50, 100, or 200 particles/L) or microplastic leachates, presumably including plastic additives from these microspheres. Gamete fertilization was not impacted by microplastic particles themselves, but some of the microplastic leachate treatments with the same polymer type significantly reduced fertilization rates for M. capitata. Additionally, a total of 17 fatty acids were seen in both years, but neither fatty acid quantity nor composition correlated with observed declines in fertilization. Instead, fertilization and fatty acid data independently varied by concentration and polymer type, likely due to the presence of different chemicals. This study is the first to directly test the toxicity of microplastic leachate to coral reproduction. These findings show that microplastic-associated chemicals are an important stressor affecting successful coral fertilization and fatty acid quantity and composition and provide evidence for the negative effects of microplastic leachate to coral reproduction. Thus, plastic additives could pose an additional threat to coral replenishment and persistence in coral reef ecosystems.
December 2023
Less than 2% of graduate students and 1% of tenured faculty in Earth, atmospheric, and ocean sciences identify as Black or African American. Discussions about diversifying ocean sciences are incomplete without acknowledging the distinctive challenges faced by Black women. We present new survey data on the dominant barriers to entry within the field, which can result from racism and discrimination, financial difficulties, and lack of access. We also discuss mitigation strategies that can be employed, with the hope that the entire ocean sciences community can collaborate to foster a culture of inclusion. We cannot have a healthy ocean if we do not support everyone who wants to study it.
February 2021
In 2018, 1.4% of the US population earned a Ph.D.(US Census Bureau). When we look at the number of Ph. Ds. across all fields held by Black, Indigenous, and People of Color (BIPOC), we see that the percentages are very low. In 2018, 35,404 total doctorate degrees were awarded in the United States to US citizens and permanent residents (NSF, see https://ncses. nsf. gov/pubs/nsf20301/data-tables).
February 2021
If we look to the future of coral reef science and see an inclusive and diverse field where researchers from a variety of disciplines are widely engaged with the community at large, it will herald the success of the issues discussed thus far in this series of essays (Cziesielski et al. 2021; Love et al. 2021; Nowakowski et al. 2021; Wilkins et al. 2021).
February 2021
The narrative that scientific advancement requires effort from one dedicated individual, the “mad” scientist cutoff from the help of others, is being replaced by new generations of scientists. This new wave of scientists is adept in communication, cooperation, and allocation of unique skills to solve a unified problem.
February 2021
Coral reef ecosystems face a number of local threats, including increasing human populations, coastal development, fisheries, and pollution, which cause severe destruction on reefs, while global anthropogenic climate change is altering the environment of coral habitats. Due to these stressors, there is a crucial need to reevaluate and implement effective management practices to protect coral reefs immediately and in the long term.
February 2021
From Australia’s Great Barrier Reef to the Caribbean islands, the message is clear: coral reefs are struggling. Many that have dedicated their lives to these ecosystems are seeing them vanish in front of their eyes. Coral reef scientists wake up to this reality every day and have been waking up to this reality for a long time!
February 2021
There is hope for coral reefs and communicating excitement around coral reef research and discoveries is a key opportunity to grow it. Amidst the trawling scars and gear tangles on the Northwestern Hawaiian Ridge and Emperor Seamounts, researchers have identified signs of coral recovery since protection measures were expanded 30–40 years ago (Baco et al. 2019). It is expected that coral ecosystems will take centuries or more to recover from anthropogenic influence, and the discovery that improvements can be seen in decades is reason to celebrate.
November 2020
With the ever‐changing advances in the aquatic sciences, more efficient coordination of projects and cooperation between scientists in different countries is needed. The inclusion of scientists across the globe to solve complex ecosystem questions requires effective international collaborations across disciplines. One way to advance this process is through international research collaborations (IRCs) which include the next generation of scientists: graduate students.
August 2020
International research collaborations are usually partnerships between people working on a single, common goal research project in different countries. However, what about international research collaborations that emerge abroad but among people from the same country? Through our shared experiences, we challenge the traditional definition of international research collaborations by starting a collaboration abroad between colleagues from the same home-institution country and exchange program: Association for the Sciences of Limnology and Oceanography: Limnology and Oceanography Research Exchange (LOREX).
July 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.
June 2020
Increases in dissolved organic matter and the consequent “browning” of some lakes in recent decades are reducing water transparency to both ultraviolet and photosynthetically active radiation with important, but poorly understood ecosystem-level consequences for zooplankton grazers. The prevailing resource-based unimodal hypothesis posits that nutrients in dissolved organic matter stimulate primary production in clear-water lakes, while shading by dissolved organic matter inhibits primary production in browner lakes, with zooplankton responses following the patterns of their food resources. Support for this hypothesis derives primarily from short-term experiments, space-for-time analyses, and modeling studies.
August 2019
International research is necessary in aquatic sciences because water moves across borders. Historically, international collaborations have been useful in conducting oceanographic research programs, which span large distances and require several funding sources. Although valuable, international research can have unforeseen challenges to the unprepared researcher. Communication with an international collaborator and professional development training can mitigate these pitfalls.