QL 626 U5313 no.16 c.2

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- Atlantic Herring 2 Underwater World

Atlantic Herring Description Distribution and migration Atlantic herring (Clupea harengus), In the northeast Atlantic, the herring one of the best known of open-sea fish is found from Spitzbergen, north of lthough Canadians have been on Canada's east coast, comprise more Norway, to Gibraltar, at the entrance eating Atlantic herring canned as than one fifth of the area's annual fish- of the Mediterranean. It is also found Asardines since the 1870s, many are not eries catch, with a total value in 1978 of in the Baltic Sea and the Gulf of Fin- aware that these are not the true sar- more than $125 million. land. In the northwest Atlantic, the dines of the genus Sardinops, which The Atlantic herring is a member of Atlantic herring ranges from northern are not found in Canada. Over the the Clupeidae family found in many Labrador and Greenland to North years, Atlantic herring also have been parts of the world, including some Caroli na. salted, smoked, or used as bait or ferti- species living in inland lakes. Among Herring form schools and migrate to lizer and by 1968 most Canadian her- Clupeidae on Canada's east coast are "spawning grounds" in order to repro- ring catches were being reduced to fish- the blueback herring, the gaspereau or duce. Those that spawn in the spring meal or oil. alewife, the shad and the menhaden. In usually do so in shallow, inshore However, with the failure of several the Bay of Fundy, juvenile herring are waters, while fall spawners reproduce major herring fisheries around the known as sardines. in somewhat deeper water, or on off- world in the early l 970s, demand in- The Atlantic herring has a stream- shore banks. creased for Canadian herring. Prices to lined, elongated body, much deeper It is not clear what factors control fishermen rose from an average of one than it is thick, with an iridescent steel- the timing and locality of spawning. cent a pound in 1969 to 12 cents a blue or greenish-blue back and silvery Some fishermen daim it is precisely pound in 1979. sides and belly that provide excellent related to the lunar cycle. Because of Now herring is seldom used for fish- camouflage in the open sea. It has a manpower and funding restrictions, meal production. It is more often deeply-forked tail, large loosely- this idea has never been fully evaluated found on the shelves of supermarkets attached scales and a single dorsal fin by scientists and the existing evidence is as Canadian sardines, and a good pro- on the back. contradictory. ln the southwest Gulf of portion is sold in Europe as frozen St. Lawrence, the peak of spring fillets . spawning is apparently related to the water temperature. However, there is also evidence of a fixed number of waves of spring spawners regulated by factors other than water temperature. Fall spawners reproduce at very dif- ferent temperatures than spring spawn- ers in the same area. On Canada's east coast, tagging studies have shown that herring migra te extensively. Tagging in the southern Gulf of St. Lawrence in 1970 and 1971 showed that the main compo- nent of the adult stock overwinters in the deep fjords of southwest Ouebec Newfoundland. In the spring the fish migrate across the Cabot Strait toward the spawning grounds and rich feeding areas of the Gulf. Spring spawning occurs along the Gaspé and Maritimes coastline, and fall spawning is locally important mainly in the Gaspé and northern New Brunswick areas. Feeding concentra- , tions of herring may be found on American Bank, Bradelle Bank, Or- phan Bank and Fisherman's Bank. In November, most adults return to New- foundland. But the large overwintering concentrations in that area disappeared

30 fathom line in the early 1970s, probably as a result

------100 fathom line of high fish catches during that period. Underwater World 3

An early spring fishery on the "Edge" For example, 25-centimetre spring- and slowed when year-old herring (year of the Laurentian Channel started at spawning herring in Chaleur Bay were classes) are abundant. Still other the same time but has recently been dis- found to contain about 30,000 eggs. At studies show fewer larvae survive if continued. 30 centimetres they produced 60,000 adults are abundant, due to predation The major stock of fall-spawning eggs, and at 35 centimetres there were by adult herring. There is also evidence herring off southwest Nova Scotia al- 130,000 eggs. The total weight of eggs that in the Gulf of St. Lawence fewer so undertakes complex migrations. produced also increases faster than the larvae and juvenile herring survive if Spawning is concentrated on the Trin- total weight of the fish. For spring the abundance of mackerel, a major ity and Lurcher Shoals area off Yar- spawners in Newfoundland, internai predator, increases. mouth. Much of the adult stock then eggs are about 28 per cent of the total Clarifying these relationships for migrates up the Nova Scotia coast to weight of herring weighing 200 grams, specific stocks could be very useful for winter in the area around Chedabucto but 40 per cent of the weight of stock management. For example, while Bay. In the spring they migra te to the 400-gram herring. it may be desirable to maintain a high Bay of Fundy where they feed during Fall spawners are about 50 per cent population biomass to encourage egg the summer off the south and more fertile than spring spawners of production, a high abundance of southwest coasts of Nova Scotia before the same length. Thirty-five-centimetre adults may lead to excessive preying on continuing to the spawning grounds. fall spawners in Chaleur Bay produce larvae, or too many larvae could mean Large concentrations of juvenile more than 200,000 eggs per female. slower growth rates. The information herring (sardines) also spend the The high productivity of fall spawners now available on any one stock is not summer along the New Brunswick is probably due to warmer water and sufficient to make management deci- coast of the Bay of Fundy and their greater availability of food during the sions on the basis of these relation- presence supports a large weir fishery summer months before spawning, ships. there. compared to the conditions in March Herring are the prey of a number of Life History and April before spring spawning. pelagic, or open-sea, predators, such as The length and age at sexual matu- Obviously, maintaining an abundant cod, silver hake, salmon, tuna, sharks, rity have varied in Canadian popula- fishable population of herring is not as dogfish, squid, sea birds, seals and tions of the Atlantic herring. It appears simple as the production of eggs. Egg whales. Herring may also fall victim to that to a certain extent herring become and larval mortality is very high, and disease. The most disastrous incident sexually mature at a smaller size as the only a tiny minority of fertilized eggs of this sort occurred between 1954 and population diminishes. Also, they have survive to become juvenile herring. 1956 when most herring in the southern been exploited by the fishery at During spawning, eggs and milt (sperm Gulf of St. Lawrence juvenile fish de- seabed until hatching, which takes ing. But for most herring populations, creased considerably, while the length about 30 days at 5°C, a typical spring fishing is still the most important cause of the majority of mature males and spawning temperature, and only 10 of mortality. Depending on the stock, females dropped from 27 .3 centimetres days at 15 °C, typical of Gulf of St. between 10 and 40 per cent of adult to 25 .6 centimetres. Lawrence fall spawning temperatures. herring are captured every year. As a rule, the youngest mature her- Fall-spawned eggs off southwest Nova The herring's principal food is tiny ring are three years old, and almost all Scotia develop at about 10°C. crustaceans, such as copepods and are mature by age five. ln 1978 in the Before 1970, when most populations euphausids. They also consume eggs, southern Gulf of St. Lawrence, three- were more abundant than they are larvae and any other organisms which year-olds were about 25 centimetres now, the water would turn white over are small enough to enter their mouths. long, while five-year-olds were 30 inshore spawning beds due to the Herring are filter feeders - they use centimetres long. Growth rates, how- release of milt from male spawners. their gills to filter food organisms from ever, vary between and within stocks Storms would carry waves of eggs onto the plankton in the water. over time. These variations are not the beaches, where in some localities fully understood, but are certainly they were shovelled into wagons and influenced by the water temperature used to fertilize the fields. Eggs are also and population size. Higher water eaten by groundfish like cod and had- temperatures often mean faster growth dock, and various flounders. rates, white competition in a larger The subsequent survival and growth population will restrain growth. of larvae and juveniles is still at the Fecundity (the production of eggs frontier of biological research. Sorne per female) accelerates as fish grow. studies have found that growth is accelerated by warmer temperatures Underwater World 4

Fishery 1975. But in recent years, most west Prior to the mid 1960s, in most areas coast landings have been attributable of Atlantic Canada, herring were to inshore fishermen. The total catch caught by small inshore boats using gill reached a record 18,000 tin 1979. nets or traps, or in weirs. Catches - The 1968 year-class of herring was made almost exclusively during spawn- abundant around the Newfoundland ing runs - were limited more by mar- coast, permitting the development of a kets than by abundance of fish. This mobile purse-seine and ring-net fleet situation has changed radically with during the early 1970s. On the east the majority of the catch now being coast, landings reached a record taken by large vessels using purse 26,000 tin 1979, when the inshore fish- seines. ery caught 70 per cent of the herring. In the Magdalen Islands, fishermen Fishing, however, will have to be catch spring spawning herring of the severely controlled during the early southern Gulf stock with floating trap 1980s, due to poor recruitment and a nets. In 1953, a reduction plant for decline in spawning biomass. The same fig. 1. Herring weir transforming herring into fishmeal and applies to the smaller fisheries in Pla- oil was opened in the Magdalens, and centia Bay, St. Mary's Bay and For- other reduction plants followed in the tune Bay. mid-60s in the Chaleur Bay area, heart In Nova Scotia, inshore fishermen in of the traditional gill-net fishery on the Sidney Bight and Chedabucto Bay fish southern Gulf stock. At the same time, local spawning runs of herring. Purse a fleet of large purse seiners developed seiners fish overwintering herring, to supply those plants and others in mostly from the large stock which southwest Newfoundland, where the spawns in the fall off southwest Nova adult stock overwintered. The subse- Scotia. The winter fishery in Sydney quent high landings were made pos- Bight began in 1968 and reached a peak sible by the abundant 1958 and 1959 of 17,547 t in 1973 . The peak catch year-classes; the catch increased from from the winter fishery off Cheda- 39 ,000 tonnes (t) in 1964 to about bucto Bay was in the order of 50,000 t 300,000 t in 1970. But the winter fish- in the early 1970s. Since 1974 the ery collapsed in the early '70s, and fig. 2. Gil/net winter fishery in Sydney Bight has been landings reached a low of 37 ,000 t in managed separately from Chedabucto 1974. Bay. The Chedabucto Bay fishery has The introduction of the purse seine been shown, by tagging studies, to be fishery has resulted in a major redistri- closely associated with the Southwest bution of catches. Sorne local inshore Nova Scotia stock and has been man- fisheries, such as in central North- aged in conjunction with the southwest umberland Strait or in the Magdalen Nova Scotia fishery since 1974. The Islands, have collapsed or have been Total Allowable Catch (TAC) for the drastically reduced. During the 1940s, fishery off Chedabucto Bay is inshore fishermen caught 1OO per cent determined according to the manage- of a catch comparable to present total ment plan for the southwest Nova yields. Today, they catch only 20 per Scotia fishery. cent. In 1981 the situation again A large stock of herring spawns on changed; of a 15,000 t quota, only the Lurcher Shoals, on Trinity Ledge 3,000 t were allocated to the purse seine and in the Tuskets area off southwest fleet, the remainder being allocated to Nova Scotia. A large purse seine fish- inshore gears. ery for juvenile and adult herring is In Newfoundland the traditional carried out there in the summer and fisheries took place in Fortune Bay and early fa!!. A weir fishery catches in the area of the Port-au-Port Penin- juveniles during the summer and fall, sula. Gill nets were the traditional gear, while the gillnetters concentrate on the fig. 3. A purse seiner but purse seines were introduced as adult fall spawning run. The total early as the 1930s. The first major catch for the southwest Nova Scotia purse seine fishery on local Newfound- stock, excluding the New Brunswick land stocks began in 1966 north of Cape Gregory on the west coast, and activity spread to St. George's Bay in Underwater World

Bay of Fundy fishery for juveniles, Research and management reached a peak of nearly 190,000 t in The difficulties of managing today's 1970, but then declined to 58,000 t in herring fisheries are twofold. One is 1979. the problem of distribution. How can The New Brunswick Bay of Fundy the fisheries be managed to take full fishery, which exploits herring schools advantage of the mobile gears' ability from several neighboring stocks, is the to pursue herring schools beyond the home of Canada's oldest purse seine spawning beds, while ensuring that fishery and sardine canning industry. local spawning runs continue to be Weirs are the main fishing gear, sup- sufficiently stable and abundant to plemented by shut-off seines and purse sustain a viable inshore fishery? seines. Landings have varied from The other problem is that of main- 75,000 tin 1968 and 18,000 tin 1971 to taining a high yield while avoiding the 41,000 tin 1978. danger of overfishing. The latter has Georges Bank was formerly the clearly occurred with disastrous conse- spawning ground for a large herring quences on Georges Bank, and more population, and an international moderate cases have struck some other fishery developed in the 1960s with Canadian stocks. the U.S.S.R. as the most active par- From the biologists' point of view, ticipant. ln 1968, Canadian vessels there are two types of overfishing - caught 13,674 t out of a total catch of y ield overfishing and recruitment 373,344 t. Overfishing eventually led to overfishing. The former occurs when the collapse of this fishery, and surveys fish are caught at too small a size, and in the area have found very few larvae the growth potential of the fish is not since then. realized. However, the maximum pos- Canada's participation in the herring sible yield does not occur when ail the fi shery in the Gulf of Maine had de- fish are old and very large, since most creased considerably in recent years will have died of natural causes before fig. 4. Gill netting for herring due to the poor state of the adult stock. reaching this stage. ln each stock, it is Since 1977, when both Canada and the possible to determine an optimum age United States extended their jurisdic- at which growth and death rates tion over fisheries to 200 miles, Canada balance. has not had a fi shery in the Gulf of In recruitment overfishing, too Maine. many immature juveniles are taken before they have a chance to spawn. As Utilization a result, there is insufficient spawning Since the 1870s, Bay of Fundy and fewer numbers of young than of juvenile herring have been canned as parents. The population becomes grad- sardines. Elsewhere, herring was tradi- ually smaller, then undergoes a sudden tionally used for salting and smoking, collapse which is often referred to as for bait and fertilizer . Reduction plants "recruitment failure" . temporarily transformed the process- Recruitment overfishing can be ing industry, with most Canadian avoided by maintaining an adequate herring catches being reduced to number of spawning fish. But scientists fishmeal and oil by 1968. Currently, have yet to determine the appropriate the most important herring products, number for any given stock of herring in order of economic importance, are in view of predation by other fish, frozen fillets, sardines, pickled and (cod, haddock, tuna, etc.) on female cured fillets, and pickled and cured and adult herring, competition among whole-dressed herring. ln southeastern young, water temperature and pol- New Brunswick, herring is salted and lution. Ali these factors affect the smoked to produce "bloaters". Whole relationship between the number of herring is also sold fresh or frozen and spawners and the number of eventual is used as lobster bait. The preparation recruits to the fishery (at age 2 or 3 of roe for the Japanese market is a lu- years). crative activity which has probably not attained its full potential in Atlantic Canada. QL 626 U5313 no.16.c.2 . . Underwater World t of Fisheri ... 6 canad a. Dep ------Atlan tic herring c.2 33668 12064592

The production of young herring The management and utilization of varies with differences of up to 80 Atlantic herring and mackerel in the times in the size of year-classes. Large 1980s. Dept. Fish and Oceans. year-classes are often succeeded by Pinhorn, A.T. 1976. Living marine re- several years of much smaller year- sources of Newfoundland-Labrador: classes. Beyond a certain age it would status and potential. Fisheries be normal to fish the less abundant on Research Board of Canada. Bull No. a large scale. But this is practically im- 194 (p. 27-30). possible, since most fishing gear is not Resource prospects for Canada 's Atlan- that selective. The result is that it is tic fisheries. 1981-1987. Dept. Fish sometimes difficult to avoid either and Oceans (p. 25-26). overfishing some classes or under- Scarratt, D.J. ed 1982. CanadianAtlan- fishing others. tic Offshore Fishery Atlas, (p. 81). To help solve management prob- Canadian Special Publication of Fish- lems, scientists must estimate quite eries and Aquatic Sciences 47. Dept. accurately the abundance of herring in Fish and Oceans. a population at a given time. One very useful guide is the catch rate of com- Others in this series: mercial fishing vessels. If they catch American Lobster more per day this year than they did American Oyster last year, this suggests fish are more American Plaice Atlantic Groundfish abundant. But the schooling behaviour Atlantic Mackerel of herring complicates this situation. If Altantic "Pelagic" Fish a stock is decreasing in size, high catch Atlantic Shellfish rates may still be maintained as long as Atlantic Snow Crab the schools can be Iocated. A smaller Capelin stock may be distributed over a smaller Harp Seal terri tory, and experienced fishermen Irish Moss using sophisticated electronic equip- Red Hake ment can usually find the fish. Aware- Red Tides ness of the complexity of the problem Roundnose Grenadier Sea Scallop has led scientists to exercise caution in Spiny Dogfish recent years in their recommendations Witch Flounder for total allowable catches. Mean- while, biological research on these PUBLISHED BY: problems continues. Communications Branch Department of Fisheries and Underwater World factsheets are brief Oceans illustrated accounts of fisheries re- Ottawa, Ontario sources and marine phenomena pre- KIA 0E6 pared for public information and education. They describe the life his- DF0/ 586 UW / 016E tory, geographic distribution, utiliza- © Minister of Supply and Services tion and population status of fish, Canada 1982 shellfish and other living marine Cat No. Fs 41-33/ 16-1982E resources, and/ or the nature, origin ISBN 0-662-12203-8 and impact of marine processes and phenomena. Disponible en français

Further Reading Leim, A.H., W.B. Scott. 1972. Fishes of the Atlantic coast of Canada. Fisheries Research Board of Canada Bull. No. 155. (Atlantic herring p. 94-97).