Mechanisms of Biological Invasions on Coral Reefs: Synergistic Effects of Biotic and Chemical Pollutants

EPA Grant Number: F13F11150
Title: Mechanisms of Biological Invasions on Coral Reefs: Synergistic Effects of Biotic and Chemical Pollutants
Investigators: Carter, Amanda Lockett
Institution: University of California - San Diego
EPA Project Officer: Lee, Sonja
Project Period: September 29, 2014 through September 29, 2016
Project Amount: $84,000
RFA: STAR Graduate Fellowships (2013) RFA Text |  Recipients Lists
Research Category: Academic Fellowships , Fellowship - Marine Biology

Objective:

Palmyra Atoll and Kingman Reef have experienced biological invasions by a corallimorph, Rhodactis howesii, which appears to be associated with shipwrecks on the reef terraces. This research will address four integral questions: (1) What factors influence invasion of the corallimorph on Pacific reefs? (2) How does invasion affect community structure and function on the reefs? (3) Are these reefs resilient to reinvasion following experimental removal of the invader? (4) Is there evidence that the invasive corallimorph is actually a nonnative species?

Approach:

Field-based experiments on Palmyra Atoll will determine how invasion of the corallimorph affects community structure, function and resilience on the reef. A series of plot-clearings along a gradient of corallimorph cover will measure rates of invasion, effects of invasion on coral cover and diversity and succession of the cleared plots over time. Population dynamics of the invader will be examined in the laboratory by extracting DNA from corallimorph tissue samples at sites around Palmyra Atoll and Kingman Reef. Isolation of the ITS1 region of the corallimorphs genome will determine whether or not the population is clonal, which would suggest that it stemmed from an invader brought over on the shipwreck.

Expected Results:

Coral reefs are among the most diverse and productive ecosystems on the planet. Yet despite their natural resilience, they are under constant stress due to such global issues as ocean warming and acidification. As these global stressors alter the delicate balance on coral reefs, small-scale, local stressors have the potential to create large-scale disturbances. These changes may make coral reefs more susceptible to biological invasions, particularly when compounded with physical disturbance and chemical stressors. These results will provide valuable insight into the effect that the corallimorph has on ecosystem structure and function.

Potential to Further Environmental/Human Health Protection

Observational reports have documented the spread of R. howesii at numerous reefs worldwide, including smaller island communities that rely on subsistence fishing for their primary source of protein. Thus, this invader presents a threat to human health and well-being by altering the basic ecosystem functions of these reefs and, ultimately, the services they provide. This research contributes to increased protection of the environment by adding to the knowledge base regarding the vectors and mechanisms of biological invasions on coral reefs so that further invasions can be prevented.

Supplemental Keywords:

conservation, coral reef, invasive species

Progress and Final Reports:

  • 2015
  • Final