The Harvest of the Sea / A contribution to the natural and economic history of the British food fishes

by James Glass Bertram

Before the reading of Mr. Cleghorn’s statistics, the natural history of the herring was not well understood even by naturalists; so difficult is it to make observations in the laboratories of the sea. Only a few persons, till recently, were intimate with the history of this fish, and knew that, instead of being a migratory animal, as had been asserted by Anderson and Pennant, the herring was as local to particular coasts as the salmon to particular rivers.

The late Mr. J. M. Mitchell, the Belgian Consul at Leith (who published a work on the National Importance of the Herring), in a paper which he read before the British Association at Oxford, three years ago, settled with much care and very effectually the geographical part of the herring question. His idea also is that the herring is a native of the coast on which it is found, and that immediately after spawning the full-sized herrings make at once for the deep waters of their own neighbourhood, where they feed till the spawning season again induces them to seek the shallow water. Mr. Mitchell gives his reasons, and states that the herrings resorting to the various localities have marked differences in size, shape, or quality; those of each particular coast having a distinct and specific character which cannot be mistaken; and so well determined are those particulars that practical men, on seeing the herrings, can at once pronounce the locality from whence they come; as, indeed, is the case with salmon, turbot, and many other fishes and crustaceans.

On the southern coast of Greenland the herring is a rare fish; and, according to Crantz, only a small variety is found on the northern shore, nor has it been observed in any number in the proper icy seas—as it would undoubtedly have been had it resorted thither in such innumerable quantities as was imagined by the naturalists of the last century. Another proof that the herring is local to the coasts of Britain lies in the fact of the different varieties brought to our own markets. As expert fishers know the salmon of particular rivers, so do some men know the different localities of our herring from merely glancing at the fish. A Lochfyne fish differs in appearance from a herring taken off the coast of Caithness, while the latter again differs from those taken by the Dunbar boats off the Isle of May. Experienced fishmongers know the different localities of the same kinds of fish as easily as a farmer will separate a Cheviot sheep from a Southdown. Thus they can at once distinguish a Severn salmon from one caught in the Tweed or the Spey, and they can tell at a glance a Lochfyne matie from a Firth of Forth one.

Turning now to the report of the commissioners appointed to inquire into the operation of the Acts relating to trawling for herring on the west coast of Scotland, we obtain some interesting information as to the spawning and growth of the herring. Upon these branches of the subject the public have hitherto been very ill informed. As has been already stated, Yarrell’s account of this particular fish is a mere compilation from Dr. M’Culloch, W. H. Maxwell, Dr. Parnell, and others, and is thus very disappointing. Again, the account in the Naturalist’s Library is compressed into five small pages, referring chiefly to authorities on the subject, with quotations from Yarrell! It is only by searching in Blue Books, by perusing much newspaper writing of a controversial kind, and by arduous personal inquiry, that I have been able to complete anything like an accurate precis of the natural and economic history of this very plentiful fish.

As to the periods at which herrings spawn, the commissioners appointed to conduct the latest inquiry that has been made inform us that they met with “singularly contradictory” statements, and after having collected a large amount of valuable evidence, they arrived at the conclusion that herrings spawn at two seasons of the year—viz. in the spring and autumn. They have no evidence of a spawning during the solstitial months—viz. June and December; but in nearly all the other months gravid herrings are found, and the commissioners assert that a spring spawning certainly occurs in the latter part of January, as also in the three following months, and the autumn spawning in the latter end of July, and likewise in the following months up to November: “Taking all parts of the British coast together, February and March are the great months for the spring spawning, and August and September for the autumn spawning.” The spawn, it may be stated in passing, is deposited on the surface of the stones, shingle, and gravel, and on old shells, at the various spawning places, and it adheres tenaciously to whatever it happens to fall upon. This, as will be seen, brings us exactly back to Mr. Cleghorn’s ideas of the herring existing in races at different places and in separate bodies, and thereby rendering the fluctuations of the great series of shoals at Wick more and more intelligible, especially when we take into account the fact that winter shoals have recently been found at that place, giving rise to what may ultimately prove a considerable addition to the great autumn fishery yet carried on there. Indeed I consider this point proved, and having taken great pains in sifting the evidence (of different spawning seasons) given on the question, both oral and written, I feel entitled to say so much.

As to the question of how long herrings take to grow, from the period of the deposition of the egg, there are various opinions, for no naturalist or practical fisherman has been able definitely to fix the time. There is reason to believe, we are told in the report, that the eggs of herrings are hatched in, at most, from two to three weeks after deposition. This is very rapid work when we consider that the eggs of the salmon require to be left for a period of ninety or a hundred days, even in favourable seasons, before they quicken into life, and that the eggs of a considerable number of fish are known to take a much longer period than three weeks to ripen. The rate of growth of the herring, and the tie at which it begins to reproduce itself, are not yet well understood; indeed, it seems particularly difficult to fix the period at which it reaches the reproductive stage.[8] I have had young herrings of all sizes in my possession, from those of an inch long upwards. The following are the measurements of a few specimens which were procured about the end of February 1861, and not one of which had any appearance of either roe or milt, while some (the smaller fish) were strongly serrated in the abdominal line, and others, as they advanced in size, lost this distinguishing mark, and were only very slightly serrated. The largest of these fish—and they must all have been caught at one time—was eight inches long, nearly four inches in circumference at the thickest part of the body, and weighed a little over two ounces. The smallest of these herring-fry did not weigh a quarter of an ounce, and was not quite three inches in length. One of them, again, that was six inches long, only weighed three-quarters of an ounce; whilst another of the same lot, four and a half inches long, weighed a quarter of an ounce exactly. I do not propose at present to enter at great length into the sprat controversy; but, if the sprat be the young of some one of the different species of herring, as I take leave to think it is, then the question of its growth and natural economy will become highly important. Some people say that the herring must have attained the age of seven years before it can yield milt or roe, whilst a period of three years has been also named as the ultimate time of this event; but there are persons who think that the herring attains its reproductive power in eighteen months, while others affirm that the fish grows to maturity in little more than half that time. If the average size of a herring may be stated as eleven and a half inches, individual fish of Clupea harengus have been found measuring seventeen inches, and full fish have been taken only ten inches in length, when should the example, noted above as being eight inches long, reach its full growth? and how old was it at the time of its capture? And, again, were the fish—all taken out of the same boat, be it observed, and caught in the same shoal—all of one particular year’s hatching? Is this the story of the parr over again, or is it the case that the fishermen had found a shoal of mixed herrings—some being of one year’s spawning, some of another? I confess to being puzzled, and may again remind the reader that my largest fish had never spawned, and had not the faintest trace of milt or roe within it. Then, again, as to the time when herrings spawn, I have over and over again asserted in various quarters that they spawn in nearly every month of the year—an assertion, as I have just shown, which has been proved by the recent inquiry.

As to the place of spawning, development of the ova, and other circumstances attendant on the increase of the herring, I promulgated the following opinions some years ago, and I see no reason to alter them:—The herring shoal keeps well together till the time of spawning, whatever the fish may do after that event. Some naturalists think that the shoal breaks up after it spawns, and that the herring then live an individual life, till again instinctively moved together for the grand purpose of procreating their kind. It is quite clear, I think, that the herring moves into the shallow water because of its increased temperature, and its being more fitted in consequence for the speedy vivifying of the spawn. The same shoal will always gather over the same spawning ground, and the fish will keep their position till they fulfil the grand object of their life. The herrings will rise buoyantly to the top water after they have spawned; before that they swim deep and hug the ground. The herring, in my opinion, must have a rocky place to spawn upon, with a vegetable growth of some kind to receive the roe; shoals may of course accidentally spawn on soft ground. It is not accurately known how long a period elapses till the spawn ripens into life. I think, however, that herring spawn requires a period of about six weeks to ripen. It is known that young herrings have appeared on a spawning ground in myriads within fifty days after the departure of a shoal, and fishermen say that no spawn can be found on the ground after the lapse of a few weeks from the visit of the gravid shoal—that the eggs in fact have come to life, and that the fish are swimming about; and some fishermen assert that the little whitebait is the herring in its first stage.

It is generally known that the sprat (Clupea sprattus) is a most abundant fish, so plentiful as to have been used at times for manure. The fact of its great abundance has induced a belief that it is not a distinct species of fish, but is, in reality, the young of the herring. It is true that many distinguishing marks are pointed out as belonging only to the sprat—such as its serrated belly, the relative position of the fins, etc. But there remains, on the other side, the very striking fact of the sprat being rarely found with either milt or roe; indeed, the only case I know of this fish having been found in a condition to perpetuate its species was detailed by the late Mr. Mitchell, Belgian Consul at Leith, who exhibited before one of the learned societies of Edinburgh a pair of sprats having the roe and milt fully developed. Dr. Dod, an ancient anatomist, says: “It is evident that sprats are young herrings. They appear immediately after the herrings are gone, and seem to be the spawn just vivified, if I may use the expression. A more undeniable proof of their being so is in their anatomy; since, on the closest search, no difference but size can be found between them.” After the nonsense which was at one time written about the parr, and considering the anomalies of salmon growth, it would be unsafe to dogmatise on the sprat question. As to the serrated belly, we might look upon it as we do the tucks of a child’s frock—viz. as a provision for growth. The fin-rays of this fish have also been cited in evidence as not being the same in number as those of the herring, but as I can testify, from actual counting, the fin-rays of the latter fish vary considerably, therefore the number of fin-rays is not evidence in the case. The slaughter of sprats which is annually carried on in our seas is, I suspect, as decided a killing of the goose for the sake of the golden eggs as the grilse-slaughter which is annually carried on in our salmon rivers.

The herring is found under four different conditions:—1st, Fry or sill; 2d, Maties or fat herring; 3d, Full herring; 4th, Shotten or spent herring. All herrings under five or six inches in length come under the first denomination. The matie is the finest condition in which a herring can be used for food purposes; and if the fishery could be so arranged, that is the time at which it should be caught for consumption. At that period it is very fat, its feeding-power being all developed on its body; the spawn is small, the growth of the roe or milt not having yet demanded the whole of the nutriment taken by the fish. A full herring is one in which the milt or roe is fully developed. The maties develop into spawning herring with great rapidity—in the course of three months, it is said. The herrings at the spawning season come together in vast numbers, and proceed to their spawning places in the shallower and consequently warmer parts of the sea. As Gilbert White says, “the two great motives which regulate the brute creation are love and hunger; the one incites them to perpetuate their kind, the latter induces them to preserve individuals.” In obedience to these laws the herring congregate on our coast, for there only they find an abundant supply of food to mature with the necessary rapidity their milt and roe, as well as a sea-bottom fitted to receive their spawn; and they are thus brought within the reach of man at what many persons consider the wrong time of their life.