IS THIS THE RIGHT TIME FOR A STRIPED BASS SLOT LIMIT?

When the Atlantic States Marine Fisheries Commission’s Atlantic Striped Bass Management Board learned that the striped bass stock was both overfished and experiencing overfishing, it initiated Addendum VI to Amendment 6 to the Interstate Fishery Management Plan for Atlantic Striped Bass, which is intended to end overfishing by reducing fishing mortality by 18 percent.

It proposes a number of possible recreational measures, which can be broken down into those which would establish a fixed minimum size of either 35 or 36 inches, and those which would create a so-called “slot” limit that allows anglers to keep bass falling within a relatively narrow size range, and requires them to release all other fish that fall either below or above the designated legal “slot.”

Slot limits have long been promoted by conservation-minded anglers, who believe that there would be benefits to protecting the larger, more fecund females, and focus harvest on smaller fish.  Such anglers point to the supposed success of slot limits in southern red drum and snook fisheries, and argue that such limits would be beneficial for striped bass as well.

Maine adopted a sort of slot limit in the late 1990s, which it didn’t abandon until 2015, after Addendum IV to Amendment 6 to the Interstate Fishery Management Plan for Atlantic Striped Bass required all coastal states to reduce striped bass fishing mortality by 25 percent.  At that point Maine joined New York and the other New England states in adopting a 28-inch minimum size.  

Maine’s erstwhile slot, which allowed anglers to take one striped bass per day that measured between either 20 to 26 inches, or one measuring at least 40 inches, was anything but a conservation measure.  Because of the detrimental impact of taking immature, 20 to 26-inch fish on the striped bass stock, Maine was forced to reduce its bag limit to a single fish at a time when the ASMFC still permitted all other states to maintain a 2-fish bag limit and a 28-inch minimum size.

The slot limits proposed by Addendum VI don’t create the same problems as the former Maine slot, as none of the coastal slot limits proposed feature a minimum size of less than 28 inches (proposed Chesapeake Bay slots do, but those must be considered separately, as Chesapeake anglers have been traditionally permitted to harvest smaller, and often immature, striped bass).

It’s not clear what anglers really think about slot limits for stripers. 

The ASMFC held meetings in every state on the striper coast, and overall, slots weren’t a popular option.  In Maine, 18 comments supported fixed limits, while 9 favored slots; in New Hampshire, the vote was even more lopsided, with 13 persons favoring a fixed limit, and just 2 supporting a slot.  In Massachusetts, which has one of the largest recreational striped bass fisheries on the coast, 57 persons commented in favor of a fixed limit, and 26 in favor of slots.  

Much of the support for slots in Massachusetts came from the charter boat community, which feared that a 35- or 36-inch minimum size would make it too hard for customers to catch a legal bass, and thus be bad for business.

Moving farther south, 24 anglers in Connecticut spoke in favor of fixed size limits, while 13 favored slots.  In New York, which saw the largest turnout of any state, 17 anglers spoke in favor of a fixed 35-inch minimum size, while just 2 supported a slot.  The ASMFC’s meeting summary noted that, in New York, 

“The shore and private angler sector generally favors a 35” minimum size while the for-hire/party boat sector generally does not support a 35” minimum size.”

Slots fared somewhat better in New Jersey, with 11 persons speaking in support, although the majority—16 anglers—still preferred a fixed minimum size.  Delaware saw few anglers turn out; two spoke in favor or a fixed minimum size, none supported slots.

Only Rhode Island and Pennsylvania saw slot limits garner more support than a fixed minimum size.  The support was strongest in Rhode Island, where 17 persons spoke in favor of slots, and 4 supported a fixed minimum size.  In Pennsylvania, three anglers supported slots, and one a fixed minimum.

The debate took a different tone in southern states, with much of the focus on Chesapeake Bay.  No one commented on specific proposals at the North Carolina meeting.

Even so, the coastwide trend in angler preference is clear:  A simple 35- or 36-inch minimum size was preferred over a slot limit by a ratio of roughly 2 to 1.  Much of the support for a slot limit came from the for-hire community, which was concerned with their customers’ ability to catch and take home legal fish.

The State of New York, like a few other states, also offered an on-line survey to anglers, to give those who didn’t attend the ASMFC meetings a chance to voice their opinions.  To the surprise of many who attended the public meetings, the preliminary results of the New York survey were completely opposite the opinions expressed at the New York meetings, and of the majority of meetings throughout the Northeast and upper Mid-Atlantic:  About three-quarters of the respondents supported some sort of slot, with a 28-35-inch slot the most popular, while just one-fourth of the respondents favored a fixed minimum size limit.

It's difficult to reconcile the two very different results.

In the end, no one should have to.  When trying to end overfishing and rebuild an overfished stock, the right management measure isn’t the one that anglers prefer, or the for-hire boats want.  The right answer is the measure that the stressed fish stock needs.

And right now, there are good reasons to believe that the striped bass need something other than a slot limit.

The first suggestion comes from Addendum VI itself, which notes

“the long term conservation benefits of implementing slot limits (i.e., protecting older, larger fish) many not be realized if effort is concentrated on fish within the slot limit, thus reducing the number of fish that survive to grow out of the slot.  While the [Plan Development Team] expects fish larger than the slot limit will be protected, concentrating effort within the slot limit may reduce the number of fish that are able to grow out of the slot thus potentially reducing the population of larger, older fish over time.”

That’s a real concern, because if a slot is put in place, that portion of the for-hire fleet that emphasizes catch-and-kill, along with all shore-based and private boat anglers who are looking to take a fish home, will be spending their time targeting those few year classes of fish that fall into the narrow 7- or 8-inch wide (e.g., 28-35-inch or 32-40-inch) slots, a concentration of effort that is likely to diminish the benefits of big year classes to the spawning stock, and decimate smaller year classes before they can make a meaningful contribution to the future of the striped bass.

While some in the for-hire fleet argue that a slot will reduce release mortality by making it easier to catch and keep a legal fish without having to winnow through a host of undersized stripers, they ignore the fact that smaller fish are much easier to release alive than the large ones are, and that a slot might very possibly increase release mortality because it is the bigger bass, that experience more stress over the course of being captured, which are the most likely to die after being returned to the water.

It’s also important to note that one of the big motivations behind the for-hire sector’s support of a slot is that it better assures that they’ll be able to find bass for their customers to take home.  But assuring that customers can still take home fish is antithetical to the notion of a fishing mortality reduction.  

If we can assume that the charter boats, at least, can currently find enough bass for their customers to take home (a dubious assumption, as sometimes even the best angler gets skunked), then the management measures adopted under Addendum VI will be at least a partial failure if all for-hire customers can all still come home with a bass in their cooler.  The entire purpose of the new Addendum is to reduce mortality by at least 18 percent—which means that for the Addendum to be a success, at least 18 percent of the for-hire customers who successfully took home a bass in 2017 need to be coming home with empty coolers next season.

When thinking about slots, we also need to think about the current structure of the striped bass spawning stock. 

2003 was a very big year class in the Chesapeake Bay, which led to very strong recruitment of Age 1 fish in 2004.  Then, it was 8 years before another strong year class, with fairly strong recruitment of Age 1 fish, occurred.  

The 2003s have experienced substantial attrition over the years, and are far less abundant than they once were.  The future of the spawning stock now depends not on the survivors from the 2003 year class, but on the survival of the 2011 year class, on the big 2015 year class and, to a lesser extent, on the marginally above-average 2017 and 2018 year classes.

As the 2003s exit the population, the 2011s and 2015s, and perhaps the 2017s and 2018s, represent the future of the striped bass population.  A 28-35-inch slot limit, which allows those year classes to be depleted as soon as the majority of them are recruited into the spawning stock, will minimize those year classes’ ability to reproduce and contribute to the future of the population.

While a 35-inch minimum size will allow anglers to harvest some of the oldest and most fecund female striped bass, it will also allow all of the striped bass to mature and spawn at least once before being caught, and will give most of those fish a chance to spawn two, three or more times before being large enough to be legally retained.

When a stock is overfished, increasing recruitment becomes critically important and the best way to do that is to keep the spawning stock as large as possible.

Under such circumstances, encouraging the harvest of barely-mature fish through the use of a slot limit could be harmful to the long-term health of the stock.

For those reasons, we can hope that, when ASMFC’s Atlantic Striped Bass Management Board meets next Wednesday, it adopts a 35- por 36-inch minimum size, and eschews anything that resembles a slot limit.

That doesn’t mean that slots are necessarily bad.  Once—IF—the striped bass stock is restored to abundance, and mistakes have relatively minor consequences, managers might want to experiment with a slot, to see whether it might be better for the bass.

But now, when a further decline in abundance could put the stock in real danger, is not the time to experiment with anything.  Managers should be prudent, and adopt a time-tested approach to ending overfishing and rebuilding the stock—a 35- or 36-inch minimum size.

There will be plenty of time to experiment with slot limits once the population is rebuilt.  But right now, the cost of making a mistake would just be too high.