Our April 28, 2008, blog entry described an experiment designed to see if feeding the young fry for 10 days before release increased their survival. To tell the two groups apart, Megan Hill, our lead studies biologist, experimentally marked the fed half with the chemical called “calcein.” The chemical is taken into bony parts of the small fish and shows up yellow under a special light.

Early indications were that the unfed fish survived the first couple of months just as well as the fed fry did. So we don’t think the extra trouble of feeding these small fish was beneficial.

The calcein dye for marking was also experimental and part of a much larger study of the use of this chemical to mass mark small fish. It appears the calcein mark degenerates over time, especially in sunlight. As monitoring continued, the marks were harder and harder to see in sampled fish.

This entry was posted on Friday, January 23rd, 2009 at 3:08 pm and is filed under Fish, Juvenile fish release. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.