Spring Spawing herring - Norwegian Sea|
Fact Sheet Title Fact Sheet |
| | Spring Spawing herring - Norwegian Sea |
Norwegian spring-spawning herring |
| Data Ownership | This document provided, maintained and owned by International Council for the Exploration of the Sea (ICES) , is part of ICES Advice data collection. |
| ident Block | ident Block | | Species List: | Species Ref: en - Atlantic herring, fr - Hareng de l'Atlantique, es - Arenque del Atlántico, ru - Сельдь атлантическая |
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| ident Block Spring Spawing herring - Norwegian Sea
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fao Div |
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27.2.a | Norwegian Sea (Division 27.2.a) |
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27.2.b | Spitzbergen and Bear Island (Division 27.2.b) |
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27.5.a | Iceland Grounds (Division 27.5.a) |
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fao Sub Div |
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27.5.b.1 | Faroe Plateau (Subdivision 27.5.b.1) |
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27.5.b.2 | Faroe Bank (Subdivision 27.5.b.2) |
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| Aq Res | Biological Stock: Yes
Value: Sub-Regional Management unit: Yes
Reference year: 2008
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Considered a management unit: An aquatic resource or fishery is
declared as [Fishery] Management Unit if it is
effectively the focus for the application of selected
management methods and measures, within the broader
framework of a management system. According to the FAO
Glossary for Responsible Fishing, "a Fishery Management
Unit (FMU) is a fishery or a portion of a fishery
identified in a Fishery Management Plan (FMP) relevant
to the FMP's management objectives." FMU's may be
organised around fisheries biological, geographic,
economic, technical, social or ecological dimensions ,
and the makeup and attribute of a fishery management
unit depends mainly on the FMP's management
objectives. |
Jurisdictional distribution: Jurisdictional qualifier (e.g.
"shared", "shared - highly migratory") of the aquatic
resource related with its spatial distribution. |
Environmental group: Classification of the aquatic
resource according to the environmental group (e.g.
pelagic invertebrate, or demersal fish) to which the
species belong. |
Reference Year: The Reference Year is the last year considered in the stock assessment and/or fishery status. |
| | | | Aq Res State Trend
Spawning biomass in relation to precautionary limits |
Fishing mortality in relation to precautionary limits |
Fishing mortality in relation to high long term yield |
Fishing mortality in relation to agreed target F |
Comment |
Full reproductive capacity |
Harvested sustainably |
Unknown |
At target |
MSY estimate not available |
Based on the most recent estimates of SSB (in 2009) ICES classifies the stock as having full reproductive capacity. Based on the most recent estimate of fishing mortality (in 2008) ICES classifies the stock as being harvested sustainably. SSB in 2009 is well above B pa and is estimated as one of the highest in the time-series. The stock contains a number of good year classes. In the last 10 years, four large year classes have been produced (1998, 1999, 2002 and 2004). However, the available information indicates that year classes after 2004 have been of low abundance. Habitat Bio Depth Zone: Shelf (50 m - 200 m). Vertical Dist: Pelagic. Geo Dist Geo Dist: Straddling between High Seas and EEZ Water Area Overview Spatial Scale: Sub-Regional Water Area Overview  | Water Area Overview Spring Spawing herring - Norwegian Sea
fao Div | 27.2.a: Norwegian Sea (Division 27.2.a) | 27.2.b: Spitzbergen and Bear Island (Division 27.2.b) | 27.5.a: Iceland Grounds (Division 27.5.a) | fao Sub Div | 27.5.b.1: Faroe Plateau (Subdivision 27.5.b.1) | 27.5.b.2: Faroe Bank (Subdivision 27.5.b.2) |
| | | | Water Area Overview |
Water Area OverviewSpring Spawing herring - Norwegian Sea fao Major | 27:
Atlantic, Northeast | Large Marine Ecosystem Areas (LME) | 19: East Greenland Shelf | 20: Barents Sea | 21: Norwegian Shelf | 22: North Sea | 59: East Greenland Shelf/Sea | 60: Faroe Plateau | 64: Arctic Ocean |
Aq Res Struct Biological Stock: Yes Exploit Factors affecting the fisheries and the stockRegulations and their effects In the rebuilding phase of the stock in the 1980s and early 1990s (SSB < MBAL = 2.5 million tonnes), the management objective was to keep fishing mortality below 0.05. With the exception of a few years, this objective was achieved. A minimum landing size regulation of 25 cm is in force in EU and Norway waters. This has prevented the exploitation of young herring. These regulations have contributed to rebuilding of the stock to levels well above precautionary limits. When the fishery expanded in the mid-1990s, a long-term management plan was agreed. For the 2006 fishery, the parties exploiting the resource (European Union, Faroe Islands, Iceland, Norway, and Russia) did not reach agreement regarding the allocation of the quota and no TAC was agreed. However, the fishing mortality in 2006 did not exceeded F pa. From 2007 onwards, the parties have reached agreement on annual TACs and allocation of the quotas in accord with the management plan. Changes in fishing technology and fishing patternsIn general, the fishery follows the migration of the stock as it moves from the wintering and spawning grounds along the Norwegian coast to the summer feeding grounds in the Faroese, Icelandic, Jan Mayen, Svalbard, and international areas. Due to limitations for some countries to enter the EEZs of other countries in 2008, the fisheries do not necessarily depict the distribution of herring in the Norwegian Sea. A special feature of the summer fishery in 2005 and 2006 was the prolonged fishery in the Faroese and Icelandic zone up to late August, where the oldest age groups were present in the second and third quarter. In 2007 and 2008 a clean herring fishery was hampered by mixture of mackerel schools in the area. This was especially the case for the Faroese fleet, which usually targets mackerel later in the year (October–November). Impacts of the environment on the fish stockThe stock undergoes extensive migrations in the Northeast Atlantic, which have been linked to changes in ocean climate and changes in zooplankton distribution. During 1995–2005, a weak relationship existed between zooplankton biomass in May and herring condition in the autumn. The March–April North Atlantic Oscillation (NAO) index in 2004 and 2005 was successfully used to predict the herring condition index in the winters of 2005 and 2006. Although no such analyses are available for the most recent years, the average biomass of zooplankton in the Norwegian Sea in May has been decreasing since 2002 and, in 2009, reached a record low level since the measurements started in 1997. The Arctic front is a central feeding area for the herring stock. During periods when the Arctic front is shifted westwards, part of the stock feeding in the western Norwegian Sea also moves westward. The position of the Arctic front is correlated with large-scale environmental events. Bio Assess Assess Models Methodology Scientific basisData and methodsIn 2008, a benchmark procedure was applied to the stock assessment. The advice is based on an analytical assessment, which takes into consideration catch data and eight surveys (acoustic surveys of adults and juveniles, larval survey, and 0-group survey), of which five surveys are continuing. The assessment is conducted using a VPA based model from the TASACS package. As agreed at the benchmark, the VPA analysis is restricted to the years 1988–2009, which is regarded as the period representative of the present production and exploitation regimes. For the period before 1988, the results are derived from the 2006 assessment, which are consistent with this year’s assessment. The present assessment is an updated assessment, using the models, configurations and procedures agreed at the benchmark. The benchmark also examined cases where individual survey points might be excluded from the assessment model. Based on the agreed examination procedures, the 2009 value from the Norwegian herring larval survey on the Norwegian shelf (survey 8) was excluded from the assessment. This data point was excluded as the abundance estimate was anomalously low and the average size of the larvae was large suggesting that the survey was late relative to spawning. A similar rationale was used in the past to exclude the 2003 data point from the Norwegian larval survey. Uncertainties in assessment and forecastThere is uncertainty about recent recruitment estimates. A source of uncertainty is caused by the lack of coherence in some of the survey information for the youngest ages. In addition, the catch in 2008 from a few directed fisheries by Norway and Russia in the 3rd and 4th quarter contained relatively high numbers of 1 and 2 year olds (year classes 2007 and 2006). The available surveys, however, indicate that these year classes are not strong. There is uncertainty in the estimate of SSB and fishing mortality related to the exclusion of the 2009 survey point of the Norwegian herring larvae survey on the Norwegian shelf. Including the 2009 survey point would have resulted in the estimate of SSB being about 10% lower. The international ecosystem survey in the Nordic Seas in May is the most important survey in the assessment and will remain so in future assessments. It is important that this survey is maintained and that the vessels participating in this survey have access to the survey grounds. As well it is essential to maintain good geographical survey coverage to avoid increases in assessment uncertainty and maintain the integrity of the assessment. While discarding of this stock is estimated to be low, an un-quantified amount of slippage is known to occur, thus it has not been possible to account for slippage in the assessment. Comparison with previous assessment and adviceThe perception of the state of the stock and its exploitation has not changed markedly. Compared to last year, the SSB for 2008 is estimated to be about 5% higher and the fishing mortality in 2007 to be about 3% lower (see Figure 9.4.5.3). The basis for the advice is the same as last year. Results  | Figure 9.4.5.1. Herring in the Northeast Atlantic (Norwegian spring-spawning herring). Summary of stock assessment: landings, fishing mortality, recruitment, and SSB. Data prior to 1988 are from the 2006 assessment year.  |  | Figure 9.4.5.2. Herring in the Northeast Atlantic (Norwegian spring-spawning herring). Stock–recruitment and PA plot. Data prior to 1988 are from the 2006 assessment year.  |  | Figure 9.5.4.3. Herring in the Northeast Atlantic (Norwegian spring-spawning herring). Comparison of current assessment with previous assessments.  | Table 9.4.5.2. Table 9.4.5.3. Herring in the Northeast Atlantic (Norwegian spring-spawning herring). Summary of the stock assessment. Data prior to 1988 are from the 2006 assessment year.
Year |
Recruitment |
SSB |
Landings |
F weighted |
|
Age 0 |
|
|
Ages 5–14 |
|
thousands |
tonnes |
tonnes |
|
1950 |
751000000 |
14200000 |
826000 |
0.0584 |
1951 |
146000000 |
12500000 |
1280000 |
0.0697 |
1952 |
96600000 |
10900000 |
1250000 |
0.0728 |
1953 |
86100000 |
9350000 |
1070000 |
0.0663 |
1954 |
42100000 |
8660000 |
1640000 |
0.1130 |
1955 |
25000000 |
9270000 |
1360000 |
0.0783 |
1956 |
29900000 |
10900000 |
1660000 |
0.1100 |
1957 |
25400000 |
9650000 |
1320000 |
0.1030 |
1958 |
23100000 |
8690000 |
986000 |
0.0787 |
1959 |
412000000 |
7180000 |
1110000 |
0.1130 |
1960 |
198000000 |
5850000 |
1100000 |
0.1360 |
1961 |
76100000 |
4390000 |
830000 |
0.1040 |
1962 |
19000000 |
3440000 |
849000 |
0.1460 |
1963 |
169000000 |
2670000 |
985000 |
0.2530 |
1964 |
93900000 |
2530000 |
1280000 |
0.2260 |
1965 |
8490000 |
3060000 |
1550000 |
0.2780 |
1966 |
51400000 |
2800000 |
1960000 |
0.6960 |
1967 |
3950000 |
1470000 |
1680000 |
1.5200 |
1968 |
5190000 |
344000 |
712000 |
3.4900 |
1969 |
9780000 |
145000 |
67800 |
0.5900 |
1970 |
661000 |
71000 |
62300 |
1.3200 |
1971 |
236000 |
32000 |
21100 |
1.5300 |
1972 |
957000 |
16000 |
13200 |
1.5000 |
1973 |
12900000 |
85000 |
7020 |
1.1700 |
1974 |
8630000 |
91000 |
7620 |
0.1140 |
1975 |
2970000 |
79000 |
13700 |
0.1900 |
1976 |
10100000 |
138000 |
10400 |
0.1060 |
1977 |
5100000 |
286000 |
22700 |
0.1110 |
1978 |
6200000 |
358000 |
19800 |
0.0434 |
1979 |
12500000 |
388000 |
12900 |
0.0238 |
1980 |
1470000 |
471000 |
18600 |
0.0341 |
1981 |
1100000 |
504000 |
13700 |
0.0215 |
1982 |
2340000 |
503000 |
16700 |
0.0200 |
1983 |
343000000 |
575000 |
23100 |
0.0291 |
1984 |
11500000 |
602000 |
53500 |
0.0903 |
1985 |
36600000 |
515000 |
170000 |
0.3790 |
1986 |
6040000 |
437000 |
225000 |
1.0700 |
1987 |
9090000 |
926000 |
127000 |
0.4040 |
1988 |
25724000 |
2768000 |
135301 |
0.045 |
1989 |
73988400 |
3409000 |
103830 |
0.029 |
1990 |
109705800 |
3702000 |
86411 |
0.022 |
1991 |
320875600 |
3877000 |
84683 |
0.023 |
1992 |
383921700 |
3767000 |
104448 |
0.027 |
1993 |
121890400 |
3641000 |
232457 |
0.064 |
1994 |
42242100 |
4122000 |
479228 |
0.129 |
1995 |
18643900 |
4976000 |
905501 |
0.229 |
1996 |
57789400 |
6545000 |
1220283 |
0.192 |
1997 |
50575900 |
7887000 |
1426507 |
0.180 |
1998 |
282407700 |
7290000 |
1223131 |
0.153 |
1999 |
227356600 |
6852000 |
1235433 |
0.186 |
2000 |
54030800 |
5837000 |
1207201 |
0.213 |
2001 |
35695300 |
4794000 |
766136 |
0.180 |
2002 |
568142000 |
4928000 |
807795 |
0.184 |
2003 |
185261300 |
6298000 |
789510 |
0.114 |
2004 |
344513300 |
7149000 |
794066 |
0.094 |
2005 |
53536700 |
7715000 |
1003243 |
0.128 |
2006* |
90770000 |
11580000 |
968958 |
0.131 |
2007* |
30990000 |
11836000 |
1266993 |
0.098 |
2008** |
103000000 |
12437000 |
1545656 |
0.125 |
2009** |
103000000 |
13300000 |
|
|
Average |
100457748 |
4646433 |
690524 |
0.3220 |
* Recruitment value has been replaced in the forecast by RCT estimate.** GM mean 1989–2005. |
Ref Point
|
Type |
Value |
Technical basis |
Precautionary approach |
Blim |
2.5 million t |
MBAL |
|
Bpa |
5.0 million t |
Blim * exp(0.4*1.645). |
|
Flim |
not defined |
- |
|
Fpa |
0.15 |
based on medium-term simulations. |
Targets |
Fmgt |
<0.125 |
Management Plan. |
PA points unchanged since 1998. |
Projection Outlook for 2010 Basis: Landings (2009) = 1643 (=TAC); Fw(2009)1) = 0.119; SSB(2009) = 13.3 million t.; SSB(2010)= 12.2 million t. The fishing mortality applied according to the agreed management plan (F(management plan)) is 0.125.
Rationale |
Landings(2010) |
Basis |
F(2010) |
SSB(2011) |
% SSB change 2) |
% TAC change 3) |
Zero catch |
0 |
F=0 |
0.000 |
12.2 |
0% |
-100% |
Status quo |
1483 |
F(2008) |
0.125 |
10.8 |
-11% |
-10% |
Agreed management plan |
157 |
F(management plan)*0.1 |
0.013 |
12.0 |
-2% |
-90% |
|
389 |
F(management plan)*0.25 |
0.031 |
11.8 |
-3% |
-76% |
|
770 |
F(management plan)*0.50 |
0.063 |
11.5 |
-6% |
-53% |
|
1132 |
F(management plan)*0.75 |
0.094 |
11.1 |
-9% |
-31% |
|
1353 |
F(management plan)*0.90 |
0.113 |
10.9 |
-11% |
-18% |
|
1483 |
F(management plan) |
0.125 |
10.8 |
-11% |
-10% |
|
1628 |
F(management plan)*1.1 |
0.138 |
10.7 |
-12% |
-1% |
|
1822 |
F(management plan)*1.25 |
0.156 |
10.5 |
-14% |
11% |
Precautionary limits |
1755 |
Fpa |
0.150 |
10.5 |
-14% |
7% |
Landings weights in thousand tonnes, stock biomass weights in million tonnes. The scenario in italics is not considered consistent with the precautionary approach.1) Fw = Fishing mortality weighted by population numbers (age groups 5–14).2) SSB 2011 relative to SSB 20103) Catch/landings 2010 relative to TAC 2009. |
Sci Advice Single-stock exploitation boundariesConsidering the options below, ICES advises on the basis of the exploitation target in the existing management plan that catches in 2010 should not exceed 1483000 t.Exploitation boundaries in relation to existing management plansThe management plan implies maximum catches of 1483000 t in 2010, which is expected to leave a spawning stock of 10.8 million tonnes in 2011. Exploitation boundaries in relation to precautionary limitsThe long-term management plan is considered to be consistent with the precautionary approach. Table 9.4.5.1. Herring in the Northeast Atlantic (Norwegian spring-spawning herring). Single-stock exploitation boundaries (advice), management, and catch.
Year |
ICESAdvice |
Predicted catchcorresp. to advice |
Agreed TAC |
ICESCatch |
1987 |
TAC |
150 |
115 |
127 |
1988 |
TAC |
120–150 |
120 |
135 |
1989 |
TAC |
100 |
100 |
104 |
1990 |
TAC |
80 |
80 |
86 |
1991 |
No fishing from a biological point of view |
0 |
76 |
85 |
1992 |
No fishing from a biological point of view |
0 |
98 |
104 |
1993 |
No increase in F |
119 |
200 |
232 |
1994 |
Gradual increase in F towards F0.1; TAC suggested |
334 |
450 |
479 |
1995 |
No increase in F |
513 |
None1 |
906 |
1996 |
Keep SSB above 2.5 million t |
- |
None2 |
1 217 |
1997 |
Keep SSB above 2.5 million t |
- |
1 500 |
1 420 |
1998 |
Do not exceed the harvest control rule |
- |
1 300 |
1 223 |
1999 |
Do not exceed the harvest control rule |
1 263 |
1 300 |
1 235 |
2000 |
Do not exceed the harvest control rule |
Max 1 500 |
1 250 |
1 207 |
2001 |
Do not exceed the harvest control rule |
753 |
850 |
770 |
2002 |
Do not exceed the harvest control rule |
853 |
850 |
809 |
2003 |
Do not exceed the harvest control rule |
710 |
7113 |
773 |
2004 |
Do not exceed the harvest control rule |
825 |
8253 |
794 |
2005 |
Do not exceed the harvest control rule |
890 |
1 0003 |
1 003 |
2006 |
Do not exceed the harvest control rule |
732 |
9673 |
969 |
2007 |
Do not exceed the harvest control rule |
1 280 |
1 280 |
1267 |
2008 |
Do not exceed the harvest control rule |
1 518 |
1518 |
1546 |
2009 |
Do not exceed the harvest control rule |
1 643 |
1 642 |
|
2010 |
Do not exceed the harvest control rule |
1 483 |
|
|
Weights in ‘000 t. 1Autonomous TACs totaling 900 000 t. 2Autonomous TACs totaling 1 425 000 t were set by April 1996. 3 There was no agreement on the TAC, the number is the sum of autonomous quotas from the individual Parties. |
Management Management unit: Yes Objectives The EU, Faroe Islands, Iceland, Norway, and agreed in 1999 on a long-term management plan. This plan consists of the following elements: - Every effort shall be made to maintain a level of Spawning Stock Biomass (SSB) greater than the critical level (Blim) of 2 500 000 t.
- For the year 2001 and subsequent years, the Parties agreed to restrict their fishing on the basis of a TAC consistent with a fishing mortality rate of less than 0.125 for appropriate age groups as defined by ICES, unless future scientific advice requires modification of this fishing mortality rate.
- Should the SSB fall below a reference point of 5 000 000 t (Bpa), the fishing mortality rate referred to under paragraph 2, shall be adapted in the light of scientific estimates of the conditions to ensure a safe and rapid recovery of the SSB to a level in excess of 5 000 000 t. The basis for such an adaptation should be at least a linear reduction in the fishing mortality rate from 0.125 at Bpa (5 000 000 t) to 0.05 at Blim (2 500 000 t).
- The Parties shall, as appropriate, review and revise these management measures and strategies on the basis of any new advice provided by ICES.
ICES considers that this agreement is consistent with the precautionary approach. Advice Management considerationsHistorically, the size of the stock has shown large variations and dependency on the irregular occurrence of very strong year classes. In 2009, SSB is estimated to be at its highest level in the last 60 years. In recent years, catches have also increased but fishing mortality has remained low and close to that agreed in the management plan. The management plan is considered precautionary. In the absence of strong year classes after 2004, the stock is expected to decline in the near future even when fished according to the management plan. This is normal behaviour of stocks which show spasmodic recruitment dynamics. The decline of the stock will result in a reduction in the projected catches in incoming years. Impacts of fisheries in the ecosystem The herring in the Northeast Atlantic stock is a straddling stock. Juveniles and adults of this stock form an important part of the ecosystem in the Barents Sea, the Norwegian Sea, and the Norwegian coast. Herring is an important food resource for higher trophic level predators (e.g. large fish, seabirds, and marine mammals), and also a consumer of zooplankton in the Norwegian Sea and capelin larvae in the Barents Sea. Little information is available on the impact of the herring fishery on the ecosystem. The fishery is entirely pelagic. There is little quantitative information on the bycatches in the fisheries for herring, but these are thought to be small. Therefore, unintended effects of the fishery on the ecosystem are probably small. Sources ICES. 2009. Report of the ICES Advisory Committee, 2009. ICES Advice, 2009. |
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