Skip to content
  • Print

Meet our Grant Recipients

Upgrade Lab Equipment - Biology

by Kent Linthicum '09Dr.  Stacy Luthy with the Dual-frequency IDentification SONar

Water is all around. For all forms of life on Earth, water is one of the three necessities for existence. The Calaveras River, which runs through University of the Pacific, is a source of water not only for the local flora and fauna, but also for the city of Stockton and the University, itself. Not only that, but the San Joaquin River, an even larger source of water for much of the Central Valley, flows right through Stockton, only a few miles away from the University. And within all of these bodies of water swim other bodies: tiny microscopic organisms, amphibians, reptiles, and certain mammals, as well as some birds. But perhaps the most obvious, swimming in the murky depths of the Deep Water Channel, are fish.

The rivers of Stockton are the habitats of many different fish species. These fishes provide an insight into the ecosystem that flows through our campus and the city of Stockton. But the problem is, how does one study fish through the turbid waters of these rivers? Well, there are nets, which might work. Unfortunately there are a few problems with nets: they cannot sink too low, or they catch the bottom, and they are potentially harmful to the species in the river. There are more technologically advanced methods of sonar, yet many tools lack the precision that is required to get a good sampling of the biomass in a river. Often the sound waves, because of their low frequency, only show part of a fish, which makes study difficult, if not inaccurate. Yet, there is a system that has been able to overcome many of the disadvantages of its predecessors: the hydroacoustic system.

Dr. Stacy Luthy, a professor of Biology at Pacific and an ichthyologist (one who studies fish), set out to acquire a hydroacoustic system for the study of the rivers around the Central Valley. She selected the DIDSON, or Dual-frequency IDentification SONar, for the job. What separates the Didson from other forms of sonar is its use of multiple beams and higher frequencies. Thus, instead of just getting a general reflection from a fish, the research team can get a full three-dimensional image of the fish. It is, in essence, an 'acoustic camera' for fluidic environments. The Didson hydroacoustic system, which is used by many branches of the military and the National Oceanic and Atmospheric Administration, would be one of only a few in California and the first in the Delta area. The instrument is so expensive that the Pacific Fund and Department of Biological Sciences had to collaborate in acquiring the Didson system. But the initial cost is well worth the investment. The system will provide valuable knowledge for the Central Valley and invaluable experience for Pacific students. Dr. Luthy commented, "This is going to really revolutionize what we know. We are in a unique position in the Delta. And now we are going to be able to step-up and study the water around us, understand the ecosystem and our impact on it."

The system itself has yet to arrive at the University, but there are already plans for its use. Currently, the San Joaquin River's trophic structure, or the structure of the feeding relationships in the ecosystem, is being investigated by Dr. Mark Brunell of the biology department and Dr. Gary Litton of the School of Engineering and Computer Science. Dr. Brunell is mainly focused on the microscopic organisms in the river and Dr. Litton is interested in the water itself. But that leaves quite a gap in the ecosystem studied, mainly the macroorganisms. Dr. Luthy plans on using the hydroacoustic system to fill that gap in the study. The timing could not be better, either, as, due to some legal action, a portion of the San Joaquin that is currently dry will be re-inundated in the near future. So, the sampling of the river needs to be taken before the new conditions are introduced and change the study.

But the impact of the Didson system will not be limited to the water. As Dr. Luthy pointed out, the students at the University will ultimately receive the greatest benefits from the new Didson system; it is Pacific students who will be using the system to gather information. They will have to take the new system into the Delta. There, from a boat, they will have to place the system in the water. The Didson will have to be monitored as it collects data from the water, and collecting data will mean going out in a boat for several days to explore the waterways around Stockton. When the data collection is completed, all of the images will have to be analyzed, which will take at least as much time as the data collection, if not more. At all points, students will be involved, from collection, to analysis, to presentation. Future master's students will be able to use the system to conduct their own studies, which will no doubt involve undergraduate assistants-all opportunities that would not exist without the support of the Pacific Fund.

And finally the information collected with the Didson will be used in the teaching of various classes, such as Principles of Biology, Ecology, Fishes of California, and Pacific Seminar 2. Thanks to the hydroacoustic system, Dr. Luthy and the University will have another tool with which to enhance the education of undergraduates. The system is then more than just a very accurate tool. In fact the most important impact of the Didson system will be on the education of Pacific students. So while the system will be used to uncover the secret lives of fish, it will be used by Pacific students to uncover possibilities that they would not have had otherwise.

Next: Academic travel