Popular Science Monthly/Volume 64/December 1903/The Salmon and Salmon Streams of Alaska
| THE SALMON AND SALMON STREAMS OF ALASKA. |
By President DAVID STARR JORDAN,
LELAND STANFORD JUNIOR UNIVERSITY.
The Salmon of the Pacific.
THE salmon of the Pacific differ notably as a whole from the single species called salmon (Salmo salar) in the Atlantic. Anatomically the Pacific salmon (Oncorhynchus) differ from the salmon of the Atlantic (Salmo) in the greater number (14 to 20) of developed anal rays (the Atlantic salmon having 10 to 12), in the greater number of branchiostegal rays, 13 to 16, the Atlantic salmon having about 11, and in the usually larger number of pyloric cæca, 65 to 180, the Atlantic salmon having 65. In habits, the distinctions are still more marked. The Atlantic salmon spawns in the small streams and runs in the rivers in the fall for a long distance. In the run, the males become hook-jawed and somewhat distorted and many are attacked by fungus, dying before reaching the sea. But they attempt to reach the sea, and a large percentage of them revive, to spawn again.
The Pacific salmon, Oncorhynchus, have more definite runs. In the process of running, they take no food of any kind. The oil in the body is consumed, the flesh becomes pale, the jaws in the males become much elongated, the front teeth are enlarged, the color is changed and the whole body is greatly distorted. After spawning the fishes drift tail foremost in the stream, and all die within about a week. There is no reason to believe that any individuals of any species of Pacific salmon survive the reproductive act.
All the salmon spawn in cold or cooling water. The eggs are hatched when the water cools to 54°. Freezing kills them but any temperature between 32° and 54° is favorable to their development. Any temperature above 54° causes the egg to develop precociously and the young salmon dies. The temperature of the streams of the north fall earliest to 54°. For this reason, the run is earlier in northern waters than in southern ones in Alaska. All the species spawn in flowing water, the male with its tail scooping out the gravel in which the female deposits the eggs and over which the male casts out the milt.
The Species of Pacific Salmon.
There are five species of salmon in Alaska and neighboring regions. These differ widely in habit and in value, a matter of vital importance to an understanding of the salmon question.
The Quinnat Salmon.
1. The Quinnat salmon (Oncorhynchus tschawytscha Walbaum). This species is called king salmon in Alaska, Chinook salmon on the Columbia, spring salmon on Fraser River, Tyee salmon where the Chinook jargon is spoken and Tchaviche among the Russians. This is the salmon of the Columbia and Sacramento, the only species having value south of Puget Sound. It reaches a larger size than any of the others, the average at four years being 22 pounds and occasionally running to 60, 80 or even 100 pounds. In quality of flesh it is also superior to any of the others, at its best no wise inferior to the Atlantic salmon. Its flesh is red, rich and tender, becoming however progressively paler in color and less rich in flavor, as the spawning season approaches, although the flesh of spawning fish is sometimes dull red. The Quinnat is readily known by its large size and the presence of round black spots on back and tail. As the breeding season approaches it becomes blackish, the sides blotched with dull red.
The Quinnat runs in the large rivers, especially those having glacial or snow-fed tributaries. Its chief run is in May in the north, in June and sometimes in early July in the Columbia and even later in the Sacramento. In the Columbia, there is a more or less distinct full run in September. In Alaska, the principal run is in May.
The Quinnat salmon runs to the very headwaters of the streams it inhabits. In the Columbia, it goes to the Sawtooth Mountains of Idaho, as well as to the headwaters of the Clackamas, Cowlitz, Des Chûtes and other streams furnishing suitable spawning beds. In the Yukon some individuals each year ascend to Caribou Crossing on Lake Bennett, a distance of 2,250 miles from the sea. In Alaska the king salmon runs in appreciable numbers in the following rivers: Stikine, Taku, Unuk, Chilkat, Alsek, Kussilof, Copper, Knik, Shushitna, Nushigak and Kvichak. Schools of king salmon are occasionally seen among the islands of southeast Alaska, in pursuit of schools of herring. It is not likely that the species goes far out to sea, or for any great distance from the stream in which it was spawned. It is commonly asserted that each salmon returns to the particular stream in which it was spawned. There is no evidence that this is true. A discussion of this point will be found in a previous article in this journal.
The Red Salmon.
The red salmon (Oncorhynchus nerka Walbaum). This fish is known throughout Alaska as red salmon. In the Columbia, it is called blue-back salmon, while in Fraser River it is known as Sockeye, a Chinook word, originally spelled Sukkegh, then Sawkwi. To the Russians it is Krasnaya Ryba, which means red-fish. This species is the neatest and most symmetrical of the salmon. Its usual weight at four years is about seven pounds, varying from six to ten pounds. The flesh is deep-red, firmer, drier and less palatable than that of the Quinnat. The flesh is more compact than that of any other salmon, hence in canning it is boiled longer. In the sea the red salmon is clear sky-blue above, silvery below, without spots. After entering the river, for the purpose of spawning, the color soon changes to crimson, at first bright, but soon blotched with darker and blood-red, the head becoming bright olive green in sharp contrast with the red. The jaws in the male become extravagantly produced and hooked.
This species runs chiefly in July, and often goes for a very long distance. In the Yukon, it ascends to 'Forty Mile,' a distance of over 1,800 miles from the sea. In the Columbia, it ranges as far as the lakes of the Sawtooth range in Idaho. It always spawns in small streams which run into the head of a lake. It never runs in any stream which does not have as a tributary a lake with available spawning grounds in the streams at its head. The red salmon often enters small streams, even those a few feet across, and sometimes in great numbers. The determining factor is always the presence of a suitable lake with spawning beds above it. The lake may be a few rods from the sea as at Boca de Quadra, or it may be many hundreds of miles as in the case of the Columbia, but the lake is always present in every stream in which red salmon run.
In certain large lakes at a distance from the sea, in Idaho, there is a dwarf form of the red salmon, exactly similar to the sea form, but rarely exceeding half a pound in weight. These are probably landlocked in these lakes as both sexes are freely represented among them. At the sea, the dwarf fish running are almost all males. In the spawning season of the Quinnat salmon, many young males but one or two years of age enter the river with the larger fish, spawning precociously, and all dying. Perhaps these dwarf red salmon are simply precocious individuals spawning and dying before their time. No females were seen among these by us at Astoria. In streams of Cook Inlet, there is a late run of very small red salmon, locally known as 'Arctic salmon.' These are doubtless young fish running prematurely. They are not confined to Cook Inlet, but many were seen by us at Karluk. Of a large number examined, all but two were found to be males. The small red-fish running in Necker Bay on Baranof Island are of the same nature. With them are some full grown red salmon. Why this particular stream is attractive to precociously spawning fish is a matter for investigation.
The Silver Salmon.
The silver salmon (Oncorhynchus milktschitsch) is called Coho about Puget Sound, Kisuteh or Bielaya Ryba (white-fish) by the Russians. This species is very similar in size and color to the red salmon. It is distinguished at once by the much smaller number of gill-rakers (23 instead of 37). Its dorsal fin is always black at tip. The flesh is less firm than that of the red salmon, and the scales fall off when the fish is handled, leaving only those along the lateral line. The fine texture and loose attachment of the scales is the most convenient mark to distinguish the silver salmon. In the spawning season it becomes hook-nosed and the color changes to blotchy red. The flesh of the silver salmon is rather pale, without the deep red hue of the red salmon. In flavor it is rather better than the latter, and only the pale color keeps it from ranking with the best of salmon.
The silver salmon runs in the fall and ascends the streams for a short distance only. It remains close in shore. The young can be taken with a seine at almost any time along the shores in Alaska, and these seem to remain in the rivers longer than the young of the other species. The species is taken in small numbers at all the fishing grounds in Alaska. When enough are taken, it is canned as 'Coho' or as 'medium red,' but no dependence can be placed on it. It runs in Alaska from August 15 to September 15. When it begins to run in the streams it is not far from its spawning time, and its flesh is deteriorated. For these reasons, although a fine food-fish, it will never have much economic importance.
The silver salmon is common in the rivers of Japan. The king salmon is unknown in Japan, there being no ice-fed rivers suitable for it. The red salmon runs in a few lakes (as Lake Akan) in the extreme north (Nemuro) of the northern island of Hokkaido or Yeso.
The Humpback Salmon.
The humpback salmon {Oncorhynchus gorbuscha) is known to the Russians as Gorbuscha and to the trade as pink salmon. This is a small fish, seldom weighing over six pounds and often not over three. It differs from the other salmon in its very small scales. The presence of oblong black spots on the tail is also characteristic. Its flesh is soft, very much less firm than in the preceding species. It is pale in color, and without much of the characteristic salmon flavor. When fresh it is fairly palatable and quite wholesome, and the bellies when salted are of good quality. The flesh becomes soft in a short time after death, becoming tainted in 48 hours or less in the cool climate of Alaska. When the species begins to run in the river, its flesh loses the little oil it has and is almost worthless as food. The humpback salmon carries the changes due to the spawning period to an extravagant degree, being hook-jawed, hump-shouldered and distorted more excessively than any other species.
The humpback is the most abundant of the salmon among the Alaskan Islands. It exists in millions, it swarms everywhere in waters near the sea, breeding in brooks, lakes, swamps and brackish estuaries—anywhere where a little fresh water can be found. It runs for a slight distance, and does not go far from the shore. From its great abundance and the ease by which it is taken in nets, this species is exceedingly cheap in Alaska, the individuals costing about a cent apiece. In the large rivers, the humpback rarely runs. It is therefore almost unknown in the Sacramento, the Columbia and even the Eraser River. Small rivers which do not rise in lakes are often crowded with humpbacks. Such streams are known as humpback streams.
The humpback is not found in Japan, where it is replaced by a closely allied species, with unspotted tail, the Masu {Oncorhynchus masou).
The Dog Salmon.
The dog salmon (Oncorhynchus keta) is known also as calico salmon and as chum, to the Russians as Hayko, and in Japan where it is especially abundant as Sake. It is rather larger than the silver salmon, averaging about ten pounds. It is plump and silvery, when taken in the sea, and may then be best distinguished from the red salmon by the tendency of the dark color of the back to form vertical bars on the side. In the breeding season, it becomes largely black, still obscurely barred, and the jaws are greatly elongated and distorted.
The flesh of the dog salmon is very pale, with little of the salmon flavor and none ot its color. When fresh from the sea it is however well-flavored and wholesome. When canned it is dirty white, soft and mushy, and with a strong taste of mud. It is then practically worthless as food. It runs in the rivers in the fall and for very short distances. Its flesh is then still more pale and mushy. It is in fact unfit for canning, and, the few firms who have packed it have been unable to dispose of the goods. The 'Rainbow Brand' was established for dog salmon.
The dog salmon takes salt well. It is the large salmon or saki of Japan, of which great quantities are salted in Japan, and Japan has also furnished a market for the same species salted in Alaska. The dog salmon—taken fresh in spring—is frozen and sent in cold storage to the East and to Germany, where it sells readily. The species is attractive in appearance, and when taken in the sea is good food, although unsuited for canning purposes.
The dog salmon enters all sorts of rivers in the fall, spawning at no great distance from the sea. It is less abundant than any of the other species, although it can be taken in almost any stream from the Columbia River to the rivers of northern Japan.
The relative food value of the five different species of salmon may be well expressed by the five digits, Quinnat five, red salmon four, silver salmon three, humpback salmon two, dog salmon one. The canned product has at the present time approximately the same relation of values, except that the aggregate value of the red salmon now considerably exceeds that of the Quinnat.
The Trout of Alaska.
Besides the five species of salmon, four species of trout are found m Alaska. These may be briefly noticed. The steel head trout (Salmo gairdneri) is frequently taken in the mouths of the large streams, which it enters for the purpose of spawning. It reaches a weight of 10 to 16 pounds. The large examples are valued for purposes of cold storage. The species is sometimes salted, but rarely canned. It is a handsome fish, black spotted, and may be known by the very short head, which it one fifth the whole length to the base of the tail.
The cut-throat trout (Salmo clarki) is found in streams about Sitka and southward to Vancouver Island. It has no economic value in Alaska. Although sometimes weighing 15 to 25 pounds in favorable lakes, it does not ordinarily exceed three pounds. The species may always be known by a concealed dash of scarlet on each side of the throat. This is wanting in the steel-head, which is likewise spotted with black.
The rainbow trout (Salmo irideus) occurs also in Alaska. It has been taken in Naha River at Loring and in some other places. It lacks the red dash of the cut-throat trout and has larger scales. From the steel-head it is separated by its larger head, larger scales and smaller size.
The Dolly Varden (Salvelinus malma), miscalled 'salmon trout' in Alaska, is one of the most abundant fishes in Alaska. It swarms in every stream and enters the sea, where it occasionally reaches the weight of eleven pounds. The young trout are the most persistent enemies of the salmon fry, destroying them by millions, although in turn the salmon feed on the fry of the trout. The Dolly Varden is one of the finest game fish—a fact little appreciated in Alaska. In the rivers, its color is rich dark blue or olive with crimson spots. In the sea, this color changes to steel gray with spots of paler gray.
The trout is an excellent food fish, but of no economic value except about the towns where it may be consumed fresh. It can not be taken in such numbers as the interests of canning require, and it is too small for advantageous sale in cold storage. The Dolly Varden is wholly wanting in the Upper Yukon region.
The Great Lake trout or Mackinaw trout (Cristivomer namaycush) is common in the Yukon region, which has a fauna very much like that of Lake Superior. It abounds in the lakes, takes a hook readily and reaches a weight of 50 pounds or more. A certain number of these are shipped fresh to mining centers, as White Horse and Dawson.
The Streams of Alaska.
The rivers of Alaska, considered in relation to the salmon industry, may be divided into three classes. King salmon streams, red salmon streams and humpback salmon streams. The streams of the first class from a quarter of a mile to a hundred miles wide at the mouth, have a long course and are fed by melting ice or snow, and the course for the most part is not through glacial lakes. In these rivers the king salmon or Quinnat salmon run in the spring, as in the Sacramento or Columbia. With them run also a certain number of red salmon, and in the river mouths humpback, dog and silver salmon. The run of the king salmon is however the chief characteristic. The species in Alaska is less valuable than in the Columbia, because owing to the shorter run the fishes are nearer the spawning season and a large percentage have white meat even in June, a larger percentage than the Columbia shows even in August. For various reasons, rough bottom, fewift current, high tides, etc., most of these streams are not easily fished. In the Stikine River, for example, traps are swept away by the currents, seines are tangled up, a deep gill net will meet an under current of salt water under the fresh water, and is thus upset. The only effective fishing gear is therefore a very shallow gill net floating in the fresh water at the surface. Rivers of the first class are the following: Yukon, Kuskoquim, Shushitna, Copper, Alsek, Taku, Speel, Whiting, Stikine and Unuk Rivers. The streams about Bristol Bay should not be placed in this class, as they flow through lakes and are essentially red salmon streams, in spite of their large size.
The streams of the second class or red salmon streams are those of large or small size which flow through lakes-or have lakes tributary to them. In all these the red salmon runs freely, spawning always in the gravelly bed of the stream at the head of some lake. The four greatest of red salmon streams are the Fraser River, Karluk River, Nushegak River and Kvichak River, all large streams flowing through lakes. In proportion to the amount of water, probably no stream in the world normally carries more salmon than the Karluk River.
The streams of the third class, or humpback salmon streams, comprise the remaining streams of Alaska. These may be large swift rivers as the Skaguay River, or they may be little brooks, in any case not frequented by the king salmon, and having no lake in the course, hence not fit for the red salmon. Their runs are confined to the ignoble species, which ascend for a short distance only. In the larger streams to the northward as Skaguay River and Dyea River, the dog salmon predominates. Southward as in Fish Creek, at Ketchikan and Anan Creek, the humpback salmon predominates, although the humpback is equally common in the red salmon streams. Some of these streams of the third class as Fish Creek flow through lakes. Presumably these lack fit spawning grounds.
The question as to what constitutes the mouth of the river is one of some importance in Alaska. The tides run very high, often twentyfive feet or more, the high tide extending far up the estuaries, which at low tide may be occupied by fresh water. The Naha Stream at Loring flows through a series of lakes, the lowermost of which (Roosevelt Lagoon) lies close to the estuary of the stream, the water flowing from the lake over a considerable waterfall at low water. At high tide this cascade is reversed, the salt water passes by an overfall into the lake, which is thus converted into a brackish lagoon. It is a well separated lake at low water, part of the sea at high water.