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Migrations
No phase of the life history of the bass arouses as much discussion among fishermen as their
migrations. And the picture still remains so puzzling that we dare not attempt anything more than
a brief summary of what has been learned to date.
It seems certain that stripers do not ordinarily travel far until they are 2 years old. Thus the
young fish from the enormous year classes of 1934 and 1942—apparently produced in the Chesapeake
Bay-Delaware Bay region chiefly— did not appear in New England waters until 2 years later. But the
fact that they did appear there and in the Gulf of Maine in hordes in the summers of 1936 and 1944
shows that a bass is capable of very extensive journeys, once it has reached its third year.
It has long been known, too, that the pound nets on Long Island and along southern New England
ordinarily make large catches only in the spring (peak in May), and again from early October into
November;[38] also that large spring catches are made progressively later in the season,
proceeding from south to north, the reverse being true in the autumn. This, of course, suggests
that part at least of the bass population follows the shore line northward and eastward as far as
southern New England in spring, to return westward and southward in autumn. And this is verified
for bass 2 and 3 years old by the returns from tagging experiments by Merriman at the eastern end
of Long Island and in Connecticut during the years 1936 to 1938,[39] for recaptures of fish that
had been tagged there in May came mostly from farther east along southern New England, one from
Cape Cod Bay, and another from Cohasset on the southern shore of the inner part of Massachusetts
Bay. But the recaptures from fish tagged in summer were mostly from nearby (evidence of a
stationary population), while those for autumn-tagged fish were scattered along the coast from the
eastern end of Long Island to Chesapeake Bay, with one from Croatan Sound, one from Albemarle
Sound (Stumpy Point), and one from Pamlico Sound in North Carolina.
But the picture is by no means so simple as the foregoing might suggest. To begin with, no
evidence is available as to the movements of large bass, other than the successive dates when they
appear or disappear off different parts of the coast.[40] And it is no less true of bass than it
is of mackerel (p. 330), that successive appearances and disappearances from place to place are
not conclusive evidence of along shore migration. Yet it is now certain that while some bodies of
bass carry out extensive migrations north and east in spring, west and south in autumn, other
bodies do not. Thus, as Merriman points out,[41] the bass of the northeastern shore of the Gulf of
Mexico are completely isolated, while those of the Atlantic coast south of Cape Hatteras form
another separate population, few of which (if any) ever spread farther north. The bass of the Gulf
of St. Lawrence and of the lower St. Lawrence River appear to be wholly isolated also. And while
some interchange may take place between the populations found in various bays and rivers around
the outer coast of Nova Scotia, it is doubtful whether these have any regularly migratory
association, either with the Gulf of St. Lawrence fish or with those of more southern waters,
except in occasional years (p. 398).
Chesapeake Bay, however, harbors both migratory bass,[42] as proved by tagging experiments (p.
393) and other evidence (p. 393), and non-migratory as proved by the fact that fish of all sizes
are taken there both in summer and in winter, though not so many of them as in spring and fall.
Similarly, some bass winter in northern waters though most of the fish appear to be migrants
there; and perhaps a considerable percentage do so in the lower reaches of the Hudson River
estuary.
Merriman[43] has suggested that these northern wintering fish may be "of two types—the individuals
that form the resident more or less isolated population" and others "that may have had their
origin farther south but spend an occasional winter in northern waters." It may prove that a good
proportion of these bass that come from the south when they are 3-4 years old may remain in the
north for the rest of their lives. And there is no way for the fisherman to tell in which of these
categories the bass belong, that he lands. The reader will find some further discussion of
migrations in connection with the status of the bass in the Gulf of Maine (p. 395). We need only
add that the existence of these non-migratory populations and the fact that the Pacific coast bass
are similarly stationary, are sufficient proof that seasonal migration is not an essential
incident in the life of the striper.
Bass spawn either in brackish water at the heads of estuaries[44] (the Hudson, for example) or in
fresh rivers, never off the open coast in salt water so far as is known. Those that enter fresh
rivers may deposit their eggs only a short distance above the head of tide as they do in the
Potomac, or they may run much farther upstream. But we have yet to learn how large a percentage of
the bass that are known to spawn 100 miles up the Roanoke, near Weldon, N. C. (a major spawning
ground), or still farther up the Alabama,[45] and up the Sacramento River in California, have come
from salt water (p. 392).
The chief requirement for successful spawning is (it seems) a current turbulent enough to prevent
the eggs from settling on bottom where they would be in danger of being silted over and smothered.
The spawning season is from late April to early May in North Carolina; in May, chiefly, in the
Chesapeake Bay region; perhaps equally early in the waters of New York.[46] Any bass that may
spawn in the rivers of Massachusetts, of Maine, and of the Bay of Fundy, probably do so in June;
those of the southern shore of the Gulf of St. Lawrence and of the lower St. Lawrence River in
June and July.
A large female during spawning may be surrounded by many small males, and the latter are described
as fighting fiercely[47] with one another.
Females stripped at the Weldon, N. C. Hatchery yielded from 11,000 to 1,215,000 eggs each, during
the period 1928 to 1938, with one of 4½ pounds yielding 265,000. Thus the oft-quoted estimate of
10 million fish for a really large one is within reason.[48]
The eggs average 1.1-1.35 mm. in diameter when they are deposited in the water, but the
pervitelline membrane swells during the first hours after fertilization to an average diameter of
about 3.6 mm. They have a large oil globule and are semibuoyant; that is, they sink in quiet
water, but are swept up from the bottom by the slightest disturbance, so that they tend to drift
downstream with the current. Consequently the eggs that are produced far upstream may not hatch
until they have reached tidewater. The eggs are reported as hatching in about 70 to 74 hours at a
temperature of 58-60°; in about 48 hours at 67°; in about 30 hours at 71-72°.
In Chesapeake Bay, the young fry of the year are about 11/5 inches (30 mm.) long by June; 14/5 to
21/12 inches (45-53 mm.) long in July; 2 to 24/5 inches (50-70 mm.) in August; and 3¾ to 8½ inches
by the following April and May; i. e., at the end of their first year.[49] According to
Merriman,[50] most of the fry of the year taken in the Hudson River during their first summer are
between about 15/8 inches (40 mm.) and about 3½ inches (90 mm.) long; a few seined in the Parker
River, Newbury, Mass., were from about 2¾ inches (71 mm.) to about 33/8 inches (85 mm.) long. And
this last is perhaps representative for whatever bass may now be produced in Gulf of Maine rivers,
for we read that great numbers of fry of 2 to 3 inches were taken of old in winter in the rivers
of Maine in bagnets set for smelt and tomcod.[51]
Two-year-old bass taken in Connecticut averaged 11 to 11½ inches (28 or 29 cm.) long in spring,
[page 395] about 12 inches (30 cm.) in June, and about 14½ inches (37 cm.) in October; the
3-year-olds about 15¾ inches (40 cm.) in spring and about 18 inches (46 cm.) in October, while
4-year-olds increased in length from about 18¾ inches (48 cm.) to about 20¾ inches (53 cm.)
between spring and autumn, on the average.[52] And the average rate of growth was about the same
for Hudson River fish examined by Greeley.[53] But the rate at which they grow is governed largely
by the food supply. Bass in captivity have been known to grow from 6 inches long to 20 inches in
11 months, while some that were kept in a certain pond in Rhode Island are described as having
gained weight from 1 pound in June to 6 pounds in October.[54]
The later growth rate has not been traced for our Atlantic bass. But it is generally believed that
the 35-50-pounders that were caught in considerable numbers in 1950, and are being taken in 1951,
were members of the very successful year classes of 1940-1942, which fits well with the growth
rate of bass on the Pacific coast, where the average age is about 7 years for 20-pound fish, 10-11
years for 30-pounders, about 14 years for 40 pounders, and 17 to 18 years for 50-pounders.[55]
On the Pacific coast females grow faster than males after the third year, which is probably true
of the Atlantic bass also.[56] This certainly is a long-lived fish for one kept in the New York
Aquarium lived to be 23 years old.[57]
Merriman[58] found that "approximately 25 percent of the female striped bass first spawn just as
they are becoming 4 years old, that about 75 percent are mature as they reach 5 years of age, and
that 95 percent have attained maturity by the time they are 6 years old," among Connecticut fish.
But a large percentage of the males had matured at 2 years, probably nearly all of them by the
time they were 3 years old. And it is probable that this applies equally to the Maine bass.
Merriman has also made the interesting discovery that only about one-tenth of the bass of northern
waters are males, but that males are nearly as numerous as females, southward from Delaware Bay.
It has been suggested that the striper may not be a regularly yearly spawner,[59] but no positive
evidence is at hand as to this.
General Range
Atlantic coast of eastern North America, from the lower St. Lawrence River and the southern side
of the Gulf of St. Lawrence to northern Florida; also along the northern shore of the Gulf of St.
Lawrence to Alabama and Louisiana; running up into brackish or fresh water to breed.[60] In the
last quarter of the 19th century it was introduced on the Pacific coast, where its range extends
now from Grays Harbor, Wash.,[61] to Los Angeles County, Calif. It is now a favorite game fish
there, and the yearly commercial catch since World War I ran between 500,000 and about 1,000,000
pounds there, until 1935, when commercial fishing for stripers was prohibited by the State of
California.
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[38] See Merriman, Fish. Bull. No. 35, U. S. Fish and Wildlife Service, 1941, vol. 50, pp. 33, 34,
fig. 24, for details.
[39] For details we refer the reader to Merriman's original account (Fish. Bull No. 35, Fish and
Wildlife Service, 1941, vol. 50, pp. 36-42, figs. 26-29; also pp. 71-73, tables 17-20), which is
the most authoritative discussion of the subject that has appeared yet.
[40] the few returns so far from bass of 5 pounds and upward that have been tagged have been from
nearby, and soon after they were released.
[41] Fish. Bull. No. 35, U. S. Fish and Wildlife Service, 1941, vol. 50, p. 42.
[42] Using this term to mean extensive seasonal journeys.
[43] Fish. Bull. No. 35, U. S. Fish and Wildlife Service, 1941, vol. 50, p. 42.
[44] See Merriman, Fishery Bulletin No. 35, U. S. Fish and Wildlife Service, 1941, vol. 50, p. 17,
for precise salinites in which bass in their first summer have been taken in the Hudson River, and
in the Parker River, Massachusetts. See Tresselt (Bull. Bingham Oceanogr. Coll., vol. 14, art. 1,
pp. 98-110, 1952) for a survey of spawning grounds tributary to Chesapeake Bay.
[45] Pearson (Bull. U. S. Bur. Fish., vol. 49, 1938, p. 829) records a female with eggs from the
Alabama River near Montgomery.
[46] Greeley (New York Conserv. Dept., Biol. Surv. Lower Hudson Watershed, 1937, p. 100) concludes
that the spawning season in the Hudson "includes May."
[47] See Smith, North Carolina Geol. Econ. Survey, vol. 2, 1907, p. 272, for an eyewitness account
by S. G. Worth.
[48] Merriman (Fish. Bull. No. 35, U. S. Fish and Wildlife Service, 1941, vol. 50, p. 19) gives an
excellent summary of information available as to spawning, characteristics of the eggs, and period
of incubation.
[49] Hildebrand and Schroeder, Bull. U. S. Bur. Fish., vol. 43, Pt. 1, 1928, pp. 248-249.
[50] Fish. Bull. No. 35, U. S. Fish and Wildlife Service, 1941, vol. 50, p. 17, fig. 10.
[51] Atkins, Fish. Ind. U. S., Sect. 5, vol. 1, 1887, p. 693.
[52] Merriman, Copeia, 1937, p. 23.
[53] New York Conserv. Dept., Biol. Surv. Lower Hudson Watershed, 1937, p. 62.
[54] Bean, Bull. New York State Mus., 60, Zool. 9, 1903, p. 527.
[55] Scaled from Scofield's graph (California Fish and Game, vol. 18, 1932, pp. 168-170, fig. 38).
[56] See Scofield, Fish Bull. No. 29, Div. of Fish and Game, California, 1931 for growth of bass
in California.
[57] Bull. New York Zool. Soc., vol. 16, No. 60, November 1913, p. 1049.
[58] Fish. Bull. No. 35, U. S. Fish and Wildlife Service, 1941, vol. 50, p. 22.
[59] Merriman, Fish. Bull. No. 35, U. S. Fish and Wildlife Service, 1941, vol. 50, p. 16.
[60] Pearson (Bull. U. S. Bur. Fish., vol. 49, 1938, p. 827, fig. 1) charts its United States
range, but does not include its Canadian range.
 Bluefish Pomatomus saltatrix (Linnaeus) 1758
Striped Bass Roccus saxatilis (Walbaum) 1792
Summer flounder (fluke) Paralichthys dentatus (Linnaeus) 1766
Weakfish Cynoscion regalis (Bloch and Schneider) 1801
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