Proper rearing of captive broodstock of spring chinook salmon requires early determination of maturity and sex, but the amount of handling now required to make those determinations can be stressful to the fish. At Eastern Oregon University, Anna Cavinato and her research group are developing a technique based on Short Wavelength Near Infrared spectroscopy (700 - 1100 nm) to make that determination without having to handle the fish extensively.
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Beginning with the spawning cycle in spring 2002, Cavinato and her team have collected the near-infrared spectra of anesthetized spring chinook salmon from the Grande Ronde Basin Captive Broodstock Program. |
| Sampling at Bonneville Fish Hatchery - May 2002 | |
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The analysis is performed under water on anesthetized fish by placing a fiber optic probe in direct contact with the skin and scales. By learning the optimal point on the fish for placing the probe and gathering data, they will develop a calibration model that will let them easily and quickly distinguish maturing from nonmaturing fish and males from females. This technique will allow early and accurate segregation of fish, reducing the number of times the fish will need to be handled and the amount and expense of feed required, among many other benefits. |
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