Bob Allen

STRIPED BASS RECOVERY — AN ECOLOGICAL Dead End? (An Essay)

Some rather broad generalizations are developing related to the relationship of industrial harvesting of Menhaden and the ecology of the Chesapeake Bay.

The elusive term “ Localized Depletion” which was coined several years ago to describe the industrial harvest effects on the ecology of the upper Bay is now considered a poor label.

Many have accepted that label , but in attempting to prove or disprove that “localized depletion” is having any effect on the ecology of the Bay has been impossible because no one has been able to define “localized depletion”. A new term is evolving : “Ecological depletion”

Much time and money has been spent to investigate the claim of localized depletion of Menhaden in the upper Bay; researchers are coming up empty handed. Proving Localized depletion is like trying to catch a cloud and put it in a bottle...an impossibility.

It has been heralded that the decision to place a total moratorium on the harvest of striped bass and the subsequent recovery of the striped bass stocks have been a rousing success by the fishery managers.

An argument is surfacing that describes a very different picture: describing the striped bass recovery as an ecological disaster.

As the striped bass biomass expanded rapidly during the total moratorium, ASMFC declared that Striped Bass was a recovered species. I have often stated that the “ASMFC knows how to manage a recovery, but once recovered, ASMFC had not a clue as how to manage a recovered species”. That is proving to be true.

Striped Bass were part of a management plan which involved a separate management plan for each species. Scientists are now recognizing that fishery management must involve many different species….a complication only recently recognized. A management plan (multi-species mangement) ,almost as difficult as attempting to define the concept of “localized depletion”.

As the striped bass moratorium achieved the goal of a strong spawning population of striped Bass , restrictions were relaxed slightly and the fishing for Striped Bass was the best ever.!

Managers have been careful to control the harvest of Striped Bass for the last 15 years, but antidotal evidence indicates that the fishing for them has measurably deteriorated.

There were several warning signs that did not gain a lot of attention when first appeared: Recreational anglers reported that the first fall run of small stripers was unusually skinny ...of poor quality. Were these fish starving? Later in the fall run, the quality of fish improved and seemed normal…..were these healthier-looking migrating fish from New England? The starving fish were forgotten once the high quality fish appeared.

Then a disease appeared: Phisteria? Difficult to nail down, as the disease had never before been reported in striped bass.

Ground breaking research revealed that starving or stressed fish often developed Phisteria lesions.

A few years later, researchers , found another killer in the Striped Bass population: Mycobacteriosis, a tubercular related bacteria? The fish appeared normal on the exterior, but the internal organs were fatally infected.

Within a short time recreational anglers were reporting that the rockfish bounty that was available seemed to be less and less abundant each year. The comments were heard: “ this past year was the worst year for fishing for striped bass”….followed by a repeated statement the next and the next...fishing for striped bass has deteriorated greatly since the moratorium has been lifted?

Finger pointing began—–The lack of forage must be the cause? The industrial harvest of Menhaden must be the cause? When one looks at the picture from a distance, that accusation may not be true...Menhaden purse nets may be a part of the problem, but there is something more complex going on.

There are too many striped bass for the amount of forage in the Bay. Fish managers have only been looking at the spawning success of Stripers. As stripers recovered, the numbers of menhaden have been declining all up and down the Atlantic(contrary to statements that there were plenty of Atlantic Menhaden) . Menhaden spawn somewhere in the ocean...their young migrate into the Chesapeake Bay ..The Bay is a Menhaden nursery.

Recent reports indicate the Bay is full of Menhaden...but different sizes come into the Bay at different times of the year. Small rockfish rely on small (1-yr or under) Menhaden as forage. If there are too many Rockfish for the Menhaden forage base, Rockfish starve and become diseased.

If there is insufficient small forage (menhaden/under 10 inches in length) for the huge numbers of baby Rockfish being born, then the Rockfish feed on anything else there is: particularly Bay Anchovies. With a depletion of Bay Anchovies, small gray trout (weakfish) have nothing to feed on inside the Bay. Without Anchovies, Terns disappear. Small Bluefish and Spanish Mackerel also depend very small anchovies to survive inside the Bay. The interaction and interdependence of one specie on another has not been considered and anglers in Virginia are now to pay the piper.

There are few large menhaden now entering the Bay because the Atlantic Ocean has suffered a long and precipitous and unreported menhaden population decline over 30 years. Large rockfish need large menhaden to survive...There are too many large Rockfish for the forage base inside the Bay. Gannets follow the schools of large rockfish feeding on the large menhaden; annually we observe fewer and fewer Gannets...a sure-fire indicator that there are less large menhaden around.

The conclusion , you may not like: Localized Depletion may not be a great factor in the fishery problem here in Chesapeake Bay! Ecological Depletion can be defined and may be the complicated problem.

Up to now, everything we fish for seemed to be in trouble , with the exception of Rockfish….now there is growing evidence that Rockfish also are in trouble. Rockfish are a big part of the ecology of the Bay . The entire Bay ecology must be considered when discussing each population.





Bob Allen,

PSWSFA & VCAC

Hampton Va