Thursday, October 15, 2015
SOME FAIRLY GOOD NEWS ON STRIPED BASS
There’s encouraging news coming out of Maryland.
The state’s Department of Natural Resources recently announced that this year’s striped bass spawn was very successful. The young-of-the-year index for 2015, which will become part of a data set that extends back, unbroken, nearly 60 years, was 24.2, twice the long-term average of 11.9 and the eighth-highest estimate in the entire time series.
For many of us, who have followed the striper’s trials and tribulations over decades of time, the news was less of a surprise than a relief. Last winter was cold, only slowly transitioning into a cool and wet spring. Those are precisely the conditions that normally result in better-than-average spawning success.
However, the previous winter was also cold, if just a little drier, and the index came in at just 11.02, which Maryland managers called a “nearly” average figure that still represented “a healthy level of reproduction.”
Thus, when this year’s above-average spawn was announced, it reassured us all that the world was, in fact, still working as it should.
Yet to properly understand the 2015 young-of-the-year figure, it must be put into context. It was twice the long-term average, but exactly what does that mean?
If one looks at the entire time series, it quickly becomes obvious that most striped bass spawns are below average; of the 59 years covered by the Maryland survey, only 19—roughly one-third—produced young-of-the-year figures above the long-term average, although a few more came pretty close.
Thus, it’s pretty clear that striped bass abundance, as opposed to mere striped bass survival, is driven by the above-average year classes. With that in mind, where does the 2015 year class fit in?
While it was a very good year class, it is nowhere near as large as some of the dominant year classes that were produced in the recent past. It is far smaller than the 1996 year class which, at 59.39, was the largest ever recorded. It is also only half the size of the 2001 year class, which returned an index of 50.75.
The 2015 year class was the second-largest year class of the past decade; over the course of those ten years, only three year classes could be called above-average, 2011 (34.58), 2015 (24.20) and 2007 (13.39). The other seven were all below the long-term average, and included the lowest young-of-the-year index ever recorded, a dismal 0.89 in 2012.
The 2015s should improve the prospects for striped bass anglers, beginning in 2021 or 2022 (except in Chesapeake Bay, where both recreational and commercial fishermen primarily target young males and immature females; there, the impact of the 2015 year class will start to be felt around 2018).
However, anglers shouldn’t expect a return to the kind of fishing that we knew in the early years of this 21st Century. In the ten years between 1992 and 2001, there were five above-average year classes, and the three largest of those, 1996 (59.39), 2001 (50.75) and 1993 (39.76), dwarfed the biggest year classes of the past decade. In fact, the average of the young-of-the-year indices for those ten years was 23.69, nearly as high as the “robust” 2105 figure (the average for the past ten years is a somewhat sub-par 11.07).
So the 2015 spawn is going to make things better, but it can only improve things so much…
Even so, we shouldn’t be surprised to if some members of the Atlantic States Marine Commission’s Striped Bass Management Board point to the 2015 numbers as proof that the stock is completely healthy and that last year’s harvest reductions weren’t really needed.
In particular, I expect the same Commissioner who argued that
“It seems I’ve been here over the years doing the same thing. We have been looking at some figures for a period of time and then decided we’re going to do a drastic cut. Two years later they’re finding out that we didn’t need the drastic cuts and had to change the regulations in New Jersey again”
to begin claiming that he was right and that the entire conservation effort was unjustified.
Of course, nothing can be farther from the truth.
We should never forget the current state of the stock.
Although no recent assessment update has been performed (a report on the state of the stock as of the close of 2014 will probably be presented at next month’s Striped Bass Management Board meeting), the 2013 Update of the Striped Bass Stock Assessment Using Final 2012 Data predicted that the female spawning stock biomass would probably fall below the "overfished" threshold this year.
Thus, the large 2015 year class won’t appear as a spike in an already healthy population; instead, it will merely serve to fill some of the hole in the stock that fishermen, with the consent of ASMFC, have dug in recent years.
We should also remember that the 2015 year class, as large as it is, is still substantially smaller than the 1970 year class which, at 30.52, was the last big year class before the stock began its historic collapse just a few years later.
So as good as the news this week was, we can’t let it seduce us. There was a good spawn in 2015, but that doesn’t mean that we can relax our vigilance and increase the kill.
Instead, we must stay the course, and keep fishing mortality under the target while giving the spawning stock time to produce additional above-average year classes, and eventually climb back to its biomass target.
There will be good news and bad news, progress and setbacks. But provided that managers keep their eye on the ball and don’t get distracted, we can have better striped bass fishing not just in a few years, but for the foreseeable future as well.