Episode 33
Copyright © John Page Williams, Jr. all rights reserved.
This is John Page Williams with another reading from Chesapeake Almanac. The month is November and this chapter is entitled "Menhaden Migrations."
As noted in the October sketch, "Harvesttime," most of the Chesapeake summer population of menhaden are headed out to their wintering grounds. Juveniles no longer dimple the surface of shallow flats in the creeks. Anglers' depth-sounders no longer show great blobs on the screens as they go over 10-foot-deep schools. Pound net fishermen down the Bay catch fewer of them to freeze for next year's crab bait. And the Reedville purse seine fleet finds itself working farther down the Bay and more often outside in the Atlantic. Today, sometime in November, the fish boat crews call it a season and go home for deer season on the Northern Neck. But years ago a few boats would head south to Beaufort, North Carolina, where there was a processing facility for menhaden and they'd fish into December.
Sometimes these crews made good money in this fall fishery. The menhaden were there in tremendous numbers. But the vagaries of weather affected the fishes' migrations. An early, cold winter like that of 1977 could shut the fishery down prematurely. Gales could keep the boats tied up for days on end, even when the fish were there. Despite these handicaps, the fishermen generally enjoyed those trips.
When the profits are there, watermen can do quite a bit of effective field work for the scientific community. Years of intensive fishing effort have given the menhaden industry a good overall picture of the fishes' movements. The first menhaden down the coast in the fall are the ones moving out of the open waters of the Chesapeake. They tend to be two- to three-year-old fish measuring eight to ten inches. After them come larger, older fish from Delaware Bay, New Jersey, New York, and New England.
There is a limit, however, to the amount of information that can be gotten from the fishery itself. More precise data are needed for managing it. A smart scientist listens to fish boat captains, and to crewmen, and to spotter planes, too. And smart fishermen listen to scientists. Together they can get a lot of work done.
Following adult fish in their travels is usually done by tagging. This most easily yields results with species like rockfish that are caught by anglers on hook and line or handled individually by watermen. But menhaden come aboard by the tens of thousands, drawn from the net through a hose by a pump. A menhaden tagging study would require an ingenious tagging and recovery system and a large sample of tagged fish to ensure a statistically useful number of returns.
Several researchers worked out in the 1980s a way to inject numbered, stainless steel tags into the menhadens' body cavities with tagging guns. The fish they then released. Tagged fish that the purse seiners caught are cooked and pressed for oil right along with the rest of the catch. Magnets, placed at various points in the processing plants, picked up the tags out of the resulting loose scrap as it is processed into fish meal. William R. Nicholson and his associates of the National Marine Fisheries Service Laboratory at Beaufort worked with the commercial purse-seiners to tag over a million adult and juvenile menhaden from Florida to New York in the late 1960s and early 70s. He published his results in the September 1978 issue of Estuaries, the Journal of the Estuarine Research Federation.
Mortality from this tagging system is apparently variable and sometimes large; still, Nicholson got over 10 percent return on his tags and a clear picture of the migrations emerged. Fish tagged in a specific area were never caught south of that area, except in the fall fishery in Beaufort. The longer the period between tagging and recapture, the further north the tags were recovered. Thus, fish tagged in the Chesapeake turned up in processing plants as far north as Gloucester, Massachusetts, and Portland, Maine, as many as six years after tagging; but slightly over 20 percent of the recoveries came from plants at Beaufort during the fall. (We should add that this story was written some time ago and that there are no more fish factories, no more processing plants, anywhere except Reedville, for processing menhaden in what's called the reduction fishery to produce menhaden oil and fish meal.) This basic pattern of northward migration by older fish holds for the menhaden tagged in the other areas as well.
Menhaden spawn primarily along the coast over the continental shelf. Greatest activity appears to be in winter, south of Cape Hatteras, but some spawning occurs throughout the year as far north as New England. The juveniles, of varying sizes depending on when they hatch, move into the estuaries for their first summer. The estuaries are thus critical to the species' life cycle. The Chesapeake is probably the most valuable of these nurseries, but that statement will come as no surprise to anyone who spent time in the Bay's tidal creeks in the summers over the last 40 years.
While the juvenile fish move into rivers and creeks, most adults stay in the main stems of the estuaries or migrate up the coast, with the oldest, largest fish moving furthest north in the summer. Then, as temperatures drop, they head back down the coast in waves. In the early winter, off the Cape Lookout–Cape Fear area in North Carolina, they disappear. Nobody knows exactly where they go, which probably means they disperse into deeper water. In the late winter and early spring, they return to the surface of inshore waters, school up in groups of like age and size, and head back up the coast.
Patterns of fish migrations are fascinating and useful, but there are always exceptions without explanations. It's not unheard of for an angler on the Severn River above Annapolis to catch a nice pickerel in December and find a fresh five-inch menhaden in its belly. Some years, large schools stay up one or another of the Bay's rivers all winter. The reasons are known only to the fish. Perhaps they do it just to keep good fishermen and scientists humble.
For more happenings around the Bay in November see our other Chesapeake Almanac podcasts and read our blog post "From Fall Colors to Dead Leaves."
