Degree SoughtMasters of Science
University Department and/or Lab
What is the feasibility of using Tripneutes gratilla, a native Hawaiian sea urchin, as a biological control agent to control the growth and spread of alien and invasive macroalgae in Hawaii?
Description of Research
My research interests involve determining the feasibility of collector urchin, Tripneutes gratilla, to act as a biological control agent in suppressing the growth and spread of alien and invasive macroalgae. Tripneutes gratilla is a native Hawaiian urchin that grazes on macroalgae. Benthic macroalgae, both introduced and native, has become a pest on Hawaiian coral reefs. Macroalgae can outgrow corals, competing for space and shading them. In protected waters, such as in Kaneohe Bay, coral are especially vulnerable to smothering as nutrient runoff and a decline in both the number and size of herbivorous fish has resulted in elevated growth rates of macroalgae. Reduction of macroalgae may be possible if T. gratilla populations are artificially increased.
In order to determine if artificially enhancing T. gratilla populations is feasible, I am looking into a number of questions: (1) Will T. gratilla survive if transplanted onto patch reefs in Kaneohe Bay where they are not naturally found? (2) What is the growth rate of T. gratilla, and how does size relate to amount of macroalgae consumed? (3) How long will transplanted urchins live? (5) Will preferences of T. gratilla for specific species of macroalgae negatively affect native algae populations?
Alien algae are spreading in Hawaiian waters at an alarming rate. If native Hawaiian urchins can effectively control algae growth, conservation efforts will not have to resort to more invasive and costly control methods. I hope my research will be able provide coral reef managers with additional information and choices when making conservation decisions.
Example of how my research is integrated into my GK-12 experience
OPIHI (Our Project In Hawaii’s Intertidal) is an intertidal monitoring program in its sixth year with nine teacher participants on four of the main Hawaiian islands monitoring between 15 and 20 intertidal sites each year. The students monitor the abundances of intertidal algae and invertebrates using standardized protocols. Due to the rigorous preparation of the students in monitoring techniques and species identification, OPIHI project data can be utilized by resource managers and researchers. For my own research I am particularly interested in the spread of alien algae to new intertidal sites and how abundances of these algae change over time. The intertidal is often where many invasive algae become established, and this ecosystem has often been overlooked by monitoring programs and is poorly studied in Hawaii. Because OPIHI encompasses so many intertidal sites, it is possible to look through six years of student generated data to track the establishment and subsequent change in abundance over time of invasive algae. If the invasive algae in an intertidal area is threatening to become a community dominant, scientists like myself can take action by increasing herbivory, perhaps by enhancing populations of Tripneutes gratilla to control algae growth.
Profile date: June 2007