STATUS OF BERING SEA HERRING STOCKS ANO FISHERIES ALASKA BOARD OF FISHERIES DECEMBER 1977

Transcription

1 ' AYK Rrn!ON HERRtN!S BOARP R~T 111 STATUS OF BERNG SEA HERRNG STOCKS ANO FSHERES ( ) A REPORT TO THE ALASKA BOARD OF FSHERES DECEMBER 1977 Alaska Department of Fish and Game Commercial Fisheries Division A-Y-K Region Bristol Bay Area

2 Timing and Distribution For the most part, Bering Sea herring stocks winter in deeper water on the continental shelf, migrate to coastal waters in the spring for spawning and feeding and move back to deeper water in the fall. Some populations may however, overwinter in nearshore waters in the more northern regions such as parts of Norton Sound and Kotzebue Sound. has been suggested by results from recent Department research studies associated with the Outer Continental Shelf Environmental Assessment Program (OCSEAP). Movements of herring to spawning grounds appear to be greatly influenced by climatological conditions, particularly the extent and distribution of the Bering Sea ice pack. Generally, most spawning populations appear near the coast immediately after ice breakup in mid This May and early June (Figure 1). Spawning proceeds in a northerly. direction along the coastline beginning in mid May in Bristol Bay and continuing until late July on the Seward Peninsula. There is some indication that spawning may occur as late as August in parts of Kotzebue Sound. pre and past spawning segments of herring populations remain in the nearshore waters throughout the early spring and su1t111er. Both A relatively small fall run of herring is known to occur in Golovin Bay, along the west coast of the Seward Peninsula and in Kotzebue Sound. Samples collected from Golovin Bay and Port Clarence in 1977 revealed that the reproductive organs were relatively undeveloped and that these herring do not spawn in the fa 11 (September and October). Primary spawning areas are associated with definite coastline morphology types. Spawn is usually found in most areas where rugged escarpments and rocky beaches are common. Shorelines typical of this 1.

3 type are found in the Togiak, Nelson sland, Cape Romanzof and Norton Sound areas. in such areas. Rockweed kelp (Fucus sp.) is the usual spawning substrate However, most any substrate including rocks is utilized under conditions of dense spawning. A second important spawning habitat is found in shallow secluded bays or inlets where eelgrass (Zosteria sp. ) is corrmon, such as Goodnews Bay. The bottom type is usua 11 y sand and/or mud in such areas and both intertidal and shallow subtidal spawning occurs in depths of less than two meters. With the exception of this latter habitat type, most spawning has been observed in intertidal waters, particularly in the Togiak district. Relative Abundance There are few sections of coastline where the Department has fl own herring surveys with any consistency prior to the more recent OCS studies. These are the Togiak district of Bristol Bay and the southeastern coastline of Norton Sound. between these areas have differed. Trends in the relative abundance of herring populations Estimates of herring abundance from aerial surveys in the Togiak area in 1977 revealed some of the largest and most numerous concentrations of herring schools ever observed in that area since surveys began in the l960 1 s. The opposite has been observed in Norton Sound where survey results have indicated a decline in herring abundance. other spawning areas along the west coast. Similar comparative data is not available for Several coastal residents interviewed during the last two years indicated that herring abundance has declined from previous levels. 'f.his possibility is also expressed in the down.ward trend of foreign herring trawl catches in the Bering Sea between 1968 and 1976, which is presented later in this report.

4 The relative abundance of herring populations along the west coast of Alaska has been more closely examined in recent years by Alaska Department of Fish and Game aerial surveys as part of the OCSEAP program. Results indicate herring abundance, based upon surface area estimates of school size, is greatest south of the Yukon River with the Togiak district in Bristol Bay having,. by far, the largest concentrations {Figure 2). Relative abundance of spawning herring north of the Yukon River is greatest in the southern and eastern portions of Norton Sound at St. Michael and Cape Denbigh. Many schools of fish believed to be herring were observed along the coast north of Cape Prince of Wales in 1977, but it was not determined whether these herring were spawners. No spawn was documented in that area at the time surveys were conducted. Subsistence Fishery Herring have been a traditional subsistence food item of numerous Bering Sea coastal residents. Most subsistence fishing for herring along the coast centers on spring spawning runs, although a number of fishermen from Golovin Bay northward to Kotzebue utilize herring of the fall run to a limited extent. Residents of villages located in close proximity to important herring spawning areas tend to make the largest catches (Table 1). A more intensive effort to monitor subsistence harvests since 1975 has provided more accurate information on the subsistence fishery. n general, villages south of the Yukon River are more dependent upon the subsistence fishery for herring than vi'llages to the north. This is believed to be due to the availability of alternative food sources (bjg game animals and marine mammals) and that herring are less abundant north of the Yukon River. Subsistence utilization of herring

5 4, is greatest in the villages between the Kuskokwim and Yukon Rivers and predominantly in the vicinity of Nelson sland (Toksook, Tanunak and Umkumiut). Harvests in these three villages amounted to nearly 74 metric tons (m.t.) in 1977 or about 92 percent of the total documented subsistence harves.t this year. Subsistence utilization of herring by residents of Bristol Bay and the Alaska Peninsula has not been monitored, but is. relatively insignificant compared to the more northerly villages. Domestic Conunercial Fishery,~ Fishery resource inventories conducted as early as the 1880's reported the presence of herring in areas of the Bering Sea. Documented utilization of herring by American fishermen in the region dates back to near the turn of this century. An inshore conunercial fishery developed in Norton Sound as early as 1909 followed later by one in the vicinity of Unalaska sland in Although some operations lasted for over twenty years, total production from these early fisheries remained small. n Norton Sound, for instance, a total of five to six million pounds of herring were harvested in a fall fishery which lasted from These early fisheries were finally terminated in the early to mid 1940's due to declining demand and prices for salted and cured herring. Following an extended period of inactivity, limited commercial utilization of herring by domestic fishermen resumed in Norton Sound in This has continued sporadically since that time and total production has amounted to around a quarter million pounds (Table 2). This fishery has concentrated on spring run herring for extraction of sac roe and is in contrast to the earlier fa 11 fishery for a sa1 t cured product. Harvests from the 1977 fishery amounted to 9.3 m.t. which falls somewhat

6 below average production in this area since The first recorded harvest of roe-on-kelp also occurred in Norton Sound in 1977 near Cape Denbigh. Gillnets have been used almost exclusively in Norton Sound for harvesting ~erring, although some seining was conducted in Further expansion of the Bering Sea domestic fishery came in the late 1960's when a fledgling herring sac roe and roe-on-kelp fishery developed in Bristol Bay's Togiak district. Until the last two years, limited fishing and processing effort along with annual variations in the abundance of fish, adverse weather conditions, low percentage roe recovery and the general logistical difficulties of operating in the area have discouraged any large scale exploitation of herring in Bristol Bay (Table 2). Annual aerial survei-llance of the resource in the Togiak district since the inception of the fishery has revealed that a sizeable population of herring are present in the area each spring. Prior to 1977 commercial harvests were generally small and not indicative of the size of the herring population observed during most years. Harvests in the Togiak district sac roe fishery, prior to 1977, fluctuated widely and average annual production was only 69 metric tons. An escalated sac roe fishery in 1977 and the combined efforts of six processors resulted in a total harvest of 2,540 m.t., which amounted to almost a 40 fold increase aver average historical catches. Gillnets have been the traditional gear type utilized in this fishery, but this year an unprecedented increase in the use of more effective seine gear occurred. Catches by seine fishermen accounted for over 80% of this years's harvest. Although a majority of the harvest occurred in the i1tdtiediate vicinity of traditional fishing areas, a combination of favorable weather, large numbers of herring and increased effort contributed to the larger than average catch.

7 Since 1~68 a more stable herring roe-on-rockweed kelp (Fucus sp.) fishery has also developed in Togiak. Harvests of this product experienced a five fold increase in 1976 with an all time high harvest of 276,000 lbs. Harvests of roe-on-kelp amounting to near peak levels continued into Regulatory management of both the sac roe and roe-on-kelp fisheries has been minimal up to this time in order to encourage development of a viable fishery. Foreign Fishery Herring stocks in the eastern Bering Sea have been heavily fished by Japanese and Soviet fleets. Exploitation of the stocks began in 1961 following the location of major herring wintering grounds by Soviet exploratory trawlers operating northwest of the Pribilof slands. These herring are believed to reproduce along the west coast of Alaska. The Japanese entered the trawl fishery in the winter of 1964 and also began a gillnet fishery east of 175 W. in The Japanese gillnet fishery operated from April to June from Bristol Bay to Norton Sound until 1977 when those coastal waters were closed to protect coastal subsistence fisheries (Figure 3). The Secretary of Commerce initiated this closure on foreign herring fishing in all waters of the Bering Sea east of 168 West longitude an~ north of 58 north latitude effective March lhe stimulus for this closure came as a recommendation from the Alaska Department of Fish and Game to the North Pacific Fisheries Management Council. This was based upon a growing concern of possible overexploitation by foreign fleets, especially in light of the heavy dependence upon herring as a subsistence food source by several coastal villages. Combined harvest information for the winter trawl fishery by both Japanese and Soviet fleets is only available since 1967, although Japanese

8 7 trawl and gillnet catches have been reported since 1964 (Table 3). The available catch data indicates that peak production occurred in when 128,000 m.t. were harvested by both the trawl and gillnet fisheries. ' Production has steadily declined since that time. Although not conclusive, observed declines in the trawl catches indicate possible overfishing of these stocks. Environmental factors are also operating to influence the observed fluctuations in herring abundance. Regardless of the cause of the general decline in herring abundance in the easterft Bering Sea, the continued exploitation of these stocks by foreign fishermen is of increasing concern to the inshore users of this same limited resource. Management Strategy To permit the development of a domestic cormiercial fishery and to meet the needs of an existing subsistence fishery, a coordinated management plan must be developed that will encourage full utilization of the resource, yet at the same time maintain and possibly enhance the condition of the affected stocks of herring. The optimum sustainable yield of herring for the eastern Bering Sea is determined by the Nortry Pacific Fisheries Management Council. A total allowable catch (TAC) of 18,700 m.t. has been established for the fishing season. Ten thousand metric tons of this quota have been allocated for domestic fisheries leaving only 8,700 m.t. for foreign exploitation. f a viable domestic fishery fails to develop, the remaining surplus [of the 10,000 m.t.] will continue to be allocated to foreign fishermen. A better understanding of the origin, distribution, movement patterns, age structures and fluctuating abundance of herring must be obtained in order to better define a11 owabl e yields. in response to the success of individual year classes. Herring abundance fluctuates Management of

9 herring fisheries must attempt to avoid overfishing on low abundance year classes so as not to further impair recruitment. Knowledge of the strength of herring year classes prior to their recruitment into the commercial fishery may help predict fluctuations in stock size far enough in advance to formulate reasonable harvest levels. The existence of separate stocks of herring in the eastern Bering Sea that differ tn distribution, age composition and abundance, is not well understood, and should be more clearly defined. involved here will tend to make the task extremely difficult. The immense geography Some of these needs are being partially met through study proposals solicited by the North Pacific Fisheries Management Council. These work proposals are to be funded for at least two years to examine continent of origin of herring captured in the foreign trawl fishery in the central Bering Sea and to develop a program to annually monitor spawning ( stocks. This latter objective will be partially met by studying the \,, magnitude, distribution and population dynamics of inshore spawning populations. n addition, a study on the impacts of a commercial herring fishery on the economy of villages in the Arctic-Yukon-Kuskokwim area is planned. Plans for future establishment of the inshore fishery will necessarily be conservative to provide for its orderly development. As effort increases, and the fishery becomes more intense, a more timely catch reporting system will have to be developed before effective management of local fisheries wi)l be possible. n the absence of a better method of assessing the relative strength of herring runs along the coast, aerial survey estimates of the number

10 a and size of fish schools remains the most commonly used tool by inshore fishery managers in these areas. Hydroacoustic techniques have not been attempted to date and there is the possibility that this may not prove useful in assessing widely scattered and constantly moving schools of herring in the shallow coastal waters along Alaska's Bering Sea coast. Consideration shou.ld a 1 so be given to monitoring the condition of exploited intertidal kelp beds as a result of the developing roe-on-kelp fishery. Since harvests have often times been concentrated in relatively small areas, the ability of the kelp to maintain itself should be investigated. Additiona 1 pro bl ems that will need to be resolved before effective management can be possible include conflicts between resource user groups (subsistence vs. cormnercial), the uneven distribution of fishing pressure on stocks, the existence of mixed stock fisheries, conflicts between gear types, the development of "local vs. outsider 11 sentiments, concerns over the relationship of herring to other organisms in the Bering Sea ecosystem, etc. Market conditions have and will probably continue to affect the status and trend of the fishery as it develops. Establishment of predominantly a sac roe fishery has led to criticism of the waste of herring carcasses following the extraction of the roe from the females. Demands for total utilization of the resource have led to the enactment of a law by the Alaska Legislature which will make it unlawful to waste conmercially caught herring in the Bering Sea north of Port Moller after January 1, Other forage fish, namely capelin, have been encountered in conjunction with herring operations and methods should be developed for identification of these other stocks during aerial surveys and as markets allow encourage the utilization of these other stocks of fish.

11 Table 1. Herring subsistence catches in pounds by Yukon-Kuskokwim delta coastal residents, Vi 11 age 1~75 197f! 1977 Tanunak 43,565 ( 26)1/ 30,593 Umkumiut 65,898 ( 38) 18,660 Toksook 68,405 85,675 Sub-totalsY 177,868 h ci~l 134,928 Hooper Bay 5,543 ( 34) 6,007 Scammon Bay 1,390 Chevak 1,400 Newtok 300 Mekoryuk 2,360 Chefornak 12,050 Kipnuk 1,500 Kwi gi 11 i ngok 21,350 Kongiganak Sub-totals- 41 5,543 nn 46,357 Grand Total 183,411 ' (143) 181,285 ( 14) 114,425 6,075 42, ,100 H# ( 28) 4,750 ( 4) ( 9) 300 ( l) ( 7) 3/ ( 12) l,!86 ( 3) ( 8) 2, ( 72) 9,l86 (114) 172,286 ( 47) f 4) 0 f- ( 28) ( 2) ( 10) ( 9) ( 6) f55) (145) lf Number of families in parentheses. 2/ Nelson sland villages - surveyed annually since / Fifteen Nekoryuk fishennen reported a catch of 20 wash tubs. 4! Subtotals for villages between the Yukon and Kuskokwim Rivers excluding the Nelson sland area. Subsistence catches, Norton Sound - Kotzebue Sound in 1976: Commercial catches, A-Y-K Region: 1976: 17,000 lbs : 20, bs. 5,600 lbs. 10.

12 ,, Table 2. Conmercial herring and herring roe-on-kelp harvests by inshore American fisheri.~~ -. ~~. ~~-. ~er~- ~~-. ~ea,.. _ l9~4~~~~ ~.1/.. _. Herring Y Herring Roe-on-kelp~ Bristol Norton Bristol Norton Year Bay Sound Total Bay Sound Total ( , , tr. 125 Total 3, , tr. 471 Average / Harvests expressed in metric tons. 7lJ Herring harvested predominantly for extraction of sac roe. Bristol Bay fishery initiated in 1967 with no fishery conducted in 1971 or Spring fishery begun in Norton Sound in 1964 with no operations conducted in or in / Kelp predominantly rockweek (Fucus sp.) First Roe-on-kelp fishery began in Bristol Bay in 1968 while first harvest totaling 743 lb. occurred in Norton Sound in 1977.

13 Table 3. Herring product1on of Japan and USSR in the eastern Bering Sea, _/ Year 2 1 Trawl Fi sher.}:'.'. Japanese Total (July - June USSR 3/ Japan Gill net Fishery l , ,117 l ,831 l ,800 9, , l 04 l ,379 50,857 1, , ,228 23, 901 1, , , ,236 4,603 88,965 l ,547 13' ,162 l , ,878 42,, ,81 o 219 3,337 20,366 l ,039 2, , ,518 2, , , , 104 1,766 5/ ,870 r lj All harvests expressed in metric tons. Source of Japanese catches from NPFC documents while USSR catches furnished under provisions of US-USSR bilateral agreements. 2/ Trawl fishery normally occurs frum Nov to Apr while the gillnet fishery lasted from April to June. 3/ The USSR trawl fishery began in 1961, but harvest data was not available until / Preliminary. 5/ Japanese gillnet fishery closed. 12.

14 U.S.S.R. /...- Lkft JUNE TO /",> EARb.Y JULY... ".,,,, KOTZEBUE SOUND LATE JULY TO EARLY UGUST? V'l MD TO LATE JUNE -- sland -z: Bay Togiak \. \ 'S\ \.)-:; rl (~. ' LATE MAY.TO EARLY JUNE Herendeen Bay -- Port Mo 11 er Figure l. Timing and distribution of Pacific herring spawning in the eastern Bering Sea. 13.

15 Figure 2. Relative abundance of Pacific herring based upon peak count surface area estimates of schools observed during aerial surveys, 1976 and 1977.,,, U.S.S.R.,_,,., _/..,./...../... ' KOTZEBUE SOUND SEWARD PENNSULA NORTON ~ SOUND pe Denbigh Cape_Romanzof ( \ - ~-Goodnews Bay ---Togiak... Port Mo 11 er -- Port Heiden

16 . ~ Gillnet Fishery ~ - Trawl Fishery Bering Sea 0 Pribilof slands _Figure 3. General distribution of Japanese and Soviet herring fisheries in the eastern Bering Sea. Solid line references foreign herring fishing closure (north of 58 N and east of 168 W) effective M:iY'rh. 1Q77