Fish Shrinkage - Oceana USA
Home / Blog / Fish Shrinkage

January 3, 2005

Fish Shrinkage

BY: sandy

Joel Gallup, an environmental and political reporter for the Newport News-Times, has an interesting column on about a potentially revolutionary mechanism for managing fish populations in the Northwest Pacific: monitor the gonads of female black rockfish, which increase and decrease in weight with the fluctuations of El Nino.

Blanchard and his friends measured the weight of female reproductive organs — incongrously, called “gonads” in black rockfish — the species that prompted Oregon’s Labor Day sport closure. They correlated the female gonads’ weight to sea surface temperatures. The gonad weights they found in the non-El Nino year of 1996 were the same they found in 1995, when there was a mild El Nino. The mild event had no effect on gonad weight, compared to the normal winds year of 1996.

But in 1997, when a full-fledged El Nino arrived, gonad weights dropped. It was a signal that went unrecognized, but it foretold of fewer groundfish being born that year — and fewer catch fish in the near future.

What do all you Oceana scientists and fish experts think of this? Here’s the full article (which, to give credit where credit is due, I came across on Gristmill).