Monday, March 1, 2010

Spring Break: Continental Shelf - Day 7 - The Dogfish Have Landed

Not a whole lot to update on today, except that spiny dogfish have started showing up in numbers in the trawls.  This is a good sign, as it seems the general trend is that they're getting more abundant as we travel south (we're currently working our way down past Delaware Bay).

 
Overexposed dogfish.

The interesting thing about the dogfish we've been catching is that so far they've all been nearly fully-grown females.  This goes against what the literature has lead me to expect, since most of the conventional wisdom on dogfish is that the large females are close to shore and the males are offshore where the Bigelow would catch them.  Instead I've seen mostly large, mature females, and these have been more abundant in the offshore samples.  This may have to do with the low water temperature in the New Jersey/Delaware stations, and goes a long way to explain the prevalence of skates in the trawls.  It'll be interesting to see how this breaks down once we get off of North Carolina.

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