ASMFC TEAM DEVELOPS SOLID PROPOSALS FOR PROTECTING THE 2015 YEAR CLASS OF STRIPED BASS

 The Atlantic States Marine Fisheries Commission’s Atlantic Striped Bass Plan Development Team continues to work on a draft Amendment 7 to the Interstate Fishery Management Plan for Atlantic Striped Bass, which will be presented to the Atlantic Striped Bass Management Board when it meets in October.  I sat in on Plan Development Team meetings held on August 31 and September 2, and was pleased with much of what I heard.

The PDT is working hard to come up with measures that will not only protect whatever remains of the big 2015 year class, but also the 2017 and 2018 year classes which, while not as large as the 2015, could make a real contribution to rebuilding the stock if given adequate protection.

Thus, the beginning of the August 31 meeting was everything that one would hope to see at a fishery management meeting—a group of fishery managers sifting through alternatives meant to conserve the striped bass, using the best available science to choose a range of alternatives most likely to protect the 2015, 2017, and 2018 year classes, which alternatives will be included in the draft Amendment 7.

A few of the alternatives are familkiar, as we saw them in Addendums IV and VI.  A couple are new.  Some may have unintended consequences that should bar them from serious consideration.  But all are being analyzed in the context of how much protection they will give the three important year classes. 

The PDT presented the current 28- to 35-inch slot as a baseline.  In 2023, the first year that any new size limit would probably go into effect (although the Management Board could change the size limit for 2022, with the understanding that the new limit wouldn’t go into effect until the middle of the season in a number of states), the existing slot limit would protect only about 33% of the 2015s, 69% of the 2017s, and 90% of the 2018s.  In future years, as the 2015s grew larger, a greater percentage would be protected by the upper end of the slot, but at the same time, more and more of the 2017s and 2018s would be growing larger than 28 inches, and so would be vulnerable to harvest.

Thus, it is clear why other alternative management measures are needed.

The options that received the greatest consideration at the August 31 meeting included a 35-inch minimum size, a 32- to 40-inch slot, and a 20- to 27-inch slot.  Each option would have a different impact on the stock.

The 35-inch minimum size, which received the strongest support from anglers during the Addendum VI comment period (comments in favor of the 35-inch minimum equalled about 250% of comments made in favor of all other options, combined), would protect about 83% of the 2015s, 99% of the 2017s, and 100% of the 2018s if it became effective in 2023.  Protection of the 2015s would decrease in future years, as would protection of the other two year classes, as the fish grew larger than the minimum size.  The impacts of a 36-inch minimum size were also calculated; in 2023, it would give marginally better protection to the 2015s (89%), but would otherwise have the same practical effect as the 35-inch minimum.

The 32- to 40-inch slot would, in 2023, only protect about 56% of the 2015s, although that percentage would increase as the fish grew larger; it would have the opposite effect on the 2017s and 2018s, protecting 95% and nearly 100%, respectively, in 2023, with those percentages declining as the fish began to exceed 32 inches in length.

The 20- to 27-inch slot was selected as an alternate approach that would protect the 2015s with a slot smaller than the one currently in effect.  In 2023, it would protect nearly 90% of the 2015s, but only 46% of the 2017s and just 26% of the 2018s, with the protection for all three year classes increasing as their lengths increased--although for the 2018s, escaping the top end of the slot would take a while.

One thing that wasn’t considered in the case of the 20- to 27-inch slot was its impact on effort.

Anglers who regularly target striped bass generally fish for sport; they may take a fish or two home every season, but for the past 35 years or so, they have released about 90% of their catch every season.  Reducing the slot size to 20 to 27 inches probably wouldn’t impact those fishermen at all.  But there is another group of anglers who do fish for meat, and tend to target whatever sort of fish that they can catch that they can also take home.  

If the 20- to 27-inch slot was put in place for 2023, there would be times and places, particularly in the New York Bight and Long Island Sound, given the big 2020 year class produced in the Hudson River, where it would probably be easier to catch a 20-inch striped bass than a 19-inch summer flounder or even a 15-inch black sea bass, particularly for anglers fishing from shore.  Such situation would lead to a significant effort shift away from traditional saltwater panfish and toward the immature bass, with resultant harm to the striped bass population.

Fortunately, the 20- to 27-inch slot no longer appears to be on the table.  At the PDT meeting held this morning (September 2), the Plan Development Team seemed to be in general agreement that dropping the lower end of the slot below 28 inches was not a good a bad idea. 

Although there was some sentiment in favor of including a smaller option—23 to 28 inches was specifically mentioned—in order to illustrate that increasing the minimum size wasn’t the only way to protect the 2015s, the suggestion didn’t have strong support, for a number of reasons.

Some believed that, because the minimum size for striped bass had been 28 inches for so many years, a smaller slot would represent too radical a change, although one PDT member noted that the 23- to 28-inch slot would be a viable option if the Management Board was willing to institute “a regime shift” in the coastal striped bass fishery.

One PDT member noted that because no slots smaller than 28 to 35 inches were analyzed in Addendum VI to Amendment 6 to the Atlantic Striped Bass Interstate Fishery Management Plan, no one was sure whether the 20- to 27-inch or 23- to 28-inch slots would achieve the 18% reduction in fishing mortality contemplated by Addendum VI.  

Another noted that while the currently contemplated measures were designed to protect the 2015 year class, and perhaps the 2017 and 2018 year classes as well, there is always the possibility that another strong year class could appear; if that happened, a 20- to 27-inch slot might not give the ASMFC enough time to put measures in place to protect such year class before it grew into the slot.

While it looks like the smaller slot limits will probably not be a part of the draft Amendment 7, it is very possible that a narrower, 28- to 32-inch slot limit might be.  Such a limit would help to protect the 2015s, which by 2023 would be approaching the upper end of the current slot; calculations suggest that in that year, the narrower slot would protect 61% of that year class, with a larger percentage protected in later years.

A 28- to 32-inch slot would also open the door to a sort of reverse-Amendment 3 management strategy.  Adopted in 1985, Amendment 3 to the Interstate Fishery Management Plan for Atlantic Striped Bass was intended to rebuild the then-collapsed stock by protecting the reasonably healthy 1982 year class, and all subsequent year classes, with a minimuAm size that increased incrementally each year, in order to protect at least 95% of such year class’ females from harvest.

A 28- to 32-inch slot limit could be adjusted in a similar way, with its upper limit increased incrementally as the 2015 year class increased in size, until the current 28- to 35-inch slot was restored, while still protecting the 2015s.

Of course, that wouldn’t do much to help the 2017s and 2018s, which would be well-protected in 2023, with 73% and 91%, respectively, smaller than the 28-inch minimum.  However, that protection would wane as the fish grew larger.  Perhaps—although the Plan Development Team didn’t discuss this—the right thing to do would be to incrementally increase the lower end of the slot as well, to protect the growing 2017s and 2018s at the same time that an increasing upper end of the slot trailed the 2015s’ growth.

The 28- to 32-inch slot would convey an additional benefit, reducing striped bass landings below the current level, and so lead to a more conservative management regime.  The one concern some PDT members had was that the narrower slot would also result in an increase in recreational release mortality, and thus erase some or all of the gains achieved by the slot limit.

The impacts of the narrower slot will be calculated in the upcoming weeks. 

One can only hope that, once the analysis is completed, the Plan Development Team will focus on such slot’s impact on overall mortality, and not merely on the number of fish that die after release.  For in the end, recreational release mortality is a red herring, that misdirects people’s attention from more important things.  

It is overall fishing mortality that matters.  

Exchanging a little more release mortality for significantly less overall fishing morality is always a worthwhile trade, particularly when, by doing so, one can also protect a cohort that is important to the future of the stock.

It would be extremely unfortunate if fear of additional release mortality got in the way of such important protections.

Some of the proposals for the other issues being considered by the PDT—release mortality, conservation equivalency and, most of all, the management triggers—remain problematic.  But the Plan Development Team has done some very good work designing options to protect the few strong year classes that represent the future of the striped bass stock.

They deserve our thanks for doing so.