SDOF Annual Science Scholarship
Presented by SeaWorld
The San Diego Oceans Foundation recognizes academic accomplishments within the community by awarding an annual $1,000 scholarship, sponsored by SeaWorld San Diego. Each year, SDOF selects a project at the Greater San Diego Science Fair that parallels our mission by combining marine science and conservation.
Congratulations to our 2009 scholarship winner:
Anisha Mudaliar, Pacific Ridge School, 10th Grade
"Eutrophication of Oligotrophic Waters by Schooling Fishes"
ABSTRACT
Photosynthesis plays a vital role in maintaining almost all of the world’s ecosystems. In the marine pelagic zone, phytoplankton are the primary producers of organic carbon, a vital energy source. However, there are vast areas of the ocean that are poor in nutrients, known as oligotrophic waters. In spite of its low productivity, schools of albacore tuna and other species are known to spawn in these oligotrophic regions, such as the North Pacific Gyre, during their trans-oceanic migration. Although depositing eggs away from coastal filter feeders is an excellent reproductive strategy, the question is the means by which the oligotrophic central gyre becomes capable of supporting tuna larvae and juvenile fish.
I hypothesize that nutrients are introduced to these oligotrophic waters (a process known as eutrophication) by schools of tuna through the excretion of ammonium, which is converted by bacteria to nitrate for phytoplankton. A requirement for this eutrophication process is that excretion is synchronous, thus creating dense patches of nutrients that are sufficient to sustain a micro-ecosystem within this vast body of unproductive waters.
To test this mechanism, the levels of ammonium concentration of a school of 200 sardines, as a surrogate for tuna, were monitored at the Stephen Birch Aquarium, where water samples were collected from the sardine tank prior to feeding and every 30 minutes post feeding. The control for this work was the inflow water entering the tank. The water samples were assayed with a Hach DR-890 Colorimeter.
My results illustrated a spike in the ammonium levels 1.5-2 hrs after each feeding, suggesting that a similar synchronous excretion of ammonium by schools of tuna possibly contributes to the enrichment of the oligotrophic waters of the North Pacific Gyre. This would enable the schooling albacore tuna to fulfill their ingenious reproductive strategy.
Past Recipients
2008 Michael Vredenburgh, Carlsbad High School2007 Conrad Wear, High Tech High School
2006 Ryan Johnson, Mt. Miguel High School
2005 Sara Nettleton, High Tech High
2004 Garen Checkley, Torrey Pines High School
2003 Marwa Kaisey, La Jolla High School
2002 Virginia Dick, Pt. Loma High School
2001 Joshua Emerick, Mt. Miguel High School
2000 Sean Rodriquez, Chula Vista High School
1999 Jessica Townsend, Mt. Miguel High School
1998 Arietta Flemming-Davis, Bonita Vista High School
1997 Erika Marambio, Mt. Miguel High School
1996 Bryn Ann Moser, Bell Junior High School
1995 Juanita Martinez, Memorial Academy
1994 Andrew Schatz, Torrey Pines High School
1993 Julieanne Grant, Torrey Pines High School
1992 Amy Ito, Morse High School
1991 Edgar Gutierrez, Chula Vista High School
1990 Allen Harker, Torrey Pines High School
1989 Sara Zedler, Hoover High School