STICKING TO THE SCIENCE ON STRIPED BASS

Just about every angler on the striper coast knows that the bass stock is troubled.

If we had any doubts, the 2018 benchmark stock assessment has confirmed that striped bass are overfished, and subject to overfishing.  Fishery managers are now deciding how to respond.

As anglers concerned with the striped bass resource, we have the right and the obligation to provide managers with our views on rebuilding the stock to abundance.  Yet, if we want to be credible and effective advocates for the resource, we need to be sure that the comments that we make are rooted in facts, and not mere perceptions.

And that means that we have to rely on the science.

That’s not always easy to do.  In our efforts to assure the health of the bass, sometimes our passions carry us away.

You can often see that on Internet message boards, where bass fishermen, many too young to have experienced the bad old days of the late 1970s and 1980s, talk about the stock collapsing again, and the need for a new moratorium on striped bass harvest.

While the good intentions behind such comments are clear, they nonetheless distort the real picture.

If you didn’t fish through the striped bass collapse, you don’t really understand how bad it was.  There were a few places where big fish were very abundant for part of the time—Block Island and the outer beach at Cape Cod come to mind—but the rest of the coast was a virtual dead sea, where just catching a bass, of any size, felt like an achievement. 

Right now, according to the benchmark assessment, overall striped bass abundance is at the 30^th percentile, measured across the entire time period for which records were kept.  That means that seventy percent of the time, there were more striped bass available.  But it also means that for part of the time, abundance was worse—at times far worse—than it is today.

Think of that, and you’ll have an idea what the collapse years really looked like.

Recruitment figures tell a similar story.  For the past 10 years, the Maryland young-of-the-year index, which has historically been the most reliable predictor of future striped bass abundance, averaged 12.01 per year, with a high of 34.58 in 2011 and a low of 0.89, the lowest in the 60-plus years of the survey, in 2012.  That 12.01 average for the last decade is actually a little above the long-term average calculated over the life of the survey.

On the other hand, for the 10 years between 1976 and 1985, which included the worst of the collapse years, the index averaged just 4.26, about one-third of the current 10-year average, with a high of 8.45 in 1978 and 1982, and a low of 1.22 in 1981. 

Perhaps more telling, over the past five years, we saw two dominant year classes in 2011 (34.58) and 2015  (24.20), one well below-average year class in 2016 (2.20) and slightly above-average year classes in 2017 (13.19) and 2018 (14.78).  

Thus, there are plenty of young fish entering the population that can rebuild the spawning stock—if managers cut landings enough to allow them to do so.

That wasn’t the case in 1985, the year that Amendment 3 to the Atlantic States Marine Fisheries Commission’s striped bass management plan was adopted.  Amendment 3 was a Hail Mary pass intended to protect the better—but still below-average, by today’s standards—1982 year class, which was seen as the striper’s last, best chance at the time.  And even Amendment 3 didn’t contemplate a complete closure of the striped bass fishery.

Thus, talking about completely shutting the fishery down in the near future is very premature, and any such talk won’t be taken seriously by fishery managers.  Before making any concrete recommendations about measures needed to rebuild the stock, we need to learn from the technical folks just what such measures might look like.

That’s why suggestions that we’re seeing now about slot limits, various combinations of bag and size limits, etc. are largely shots in the dark.  We have no idea what such measures, if put in place, would do to the population.

Slot limits are probably the best example.

Quite a few anglers are suggesting that slot limits would represent a big step forward with respect to conservation, based on the seemingly successful use of such limits in the red drum fishery, but the facts don’t support that premise. 

But when we have seen slot limits used in the striped bass fishery, the conservation impacts have always been negative.

The example that I’m most familiar with occurred in the New York commercial fishery where, in order to minimize the concentrations of polychlorinated biphenyls (PCBs) in the flesh of bass sent to market, New York once implemented a 24-inch to 36-inch commercial slot limit, as PCB levels tend to be higher in older, larger fish.  Because that slot allowed New York fishermen to take 24 to 28 inch fish, which fell below the ASMFC-mandated minimum size, New York’s commercial quota had to be reduced by more than 20% to account for the harm fishermen caused to the stock when they landed the undersized bass.

Something similar occurred in the Maine recreational fishery.  There, regulators imposed a slot limit that allowed anglers to keep striped bass that either fell into a 20 to 26 inch slot, or were no less than 40 inches long.  Again, taking the small fish was seen as harmful to the health of the stock; as a result, Maine had to cut its bag limit to only one bass, at a time when two fish at 28 inches was the standard elsewhere on the coast.

Such examples make it clear that slot limits that promote the killing of immature female bass do not benefit the population.

Whether a slot with a higher minimum size—say, something like 28 to 40 inches—designed to protect the largest, most fecund females would be good for the stock remains an open question.  Such a slot would direct a lot of fishing effort on a relatively small component of the population.  That in itself could cause problems, as the health of the striped bass spawning stock is notoriously dependent upon the occasional dominant year class that occurs amid a spate of average and below-average spawns.

The frequency of such dominant year classes is determined primarily by weather conditions, with a cold winter and wet spring typically producing more Year 0 bass than do warm, dry conditions (the worst Maryland young-of-the-year index ever recorded occurred in 2012, after an unusually warm winter that saw little spring precipitation in the Chesapeake Bay watershed).  No one has yet determined how a slot would impact such dominant year classes, and whether it would be detrimental to the health of the spawning stock.  

Until they do, and until it is clearly established that a slot would not hurt the striped bass, we should not be promoting such a measure.

We take a similar risk when we talk about any given combination of size and bag limits that are plucked from the air without scientific advice.  Because, in the end, we have no real idea of whether the measures that we’re promoting are more restrictive than needed, not restrictive enough, or just right for the striper’s recovery.

What we do know, and what the science confirms, is that the striped bass stock is overfished, and that the current striped bass management plan calls on ASMFC to rebuild it.

So right now, that should be our focus.

We should be calling on our state fishery managers, and on ASMFC, to take prompt action to rebuild the striped bass population to target levels, within the 10-year time period mandated by Amendment 6 to the management plan.

That’s what the science supports, that’s what the management plan calls for, and that’s no more than the striped bass, and striped bass fishermen, deserve.