THE MOST IMPORTANT FISH IN THE SEA, by H. Bruce Franklin. Island Press / Shearwater Books, Washington, 2007, 266 pages.

Eleven years ago, a group of Island fishermen went to Sandwich to attend a public hearing on the management of striped bass. We all sat in an overcrowded auditorium and listened. One commercial lobsterman stood before the regulators and complained too many striped bass were eating his lobsters and ruining his fishery.

At the time we all thought the opinion preposterous. How could a lobsterman complain about the recovery of striped bass? Striped bass eat fish. They usually aren’t inclined to eat the fearsome lobster.

The issue of starving striped bass being driven to eat lobsters didn’t go away. What fish in the ocean could go hungry? Isn’t there enough bait to sustain the recovery of all troubled fish stocks?

But in the last decade, more and more fishermen have expressed concerns that there may not be enough bait swimming in these waters as before. Alewives seem to have disappeared. The spring run of squid and mackerel are in lower numbers than anyone can remember. Where is the bait?

There is a new book out that should be required reading for any fisherman who is concerned about the future of either his industry or his sport. The Most Important Fish in the Sea isn’t about the fish we all love to eat. The book is about menhaden, a fish that has undergone two centuries of intensive fishing and for more than a century overfishing.

Menhaden are the poster child for all that may be wrong with the waters from Maine to Florida. They are an essential ingredient in the ecosystem. The author of the book writes that menhaden are the most important fish in North America for two significant reasons: they are forage fish for every species of edible fish that swims in the sea. And they are an essential part of the ecosystem, a key ingredient to restoring water quality to coastal ponds and waterways, not to mention the ocean.

Menhaden eat plankton and tiny microscopic plants. Like oysters and shellfish they are filter feeders, a necessary prescription for saving the water quality in saltwater ponds.

So much has been written over the years about protecting estuaries from nutrient loading. One adult menhaden filters four gallons of water in one minute, according to the author. The author explains: “Even more important, the menhaden’s filter feeding prevents or limits devastating algal blooms. Most of the phytoplankton consumed by menhaden consists of algae. Excess nitrogen can make algae grow out of control and that is what happens when overwhelming quantities of nitrogen flood into our inshore waters from runoff fed by paved surfaces, roofs, detergent-laden wastewater, over-fertilized golf courses and suburban lawns, and industrial poultry and pig farms.”

What is so striking about this book is the fact that a lot of the new information is really old information. I didn’t know for instance that these waters were filled with menhaden for as far as the eye could see. In my lifetime, I remember seeing menhaden swimming in large schools in Vineyard waters. As a child, I could put my dinghy in the middle of Edgartown harbor and watch a large school of menhaden rolling underneath. Hundreds of nicely packed fish were swimming in a tight area. In the past 20 years I’ve seen that these fish are in sharp decline.

Mr. Franklin tells us that menhaden were everywhere along the inner coastal waterways. Their schools were measured in acres, not in square feet. The menhaden story goes back to colonial times. Pilgrims were taught how to plant corn by Native American Indians and they were easy to snag.

Harvested menhaden and alewives were used for fertilizer, we all knew that. Since colonial times schools of menhaden filled the openings of rivers and streams entering the ocean all the way up in Maine and attracted all kinds of bigger fish. The author reports that through intensive directed fishery, menhaden abundance are today a skeleton of what they were.

“The theory that the population of menhaden might be cyclical was originally advanced in 1879 to explain the sudden disappearance of the fish from Maine as a natural phenomenon,” Mr. Franklin writes. More than a century later, menhaden, by any significant number, have yet to return to Maine. The fishery has collapsed in New Hampshire, Massachusetts, Rhode Island and farther south. Mr. Franklin writes about a huge factory operating in Narragansett Bay that has long gone. Coincidentally, menhaden got its name from the Narragansett Indian.

While there has been much written about man’s overfishing of whales worldwide for oil, there is very little written about man’s aggressive effort to harvest menhaden from coastal waters. It is not an attractive topic. Yet, according to the author, menhaden, by weight, was the most landed fish on the East Coast.

The author reports with detail that there were processing factories from Maine to Virginia in the late 1800s that did nothing more than convert harvest menhaden into fertilizer and agriculture feed and oil. The industry was profitable and the resource at the time limitless.

The population of menhaden in those times was colossal. Menhaden were everywhere and there were plenty of fish to feed on them.

When the fish disappeared, so did the factories. As the populations collapsed, state fisheries managers imposed prohibitions on the fishing boats that targeted the menhaden, but usually it came after the horse had already left the barn. Menhaden fishing boats are still prohibited from fishing in all the state waters except Virginia but they continue to fish unrestricted in federal waters.

“Overfishing was not the only human activity menacing menhaden, as well as almost every other marine species that had once thronged America’s north Atlantic coast. The area was already an ecological nightmare by the beginning of the twentieth century. Factories were spewing pollutants into the rivers, dams blocked fish from spawning, the great harbors were awash in sewage.”

Of course the restoration of coastal waterways in the last few decades have brought about a reversal of the trend of polluting waterways. Yet, the author contends that overfishing of what remains of menhaden in the Atlantic is the biggest crime.

He describes factory fishing vessels, aided by airplanes scoping huge areas, that go out and with purse nets the size of football fields, encircle schools of fish. Unlike many species of fish, menhaden in the Chesapeake and in the Gulf of Mexico are still being overfished.

He contends that menhaden could perform a critical part in the restoration of waterways and the restoration of other species of fish if the overfishing were stopped.

“Never, in the entire history of the reduction industry on either coast, has it provided any products that we could not get from other sources,” he wrote.

Martha’s Vineyard, Nantucket and the Cape are a destination for anglers. Fishermen, whether they are commercial or recreational, come here to fish. And the reason they fish here is simple. These waters are the most productive fishing grounds along the East Coast.

From the perspective of bluefish, striped bass, and for that matter cod, mackerel and the flounders, these fish come here for their own reason.

Fish come here not to vacation or for the underwater views, they come here to eat. Their source of food is here. They come for squid, and a host of bait fish as small as sand eels and as big as large size menhaden.

Ask any striped bass angler who knows how to catch big fish. When it comes to picking a menu item, striped bass prefer menhaden above all other bait fish, not lobsters.