Rockfish Futures Bright?

By Dennis Doyle

By now I’m sure you’ve heard the news. The 2012 rockfish spawn was a disaster: the lowest on record.
    Last year’s warm winter followed by unusually low rainfall and high water temperatures in the spring set the stage for a .90 Young of Year count. That number means almost no yearling rockfish survived from this year’s spawn.
    Maryland Department of Natural Resources has been quick to point out that big swings in reproductive success are normal: There’s not really much to worry about; 2011 was the fourth highest spawn. Things should even out.

    Really?
    Five of the last seven Young of Year counts, measuring the success of rockfish reproduction, have been well below the levels necessary to maintain the striper population in the Chesapeake.
    Many Bay anglers — myself included — believe we’re in the midst of a significant decline. Numbers of resident fish are lower than in many years. If this continues, the population will decline. The proof will come in the comprehensive striped bass stock assessment due next year by the Atlantic States Marine Fisheries Commission.
    One of the essential dynamics of our Chesapeake’s striped bass is that the overwhelming majority spawned here reside in the Bay only six short years. Having reached migratory size and age at that point, they leave the Chesapeake to live along the Atlantic Coast, returning briefly each spring to reproduce.
    It takes about three years for a young striper to reach 18 inches, the legal size for harvest in the Bay. The resident fish population in the Chesapeake of harvestable size this year was thus composed of rockfish spawned in the years 2007 through 2009.
    Recreational and commercial harvests take over four million pounds of striped bass from the Chesapeake every year. Infection and disease claim more. But all of those numbers pale in comparison to an entire year class migrating out of the Bay. The 2007 year class of rockfish is now beginning to leave.
    That year class was not only the largest numerically of the three but also the largest by far. The remaining harvestable resident year classes of 2008 and 2009 were all from very poor spawns. Combined, they are smaller than the single 2007 year class that is migrating to the Atlantic.
    2013 will undoubtedly continue the downward trend as the 2010 class, just reaching minimum harvestable size, is the result of yet another poor reproduction — less than half the long-term average. This class will hardly make up the difference in the numbers of departing fish. My own ballpark estimate is that the population of resident legal-length stripers in the Bay will fall by 20 to 25 percent in 2013.
    Not until 2014, when the big 2011 year-class reaches minimum size and joins the mix, will there be any increase in the catching-sized population of striped bass. That abundance may prove temporary because 2012 was such a bust.
    Supposing next year’s rockfish spawn proves yet another disappointment (and the last seven years paints a 70 percent chance of that), our resident rockfish population will, once again, be poised to resume its decline.

Twiddle Our Thumbs?
    Officials seem to be content with maintaining a wait-and-see approach, saying that there’s not much they can do about the weather, which they maintain is the single determining factor.
    I’m not so sure about that.
    At the least, I think it’s time we take a serious look at the possible effects of spawning season catch-and-release fishing as well as possibly delaying the starting date of the trophy season. Small changes in these areas could have a large impact.