Stream Scientist

Cory Yap

What is your Job description?

I am a full time graduate student and a part time research assistant at the University of Hawai'i at Manoa. I am also a guest lecturer for classes from kindergarten-college, and a quarter time party animal.

What do you study now?

This is going to sound complex but here you have it. For my thesis research I work with Eleotris sandwicensis, which is a native Hawaiian freshwater stream fish and occurs on all Hawaiian islands that support streams. To ensure the management and preservation of this endemic fish and its habitat, we need to better understand its basic ecology. In my study, I will analyze its feeding ecology by examining several aspects of its diet. I will attempt to determine to what extent the diet is influenced by availability of prey items found in its natural environment and whether fish are actively selecting specific prey items as indicated by the non-proportional occurrence of food items in the gut to environmental abundance of food items. My initial research suggests that E. sandwicensis in Limahuli stream on the island of Kauai is selecting benthic invertebrates. I will conduct gut content analysis of fishes from a pristine stream on Kauai from November 2006 through October 2007 and I will compare the proportion of prey items in the gut to the proportion of food items available in their habitat as determined by benthic sampling. I will also address whether juveniles are feeding on the same proportion of food types as adults, and if adult males and females are feeding on the same proportion of food types. Juveniles and adult males and females may have different food requirements due to different energetic investments into reproduction and growth. I will aslo performe a comparison of stable carbon and nitrogen isotopes in the muscle tissues of fishes to determine whether the diet and trophic position of E. sandwicensis varies between the adult males and females and between adults and juveniles.

I also participate in the Hawaii Stream Bioassessment Protocol (HSBP) for a research assistantship for the Center for Conservation Research and Training (CCRT) and Hawaii Stream Research Center (HSRC). The purpose of the protocol is to assess water quality through analyses biological data (habitat conditions for native stream organisms and quantification of the abundance of native and introduced species) in streams throughout the State of Hawaii. The streams associated with diverse/robust populations of native species, or high biological integrity, are considered reference streams and produce a baseline to which other streams in Hawaii can be compared to. Streams that are at higher risk of losing its native species should be the first ones implemented towards methods of conservation and restoration to a more natural state.

Whats the best thing about your job?

I get paid to do what I love. I learn or see new things everytime I go into the field, get to travel to many of the main Hawaiian Islands, hike to areas that are often untouched or unseen by many other people, and swim in streams that are clean and have high numbers of native freshwater species.

What is the worst thing about your job?

I cannot share, through my eyes, everything that I see when I am in these remote places is amazing.

What inspired you to first study science?

Before I could even walk, my grandfather would take me to Honolulu's Waikiki Aquarium. My parents said he did this every weekend because of how interested I looked when observing the fish and slapping the glass of the large fish tanks with my hands. This fascination with fish and other marine and aquatic life at such a young age has not ebbed.

Early in grade school until intermediate school, I enrolled in summer science courses at the University of Hawaii Laboratory School. Instead of playing with my friends in "Summer Fun" programs at neighborhood recreation centers, I took classes every year in marine and aquatic science to quench my thirst to learn more about life in the water. At home I sketched pictures of what I saw on field trips and wanted to bring home the creatures that inhabited the tide pools and streams, extending my all-encompassing absorption. Studying fish became my favorite hobby.

Participating in extracurricular activities, working in a pet store, and taking classes in biology increased my interests in marine life in high school. During my freshman year at Aiea High School, under the direction of Mr. Jason Brennan, a few of my classmates and I established the Hydroponics-Aquaculture Program of Aiea, or HAPA. Students at our high school flocked to join this new club where we received a hands-on experience and participated in science-related activities surrounding the aquaculture and hydroponics facilities. The ornamental fish that were raised by the program were sold to local pet stores, including the pet store where I was employed. Working in the pet store allowed me to observe ornamental fish more closely, provoking ideas to successful breeding strategies to help the HAPA program. In conjunction with this program, I also enrolled in a directed research course in aquaculture and biology. Performing experiments to solve problems in breeding ornamental fishes, I developed a successful methodology for optimal breeding conditions of Barbus conchonius, a common tropical aquarium fish. Many members of the HAPA club also joined Paradise Pursuits, a statewide high school competition with students from over 30 public and private schools about facets of Hawai'i's environment. During my senior year, our team won the State competition. Because of my performance, the Hawaii Audubon Society, the group that sponsors the competition, awarded me a one-year full tuition scholarship to the University of Hawaii at Manoa.

What do you do in a typical day?

A typical day as a graduate student would depend on whether I am in the field or in the lab. In the field (in a field station on North Kauai), I put on my wetsuit and snorkel, get my clipboard, and head to the stream to do some underwater visual bioassessment (counting fish and other invertebrates). I would also do benthic scrubs as another means of bioassessment. After that I would probably net and anesthetize fish, then perform gastric lavage or stomach flushing (this process is non-lethal) to see what types of organisms are part of the diet. The visuals count data and the rest of the collected samples are then taken back to the lab to be quantified. The components from the fish stomachs are then compared to the components found in the environment to determine what food choices fishes are making in their environment. Are fishes selecting more common or less common foods, and if they are selecting the less common foods, why?

What advice would you give to someone interested in becoming a biologist?

There is no greater satisfaction than doing what you are passionate about. This for me is being a biologist. Challenge yourself to answer the who's, what's, where's, when's, and why's of the natural world and you will soon realize being a scientist can be very gratifying. In addition, being able to educate others to what you have learned as a scientist can give you a great sense of accomplishment. Learn something new every day and remember that no journey is too great once you find what you seek.

__________________________
Cory Yap
Graduate Student
Department of Zoology
University of Hawaii at Manoa
Honolulu, HI 96822
Email: coryy@hawaii.edu
Phone: 808.218.5301
____________________________

Can't find what you're looking for? Search The Wild Classroom: