Questionnaire Report for San Francisco Bay herring
(MERA version 5.4.3)
Brett van Poorten (brett.vanpoorten@gmail.com)
2019-11-26
About this document
This is a prototype of an automatic report that documents how the user specified the operating model and their various justifications.
Introduction
- Describe the history and current status of the fishery, including fleets, sectors, vessel types and practices/gear by vessel type, landing ports, economics/markets, whether targeted/bycatch, other stocks caught in the fishery. The fishery is composed of herring eggs on kelp (HEOK - kelp placed in spawning areas and kelp/roe sold together), sac roe and live herring (both gill net). Recent creation of a local market has helped bolster the live fishery; the roe fishery began in earnest in 1972 when Japan began imports. “Recreational fishers typically use cast-nets to capture herring as they move inshore to spawn around pier pilings and jetties. Herring are typically used for human food or bait for other recreationally caught sport fish.” (http://opc.ca.gov/webmaster/ftp/project_pages/Rapid%20Assessments/Pacific%20Herring.pdf) Bycatch: “The gill net gear specified in regulations specifically targets Pacific herring based on a minimum mesh size and maximum overall net length. Based on the DFW commercial sampling data and staff observations, there is very little incidental take of non-target species. By-catch is typically limited to Jacksmelt (Atherinops californiensis) and sardines (Sardinops sagax); however, these species do not frequent areas targeted by the commercial herring fleet during the winter months and incidence as by-catch is minimal.” (http://opc.ca.gov/webmaster/ftp/project_pages/Rapid%20Assessments/Pacific%20Herring.pdf)
"Historical Fisheries
Herring fishing in California dates from at least the mid 1800’s. Catch records are not well documented prior to 1916, but annual catches were low with most of the fish sold fresh. Small amounts also were salted or pickled for human consumption. Harvesting occurred near the populated areas of Humboldt Bay, Bodega Bay, Tomales Bay, San Francisco Bay, Monterey Bay, and San Diego Bay. From 1916–1919 herring were canned or reduced into oil and meal (Scofield 1918). In 1918 the catch reached 8,000,000 lb (3,629 mt), mostly from Tomales Bay (Table 1). The Reduction Act of 1919 prohibited the reduction of whole herring into fish meal. This action ended the largest component of the fishery, although a small fishery for human consumption continued. Annual landings remained low until the late 1940’s when processors began to can herring as a replacement for sardines because that fishery was declining (Scofield 1952). This product was not well accepted by the public and by 1954 landings dropped to less than 1 million lb (454 mt) (Table 1). The fishery for human consumption (fresh and pickled herring) and bait has continued and today composes a minor part of the catch. Herring Eggs on Seaweed Fishery
In 1965 a new use for California herring products developed when Japan began importing herring roe on seaweed, “Kazunoko Kombu”, which is considered a delicacy. The Fish and Game Commission accepted separate sealed bids for the right to harvest herring eggs on seaweed in Tomales and San Francisco Bays. The highest bidder for each bay was awarded the opportunity to take 5 tons (4.5 mt) of eggs on seaweed. The amount of the bid was a royalty per ton paid to the Department after harvesting took place. The quota included the total weight of the seaweed with eggs attached. Herring eggs on Gracilaria spp. and Laminaria sp. are preferred and harvesting was done by divers. This fishery expanded to San Francisco Bay in 1966. The 5-ton quota has never been reached in either bay, but this continues to be a viable fishery with harvests every year since 1965 (Table 2)."(https://oac.cdlib.org/view?docId=kt3199n5xp&brand=oac4&doc.view=entire_text)
Describe the stock’s ecosystem functions, dependencies, and habitat types. “While in the ocean, adult herring feed on macroplankton such as copepods and euphausiids. Larval and juvenile herring are believed to feed on molluscan larvae and other zooplankton while in bays and estuaries. Herring are a forage species for a diverse group of marine fishes, birds, and mammals. Spawning events in particular provide an opportunity for feeding. As herring move into shallow water to spawn, a feeding frenzy may commence which can last for several days. Gulls, cormorants, pelicans and other marine birds; California and Stellar sea lions, harbor seals, invertebrates and a variety of fishes (including sturgeon in San Francisco Bay) feast on adult herring and embryos.” (http://opc.ca.gov/webmaster/ftp/project_pages/Rapid%20Assessments/Pacific%20Herring.pdf)
Provide all relevant reference materials, such as assessments, research, and other analysis.
Pacific Herring Rapid Assessment.pdf (also http://opc.ca.gov/webmaster/ftp/project_pages/Rapid%20Assessments/Pacific%20Herring.pdf) Scientific review of the draft Fishery Management Plan for Pacific herring (Clupea pallasii): (Herring Peer Review.pdf) Monterey Bay Aquarium Seafood Watch evaluation of the bottom gill net fishery (Seafood Watch Herring-Pacific-California.pdf) Pacific Herring Commercial Fishing Regulations (https://nrm.dfg.ca.gov/FileHandler.ashx?DocumentID=148632&inline) Status of The Pacific Herring, Clupea Harengus Pallasii, Resource In California 1972 to 1980 (https://oac.cdlib.org/view?docId=kt3199n5xp&brand=oac4&doc.view=entire_text)
Fishery Characteristics
Longevity
| Answered |
|---|
| Very short-lived (5 < maximum age < 7) |
| Short-lived (7 < maximum age < 10) |
| Moderate life span (10 < maximum age < 20) |
| Moderately long-lived (20 < maximum age < 40) |
| Long-lived (40 < maximum age < 80) |
| Very long-lived (80 < maximum age < 160) |
| Justification |
|---|
| “California herring can live to 9 years old and reach a maximum length of about 10 in (25 cm). However, it is extremely rare to find fish that are older than 7 years of age.” (Rapid Assessment Pacific Herring.pdf) |
Stock depletion
| Answered |
|---|
| Crashed (D < 0.05) |
| Very depleted (0.05 < D < 0.1) |
| Depleted (0.1 < D < 0.15) |
| Moderately depleted (0.15 < D < 0.3) |
| Healthy (0.3 < D < 0.5) |
| Underexploited (0.5 < D) |
| Justification |
|---|
| Historical record (Table 1 from the status 1972-1980) show catches as high as 15,000 tons in the 1980-90s period, and total abundance is similar to those periods. Early fishery (1910s) was never very high, but the fishery extends back to the 1880s, so relative depletion unknown (may have crashed early). |
Resilence
| Answered |
|---|
| Not resilient (steepness < 0.3) |
| Low resilience (0.3 < steepness < 0.5) |
| Moderate resilence (0.5 < steepness < 0.7) |
| Resilient (0.7 < steepness < 0.9) |
| Very Resilient (0.9 < steepness) |
| Justification |
|---|
|
Early fishng history (<1916) unknown. “In recent years a decline in the price of sac-roe has led to a decline in effort. Effort has remained relatively stable over the past five years (Ryan Bartling, personal comm., 2013). Historically there were as many as 400 permits issued to approximately 100 boats, but in recent years this has dropped to approximately 180 permits issued each year to 25-35 vessels (Ryan Bartling, personal comm., 2013; CDFW Commercial License Data 2000-20121). Although herring sac-roe permits are still issued for San Francisco Bay, Humboldt Bay, Tomales Bay, and Crescent City Harbor, the sac-roe fishing effort has only occurred in San Francisco Bay in recent years. This is due to decreased product demand and lower price, which makes fishing effort in the other bays less economically viable (Ryan Bartling, personal comm., 2013). Historically San Francisco Bay has accounted for over 90% of the state landings, even when other bays were actively fished. Total sac-roe landings and quota for San Francisco Bay are in Figure 1. The other two components of the fishery, the fresh fish fishery and HEOK, are much smaller and receive a minor portion of the annual quota. Currently, the fresh fish fishery season is open for a brief period before the sac-roe fishery opens and for a few of weeks after it closes. The HEOK fishery operates only in San Francisco Bay through the winter months. In general the fresh fish fishery has little to no effort. During the 2012-2013 herring fishing season no fresh fish were landed under this fishery quota (20 tons). The HEOK fishery is highly variable due to a variety of reasons (Ryan Bartling personal comm., 2013). The fishery can receive a much higher price per pound than the sac roe fishery, but is a much riskier investment since there is the possibility of not landing any herring roe. This fishery has a 10 permit limit and vessels in the gillnet fishery have the option to convert their sac-roe permits to a HEOK permit annually. Figure 2 shows landings data for the HEOK fishery. During the 2012-13 season, the fishery landed close to its entire quota of 176 tons (Ryan Bartling personal comm., 2013).” (Pacific Herring Rapid Assessment.pdf) |
Historical effort pattern
| Answered |
|---|
| Stable |
| Two-phase |
| Boom-bust |
| Gradual increases |
| Stable, recent increases |
| Stable, recent declines |
| Justification |
|---|
| Commercial licenses (found at https://www.wildlife.ca.gov/Licensing/Statistics/action/review/content/6949#commfishinglicensespermits) have bounced around 300-400 until early 2000s, where numbers steadily dropped due to price declines. |
Inter-annual variability in historical effort
| Answered |
|---|
| Not variable (less than 20% inter-annual change (IAC)) |
| Variable (maximum IAC between 20% to 50%) |
| Highly variable (maximum IAC between 50% and 100%) |
| Justification |
|---|
| Fishing method has not changed over time and fishing areas are generally targeted in nearshore areas (no technology changes apparent). I would presume the efficiency has remained stable. |
Historical fishing efficiency changes
| Answered |
|---|
| Declining by 2-3% pa (halves every 25-35 years) |
| Declining by 1-2% pa (halves every 35-70 years) |
| Stable -1% to 1% pa (may halve/double every 70 years) |
| Increasing by 1-2% pa (doubles every 35-70 years) |
| Increasing by 2-3% pa (doubles every 25-35 years) |
| Justification |
|---|
| Fishing method has not changed over time and fishing areas are generally targeted in nearshore areas (no technology changes apparent). I would presume the efficiency has remained stable. |
Future fishing efficiency changes
| Answered |
|---|
| Declining by 2-3% pa (halves every 25-35 years) |
| Declining by 1-2% pa (halves every 35-70 years) |
| Stable -1% to 1% pa (may halve/double every 70 years) |
| Increasing by 1-2% pa (doubles every 35-70 years) |
| Increasing by 2-3% pa (doubles every 25-35 years) |
| Justification |
|---|
| No changes anticipated. |
Length at maturity
| Answered |
|---|
| Very small (0.4 < LM < 0.5) |
| Small (0.5 < LM < 0.6) |
| Moderate (0.6 < LM < 0.7) |
| Moderate to large (0.7 < LM < 0.8) |
| Large (0.8 < LM < 0.9) |
| Justification |
|---|
| “Some herring reach sexual maturity at age two when they are about 7 in (18 cm) in length; all are sexually mature at age three. California herring can live to 9 years old and reach a maximum length of about 10 in (25 cm)” (Pacific Herring Rapid Assessment.pdf) |
Selectivity of small fish
| Answered |
|---|
| Very small (0.1 < S < 0.2) |
| Small (0.2 < S < 0.4) |
| Half asymptotic length (0.4 < S < 0.6) |
| Large (0.6 < S < 0.8) |
| Very large (0.8 < S < 0.9) |
| Justification |
|---|
| Only mature fish are targeted, so selectivity should be similar to maturity ogive. However, recent catches have included immature fish, partially due to small mesh gill nets used (see Seafood Watch Figure 9.pdf) |
Selectivity of large fish
| Answered |
|---|
| Asymptotic selectivity (SL = 1) |
| Declining selectivity with length (0.75 < SL < 1) |
| Dome-shaped selectivity (0.25 < SL < 0.75) |
| Strong dome-shaped selectivity (SL < 0.25) |
| Justification |
|---|
| Small mesh gill nets likely avoid larger fish - they have disappeared from the catch in recent years (which may either be due to depletion or changes in gear. However, older assessments (https://oac.cdlib.org/view?docId=kt3199n5xp&brand=oac4&doc.view=entire_text) indicate only selectivity for larger fish with no indication of dome-shape (though not much evidence either way) |
Discard rate
| Answered |
|---|
| Low (DR < 1%) |
| Low - moderate (1% < DR < 10%) |
| Moderate (10% < DR < 30%) |
| Moderate - high (30% < DR < 50%) |
| High (50% < DR < 70%) |
| Justification |
|---|
|
“There is no bait used for the gillnet fishery. Because bycatch rates are negligible for the sac roe and fresh fish fishery (<1%), it is safe to assume that the ratio of discards to total landings is less than 20%.” (Seafood Watch Herring-Pacific-California.pdf) - ‘Bycatch’ here refers to non-target species I would presume this does not account for escapes from the nets, which would elevate discards of injured fish (hence raising to 10%) |
Post-release mortality rate
| Answered |
|---|
| Low (PRM < 5%) |
| Low - moderate (5% < PRM < 25%) |
| Moderate (25% < PRM < 50%) |
| Moderate - high (50% < PRM < 75%) |
| High (75% < PRM < 95%) |
| Almost all die (95% < PRM < 100%) |
| Justification |
|---|
|
Interannual variation in total spawning biomass (Figure 3 Rapid Assessment.pdf) suggests moderate variation in abundance and therefore, relatively high IAC in recruitment variability. ** Found recruitment index which shows very high recruitment variation (Recruitment.pdf - from 2015 Final Supplemental Document Pacific Herring.pdf) - see rec var.xlsx |
Recruitment variability
| Answered |
|---|
| Very low (less than 20% inter-annual changes (IAC)) |
| Low (max IAC of between 20% and 60%) |
| Moderate (max IAC of between 60% and 120%) |
| High (max IAC of between 120% and 180%) |
| Very high (max IAC greater than 180%) |
| Justification |
|---|
|
“Waters of Districts 12 and 13 and that portion of District 11 lying south of a line extending from Peninsula Point (the most southerly extremity of Belvedere Island) to the easternmost point of the Sausalito ferry dock. 1) Regulations prohibit the setting or operating of nets within 300 feet of the following piers and recreation areas: Berkeley Pier, Paradise Pier, and San Francisco Municipal Pier (between the foot of Hyde Street and Van Ness Avenue), Pier 7 (San Francisco), Candlestick Point State Recreation Area, the jetties in Horseshoe Bay, and the fishing pier at Fort Baker. Regulations also prohibit the setting or operating of nets within 70 feet of Mission Rock 2) Regulations prohibit the setting or operating of nets in Belvedere Cove (north of a line drawn from the tip of Peninsula Point to the tip of Elephant Rock). Regulations also prohibit the setting or operating of gill nets from November 15 through March 17, in the area bounded by a line drawn from the middle anchorage of the western section of the Oakland Bay Bridge (Tower C) to the Lash Terminal buoy #5 to the easternmost point at Hunter’s Point (Point Avisadero), from Point Avisadero to the Y “A” buoy to Alameda NAS entrance buoy #1 (entrance to Alameda Carrier Channel) to the Oakland Harbor Bar Channel buoy #1, and then from the first Bar Channel buoy to Tower C of the Bay Bridge. 3) Other closures affecting the fishery include United States Coast Guard enforced Homeland Security Zones: 25 yards around all Golden Gate and Bay Bridge abutments and piers; 100 yards around and under any High Interest Vessels; and Naval Vessel Protection Zones which extend 100 yards around all Naval Vessels at all times and a 500 yard slow zone surrounding all Naval Vessels. The United States Coast Guard will also enforce Rule 9 of the Code of Federal Regulations (CFR) regarding channel and harbor blockages." (2015 Final Supplemental Document Pacific Herring.pdf) (I’m not sure of the geography, so assume this is relatively low proportion of the spawning areas) |
Size of an existing MPA
| Answered |
|---|
| None |
| Small (A < 5%) |
| Small-moderate (5% < A < 10%) |
| Moderate (10% < A < 20%) |
| Large (20% < A < 30%) |
| Very large (30% < A < 40%) |
| Huge (40% < A < 50%) |
| Justification |
|---|
| Movement during the spawning season will be relatively low. |
Spatial mixing (movement) in/out of existing MPA
| Answered |
|---|
| Very low (P < 1%) |
| Low (1% < P < 5%) |
| Moderate (5% < P < 10%) |
| High (10% < P < 20%) |
| Fully mixed |
| Justification |
|---|
| No changes anticipated |
Size of a future potential MPA
| Answered |
|---|
| None |
| Small (A < 5%) |
| Small-moderate (5% < A < 10%) |
| Moderate (10% < A < 20%) |
| Large (20% < A < 30%) |
| Very large (30% < A < 40%) |
| Huge (40% < A < 50%) |
| Justification |
|---|
| No changes anticipated |
Spatial mixing (movement) in/out of future potential MPA
| Answered |
|---|
| Very low (P < 1%) |
| Low (1% < P < 5%) |
| Moderate (5% < P < 10%) |
| High (10% < P < 20%) |
| Fully mixed |
| Justification |
|---|
| Same as above - movement during spawning season will be limited. |
Initial stock depletion
| Answered |
|---|
| Very low (0.1 < D1 < 0.15) |
| Low (0.15 < D1 < 0.3) |
| Moderate (0.3 < D < 0.5) |
| High (0.5 < D1) |
| Asymptotic unfished levels (D1 = 1) |
| Justification |
|---|
| The fishery is certainly not unfished at the start of the time-series I could find (1916 and on). However, the level of fishing in early years (1880s-1916) is unknown. |
Management Characteristics
Types of fishery management that are possible
| Answered |
|---|
| TAC (Total Allowable Catch): a catch limit |
| TAE (Total Allowable Effort): an effort limit |
| Size limit |
| Time-area closures (a marine reserve) |
| Justification |
|---|
|
1. Describe what, if any, current management measures are used to constrain catch/effort. Fishery is focussed on spawning herring. Herring may be caught Dec 1-March 31 (HEOK fishery) or Jan 1-March 15 (gill net fishery). There are measures to constrain fishing days (which days of the season you may fish based on your license number); closed areas. Commercial fishers must have a license. Recreational fishery is essentially unlimited but relatively low. “The fishery is also managed by seasonal closures that are set every year, gear restrictions such as a minimum mesh size of 2 inches, and a limited entry (LE) permit system. The fishery is only open in state waters; open ocean fishing was prohibited in 2009.”; “Additionally tools such as port sampling, landing receipts, logbooks, and observer coverage are used to monitor catch and ensure vessels have the correct permits for the catch they are landing. Violators are prosecuted under the law. There is no evidence of systemic non- compliance.” (Rapid Assessment Pacific Herring.pdf) “ 2. Describe historical management measures, if any. The fishery has been managed using a quota set based on survey biomass. ”DFW has managed the commercial Pacific herring sac-roe fishery in San Francisco Bay since the opening in 1972. DFW’s biological and enforcement staff have worked closely with the fishing industry throughout this period to provide for a sustainable and orderly fishery. This has been achieved through annual population assessments, California Environmental Quality Act review, evolving regulatory changes (fishery regulations) and oversight by the FGC. The FGC has regulatory responsibility for management of this fishery with DFW providing recommendations and managing the fishery directly." (Rapid Assessment Pacific Herring.pdf “Quotas are the principal regulatory tool used to establish adequate protection of herring as an important forage species and to provide for the long-term yield of the commercial fishery. Each year, the Department recommends a harvest percentage that is not determined by a fixed mathematical formula; rather, the recommendation is based upon modeling results and takes into account additional data collected each season, such as ocean productivity and bay conditions, growth rates of herring, strength of individual year- classes, and predicted size of incoming year-classes (i.e., recruitment). In response to poor recruitment, indication of population stress, and/or unfavorable oceanographic conditions, harvest percentages beginning in 2003 have been set at or below 10 percent. Since the 2003-04 season, harvest percentages on average have allowed over 90 percent of the spawning biomass to return to the ocean after spawning in the bay. The Department and DHAC recommended a no fishery option (zero ton quota) for the 2009-10 season, when the herring spawning biomass in 2008-09 fell to a new low of 4,833 tons. The Commission adopted this recommendation and the commercial fishery was closed in San Francisco Bay for the 2009-10 season. Since the re-opening of the fishery for the 2010-11 season, the Department has recommended harvest percentages at five percent or less of the spawning biomass. Based on accepted fishery management principles these harvest percentages are conservative and represent a precautionary approach to safeguard the population as forage and to provide a robust reproductive base to allow for stock rebuilding.” (https://nrm.dfg.ca.gov/FileHandler.ashx?DocumentID=148632&inline) 3. Describe main strengths and weaknesses of current monitoring and enforcement capacity. Monitoring is relatively high, though no on-board observers. 4. Describe and reference any legal/policy requirements for management, monitoring and enforcement. references above |
TAC offset: consistent overages/underages
| Answered |
|---|
| Large underages (40% - 70% of recommended) |
| Underages (70% - 90% of recommended) |
| Slight underages (90% - 100% of recommended) |
| Taken exactly (95% - 105% of recommended) |
| Slight overages (100% - 110% of recommended) |
| Overages (110% - 150% of recommended) |
| Large overages (150% - 200% of recommended) |
| Justification |
|---|
| Fishery season is set, so overages do occur. Recent years has seen close adherence to quota after consistent underages in early 2000s (see Quota.pdf) |
TAC implementation variability
| Answered |
|---|
| Constant (V < 1%) |
| Not variable (1% < V < 5%) |
| Low variability (5% < V < 10%) |
| Variable (10% < V < 20%) |
| Highly variable (20% < V < 40%) |
| Justification |
|---|
| TAE is in the form of ‘limited entry’, but I do not perveive that they have limited entry in quite a while. Effort actually went down recently as price dropped. |
TAE offset: consistent overages/underages
| Answered |
|---|
| Large underages (40% - 70% of recommended) |
| Underages (70% - 90% of recommended) |
| Slight underages (90% - 100% of recommended) |
| Taken exactly (95% - 105% of recommended) |
| Slight overages (100% - 110% of recommended) |
| Overages (110% - 150% of recommended) |
| Large overages (150% - 200% of recommended) |
| Justification |
|---|
| TAE is in the form of ‘limited entry’, but I do not perveive that they have limited entry in quite a while. Effort actually went down recently as price dropped. |
TAE implementation variability
| Answered |
|---|
| Constant (V < 1%) |
| Not variable (1% < V < 5%) |
| Low variability (5% < V < 10%) |
| Variable (10% < V < 20%) |
| Highly variable (20% < V < 40%) |
| Justification |
|---|
| Effort really only varies based on license purchases |
Size limit offset: consistent overages/underages
| Answered |
|---|
| Much smaller (40% - 70% of recommended) |
| Smaller (70% - 90% of recommended) |
| Slightly smaller (90% - 100% of recommended) |
| Taken exactly (95% - 105% of recommended) |
| Slightly larger (100% - 110% of recommended) |
| Larger (110% - 150% of recommended) |
| Much larger (150% - 200% of recommended) |
| Justification |
|---|
| No minimum size, just restrictions on minimum mesh size in gill net fishery |
Size limit implementation variability
| Answered |
|---|
| Constant (V < 1%) |
| Not variable (1% < V < 5%) |
| Low variability (5% < V < 10%) |
| Variable (10% < V < 20%) |
| Highly variable (20% < V < 40%) |
| Justification |
|---|
| No size limits |
Data Characteristics
Available data types
| Answered |
|---|
| Historical annual catches (from unfished) |
| Recent annual catches (at least 5 recent years) |
| Historical relative abundance index (from unfished) |
| Recent relative abundance index (at least 5 recent years) |
| Fishing effort |
| Size composition (length samples) |
| Age composition (age samples) |
| Growth (growth parameters) |
| Absolute biomass survey |
| Justification |
|---|
|
1. Provide the time series (specify years, if possible) that exist for catch, effort, and CPUE/abundance indices. Catch data are available from 1916 Effort directed at herring (measured as commercial licenses) are available since 1976 CPUE is not available; abundance index is a hydroacoustic survey conducted each year 2. Describe how these data collected (e.g., log books, dealer reporting, observers). “Additionally tools such as port sampling, landing receipts, logbooks, and observer coverage are used to monitor catch and ensure vessels have the correct permits for the catch they are landing.” (Rapid Assessment Pacific Herring.pdf) 3. Describe what types of sampling programs and methodologies exist for data collection, including the time-series of available sampling data and quality. Hydroacoustic surveys are conducted to create abundance estimates landing receipts are used to generate total catch Effort is based on purchased licenses Age composition based on research surveys conducted by California Department of Fish and Wildlife 4. Describe all sources of uncertainty in the status, biology, life history and data sources of the fishery. Include links to documentation, reports. Growth, timing of maturity are all fairly well known. Biology when offshore is poorly understood, but that has little impact on management. Status also unknown because unfished abundance uncertain. “Currently the stock assessment for the San Francisco Pacific herring stock consists of spawning biomass estimates each year, which are used to set precautionary targets for harvest. Other reference points (unfished biomass, B0; biomass needed to obtain maximum sustainable yield, BMSY; and fishing mortality needed to obtain MSY, FMSY) are not available, and neither is an estimate of unfished age distribution.” (Seafood Watch Herring-Pacific-California.pdf) Annual uncertainty in productivity is acknowledged. Assessment models attempt to predict available biomass based on ocean conditions when setting quota. (https://nrm.dfg.ca.gov/FileHandler.ashx?DocumentID=148632&inline) |
Catch reporting bias
| Answered |
|---|
| Strong under-reporting (30% - 50%) |
| Under-reporting (10% - 30%) |
| Slight under-reporting (0% - 10%) |
| Reported accurately (+/- 5%) |
| Slight over-reporting (less than 10%) |
| Justification |
|---|
| Reporting is quite accurate. There are no concerns |
Hyperstability in indices
| Answered |
|---|
| Strong hyperdepletion (2 < Beta < 3) |
| Hyperdepletion (1.25 < Beta < 2) |
| Proportional (0.8 < Beta < 1.25) |
| Hyperstability (0.5 < Beta < 0.8) |
| Strong hyperstability (0.33 < Beta < 0.5) |
| Justification |
|---|
| No reports of hyperstability; however given that the fishery targets the spawning aggregations, hyperstability could be a problem. However, catches are so low relative to the available biomass, it is doubtful that it is an issue. |
Available data types
| Answered |
|---|
| Perfect |
| Good (accurate and precise) |
| Data moderate (some what inaccurate and imprecise) |
| Data poor (inaccurate and imprecise) |
| Justification |
|---|
| Annual catches are accurate; abundance is based on hydroacoustic and assumptions of how ocean conditions affect recruitment. Length/age compositions seem reasonable (though sample size is unknown). |
Version Notes
The package is subject to ongoing testing. If you find a bug or a problem please send a report to t.carruthers@oceans.ubc.ca so that it can be fixed!
tcar_-2019-11-26-10:25:40
Open Source, GPL-2 2019