SunSpecial: Fish Fry   Leave a comment

In an extraordinary decision, the California Department of Fish and Wildlife have released all fish from two up-river hatcheries because of the unusual low water levels of neighboring streams and rivers, and the rising temperature of water that’s still flowing. The young fish – called ‘fry’ or ‘fingerlings’ or ‘juveniles’ – are normally kept in hatcheries through the fall and winter, only released into the river system when they are old enough to care for themselves; but this year, in order to save as many fish as possible, officials have taken the never-before step of, literally, opening the flood gates and setting loose over 430,000 fingerling Steelhead Trout (Oncorhynchus mykiss); Rainbow Trout (Oncorhynchus mykiss) and Chinook Salmon (Oncorhynchus tshawytscha).

The fish, which require water temperatures no more than 63 degrees, will hopefully seek out deeper and cooler lakes and reservoirs on their way to the ocean – but even so, the fish may be too young to follow their ‘swim to the ocean’ instinct and scientists are monitoring the fish populations to better understand how these little fish will respond to life in an even-more-harsh-than-normal environment, and this research could help in future release schedules and planning. What is certain, with all of these snack-size fish set free in ever-more shallow water, could lead to a feast for raccoons and hawks and eagles and bears and most any other animal that isn’t about to let a fish lunch swim by.

In past times of low-waters or rising temperature, hatchery officials have requested fresh, cool water be released from nearby lakes. But with the severe, almost unimaginable drought in California and through most of the Western US, there’s not enough water in many lakes to even reach spillway level, the parts of a dam that are designed to allow water to pass. And the water that is in the lakes is too shallow and warm – in some places estimated to reach 78 degrees or warmer – to do the fish any good.

While it’s expected the fish in most of California’s hatcheries should be fine and can remain in their nurseries though the summer, it’s ironic that this mass release comes only a year after one of the most successful fish count-and-release seasons on record. In the 2013 season (fish grown large enough for normal release through the autumn and winter of 2013 – 2014), more Trout and Salmon passed through fish-counting stations, on their way to the ocean, than any previous season.

With fall and winter rain and snow the hatcheries will be able to re-stock and help grow another generation of Trout and Salmon that will help maintain a healthy ecology and provide recreation and income for fishermen and business owners that rely on a balanced environment. But if the expected (and hoped for!) precipitation doesn’t come, in a worst-case situation we could be seeing fewer fish fry – and more fried fish.

Folsom Lake, California, March 2011 on the left – on the right, January 2014

Folsom Lake, California, March 2011 on the left – on the right, January 2014

 

Posted June 29, 2014 by ECOVIA eco-adventure® in SciSun

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