S H 
 
 EFFECTS OF THE MENHADEN AND MACKEREL 
 FISHERIES UPON THE FISH SUPPLY ^ ^ ^ 
 
 From BULLETIN OF THE BUREAU OF FISHERIES, Volume XXVIII, 1908 
 
 Proceedings of the Fourth International Fishery Congress : Washington, 1908 
 
 WASHINGTON ::::;: GOVERNMENT PRINTING OFFICE 
 
 1910 
 
Qass 3J12^\ 
 
 Book^ [^^J^ 
 
EFFECTS OF THE MENHADEN AND MACKEREL 
 FISHERIES UPON THE FISH SUPPLY ^ ^ ^ 
 
 From BULLETIN OF THE BUREAU OF FISHERIES, Volume XXVIII, 1908 
 Proceedi?igs of the Fourth Interjtational Fishery Congress : : Washington, igo8 
 
 /\i.\.vO<^<X.UC 
 
 WASHINGTON :::::: GOVERNMENT PRINTING OFFICE :::::: 1910 
 
^^i^^ 
 
 BUREAU OF FISHERIES DOCUMENT NO. 658 
 
 Issued February, 1910 
 
 MAR 2 1910 
 
EFFECTS OF THE MENHADEN AND MACKEREL FISHERIES 
 UPON THE FISH SUPPLY 
 
 J- 
 
 By W. C. Kendall 
 
 Assistant, U. S. Bureau of Fisheries 
 
 J- 
 
 Paper presented before the Fourth International Fishery Congress 
 held at Washington, U. S. A., September 22 to 26, 1908 
 
 279 
 
CONTENTS. 
 
 Page. 
 
 Schooling of fishes 281 
 
 Inadequacy of available information 282 
 
 Habitat and movements of menhaden and mackerel 283 
 
 Spawning migrations of the mackerel ' 287 
 
 Spawning of menhaden 288 
 
 Relation of menhaden to fishes that feed upon them 290 
 
 Conclusion 293 
 
 280 
 
EFFECTS OF THE MENHADEN AND MACKEREL FISHERIES 
 UPON THE FISH SUPPLY. 
 
 By W. C. KENDALL, 
 Assistant, United States Bureau of Fisheries. 
 
 SCHOOUNG OF RSHES. 
 
 There are various degrees of gregariousness among fishes. Probably there are 
 but few fishes that do not swim in schools at some stage of their existence, and 
 there are few, if any, that are always in schools. The very young of most species, 
 as a rule, occur in schools of greater or less extent. The broods of fishes from 
 ova laid in more or less stationary collections or floating agglutinated masses 
 naturally occur in family groups of brothers and sisters. Floating eggs, while 
 sometimes scattered, are perhaps oftener assembled through the effects of winds, 
 minor currents, etc. The young from such eggs to some extent constitute 
 brotherly and sisterly aggregations, though probably they are more frequently 
 mixed broods. Some species commonly regarded as nongregarious are occasion- 
 ally observed in schools in their yoiuig or adult stages. 
 
 The schooling habit is so common among fishes that it must in some way be 
 an advantage to them, although it not infrequently is an obvious and decided 
 disadvantage. The most pronounced types of gregarious fishes are comprised 
 in the scombroid and clupeoid groups, but among the species of these groups 
 there is considerable diversity in respect to the habit. The most representa- 
 tive and perhaps the most perfect examples of the schooling fishes of these two 
 great groups are, respectively, the common mackerel and menhaden. 
 
 The eggs of the mackerel float. They are supposedly deposited at the 
 bottom, whence they rise to the surface and are subject to the influences of winds, 
 waves, and currents, which factors determine whether they shall be scattered or 
 aggregated. 
 
 Practically nothing is known of the place of spawning of the menhaden or the 
 character of its eggs — whether agglutinated, attached to objects, or free, or 
 whether they sink or float. But the fact remains that as soon as the young of 
 either the mackerel or the menhaden are observed they are in schools. The 
 very young of either species have not been observed except in the case of arti- 
 
 281 
 
282 BULLETIN OF THE BUREAU OF FISHERIES. 
 
 ficially hatched mackerel. When naturally hatched mackerel are first observed 
 they are at least 3 or 4 inches long, and menhaden have never been seen under i 
 inch in length. 
 
 Eggs that are stationary" or agglutinated, if they are from a single parent and 
 all subject to the same conditions, will hatch at approximately the same time 
 and produce fish of comparatively uniform size. Aggregations of floating eggs 
 are likely to be derived from several parents, laid at somewhat different 
 times, and consequently will produce young of somewhat more diverse sizes. In 
 both instances the rate of gro\\i:h of individuals varies, causing a difi'erence in 
 size, but on the whole each school of young fish is composed of individuals of 
 fairly uniform sizes. This uniformity appears to be to a great extent perma- 
 nently maintained; yet it not infrequently happens that schools of two or 
 more sizes become mixed, especially when a school is first broken up by any 
 means and the scattered fish subsequently join other schools. 
 
 Whether the schooling habit of the early stage is retained and is the basis 
 of the schools of larger sizes up to adults is impossible to say. That such is the 
 case is indicated by the comparative uniformity in size of individuals of schools 
 of larger fish. Sometimes, however, a school is so large that it could hardly be 
 the original brood or aggregation only, but several, or perhaps many, broods. 
 But such a "raft " is composed of individuals of comparatively uniform sizes, or 
 of sizes suggesting that the fish are of about the same age. 
 
 The occurrence of such extensive " rafts " or " bodies " of uniformly sized fish 
 in the spring of the year suggests that possibly the younger fish have a somewhat 
 different habitat from the older ones at that season of the year when they are 
 beyond observation — that is, after they have "left the coast" and prior to their 
 "return." But, as mentioned in the case of young fish, accidentally mixed 
 schools of older fish of the same species, as well as schools containing unre- 
 lated species, are not uncommon. Mixed schools of large and smaller fish, or 
 schools containing adventitious species, are likely to occur when the schools 
 have been broken up and driven about by predaceous animals or by purse- 
 seiners. Such broken-up schools or straggling individuals, or even small schools, 
 are prone to fall into the procession when a larger body of fish happens along, 
 even though it is of a widely different species, if it is not inimical. Another 
 possible cause of mingling is when the fish are feeding upon the same kind of 
 food and the food happens for any reason to be bunched. 
 
 INADEQUACY OF AVAILABLE INFORMATION. 
 
 Since the History of the American Menhaden, in 1877, and a brief 
 summary of that work in 1884, also by G. Brown Goode, there has been little 
 published regarding the habits of this fish. This history is remarkably compre- 
 hensive, there being hardly a point regarding the menhaden that is not treated 
 more or less exhaustively. The work was, however, an enlargement of manu- 
 
EFFECTS OF THE MENHADEN AND MACKEREL FISHERIES. 283 
 
 script notes furnished by Professor Baird, based upon opinions and information 
 elicited by means of circulars from fishermen, manufacturers, customs officers, 
 light keepers, etc., supplemented to some extent by observations by United 
 States fisheries agents. Doctor Goode states that it was found necessary to 
 make allowances for many inaccuracies of statement on the part of his corre- 
 spondents, and that some of them, having been unable to qbtain exact informa- 
 tion, had ventured to guess at what they did not really know from experience. 
 It might possibly have been added that some of that which they ' ' really did 
 know from experience " may have been inaccurate from misinterpretation of 
 phenomena or errors of observation. Doctor Goode admits also that there 
 remains much to be learned, but presents his views regarding the most plausible 
 theories, which must, until more thorough and systematic investigations are 
 made, take the place of actual knowledge. These theories have taken the place 
 of actual knowledge, so far as publication is concerned, to the present day, for 
 since Goode's History there is no adequate account of the menhaden accessible 
 to the student or the public. 
 
 During the early nineties the United States Bureau of Fisheries made the 
 menhaden and mackerel subjects of special investigation, and a vast amount of 
 data was accumulated , though never utilized , at least in publication. The present 
 writer was engaged in both investigations during those years and has since 
 from time to time had opportunities, of which he has availed himself, to observe 
 both species under various conditions and in various places. It is upon the 
 personal obserx^ations thus made, together with some of the unpublished notes 
 in the files of the Bureau of Fisheries, that this essay is based. Owing to present 
 limits of space, however, the writer is compelled to leave his statements mainly 
 unsupported by any transcription of the copious notes mentioned, and also 
 must assume that the audience is familiar with the published literature upon the 
 species herein treated. 
 
 HABITAT AND MOVEMENTS OF MENHADEN AND MACKEREL. 
 
 That the habits of some fishes of different ages differ to some extent in regard- 
 to their food, and consequently their habitat, is well known. It is a matter of 
 common observation to those who have given attention to the habits of the 
 menhaden that the different sizes, as a rule, are found in different places and 
 under different conditions. The smaller the fish, the shallower the water and 
 the farther up creeks and streams it occurs, even in fresh water. This may be 
 for either or both of two reasons: (i) Owing to different character of food of 
 the different sizes, or (2) for protection against enemies. Perhaps the latter is 
 the more probable. 
 
 Young mackerel 4 to 5 inches long occur sometimes abundantly well up 
 harbors, even about the docks, where larger mackerel never appear. They have 
 been plentiful in Gloucester and Portland harbors, in the former place sometimes 
 
284 BULLETIN OF THE BUREAU OK FISHERIES. 
 
 close to shore in shallow water. As suggested before, in the case of menhaden, 
 they may enter these places for food or for protection, but as they subsist to a 
 great extent upon minute crustaceans which abound outside they could hardly 
 be there solely for the sake of food. 
 
 During the period when they are beyond observation it is, of course, not 
 known to what extent menhaden and mackerel feed. But the inference is that 
 mackerel, at least, and probably menhaden, do not feed during this time, as the 
 fish appearing in the spring, which apparently could be only those of the pre- 
 vious season's production, are about the same size as when they left, and early 
 adult mackerel are always lean. A similar condition seems to obtain to some 
 extent among the menhaden, for often the early menhaden are very poor, 
 according to the reports of the fishermen. It can hardly be imagined that the 
 fish would refrain from eating for a long period if food were plentiful unless they 
 to some extent hibernate. If they do not hibernate — become more or less 
 dormant and inactive — it is hard to explain why they should resort to a foodless 
 region when food abounds in other places. 
 
 In respect to the menhaden, not so much is known regarding its food as is 
 known of the mackerel, but it has been shown to feed to some extent upon 
 minute crustaceans, as do mackerel, and such food abounds in the winter months 
 in the localities that both menhaden and mackerel have apparently left. The 
 natural inference is then that temperature is the controlling factor. Both 
 menhaden and mackerel endure a rather wide range of temperature and both 
 linger late in the fall in northern littoral waters. Rather curiously, young 
 menhaden seem to remain longer than adult fish and will stand reduction of 
 temperature to a low degree. An experiment made by Mr. Vinal Edwards at 
 Woods Hole, which will be described, supports the statement. The ultimate 
 death of the fish may have been due to the sudden changes of conditions to 
 which they were subjected rather than to the low degree of temperature alone. 
 
 On October 1 6 Mr. Edwards placed in the inner pool of the United States 
 fisheries station about i barrel of young menhaden from 2 to 6 inches long. 
 In three or four days they formed together in one school and continued so until 
 December 21, when the temperature fell to 35° F. The school then broke up 
 and scattered about in the pool, some swimming near the surface, others near 
 the bottom. When the sun was shining all would seek the sunny portions of 
 the pool, avoiding the shade. On December 24 the temperature in the pool 
 was 31.5° F. and most of the menhaden swam near the surface but seemed 
 otherwise undisturbed. On December 26 the temperature dropped to 30° and 
 the fish were less active, some swimming on their sides. On the night of Decem- 
 l^er 26-27 it became much colder and snowed, and in the morning all of the fish 
 were dead. 
 
 Thus it would seem that the disappearance of young and old in the late 
 fall is to avoid extreme and sudden changes of temperature. They disappear. 
 
EFFECTS OF THE MENHADEN AND MACKEREL FISHERIES. 285 
 
 but where they go has not been determined. Like all species whose winter 
 quarters are unknown, the menhaden has been consigned by theory to the 
 mysterious depths or contiguities of the Gulf Stream, a region ichthyologically 
 lying beyond the "Pillars of Hercules." Warned by falling temperature, the 
 fish is said to seek a stratum of congenial thermal conditions. All the known 
 facts regarding this species indicate that it makes no extensive coastwise migra- 
 tions, and since the requisite equable temperature, it is thought, can not be 
 found anywhere else, the fish must find it in or near the Gulf Stream, notwith- 
 standing the fact that so little is actually known about the winter conditions 
 there. But why the fish should seek that locaHty for so brief a period has not 
 been shown. Mackerel remain in northern waters until November and Decem- 
 ber and menhaden have been taken in quantities in southern Massachusetts in 
 January, where they reappear in April. 
 
 Waters corresponding in temperature with those to which the fish have 
 been accustomed in the summer or early fall could hardly be conducive to 
 inactivity. Activity necessitates food. If the fish are sojourning in the midst 
 of food and in an active condition, they would necessarily eat. Eating, they 
 would continue fat. But mackerel and menhaden when first seen in the spring 
 are as a rule very thin, indicating abstinence from food. If the fish live among 
 an abundance of food, abstinence must be due to disinclination to eat. Such a 
 condition could be ascribed to some degree of hibernation, but that would 
 be inconsistent with warm waters. If, then, the fish is in such winter abode, 
 it must be assumed that there is little or no food there. This, too, is contrary 
 to the usual conditions. Food such as mackerel subsist on extensively, and 
 menhaden to some degree in early spring, is particularly abundant in the 
 spring, at least, in the Gulf Stream. and its neighborhood. Moreover, dur- 
 ing the alleged fall migrations the fishes are not observed moving offshore. 
 Such movements as are obser\'ed are coastwise. After all, the fish are some- 
 where, but where is yet to be learned. Theory does not satisfy. As spring 
 approaches immense bodies of fish often appear swimming at or near the surface. 
 This appearance of the fish has been ascribed to rising temperature and the 
 breeding instinct. Surely the depths of the Gulf Stream or the equable stratum 
 have not become uncomfortably warm and forced them into the ' ' cold wall ' ' or 
 arctic current? It is conceivable, however, if the fish were at or near the surface 
 of the stream the warming water spread by southerly winds would cause the 
 fish to advance with it. But these conditions are not invariable, and even if 
 they were it would require some other impulse to force them into the much 
 colder northern coastal waters. ' ' Breeding instinct ' ' fails to explain why 
 immature fish are impelled to move in the same way as the adult breeders. 
 
 Let it be assumed that the fish — mackerel, menhaden, or other species — 
 have not gone in the winter ' ' migrations ' ' quite beyond the m3-sterious ' ' pillars ;" 
 that they are lurking somewhere along the coast, outside or within the bays, or 
 
286 BULLETIN OF THE BUREAU OF FISHERIES. 
 
 both, according to the size of the fish; at a greater or less depth, and, if not 
 dormant of hibernating, that they are more or less inactive and disinclined to 
 rise to the surface, where the temperature and other conditions are so variable 
 and subject to sudden changes; that is to say, they are residing quietly at a 
 depth of comparatively constant and uniform temperature, but of such degree 
 that the fish are disinclined to activity, therefore requiring no food, but sub- 
 sisting, as it were, upon the accumulated fat of the previous festal period. The 
 regions, too, where, under this hypothesis, the fish reside are different for those 
 of different sizes ; in this instance, however, not on account of different feeding 
 habits, but owing, perhaps, to the instinct of self-protection. 
 
 It is a well-known fact, as has been previously stated, that young or small- 
 sized menhaden, up to 6 or 8 inches long, linger in the bays long after the larger 
 ones have disappeared. It would therefore seem that the smaller fish are either 
 less susceptible to the changes due to approaching winter, or that some other 
 force predominates over their inclination to leave. 
 
 Granting, then, that the foregoing assumptions are true, when spring brings 
 milder weather and less rigorous and sudden changes, the fish appear at the 
 surface and their movements are again to some extent observable. 
 
 Regarding adult mackerel, it is known that these movements or so-called 
 "migrations" precede the spawning process, but in immature fish — "blinks," 
 "spikes," "tinkers," etc., which have like movements — this can not be so. In 
 menhaden as a whole it is not evident that the spring ' ' migrations ' ' are for 
 spawning purposes. In the adult of both species the growing ova and milt 
 doubtless warn the fish of the approaching "critical period," but this can not 
 be the case with the immature fish. What, then, is the impelling force that 
 causes the fish to come to the siu-face and move about in definite or indefinite 
 directions? If the previously suggested hypothesis is still followed, it may be 
 reasonably assumed that the fish, having consumed their accumulated fat, are 
 impelled by their desire for food. If such is the case their movements will be 
 in search of food and in the line of least resistance. Their subsequent move- 
 ments also, except as controlled by the breeding instinct, whether at the surface 
 or below, will be for food, although they may be directly and indirectly affected 
 by the same meteorological conditions, such as light, temperature, etc. When 
 feeding the schools do not seem to move about very fast in any direction ; there- 
 fore when in rapid motion they are probably in search of "pastures new." In 
 support of this is the well-known fact that fish are seen going swiftly in directions 
 exactly opposite to those that should be followed according to the ' ' migratory ' ' 
 or breeding instinct. Such movements are usually, and sometimes correctly, 
 ascribed to enemies heading them off and driving them in that direction. But 
 if this were true in every case there should be, and surely would be, some further 
 evidence of the enemies ; for whenever the fish have been observed to be pursued 
 by predaceous animals these animals are quite conspicuously manifest. 
 
EFFECTS OF THE MENHADEN AND MACKEREL FISHERIES. 287 
 
 The movements of both mackerel and menhaden when feeding, as men- 
 tioned before, are not rapid from place to place for any great distance, but up 
 and down, here and there, and around and around in that movement termed 
 "cart-wheeling." WTiile the latter movement is considered by many "just 
 play," the manner of occurrence of minute organisms in aggregations of greater 
 or less extent suggests that the fish are circling about in a school of these organ- 
 isms, "scooping them in." 
 
 SPAWNING MIGRATIONS OF THE MACKEREL. 
 
 Regarding the migrations of fishes to their spawning places, every known 
 fact in relation to menhaden points to no extensive migration for the majority 
 of the lish. Mackerel apparently travel greater distances, but there is no 
 evidence in support of the former belief that they traverse the whole length of 
 the coast from Hatteras to Labrador and the Gulf of St. Lawrence. It is hardly 
 possible that one man would have sufficient endurance to obsers'e day and night 
 a body of fish for so long a period, and a change of watch would vitiate the 
 evidence. While it is perhaps possible that a body of mackerel would remain 
 at the surface continuously day and night, it is more than merely probable that 
 it would occasionally sink below the surface. If it did, the observer could not 
 be sure that the fish appearing subsequently were the same school. 
 
 Some years ago mackerel sighted by the seining fleet off Liverpool, Nova 
 Scotia, were "followed" along the coast and around the eastern extremity of 
 Cape Breton. The fish were up and down, sometimes a day or a night elapsing 
 with no fish seen. It was noticed that while the schools of mackerel along the 
 western portion of the Nova Scotia coast had alewives and shad mixed with 
 them, those caught after rounding the eastern end of Cape Breton had none 
 of these adventitious fishes, but many schools were mixed with large herring, 
 called by the fishermen "Newfoundland bloaters." Here, too, the mackerel 
 were somewhat larger than those on the south shore. 
 
 Of course in the nature of things there is nothing to prevent the mackerel 
 constituting the "body" from varying in size in different schools, each school 
 perhaps having different fish mixed with it. But it is hardly probable that 
 had the alewives gone around Cape Breton, or the herring been at the south or 
 west of that point, some would not have been caught there. This gives rise 
 to the suspicion that extensive migration is more apparent than real. 
 
 The condition of the reproductive organs of these fish, too, indicated that 
 they were near the spawning time. According to the observer, each batch 
 examined was thought to be within a week or so of it, which suggests that the 
 fish may have been spawning along the coast. That those caught were not 
 ripe ofters no contra-argument. For it is possible that as the fish ripened they 
 sank to some depth below the surface, where they spawned, and occasional few 
 spent fish indicated that all did not reappear immediately afterwards. It is 
 
288 BULLETIN OF THE BUREAU OF FISHERIES. 
 
 well known that some fishes linger on their spawning grounds long after they 
 have spawned, and it is not impossible that mackerel remain near the place 
 where the spawn is deposited for some time afterwards. The same may be said 
 of menhaden. In support of this is the fact that sooner or later all adult men- 
 haden disappear from the Virginia shores and, temporarily at least, from the 
 Carolina coast. There are not wanting fishermen, however, who aver that they 
 catch menhaden along the CaroHna shores at any time in suitable weather 
 throughout the winter. 
 
 SPAWNING OF MENHADEN. 
 
 The time, place, manner, and duration of the spawning act of the menhaden 
 are not known, and such meager data as are available on that subject are con- 
 fusing. Direct observations by persons qualified to solve the problem have not 
 been, made, and the testimony of those who handle the greatest number of the 
 fish is contradictory; individuals not infrequently change their Aaews — some- 
 times even while being interviewed. Conjecture, however, is not evidence, and 
 until thorough observations are made throughout the year the question can not 
 be positivelv settled. But careful study of such data as are at hand suggests 
 that there is no one definite spawning season such as appears to be the case 
 with mackerel, but that the conditions are analogous to those of the common 
 herring, which spawns in some localities in spring or early summer and in others 
 in late fall or early winter, and perhaps more or less all summer. Some men- 
 haden taken in Buzzards Bay throughout May and June up to July 15 are well 
 advanced, and a few ripe fish have been observed; but of the many examined 
 few are found that are more than "well advanced," and it is unsatisfactory 
 to try to estimate the length of time necessary to ripen the "well-advanced" 
 fish. Out of 500 large menhaden taken at Sakonnet, R. I., on July 5, 1892, 
 410 were females in various stages of development from very small to "nearly 
 ripe." Of the 90 males, the majority contained milt "well advanced" and 
 some were "ripe." From November 17 to 20, during the same season, at North 
 Truro, Cape Cod, large menhaden were found with ova and milt in various 
 degrees of development, some males being "well advanced" and a few females 
 "nearly mature." 
 
 From the last part of October to the first of December, 1894, a large body 
 of menhaden was observed to extend from Delaware Bay to Cape Lookout, 
 "outside." These fish differed in appearance from the few taken within the 
 bays at this time, being longer and their reproductive organs apparently very 
 near maturity. Very many taken off' Chesapeake Bay were examined, and the 
 organs of those over 10.5 inches long always seemed to be in the same condition, 
 which the observer could account for in no other way than that the fish were 
 passing south toward warmer water to spawn. Subsequent obseiv^ations off the 
 
EFFECTS OF THE MENHADEN AND MACKEREL FISHERIES. 289 
 
 coast of North Carolina in the vicinity of Beaufort, however, revealed hardly any 
 appreciable change in the conditions of the reproductive organs. 
 
 It is the consensus of opinion among the fishermen of the Chesapeake that 
 the "bay menhaden" spawn in February and March, and they present evidence 
 to that effect. But they believe that the outside fish in late fall spawn at sea 
 near the Gulf Stream or off the coast farther south. 
 
 In May, 1908, there was received at the United States National Museum 
 a portion of a menhaden the length of which indicated that the whole fish 
 was about 13 inches long. It contained undoubtedly nearly ripe roe. It was 
 caught in the Chesapeake on the 8th of April and was brought in to Solomons, 
 Calvert County, Md. This suggests, at least, that the opinions and statements 
 of the fishermen regarding the spring spawning of menhaden in the Chesapeake 
 may be correct. 
 
 The above-mentioned occurrence of large bodies of menhaden outside, 
 apparently near spawning condition, suggests also a fall or early winter spawn- 
 ing in that region, as do the data regarding the fish at North Truro. But the 
 lack of knowledge regarding the length of time that would be required for the 
 ova to mature prevents positive conclusions, for, instead of a few days or a week 
 or two, a month or two or more might be necessary. The latter condition would 
 bring the fish to maturity in February or March. In favor of the fall spawning, 
 however, is the fact that a few undoubtedly recently spent fish were secured. 
 
 The evidence derived from young fish is unsatisfactory, since very little is 
 known of their rate of growth. Young menhaden are seldom seen in the Woods 
 Hole (Mass.) region before July, when they range from i^ to 3 inches in length, 
 more often from i ' < to 2 inches. In November in the same locality they range 
 from 2 to 5 inches in length, the majority being about 3 inches long, and all 
 through the season there is another lot of immature fish, which, perhaps, average 
 8 inches in length. 
 
 In Chesapeake Bay young menhaden are said to appear in May, when they 
 run from i '^ to 2 inches in length. In March, 1894, young menhaden from 4 and 
 5 to 6 and 8 inches long were collected, and again in July from i X to 5 inches. 
 This indicates that there are two stocks of young fish — the earlier, perhaps, from 
 the breed of the previous fall, and the later and smaller from that of the spring 
 of the same year. 
 
 It has been suggested, because adult menhaden are seen far up bays and 
 streams and the. young are found still farther up, that the fish spawn in these 
 localities; but there is nothing to indicate this. Fish, especially the young, run 
 into shallow waters and often long distances up streams — even to the head- 
 waters of small streams and creeks — probably, as has been previously stated, to 
 escape enemies. 
 
 The most that can be said regarding the spawning places of menhaden is 
 that nothing is positively known. 
 
 B. U. F. 1908—19 
 
290 BULLETIN OF THE BUREAU OF FISHERIES. 
 
 RELATION OF MENHADEN TO FISHES THAT FEED UPON THEM. 
 
 Goode says: 
 
 Among the enemies of menhaden may be counted every predaceous animal which 
 swims in the same waters. Whales and dolphins follow the schools and consume them 
 by the hogshead. Sharks of all kinds prey upon them largely ; one hundred have been 
 taken from the stomach of one shark. All large carnivorous fishes feed upon them. 
 The tunny is the most destructive. * * * The pollock, the whiting, the striped 
 bass, the cod, the squeteague, and the garfish are savage foes. The swordfish and the 
 bavonet fish destroy many, rushing through the schools and striking right and left with 
 their powerful swords. The bluefish and bonito are, however, the most destructive 
 enemies, not even excepting man; these corsairs of the sea, not content with what thev 
 eat, which is of itself an enormous quantity, rush ravenously through the closely crowded 
 schools, cutting and tearing the living fish as they go, and leaving in their wake the 
 mangled fragments. Traces of their carnage remain for weeks in the great "slicks" 
 of oil so commonly seen on smooth water in summer. * * * I estimate the total 
 number destroyed annually on our coast at a million million of millions; in comparison 
 with which the quantities destroyed by men yearly sink into insignificance. 
 
 Such estimates, Goode states, are only approximate. It may be a question 
 as to whether they are even approximate. If he deduces his estimates from a 
 sufficient number of well-estabhshed facts, they may be considered approximate; 
 but the evidence is that he reaches his conclusion by induction from a limited 
 number of facts. One shark is known to have eaten 100 menhaden. One shark 
 might contain 1,000 menhaden as a day's feast, but that would not be sufficient 
 evidence upon which to base a conclusion that all sharks eat 1,000 menhaden 
 each day in the year. One tunny may have been observed to almost annihilate 
 a school of menhaden, but it does not follow that all the tunnies in the region 
 consume a school of menhaden each every day. A school of bluelish is occa- 
 sionally seen to wreak havoc upon hundreds of menhaden, but it does not suffi- 
 ciently indicate that they do it every day. One squeteague having been found 
 to devour nearly 50 menhaden does not clearly prove that the exclusive menu of 
 the squeteague is nearly 50 menhaden a day. An average of 100 menhaden a 
 day to a shark or its equivalent for three hundred days would require 333,333,- 
 333,333,333 sharks, or their equivalent in eating capacity, to devour a million 
 million of millions menhaden in that length of time. 
 
 It is not a justifiable assumption that all of the predaceous animals previously 
 enumerated feed exclusively and daily upon menhaden, even during the time 
 that they are concurrently on the coast. Among fishes concerning whose habits 
 we are better informed than those under discussion, it is known that they change 
 their diet from time to time, and there are periods of days when they do not feed 
 at all. One is almost as fully justified in assuming that a fish which is found to 
 have eaten nothing during the day does not feed at all as that one found to con- 
 tain a few menhaden feeds continuously and exclusively upon menhaden. Yet 
 undoubtedly enormous quantities of menhaden are destroyed annually by fishes 
 and other predaceous animals. Professor Goode further remarks that in estimat- 
 ing the importance of the menhaden to the United States it should be borne in 
 
EFFECTS OF THE MENHADEN AND MACKEREL FISHERIES. 29 1 
 
 mind that its absence from our waters would probably reduce all our other sea 
 fisheries to at least one-fourth their present extent. If his premises are sound, 
 the estimate is probably approximately correct, otherwise it is subject to criti- 
 cism. In the Gulf of St. Lawrence, where, for a portion of the year at least, the 
 principal food of the cod is capelin and herring, the absence of these foods is 
 concomitant with the absence of cod. 
 
 In the second report of the Commissioner of Fisheries of the United States, 
 Baird ascribes the decadence of the inshore cod fishery of New England to the 
 enormous diminution in the number of alewives; "at least," he says, "the 
 coincidence is remarkable." If the same relation is known to exist between 
 the cod and the alewives on the New England coast as between the cod and 
 herring or capelin in the Gulf of St. Lawrence, then such a conclusion is well 
 founded. But as it is not shown to be a fact, it can be considered only a con- 
 jecture. Surmises based on coincidences will not solve problems. Therefore, 
 in order to determine even with any degree of approximation the effects of 
 the reduction in numbers of any species in our waters upon other species to 
 any extent feeding upon them, the habits of not only these forms but others 
 as well must be very thoroughly known in all their intricate interrelations. 
 
 The list of fishes enumerated by Goode as destructive enemies of men- 
 haden does not comprise all the species that at times eat menhaden, and it 
 includes some that are not known to feed upon them at all. The assumption 
 that they do is made partly from the fact that they are built on the model of 
 predaceous fishes, and partly because they are sometimes caught on menhaden 
 bait. The first part is to some extent justified, since it is safe to assume that 
 a species which to any extent eats other fishes will eat menhaden if it can get 
 them; but it is not safe to infer that it consumes enormous quantities, as its 
 habits may be such that it is not brought in contact with such numbers, or food 
 which it prefers may be at the same time present. That a fish is caught on 
 certain kinds of bait or that the bait is the most successful to use does not 
 signify that the principal food of the fish is the species used as bait. Not 
 infrequently the best bait for some fishes is something that does not coinhabit 
 those waters. 
 
 To what extent any species subsists upon menhaden and the number of 
 species that feeds to some extent upon them is not known. Therefore no 
 reliable deductions can be made regarding the effect upon such fishes were 
 they deprived of the supply of menhaden. However, every menhaden caught 
 reduces the number of those fish by one ; every thousand or million reduces the 
 number by a thousand or a million. Therefore the menhaden fisheries must, 
 theoretically at least, have their effect upon the species that feed upon the men- 
 haden by depriving them of so much food. They also have effect upon the 
 menhaden sought by rendering those that escape captiu-e more Hable to be eaten 
 by predaceous enemies. 
 
292 BUI.LETIN OK THE BUREAU OF FISHERIES. 
 
 Whether the effects of fishing are of appreciable injury to the fish depends 
 upon the time, place, and amount of fishing, as well as upon the habits of the 
 fish and the number caught. If the fish have a limited spawning ground to 
 which they resort every year — for instance, a small bay, estuary, or mouth of 
 a stream — constant fishing with piu'se seines and obstructive poimds and traps 
 must necessarily seriously affect the number of fish reaching the spawning 
 ground, consequently the number produced that season. And if such fishing 
 is carried on at or near every spawning place of the species, as well as at a dis- 
 tance from it, the injurious effects would obviously be still greater, and in time 
 would result in a diminished number of the species. If the species is greatly 
 reduced in numbers, then the food supply of the fishes depending upon this 
 particular species for subsistence is correspondingly reduced. The consequence 
 of this would be that this species would be reduced by starvation or would be 
 forced to depend upon other species for food. The latter is the most natural 
 effect, and this in turn would deprive still other species of their food or reduce 
 their numbers either as adults or young, or both. Other species being deprived 
 of their food would repeat the process, and thus it would go on until nothing 
 remained. 
 
 While such a condition is theoretically conceivable, it is not so in fact, 
 except to the extent that if for any reason the food of a species is withdrawn 
 the species disappears, doubtless in search of food elsewhere, and when its prin- 
 cipal food is abundant the fish feeding upon it would naturally be plentiful. 
 Exceptions that might be cited may be only apparent, for, as has been pre- 
 viously suggested, probably no fish feeds exclusively upon any one thing or 
 depends upon any one species. The shark, tunny, or bluefish would hardly 
 be likely to distinguish schools of menhaden from schools of other silvery fishes 
 like the alewives, which sometimes equally abound with the menhaden along 
 the coast. Thus the absence of bluefish from any section when menhaden 
 are present or the presence of bluefish when menhaden are absent in each 
 instance is due to the same thing — the presence of satisfactory food in one 
 place or the other. There is no doubt that the bluefish disastrously pursues 
 menhaden, but it is known to pursue other species with equal disaster. 
 
 The effects of the complete extermination of menhaden from the seas may 
 be inferred from the effects of local disappearances for a term of years and 
 where there is no evidence that the fishes that fed upon them there suffered 
 in consequence of their departure. It may with propriety be stated here that 
 such " unaccountable " disappearances took place long before modem fish 
 traps and purse seines were known. Subsequent like disappearances and 
 reappearances, again disappearances without reappearances, can not, then, 
 logically be laid to the purse seines and steamers. But there can be no doubt 
 in the minds of those who have observed the operations of menhaden and 
 mackerel purse seines that there is at least a temporary more or less modifying 
 
EFFECTS OF THE MENHADEN AND MACKEREL FISHERIES. 293 
 
 effect upon the movements of the schools of fish. It may still, however, be 
 an open question whether the mackerel have not always been fully as intelli- 
 gent as they now seem to be when they evade the nets so successfully that the 
 fishermen call them "educated fish." 
 
 CONCLUSION. 
 
 In this paper there has been no attempt to explain the mysterious phe- 
 nomena exhibited by the fishes discussed, but merely to suggest lines of inves- 
 tigation that might be worth making. There have been frequent more or less 
 critical references to the contributions of Baird and Goode, but with no wish 
 to attempt to controvert any of their sound arguments. The theories advanced 
 by them are as logical and sound as the evidence upon which they were based 
 would permit, since the conclusions were reached by assembling and sifting 
 the testimony of unscientific observers. Such evidence is difficult to collate 
 satisfactorily, owing to the more than frequently contradictory character of 
 even that obtained from intelligent, observant, and equally honest persons. 
 The views of the purse seiner may be quite contrary to those of the gill netter, 
 trap, or pound fisherman, yet each probably is honestly convinced of the 
 correctness of his views. 
 
 It is needless to say that in this paper few, if any, new facts have been 
 added to the knowledge of the fishes to which it refers. But its object will 
 be attained if, by indicating possible errors in the theories previously held, it 
 causes a realization of the prevalent profoimd ignorance regarding the greater 
 part of the life of many of our common and commercially important fishes 
 and almost total lack of knowledge of the habits and life history of the men- 
 haden, and thus proves instrumental in instigating the much needed thorough, 
 systematic investigations of those subjects.