Sunday, October 24, 2021

MORE BAD NEWS FOR STRIPED BASS

Fishermen concerned about the future of Atlantic striped bass now have more reason to worry: On October 15, the Maryland Department of Natural Resources released the results of its 2021 juvenile abundance survey, which reported a poor striped bass spawn for the third year in a row.

 

The juvenile abundance index (JAI) for 2021 is 3.2, compared to a long-term average of 11.4. The JAIs for 2019 and 2020 were 3.4 and 2.5, respectively.

Maryland’s juvenile striped bass abundance survey measures the production of young-of-the-year striped bass by sampling 22 established locations within the Chesapeake Bay, and producing an index reflecting the number of young-of-the-year bass caught in each sample. The survey, which has been performed annually since 1954, provides the longest continuous set of striped bass recruitment data available anywhere, and is probably the best single indicator of future striped bass abundance.

 

The recent JAI values are troubling because the Atlantic States Marine Fisheries Commission’s Atlantic Striped Bass Management Board (Management Board) is obligated to rebuild the striped bass stock by 2029, but it isn’t clear that they have the building blocks—that is, enough younger striped bass—needed to do so. That was acknowledged by Massachusetts fishery manager Michael Armstrong at the May 2021 Management Board meeting when he said, “we’ve got five-year classes locked and loaded, with nothing behind 2014 [sic]. We have the 2015-year class, and 2014 was not bad out of the Hudson. That is all we’ve got to rebuild with…We have to start doing draconian things to get this stock back.”

 

Despite such need for action, the Management Board continues to move forward slowly. It is considering measures to protect the 2015 year class, but such measures will probably not be in place until 2023. In the meantime, immature bass from the 2017 and 2018 year classes are being removed from the stock in the Chesapeake Bay, while the population of fish from the 2014 and 2015 year classes is being whittled down all along the coast. Given the poor 2021 JAI, it is very possible that striped bass population in October 2021 is already smaller than it was when Mr. Armstrong made his comments in May.

To understand the current threat facing the fishery, it’s probably necessary to take a deeper look at striped bass recruitment.

The coastal migratory stock of striped bass spawns in the Hudson River, Delaware River, Chesapeake Bay, and the Albemarle and Roanoke rivers of North Carolina. However, as the 2019 striped bass stock assessment reveals, “Tributaries of Chesapeake Bay, most notably the Potomac River, and also the James, York, and most of the smaller rivers on the eastern shore of Maryland, are collectively considered the major spawning grounds of striped bass.” Thus, the Maryland JAI is a particularly important bellwether for striped bass abundance; the Atlantic States Marine Fisheries Commission’s Atlantic Striped Bass Plan Development Team has stated that “the Maryland JAI is closely correlated to the coastwide age-1 estimates from the stock assessment model.”

 

Since the turn of this century, four large year classes of striped bass have been produced in the Chesapeake Bay: 2001 (JAI=50.75), 2003 (JAI=25.75), 2011 (JAI=34.58), and 2015 (JAI=24.20). Of those four, the 2001s and 2003s, due to their age and years of harvest, now form a very small and steadily declining segment of the population. And, although the 2011 JAI was nearly 50% higher than the JAI for 2015, the number of 2015s that survived to age 1 was significantly greater.

 

Thus, the 2015 year class must be the focus of any rebuilding effort.

Over the past ten years, with the exception of 2015, striped bass recruitment in the Chesapeake Bay has been disappointing. The decade began with a 2012 JAI of 0.89, the lowest ever recorded in the history of the Maryland survey. Recent recruitment has proven so poor that the JAI’s long-term average has dropped from 11.9 in 2015 to 11.4 today.

 

Over the entire ten-year period between 2012 and 2021, the average JAI was 8.12, which is substantially below the long-term average. What is more troubling is that the average JAI for the past decade is well below the JAI average of 10.85 for the decade between 1967 and 1976, which immediately preceded the stock collapse of the late 1970s and early 1980s.

Fortunately, the patterns of the past do not dictate the striped bass’ future. Whether the stock rebuilds, languishes near current levels, or declines into collapse depends not on what happened a half-century ago, but on what happens over the next few years, both in the spawning rivers and at meetings of the Management Board.

Striped bass recruitment is heavily dependent upon environmental conditions in the spawning rivers. When a cold winter is followed by a wet spring, and spawning bass experience cool water temperatures and high freshwater flows, recruitment is usually high; warm winters followed by dry springs lead to unsuccessful spawns. During the late 1970s and early 1980s, spawning conditions were uniformly poor; between 1975 and 1988, the JAI never rose above 8.45 in any year, and averaged just 4.35.

Recent environmental conditions in the Maryland spawning rivers have also been unfavorable for striped bass recruitment, and no one can predict when favorable conditions will next occur. When the striped bass stock began its collapse fifty years ago, conditions remained unfavorable for nearly two decades; after a large year class (JAI=30.52) emerged in 1970, it took 19 years before another large year class (JAI=25.20) was produced in 1989.

Yet, while the weather remains beyond human control, it is Management Board action—or inaction—that will determine whether the striped bass spawning stock is given the protections it needs to endure until favorable spawning conditions recur, or whether it will be allowed to dwindle and perhaps collapse in the face of an extended period of low recruitment.

Prior to, and even during, the stock collapse of the 1970s and early 1980s, the striped bass fishery was effectively unregulated. No single entity had the authority to implement coastwide management measures, and the individual states seemed more concerned with maintaining a level playing field for their own fishermen than they were in rebuilding the overfished stock.

There were no commercial quotas, and few states imposed bag limits on anglers. The size limit, typically 16 inches fork length on the coast, and smaller in the Chesapeake Bay, was dictated by market demand rather than by science. Although a very few “gamefish states” prohibited the sale of striped bass, in most places, there was no significant distinction between commercial and recreational fishermen; fish could be sold by anyone, with no commercial license required. Under such circumstances, few anglers released their striped bass; fish that they didn’t intend to eat themselves were sold to local restaurants and markets.

Today, the striped bass fishery is regulated by the Management Board which, in 1984, was empowered by Congress to develop effective coastwide management measures that must be adopted by all of the states between North Carolina and Maine. The problem is no longer a lack of coastwide regulation, but a Management Board that functions reasonably well while the stock remains healthy, but has proven reluctant to act proactively in order to avert a crisis and instead waits for a crisis to occur before taking action.

 

Such crisis has now arrived.

The striped bass stock is already overfished, and appears to be entering a period of low recruitment. Four of the last six years have seen JAIs that were lower than the average JAI for the years when the stock had collapsed, and it is impossible to predict when, or even if, things will turn around.

It is possible that the Chesapeake Bay will produce a big year class in 2022; however, given that North America is heading into another La NiƱa cycle, which is expected to usher in another warmer-than-usual winter into the Mid-Atlantic region, it is far more likely that the 2022 JAI will again reflect poor spawning success.


Thus, the fate of the striped bass is in the Management Board’s hands.


It can take a precautionary stance, assume continuing low recruitment, and adopt measures to substantially reduce fishing mortality and conserve the spawning stock until environmental conditions improve. Or, it can continue on its current path, assume that recruitment will return to more typical levels and, by doing nothing, risk driving the stock into a second collapse.


Whatever it chooses to do, the decision, and any resulting credit or blame, sits squarely on the Management Board’s shoulders. Stakeholders can only hope that it proves up to its task.

 

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NOTE:  This essay first appeared in “From the Waterfront,” the blog of the Marine Fish Conservation Network, on October 18, 2021.  “From the Waterfront” can be found at http://conservefish.org/blog/

Since it appeared there, the ASMFC’s Atlantic Striped Bass Management Board met on October 20, and directed the Atlantic Striped Bass Plan Development team to develop a formal rebuilding plan that will restore the spawning stock biomass to its target level no later than 2019, and to incorporate low recruitment scenarios into such plan.  While it is not certain how the Management Board will receive such plan when it is presented to them at their next meeting, which is scheduled to occur in January 2023, at this moment, it appears that the Management Board has taken an important step toward addressing both the overfished status of the stock and the current below average recruitment.  Hopefully, the Management Board will follow up on its initial action, and take meaningful action to fully restore the striped bass population.

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