Sea Sturgeon Acipenser sturio Linnaeus, 1758 ^[86]

Description—

The skin of the sturgeon is armored with a row of large bony shields or bucklers along the middle of its back (the successive bucklers touching or even overlapping) with a second row of smaller bucklers high up along each side of the body; and with a third row, also smaller, lower down, along the line of transition from side to belly. Each buckler has a longitudinal keel with a spur, which is so sharp on small fish that these are hard to handle, lower and blunter on large. On the average there are 10 or 11 (10-16) bucklers in the mid-dorsal row; 28 or 29 (26-34) in each upper lateral row; and 9 to 14 in each of the lower lateral rows. The dorsal row runs from above the gill covers back to the dorsal fin, and each of the dorsal shields reaches to the next shield or even overlaps it. The upper lateral rows run from the gill openings back to the root of the tail fin; the lower lateral rows from close behind the pectoral fin to the pelvic fin, also from the pelvic fin back as far as the anal fin. And each shield in each of the two lateral rows is separated from the next shield by a space up to one-half as long as the shields.

The body is rather slender and rendered more or less pentagonal in cross section by the five rows of shields, instead of rounded as it is in the majority of bony fishes. The snout is narrow in young sturgeons less than 2 to 21/2 feet long, depressed below the level of the forehead, nearly flat below, and longer (from the eyes forward) than the distance is from the eyes rearward to the upper corners of the gill openings. But it changes shape as the fish grows, becoming blunter, straight in dorsal profile, and considerably shorter relatively. The mouth, situated on the under side of the head, is small, toothless (except in larval stages), with protractile lobed lips, and there are four pointed barbels in a row across the lower side of the snout in front of the mouth. The single rather small triangular dorsal fin stands far back, with its rear edge over that of the still smaller anal fin. The ventral fins are likewise far back. The pectorals are set almost as low as the plane of the belly.^[87]

Color—

Olive greenish or bluish gray above, gradually fading on the sides and changing rather abruptly below the upper lateral rows of shields to the white of the belly.

Size—

The sea sturgeon is a very large fish. In the Delaware River where sturgeon persisted until recently in larger numbers than in New England, ripe males are up to about 6 to 7 feet in length, averaging 65 pounds in weight; the, spawning females (which are larger), up to about, 10 feet and to about 250 pounds,^[88] with a larger one taken from time to time. And the general run was about the same in the Kennebec, to judge from an average weight of 120 pounds for males and females together, during the years when a fishery was carried on there. But some still grow considerably larger in Gulf of Maine waters. Thus 9 weighing between 350 pounds and 600 [page 82] pounds were landed in Portland, Maine, from the South Channel, Georges Bank, Browns Bank, and Western Bank off Nova Scotia during the period 1927-1935.^[89] About 12 feet is perhaps the greatest length to be expected today. But 18 feet, reported for New England many years ago, may not have been an exaggeration, for sturgeon as long as that have been reported from Europe also. The heaviest Gulf of Maine sturgeon reliably reported (to our knowledge) was one of 600 pounds, landed in Portland by the steam trawler Fabia from Georges Bank, December 21, 1932.

The following relationship between length and weight, for sea sturgeons up to 71/2 feet long, taken in the lower St. Lawrence River,^[90] would probably apply to Gulf of Maine fish, equally: 7 to 9 pounds at 30 inches (to fork of tail); 15 to 18 pounds at 40 inches; about 35 pounds at 50 inches; 55 to 57 pounds at 5 feet; about 100 pounds at 6 feet; and about 190 pounds at 71/2 feet.

Habits—

The sturgeon makes most of its growth in salt water but enters fresh-water rivers to spawn, as do the salmon, the shad, and the alewife. The large adult fish enter (or once entered) the Gulf of Maine rivers late in the spring, working their way slowly upstream beyond tidewater before depositing their eggs. So far as known, spawning takes place in our rivers in May, June, and perhaps as late as July. It has been suggested that some may spawn in brackish water from the fact that females with large eggs have been taken near Woods Hole in June and July (i. e., in the spawning season). Spawning leaves the spent "cows" in very poor condition. In the Delaware, however, and presumably in Gulf of Maine rivers, they "become again quite plump, acquiring considerable additional weight"^[91] before they go down stream again, which some of them do not do until September, according to observations in the Delaware. But we do not know how many years in succession a given fish may spawn.

A single female may produce as many as 2,400,000 eggs which hatch in about a week after they are fertilized.^[92] Judging from European observations on artificially reared sea sturgeon, the larvae may be expected to grow to 12 mm. in length within 5 days after hatching; to 16-17 mm. in 2 weeks; to 20 mm. in 4 weeks; and to 4-51/2 inches in 2 months.

Some young sturgeon may live several years in the lower tidal reaches of the rivers in which they are spawned, until they have grown to a length of 21/2 to 3 feet, as appears to be the case in the Hudson.^[93] And it seems that they pass their entire growth period in the salt estuary of the St. Lawrence River, for sturgeons are taken there of all sizes from a few inches long up to 7-8 feet or longer.^[94] But others may descend during their first year, for sperlets only 5 to 6 inches long have been found at the mouth of the Delaware River and of the Elbe in Europe.^[95]

Some Gulf of Maine sturgeon have taken to the sea by the time they have grown to 3 feet or so, as proved by the capture of sturgeons of that size at various points around the coasts of the Gulf, and off southern New England. And recent observations in the Hudson by Greeley make it likely that all the sturgeon that are spawned in rivers emptying into the Gulf of Maine go to sea sooner or later to complete their growth.^[96]

Sturgeon grow rather slowly at first while still in their parent streams. Four, for example, that were tagged in the lower St. Lawrence when 29 to 33 inches long, and recaptured nearby 2 to 31/2 years later, had gained only about 2 to 5 inches in length per year.^[97] Very slow growth is also indicated by ages of 5 to 6 years at 24 to 28 inches; 7 years at 25 to 31 inches; and 8 years at 32 to 34 inches, for sturgeon from the tidal waters of the lower Hudson, as estimated from the markings on their otoliths.^[98] It also seems that sturgeon, like many other fish, make most of their growth during the warm season in such situations for one marked fish in the Elbe did not grow at all between November and the following February, whereas a second grew from 17 cm. (61/2 in.) to 38 cm. (15 in.) in length between January 17 and [page 83] the following April, and a third from 431/2 cm. (171/4 in.) to 64 cm. (251/4 in.) from April 9 to the following December. But sturgeon grow much more rapidly after they go to sea, if ages (estimated from otoliths) of 11 years for a 75-inch sturgeon, and 12 years for two others of 88 and 100 inches are anywhere near the truth.^[99]

The sturgeon is a bottom feeder, rooting in the sand or mud with its snout like a pig (the barbels serving as organs of touch) as it noses up the worms and mollusks on which it feeds and which it sucks into its toothless mouth with considerable amounts of mud. It also consumes small fishes, particularly sand launce. Small ones, while living in estuaries and around river mouths, subsist largely on amphipod and isopod crustacea. Sturgeon, like salmon, eat little or nothing while traveling up river to spawn.

When at ease sturgeon swim slowly to and fro, seeming very sluggish. But they are capable of darting ahead like an arrow on occasion, and they often come to the surface to jump clear of the water. Though they usually offer no resistance when netted, large ones are very strong.

General range—

Coastal waters from the St. Lawrence River to the Gulf of Mexico, running up into rivers to spawn; reported from Hudson Bay, also Scandinavia to the Mediterranean, if the American and European sea sturgeons belong to the same species.

Occurrence in the Gulf of Maine—

The sea sturgeon is (or was) well known in the St. John, Penobscot, Kennebec, and Merrimac Rivers, and has even been taken some distance from the mouths of streams no larger than the Charles River and the Parker River in Essex County, Mass.,^[1] where some are still seen jumping in July and one is taken occasionally. In fact, sturgeon once entered practically every stream of any size emptying into the Gulf of Maine. Wood, writing of Massachusetts in 1634,^[1a] described them as "all over the country, but best catching of them be upon the shoales of Cape Code and in the river of Merrimacke, where much is taken, pickled and brought for England, some of these be 12, 14 and 18 foote long." In fact, an odd sturgeon still enters the mouth of the Merrimac, witness one of 230 pounds netted there on September 14, 1938 and landed in Newburyport.^[2]

Sturgeons may be expected anywhere off the coasts of the Gulf of Maine during their sojourn in salt water. There is definite record of them at sundry localities on both sides of the Bay of Fundy; off Mt. Desert Island; in Penobscot Bay; in Casco Bay; at the mouth of the Piscataqua River; on the Boars Head-Isles of Shoals fishing ground, where several 3 to 4 feet long were taken in gill nets during April and May 1913; at the mouths of the Essex and Ipswich Rivers, where jumping sturgeon have been reported recently in the daily press;^[3] at the mouth of Gloucester Harbor, where an angler reports catching one of about 12 pounds while fishing for tautog; inside and outside Boston Harbor; at Provincetown; off Truro, Cape Cod, and at Nantucket, as well as along the southern New England coast to the westward. Some also extend their wanderings to the offshore fishing banks as they grow. Thirty, for example, ranging in weight from 120 to 600 pounds were landed in Portland and Boston by otter trawlers from Nantucket Shoals, from South Channel, and from Georges and Browns Banks, during the years 1927-1936.^[4] Probably all of these were on bottom when caught, to judge from their diet (p. 83), and from the fact that sturgeon have been hooked on cod and haddock lines as deep as 25 fathoms in Scandinavian waters. Nothing beyond this is known of their movements in our Gulf.

Importance—

It is only the scarcity of the sea sturgeon in the Gulf of Maine that limits its commercial importance there and in the tributary rivers. The few taken are picked up accidentally in traps or weirs, in drift nets, or by the otter trawlers.

In former years, when our streams were less obstructed and sturgeons more plentiful, the catch was of considerable value in some of the larger rivers. It is interesting, for instance, to read that sturgeon, doubtless from the Kennebec River and cured near what is now Brunswick, Maine, were shipped to Europe as early as 1628; and that large quantities were also shipped to Europe from near Ipswich, Mass., in 1635. In the Kennebec, where an intermittent fishery had long been maintained. [page 84] The catch was about 250 fish in 1880, yielding 12,500 pounds of meat, and not much less in 1898 (10,875 pounds). But the yearly landings were only about one-fourth as great there (2,777 pounds) by 1919. And the reported landings of sturgeon from the entire coastline of Maine (including what few were brought in from offshore) had fallen to only 300 pounds in 1940, and 400 pounds in 1947. Reported landings in Massachusetts of 5,300 pounds in 1940 (all by otter trawlers) and of 6,600 pounds (5,000 pounds by otter trawlers, from off shore), corresponding to some 50 to 70 fish, if they weighed as little as 100 pounds each, will further illustrate their present-day scarcity.

We have never heard of a large sturgeon hooked by an angler in the Gulf of Maine. But we hear from time to time of a small one caught in this way, as already remarked (p. 83).^[5] And the skill of a woman angler^[6] who foul-hooked a sturgeon about 6 feet long, and beached it on surfcasting tackle after a long fight, fishing alone at Wasque Point, Marthas Vineyard, on July 15, 1950, was widely heralded in the daily press.