Rosefish Sebastes marinus (Linnaeus) 1758

OCEAN PERCH; REDFISH; RED SEA PERCH; RED BREAM; NORWAY HADDOCK

Description—

The rosefish is perchlike in its general appearance, moderately flattened sidewise, about one-third as deep as it is long (to base of tail fin), with a large bony head; and its trunk tapers back from the shoulders to a moderately slender caudal peduncle. The dorsal profile of the head is concave, the mouth is large, very oblique, and gapes to below the eyes, the lower jaw projects beyond the upper, and there is a bony knob at its tip that fits into a corresponding notch in the upper jaw. Both of the jaws are armed with many small teeth. The eyes are very large and set high. The sides of the head are armed with spines, the most prominent of which are two near the rear angle of each gill cover, and a series of five confluent ones on each cheek. These, with a ridge behind and above each eye socket, give the head a bony appearance that is extremely characteristic.

The gill openings are very wide, with pointed gill covers. There is one continuous dorsal fin running from nape of neck to caudal peduncle; the spiny part (14 or 15 spines) is considerably longer than the soft part (13 to 15 rays), but the latter is higher than the former. The precise outline of the fin is easier illustrated (fig. 222) than described. The anal fin, consisting of three graduated spines and 7 or 8 longer rays, is shorter than the soft portion of the dorsal, under which it stands. The caudal fin is noticeably small, its rear edge moderately concave, and with angular corners. The pectoral fins are very large, and the smaller ventrals are situated below them. Both head and body are clad with scales of moderate size. There are about 60 to 70 oblique rows of scales from the gill opening to the origin of the caudal fin, just below the lateral line.

The rosefish agrees with the cunner, tautog, and sea bass in the union of the spiny and soft portions of its dorsal into a single long fin, and in its generally [page 431] perch-like conformation. But it is seperable from the first two by its much larger mouth, spiny head, large eyes, more slender caudal peduncle, and larger pectorals; and from the sea bass by its large spiny head, by the shape and small size of its caudal fin, and by the fact that its anal fin and the soft portion of its dorsal are relatively much lower. Its brilliant red color is a sufficient field mark.

Color—

Orange to flame red, occasionally grayish red or brownish red, with a belly of paler red that fades to white after death. The black eyes contrast vividly with the brightly colored body. Medium sized rosefish usually have a dusky blotch on each gill cover, and several irregularly broken dusky patches along the back. These dark markings are more conspicuous on small fish, and young fry up to 3-4 inches long are only faintly redish, if at all so.

Size—

The rosefish matures sexually when 9 to 10 inches long, males when a little smaller than females. In the Gulf of Maine they are said to grow ordinarily to a maximum length of perhaps 2 feet. The largest measured specimen taken recently in the Gulf of Maine of which we have heard was 22 inches long, and weighed 5 pounds 11 ounces.^[14] The largest we have seen measured was 18¾ inches.^[15] But Goode^[16] reported one of about 24 inches, weighing about 14 pounds brought into Gloucester; a 27½-inch specimen has been reported from the southern edge of the Newfoundland Bank, near the Whale Deep.^[17] Another 27-inch fish, said to have weighed 13½ pounds was landed in Gloucester by the dragger Estaela on February 7, 1951, from somewhere off Newfoundland. And rosefish grow even larger (maximum about 31-32 inches) in the other side of the Atlantic and in Arctic seas.^[18]

Rosefish run smaller near the coast (usually 8 to 12 inches long) than on the offshore banks. In European waters, where a similar size relationship occurs, the small inshore form represents a seperate species (Sebastes viviparus) for it has many fewer scales than the larger offshore form (S. marinus). But no racial distinctions have been found between the inshore populations and those offshore among the American rosefish.

The relationship between length and weight runs about as follows for Gulf of Maine rosefish: 9½ inches, ½ pound; 12 inches, 1 pound; 15 inches, 2 pounds; 17-18 inches, 2½-3 pounds; 20 inches, perhaps 4 pounds.

Habits—

The young rosefish drift in the upper and intermediate water layers (p. 435) until they are nearly an inch long. Fish upwards of a [page 432] couple of inches long tend to hold close enough to the bottom in our Gulf for great numbers of them to be caught in otter trawls. But some may also live pelagic over the deep basins as they are known to do in the Gulf of St. Lawrence; also, in the Norwegian Sea, where there is a population of all sizes living mostly at depths of about 50 to 100 fathoms, over much greater depths.^[19] When they are on bottom the rosefish are chiefly on rocky or hard grounds or on mud, seldom on sand, if ever. Their depth range on the bottom is from within a few feet of tide line (p. 434) down to 350 fathoms at least; perhaps to 400 fathoms (p. 434) with the greater part of the commercial catch trawled at about 40 to 175 fathoms; and fry, living pelagic, have been taken as deep as 270 fathoms in north European waters.

Our rosefish inhabit a wide range of temperature. The maximum may be set at about 48° to 50° F., and probably it is the low temperature of parts of the Bay of Fundy, where the upper 10 fathoms or so may be as cool as 50°-52° even in midsummer that allows them to remain in shoal water there the year round (p. 435). At the other extreme they winter in Massachusetts Bay and in Passamaquoddy Bay in water as cold as 33° to 35°, and perhaps colder, though they could easily avoid these low temperatures by a short offshore migration. In fact, the rosefish has often been described as an Arctic species. But while this is true to the extent that its range extends to Arctic Seas, it is a misnomer if taken to mean that it is characteristic of Polar temperatures, for the records of its occurrence, horizontal and bathymetric, prove that the great majority of them inhabit waters warmer than 35°-36° over the greater part of their geographic range.

The distribution of the rosefish^[20] in the Gulf of St. Lawrence is especially instructive in this respect, for it inhabits the comparatively warm water (39° to 42° F.) in the bottoms of the deep channels, and not the icy intermediate layer (about 32°) which, generally speaking, is so nearly an impassable barrier to its upward migration that it is seldom if ever taken on the shoal banks. And its vertical range in relation to temperature seems to be much the same as this off the southwest coast of Greenland, where rosefish are taken chiefly deeper than 90 fathoms, in water of about 37°-39°, not in the icy layer above, and where numbers of them (says Jensen) sometimes come to the surface dead in winter, apparently having succumbed to cold.^[21] In the Norwegian Sea, however, rosefish of this species are caught only in the overlying layer of water of Atlantic influence at temperatures of 37°-39° or higher, never deeper in the icy cold Polar water.

Temperatures of 37°-39° are the lowest in which young rosefish are born in any numbers in our Gulf; there is no water there colder than this by the time production is well under way, say late June or early July. At the opposite extreme, practically the entire production of rosefish takes place in water colder than 46°-48°, this being the maximum to which the water warms at the 20-fathom level and deeper, except in regions of active vertical mixing where the temperature may rise a degree or two higher. In the Gulf of St. Lawrence, rosefish have been found breeding in 39°-42°. Cursory examination of station data might suggest that young are born in colder water on the Grand Banks as well as along the south and east coasts of Newfoundland, for they have been taken there in tow nets at many localities where the temperature was lower than 32°, either on the bottom or at some intermediate depth. But it is more likely that the parent fish, and the young fry also, were living above this icy layer, not in it; i. e., in water at least as warm as about 35° (1.5° C.), and warmer than about 36°-37° for the most part.

Thus the range of temperature within which American rosefish fry are produced in one place or another is from about 37° to 47° or 48°, which is about the same as for north European waters.^[22] In fact it is not likely that rosefish breed successfully in temperatures lower than 35° anywhere in either side of the Atlantic.

The salinity in which rosefish breed in our Gulf is as definitely limited in one direction as is the temperature, if not in the other, for its young are produced for the most part in salinities upward of 32 per mille.

[page 433]

Food—

The diet of the Gulf of Maine rosefish includes a great variety of crustaceans, especially mysid, euphausiid, and decapod shrimps; small mollusks; and various other invertebrates, and small fish.^[23] It bites on almost any bait. In turn, it is the prey of all the larger predaceous fish, its fry being devoured in quantity by cod, by older rosefish, and by halibut.

Reproduction and growth—

It has long been known that the eggs of the rosefish develop and hatch within the oviduct of the mother, and the number produced by large females may run as high as 25,000-40,000 yearly. This is a small brood compared to the numbers produced by many of the marine egg-laying fishes. But the protection offered the eggs by being retained inside the mother's body during incubation gives the young a greater chance for survival.

The larvae are about 6 mm. long at birth (fig. 223B), with the yolk mostly absorbed, the mouth already formed, and the first traces of the caudal rays already visible. At a length of 12 mm. (fig. 223D) the dorsal and anal fin rays have appeared, the ventrals are visible, and the head spines are prominent. And though the red color is not developed until the little fishes are about to take to bottom, or later, all but the very youngest larvae are recognizable as rosefish by their large spiny heads, large eyes, short tapering bodies, very short digestive tract, and by the presence of two rows of post anal pigment cells, a dorsal and a ventral row.

This is a very slow-growing fish. Available information is to the effect that they average about 2½ inches when 1 year old.^[24] Studies of the scales of rosefish of different sizes^[25] indicate that 5-inch fish are likely to be 4 years old; 6-inch fish, 6 years old; 7-inch fish 7 or 8 years old; 8-inch fish 8 or 9 years old; 9-inch fish 9 or 10 years old, and that many of the largest fish of 18 inches and upward may be 20 years old, or older. Thus the mature fish are 8 to 9 years old and older, with the greater part of the commercial catch 10 years old and upward. And about as slow a growth rate has been reported for the immature rosefish of this same species of Barents Sea, on the other side of the Atlantic.^[26]

General range—

Both sides of the North Atlantic; northward to Spitzbergen, Nova Zembla, Iceland, West Greenland, Davis Strait, southeastern Labrador, coasts and Banks of Newfoundland, and Gulf of St. Lawrence; southward to the offing of southern New England and as far as the offing of New Jersey in deep water along the American coast,^[27] to the northern part [page 434] of the North Sea and to the southwestern coast of Iceland along the European coast.

Occurrence in the Gulf of Maine—

This is one of the most plentiful of the commercially important fishes in all but the shoalest parts of the Gulf: on the offshore banks, in or over the deep central basin, and along shore. To list its known occurrences would be to mention practically every station where hook-and-line or otter-trawl fishing is carried on deeper than 20 fathoms. Thus considerable numbers are sometimes taken on lines or trawls in 20 to 35 fathoms or more in the Massachusetts Bay region both winter and summer, especially on or near rocky bottom, while many are caught on and near Jeffreys Ledge and at other spots between Cape Ann and Boon Island.

The fact that the Grampus took rosefish in 6 out of 7 hauls in 25 to 60 fathoms with a trawl only 8 feet across the mouth, between Cape Ann and Penobscot Bay in July 1912, and that Atlantis took 2,469 rosefish in 12 hauls with a 30-foot shrimp trawl in 66 to 96 fathoms in the mud-floored trough west of Jeffreys Ledge in August 1936, show how universal they are in the western coastal belt of the Gulf at appropriate depths; and the depth is not too great for them anywhere in the troughs of our gulf. The number of rosefish there seemed to be independent of the numbers of shrimp (Pandalus) on which we may assume they were feeding, the average catch per haul being almost the same (216 fish) for the group of stations where shrimp were scarce as for the group where they were plentiful.^[28]

Rosefish are also caught in plenty all along the northern shores of the Gulf in depths of 25 fathoms or more; they are common in the Bay of Fundy, even in such enclosed waters as Passamaquoddy Bay; Huntsman found them in St. Mary Bay; and large commercial catches are made off the western coast of Nova Scotia (5,253,962 pounds reported in 1946).

Turning offshore, the vaguely outlined trough known as "South Channel" that separates the Cape Cod-Nantucket Shoals area from Georges Bank is one of the most productive and hardest fished of the rosefish grounds (19,016,052 pounds taken there in 1946); rosefish are generally distributed on and around Georges Bank itself, except perhaps on its shoalest parts; also on and around Browns Bank, and they range down to a depth of at least 260 fathoms on the southern slope of Georges Bank;^[29] very likely down to 300 fathoms.

The relative yearly catches, from different areas, show that the inner and central parts of the Gulf in general are considerably more productive of rosefish than the offshore banks, for the poundage reported from off western Nova Scotia, from the Bay of Fundy, from the coasts of Maine and Massachusetts, and from the west-central part of the Gulf (including the Cashes Bank region and part of the deep basin) which is referred to as the "inshore grounds" in the statistical reports, were about three times as great as from the South Channel, Georges Bank, and Browns Bank combined in 1940; about 31/3 times as great in 1946, and the regional contrast has been of this same order in other recent years of record. The South Channel in turn, has been many times as productive as the much more extensive area of Georges Bank,^[30] though there were enough of them on Georges formerly for 22 successive trawl hauls to have yielded 3,887 rosefish there, September 26 to 30, 1913 (more than one-third as many as haddock).

During 1913, rosefish made up 1.8 percent of the total catch of fish of all kinds made by several trawlers operating on Georges Bank, June to December, and 5.9 percent in the South Channel.

This regional contrast between Bank and Channel emphasizes the very interesting fact that the rosefish of our Gulf, and those of outer Nova Scotian waters as well, are decidedly more plentiful in the deeper basins and depressions, and on soft bottom, than they are on the grounds that are the chief centers of abundance for cod and haddock, and for most of the commercially important flat fishes.

The statistics do not suggest any very great difference in the abundance of rosefish as between Georges Bank and the Nantucket Shoals-Nantucket Lightship [page 435] fishing grounds, for while the catch has averaged only about one-third as great for the latter as for the former, the statistical area in question is about one-third as extensive. But the catches of rosefish (1937-1946), made by United States vessels from southern Nova Scotia out across Browns Bank, are of the same general order of magnitude^[31] as for the South Channel. And a catch of 1,400 rosefish in two sets of a line trawl on Browns Bank, April 4, 1913, will illustrate how plentiful they were there, before they were so hard-fished as they have been of late.

Large catches of rosefish are also made all along the outer Nova Scotian shelf to the eastward. There is an abundant population on the Newfoundland Banks still awaiting exploitation; some 7,000,000 pounds were taken in Hermitage Bay, on the south coast of Newfoundland from 1947 to 1950.^[32] And fry have been taken along both coasts of Newfoundland; also northward from Flemish Cap, "where the Gulf Stream and the Labrador current struggle for mastery."^[33] The most northerly record for the rosefish on the American coast is from the outer coast of Labrador (Camp Islands), a few miles north of the Strait of Belle Isle.^[34]

It has been known for many years that there are rosefish in the deep waters of the Gulf of St. Lawrence. But we still await information as to how plentiful they may be there.

The upper limit to the vertical range of the rosefish in different parts of our Gulf is clearly correlated with temperature. Thus it is only deeper than 15 to 20 fathoms that rosefish are found during the warm half of the year in the southwestern part of the Gulf. But they have been known to run up into Gloucester Harbor in numbers in winter^[35] (never in summer). Many have been taken near the surface in the spring in the drift-nets near the Isles of Shoals where it is only near bottom that they are reported in summer. We have taken them as shoal as 10 fathoms in summer off Mount Desert Island, Maine, where the water warms to about 52°-54° at that depth, and they occur in Pasamaquoddy Bay in water no deeper than 5 fathoms at that season, according to Huntsman. Verrill,^[36] in fact, described them as round the wharves at Eastport, no doubt in late summer or early autumn, the season he studied the fauna there.

Apart from shifts in depth of the sort just mentioned, with the seasonal rise and fall of temperature, there is no evidence that the adult rosefish of our Gulf carry out any regular migration. But the larvae may journey for long distances while they drift helpless in the upper layers of the water (p. 436).

In 1930, we saw gravid females during the last half of April, with young nearly ready for birth, evidence that some rosefish may be born in the Gulf of Maine as early as the first part of May. Females also, with well-developed eggs, and males with well-developed milt, are taken commonly by mid-May, both within the Gulf and on Georges Bank,^[37] while we have towed a few newborn fish (7 to 10 mm.) off Boothbay and off Mount Desert on May 31 and on June 14. But July 8 is the earliest that we have taken them in any numbers in our tow nets (57 larvae off Cape Cod on that date in 1913.)

Evidently the production of young continues right through July and August, for the Albatross II trawled many gravid females, 10 to 13½ inches long, in the central basin of the Gulf in July (1931), one of them containing about 20,000 young, 6-7 mm. long, practically ready for birth, while we have towed newly born larvae (6.5-7 mm.) in one part of the Gulf or another on July 24 and 29 and August 4, 7, 12, 14, 16, 22, and 31, and as small as 10 mm. on September 2.^[38] But it is not likely that many young are produced after the first week in September.

Records for rosefish larvae and fry for late June, July, and August along the outer Nova Scotian shelf, and in the Gulf of St. Lawrence, as well as from May until into September around the Grand Banks and up the two coasts of Newfoundland, show that the season of production commences nearly as early in the season in these more northerly waters as it does in the Gulf of Maine and [page 436] that it continues equally late. In north European waters young rosefish are produced from mid-April through August, according to locality.

Seemingly the rosefish fry are ready to sink to near the bottom when they are about 25-30 mm. long, for we have not taken any larger than 27 mm. in our tow nets, while fry of 1½ inches and upwards are plentiful on bottom, both in the Bay of Fundy and in deep water off southern New England. And our failure to take any young rosefish in our tow nets off Massachusetts Bay in November or anywhere in the Gulf in winter is evidence that their descent to the bottom takes place early in their first autumn.

In north European waters such of the young rosefish as are fated to take to the bottom at all are described as continuing pelagic in the upper layers until they are 2 - 2½ inches (to 60 mm.) long.

Apparently rosefish never produce their young in less than 20 to 30 fathoms west or south of Penobscot Bay; and while they may perhaps do so in shoaler water about Mount Desert, and further east along the coast of Maine, Huntsman^[39] reports that the spawning individuals move out into deep water. With this qualification, we have taken pelagic young in our tow nets at so many localities in the northern part of the Gulf including Southwest Harbor on Mount Desert Island, and so generally distributed, as to show that rosefish produce their young wherever they may chance to be, and do not gather on special grounds for the purpose. Rosefish (unlike most of the fishes producing buoyant eggs) also breed successfully in the Bay of Fundy, their larvae having been found both at the mouth of the bay and for some distance up the center, during the late summer.^[40]

In the inner parts of the Gulf, our largest catches of its drifting young have all been located within a few miles, one side or the other, of the 50-fathom contour line. Examples are catches of several hundred off Cape Elizabeth on July 29, 1912; near Cape Sable on August 11, 1914; near Cashes Ledge on August 10, 1913, and on September 1, 1915; in the sink off Gloucester on August 9, 1913; on Platts Bank on August 7, 1912. And Goode and Bean^[41] report the fry as caught "by the bushel" in the trawl by the Fish Hawk at 55 fathoms, presumably off Cape Cod, that being the only Fish Hawk station where the rosefish is listed by them. These last catches rival the swarms of young Sebastes that have been encountered between Iceland and the Faroes.^[42]

On the other hand, most of our records for their pelagic young outside the 100-fathom contour line have been based on occasional specimens only. We have seldom taken young Sebastes in the western basin, though we have towed there frequently at all seasons, and never in the deep southeastern trough of the Gulf nor in the eastern channel between Georges Bank and Browns. All this suggests that the chief production of rosefish within the Gulf of Maine occurs at about 50 fathoms.

The presence of gravid females and ripe males on Georges bank (p. 435), together with the abundance of mature fish in the so-called "South Channel," shows that this general region is an important center of production. And the rosefish also breeds considerably farther west than this on the outer edge of the continental shelf, for young fry and adult females full of eggs were collected in 100 to 180 fathoms off the southern coast of New England during the early years of the United States Fish Commission.

The shelf along outer Nova Scotia (especially the depressions between the banks), the basin of the Gulf of St. Lawrence, and the waters around Newfoundland, must be productive nurseries, also, to judge from the abundance of young drifting stages that have been collected there.^[43]

Importance and abundance—

The only measure of abundance of rosefish in our Gulf available before 1935 was the number taken in a few experimental trawl hauls, or on long lines (p. 434), for there was so little demand for them that nearly all of those caught incidentally were thrown back by the fishermen. Thus the reported catch for our Gulf was only 54,095 pounds in 1919, rising to a yearly average of about 209,000 pounds for the period 1931-1933. But the rosefish is a good table fish, excellent for quick freezing and filleting. The marketing of it as frozen fillets in 1935 so increased the demand that the landings from the Gulf of Maine, plus fish taken from southern Nova Scotia [page 437] out to Browns Bank rose to 17 million pounds in that year, to about 55 million pounds in 1936, about 66-89 million pounds in 1938 and in 1939, to about 106 million pounds in 1940, and to about 136 million pounds in 1941. The landings fell to about 100 million pounds in 1943, but rose again in 1945 to a peak of 151 million pounds. This corresponds to about an equal number of individual fish, a number larger than that for any other fish commercially important in our Gulf, except the herring.

lt is now generally believed that this yearly drain was greater than a fish requiring 8 or 9 years to reach marketable size could withstand; the catch (Gulf of Maine and southwestern Nova Scotia) fell by about 30 percent the next year, and to only about one-fourth as much in 1949 as had been landed from these areas in 1945.^[44] And this would have been calamitous for the fishery had the fleet not been able to draw on the rosefish to the eastward, along the Nova Scotian shelf, whence something like 133 million pounds were landed in New England ports in 1949, or between three and four times as much as from the Gulf of Maine.

We refer the reader to the table on page 333 for the monetary value of the catches of rosefish in recent years, as compared with cod, haddock, and mackerel.

George F. Kelly, writing in the Maine Coast Fisherman,^[45] has recently emphasized the probability that the Nova Scotian catch may also be expected to decline from its present high level as soon as the accumulated stock of old fish is reduced there, as it has been in the Gulf of Maine. The fishery would then have had to depend on the annual increment of growth of a stock that has stabilized at a level considerably below its virgin state, unless operations had been extended to Newfoundland waters, where the same chain of events will eventually follow. And we must expect this increment to be far smaller for the slow-growing rosefish than it is for faster growing fishes, such as the cod or the haddock.

Finally, almost the entire commercial catch is taken in otter trawls; also while the rosefish is of such great importance to the commercial fishermen, it offers nothing to the angler; most of them live too deep to be within his reach, and any hooked would come in with very little resistance.