Sunday, October 21, 2012

Chesapeake Striped Bass Reproduction At Record Low

From CBS Baltimore:  Chesapeake Striped Bass Reproduction At Record Low

striped bass 
 
BALTIMORE (WJZ)– A record low number of young striped bass were counted this summer in the Chesapeake Bay.

Alex DeMetrick reports it’s the smallest number of newly-spawned fish in nearly 60 years.
Every summer for 59 years, state biologists string nets in rivers feeding the Chesapeake to catch and count that year’s spawn of striped bass. In the latest survey:

“2012 is a below average year for striped bass reproduction,” Eric Durell of Department of Natural Resources Fisheries Service, said.

The average has a numerical value of 12. But this year it was less than one– a record low. That follows a record high of 35 last year.

So what’s happening? It’s the water.

Striped bass spawn in the bay’s fresh water tributaries. This spring and summer, hydrologists who monitor stream flow found a number of Maryland waterways with extremely low levels.

“It’s not only dry. It’s been excessively hot,” Wendy McPherson, a hydrologist with the United States Geological Service (USGS), said. “There’s been several temperature-setting records.”

Those are the perfect conditions to kill off striped bass long before they get to adult size. But there are numbers that balance out the decline, starting with the 20 years striped bass live.

“Fortunately, striped bass are long-lived repeat spawners,” Durell said. “So the impact of one poor year is not as dramatic as would otherwise be if they spawned once and died.”
And in this year’s spring survey of adult striped bass, biologists found a healthy number of reproductive fish whose offspring will hopefully have a better chance at survival next year.
Because the Chesapeake is the East Coast spawning ground for striped bass, federal regulators keep close track of the surveys. It takes three consecutive years of below-average numbers to trigger stricter conservation rules.

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