Sunday, July 10, 2022

RANDOM THOUGHTS ABOUT BLACK SEA BASS

 

Of all the recreational fisheries managed by the Atlantic States Marine Fisheries Commission and/or the Mid-Atlantic Fishery Management Council, few provide more challenges than black sea bass.

That’s not because the fish are scarce.  2011 produced the largest year class ever recorded, which was followed in 2015 by another smaller, but still very strong cohort.  Except for 2017, which produced the smallest cohort in many years, recruitment has remained good. 

As a result, black sea bass seem to be everywhere.  I grew up fishing the western end of Long Island Sound, when catching even a single black sea bass was a noteworthy event.  Today, in the same waters that I fished for the first 27 years of my life, they are avidly sought when the season opens in May.

The same thing is apparently happening in the Chesapeake Bay.  In Maryland, black sea bass were once thought of as a denizen of ocean reefs, but are now being caught in the upper bay, where they provide a viable alternative for anglers faced with a declining striped bass population.

Angler effort has spiked in response.  New England anglers made a little over 125,000 directed black sea bass trips in 2011; that number spiked to nearly 785,000 directed trips—a sixfold increase—by 2021.  Something similar occurred in New York, where angler effort tripled from somewhat over 100,000 directed trips in 2011 to about 320,000 last year.  (Those two areas were selected because their combined landings account for the largest share of the recreational black sea bass harvest in the northeast/mid-Atlantic region.)

Such effort routinely drove landings above the recreational harvest limit, which led to more restrictive limits which, given the undeniable abundance of black sea bass, generated more and more vehement complaints, particularly from the for-hire community.  Neither the ASMFC nor the Mid-Atlantic Council was ever able to breakthe cycle, and constrain recreational fishermen to their sector’sallocation—although, in truth, they didn’t try very hard, never creating abuffer to account for management uncertainty and, in the end, often settingrecreational harvest limits that were almost certain to be exceeded.

In the end, they effectively threw up their hands and surrendered, adopting something they called the “Harvest Control Rule,” a management approach that will allow recreational fishermen to kill more black sea bass (along with scup, summer flounder and, eventually, bluefish) than they previously might have when the fish are particularly abundant, but might constrain landings more than strictly necessary when abundance is low.

The last stock assessment update, issued last year, indicated that the spawning stock biomass at the end of 2020 was in steady decline, although it remained about double the target level.  Biologists are now preparing a new “research track” assessment that should be completed last fall, which will take a comprehensive look at the health of the black sea bass population north of Cape Hatteras, North Carolina; the results of such assessment will inform management over the next couple of years.

As part of the assessment process, a work group of scientists held a Black Sea Bass Stakeholder Engagement Meeting on May 16, to get fishermen’s perspective on issues relevant to the black sea bass fishery. 

A few themes emerged.

One was the overall abundance of black sea bass, along with observations of recent incursions into places where larger fish, or any fish at all, were not seen before.  Those places not only included the Chesapeake Bay, but also New Jersey’s back bays and estuaries.  A Rhode Island fisherman also noted that larger sea bass had become more abundant in Narragansett Bay, and that some sea bass were now remaining in Narragansett Bay throughout the winter.

There also seemed to be some concerns, or at least comments, relating to the size of the black sea bass being caught, particularly in the upper mid-Atlantic and southern New England.

The results of a study published in 2009 suggested that there are three sub-stocks of black sea bass in the New England/mid-Atlantic region that may mix on the wintering grounds, but rarely did so during the late spring/early summer spawning period.  The northern sub-stock summers between eastern Fire Island, New York and New England; most of those fish wintered off New York/New Jersey, in the vicinity of Hudson Canyon, although a few traveled as far south as North Carolina, with a concentration of fish off the DelMarVa Penninsula.

The central sub-stock summers between tidewater Virginia and Fire Island; its winter migration is shorter, tending to move south and into deeper water.  The southern sub-stock, which summers between Cape Hatteras and the Chesapeake Bay, migrates offshore into deeper water during the winter.

That stock structure seemed to color some of the stakeholder comments.

For example, one New Jersey fisherman noted that

“Large [black sea bass] appear in winter time, seeing 3-5 lb. males.”

That would make sense, as large sea bass, which summer in the structure-rich waters of New England and the East End of Long Island, move south as waters cool and spend the winter in the warmer seas off New Jersey.  Yet the presence of northern stock fish off New Jersey during the winter months creates an issue that no one has yet made a serious effort to resolve.

The ASMFC has grouped New York into the same region as New England, which is somewhat problematic. It makes some sense given that eastern Long Island does share the northern sub-stock with the New England states.  However, the remainder of coastal New York (with the possible exception of The Bronx and Westchester County, which were not included in the study of stock structure) fishes on the central sub-stock over the summer.  Thus, as a member of New York’s recreational fishing community observed,

“[New York] is the border between the northern and southern portions of the stock.  Having different size limits and bag limits is another issue since New York’s regulations require discarding more fish than New Jersey in the summer months.  This has also been an issue in winter, but less so.”

While that situation certainly creates difficulties for New York’s anglers, particularly during the summer season off western New York, when New Jersey’s earlier start and smaller size limit results in far fewer New York-legal fish remaining on the wrecks and the reefs by the time New York’s season opens on June 23, it also makes little sense for the northern fish, which are now protected by a 16-inch size limit during the summer but, once they migrate onto their wintering grounds, are vulnerable to New Jersey’s 13-inch minimum size (as well as to New Jersey’s 15-fish bag limit, which is more than twice the 6-fish bag governing New York vessels), even though boats from both states may be sharing the same wreck or piece of hard bottom.

Given that New Jersey shares New England’s fish during the winter, and that both New Jersey and western New York fish on the same central sub-stock during the summer, it would make sense to include New Jersey into the northern region, along with New York and New England, to better assure that the same fish are governed by the same rules.

Unfortunately, that approach was proposed at the February 2018 meeting of the ASMFC’s Summer Flounder, Scup, and Black Sea Bass Management Board, but was defeated after New Jersey objected and convinced the southern states to support its position.

I don’t like the idea of regulations that change through the season, because the data isn’t precise enough to provide a reasonable assurance that such shifting rules are going to serve their intended purpose.  But given that New Jersey already has sea bass regulations that see the bag limit shift six different times over the course of the season (10 fish from May 17 through June 19, then -0- for the rest of June, increasing to 2 from July 1 through August 31, going back to -0- until October 7, at which point it goes back to 10, drops back to -0- on October 27, and finally, beginning on November 1, rises to 15 for the rest of the year), it might make sense to at least increase the New Jersey size limit, beginning on November 1, to 16 inches, so that the northern sub-stock will at least enjoy a consistent size limit throughout the year.

Of course, such a suggestion probably wouldn’t seem reasonable to New Jersey.

Despite the current size of the black sea bass biomass, there are some indications that current fishing effort might be having some impact on the stock.  

As I noted in my written comments to the Stakeholder Engagement Meeting, I’ve observed a marked decline in the size of the fish that I’ve been catching on wrecks south and east of Fire Island Inlet (central sub-stock).  In 2010, fishing in early July, I had no problem catching a 15-fish limit, with perhaps one-third of those fish males in the 3 to 4 pound range.  By 2014, the bag limit had dropped to 8 fish, but I could limit out on the same, well-known wrecks in less than an hour, still with fish between 3 and 4-plus pounds in the bag, and nothing under 15 or 16 inches.  By 2016, increasing fishing pressure forced the bag limit to drop to just 3 black sea bass; fishing in the same places at the same time as before, it was now taking me a couple of hours to limit out, with most of my fish just over the increased, 15-inch minimum size.

A large population of smaller fish can still be sustainable in the long term, but the drop in the numbers of larger males can be an early sign that the stock may be more vulnerable than it was before.

Other stakeholders have noticed the same thing.  At the Stakeholder Engagement Meeting, one New Jersey fisherman expressed concern that

“Removing the large males may result in a continuous [black sea bass] sex ratio in local areas, causing females to switch to males [black sea bass are protogynous hermaphrodites, that usually, but not always, begin life as females and become male later in life] therefore reducing the number of females.”

Another New Jersey stakeholder cautioned that

“When considering stock shifts, it is usually blamed on oceanic changes, although they are relatively minor.  Need to pay more attention to fishing pressure.”

A Rhode Island angler also connected recreational fishing activity to black sea bass abundance, saying that

“There was certainly a correlation between the explosion of [black sea bass] and the closure of the wave 1 [January/February]/wave 2 [March/April] offshore recreational [black sea bass] fishery.  It has always been the assumption that those are the spawners critical to the stock.”

Despite the current black sea bass abundance, it probably wouldn’t hurt to take a longer look at recreational fishing, and consider its potential impact on the long-term health of the stock—if doing so is even still possible under the new “control rule” approach.

The other effort-related concern, particularly in recent years of high size limits, is rising discard mortality.

Multiple stakeholders noted that the critical depth for barotrauma—injury to the fish caused by changing water pressure—is about 100 feet.  In my own experience, I’ve noted that the critical depth is a little shallower, about 15 fathoms; there is a wreck that I frequently fish in 85 feet of water, where released fish rocket right back to the bottom, and another wreck in 95 feet, where about one in every four released fish floats on the surface, and requires some help to return to the depths.  Whatever the depth at which barotrauma begins, there is widespread agreement that it becomes a problem in the winter fishery, which typically takes place in 180 to 240 feet of water.  A 2019 study indicated that, at those depths, no more than 50% of released fish survive, unless they are either vented or helped to the bottom with a weighted descending device.

Despite such study, the biologists who produce the stock assessments still assume that only a 15% discard mortality rate throughout the entire year.  When asked about that assumption, the Work Group responded that

“Currently, the assessment uses only one discard rate across the entire year and area.  Mortality rates may be different at different times of year, so the assessment may be able to incorporate that.”

A Rhode Island stakeholder supported that idea, noting that the depth at which black sea bass are caught, and so the discard mortality rates, vary during the season, and told the Work Group that

“You need to include seasonal and depth-related discard mortality rates.”

So did a Massachusetts fisherman, who opined that

“In Massachusetts, the fishery from May to September is in 15-40 feet of water.  It is not appropriate to lump in discard mortality with boats that fish in 200 feet of water.”

Using depth-based discard mortality rates would undoubtedly improve the accuracy of the assessment.  However, if the assessors decide that doing so isn’t practical, it would make sense for regulators to take a page from the book of their southern colleagues, and require anyone fishing for black sea bass in depths exceeding 100 feet to keep a venting or descending device on hand, in order to reduce the impacts of barotrauma.  A federal statute informally called the “DESCEND Act” incorporated such requirement into federal fisheries law.  A similar requirement applicable to black sea bass, whether created by regulation or statute, would help reduce barotrauma in the deep-water fishery.

In the end, many of the stakeholders’ messages repeated the same common themes:  There are a lot of black sea bass out there right now.  Current management is, if anything, too conservative.  However, there are also real issues in the fishery that should be addressed.

Addressing those issues now would be a very good idea, for the best way to address a fisheries problem is to prevent it from cropping up in the first place.

 

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