Rebuilding plan for yellowtail flounder – NAFO Division 5Z

Foreword

Picture of yellowtail flounder
Yellowtail flounder
(limanda ferruginea)

Fisheries and Oceans Canada (DFO) has developed A fishery decision-making framework incorporating the precautionary approach under the auspices of the Sustainable Fisheries Framework.  It outlines the departmental methodology for applying the precautionary approach to Canadian fisheries.  A key component of the precautionary approach framework requires that when a stock has reached or fallen below a limit reference point (LRP), a rebuilding plan must be in place with the aim of having a high probability of the stock growing above the LRP within a reasonable timeframe.

The purpose of this rebuilding plan is to identify the main objectives and requirements for yellowtail flounder in NAFO division 5Z, as well as the management measures that will be used to achieve these objectives.  This document also serves to communicate the basic information on 5Z yellowtail flounder and its management to DFO staff, First Nations and other Indigenous organizations, and other fishery interests.  DFO does not currently have an accepted analytical assessment model or LRP for this stock and uses an empirical approach to provide advice on removal levels for the stock.  This plan provides a common understanding of the basic rules for rebuilding this stock under the assumption that rebuilding is possible, regardless of whether it is likely. The objectives and measures outlined in this plan are applicable as long as 5Z yellowtail flounder presence remains at a very low level.  Management measures outlined in this rebuilding plan are mandatory, and may be modified to include additional catch restrictions if they fail to result in stock rebuilding.

This rebuilding plan is not a legally binding instrument which can form the basis of a legal challenge.  The plan can be modified at any time and does not fetter the Minister's discretionary powers set out in the Fisheries Act. The Minister can, for reasons of conservation or for any other valid reasons, modify any provision of this rebuilding plan in accordance with the powers granted pursuant to the Fisheries Act.

Signed: Regional Director, Fisheries Management, Maritimes Region

Preamble

In 2017, a new 4VWX5 Groundfish Integrated Fisheries Management Plan (IFMP; DFO 2018) was developed by DFO and the Scotia-Fundy Groundfish Advisory Committee (SFGAC). Information that pertains to the mixed groundfish fishery, which includes yellowtail flounder, can be found in the IFMP and is referenced throughout this document.

Georges Bank yellowtail flounder is a transboundary resource managed collaboratively with the United States (US).   The management for the Georges Bank stock includes the entire bank east of the Great South Channel to the Northeast Peak, encompassing Northwest Atlantic Fisheries Organization (NAFO) Division 5Zhjmn (Figure 1).

The Gulf of Maine Advisory Committee (GOMAC) is a forum wherein representatives of the Canadian fishing industry and governments can jointly develop and provide advice on matters pertaining to Gulf of Maine fisheries issues. For 3 transboundary groundfish stocks in NAFO Division 5Z (Eastern Georges Bank cod and haddock and Georges Bank yellowtail flounder), GOMAC is the primary advisory body to DFO on issues related to total allowable catch (TAC) and other fisheries management measures (see Appendix 4 of the 4VWX5 Groundfish IFMP for Terms of Reference ).

The last scientific benchmark for yellowtail flounder was completed in 2014 and stock status updates are provided yearly through the Transboundary Resource Assessment Committee (TRAC) process. Prior to 2014, a series of different virtual population analysis (VPA) models had been used to assess the stock; however, there were problems with the retrospective pattern of the VPA models. Several approaches to address the retrospective pattern were attempted (TRAC 2014), but none were unable to resolve the issues. After  issues with the model had been identified over several years, it was determined that it was no longer usable for providing catch advice. In the absence of an analytical model, an empirical approach that relies directly on survey indices was developed in 2014.

Outcomes from the application of this plan will be reviewed yearly to determine if changes to the plan might be required, and this Rebuilding Plan will be reviewed and revised as needed following any future framework assessment.

I. Biological synopsis

Yellowtail flounder is a bottom-dwelling North Atlantic flatfish that ranges from Newfoundland and Labrador to Chesapeake Bay, US.  In Canada, yellowtail flounder occur mostly along the continental shelf of the Grand Banks with a concentration occurring on Georges Bank (5Z) from the Northeast Peak to east of the Great South Channel.

On Georges Bank (5Z), spawning occurs during late spring and summer.  Yellowtail flounder mature between the ages of 2 and 3 and have been caught in Canadian waters as old as 12, but rarely make it past 10 years.  Yellowtail flounder exhibit short seasonal migrations and low frequency of movement between fishing grounds (Cadrin and Westwood 2004).

Northwest Atlantic Fisheries Organization (NAFO) Divisions 5Z (DFO 2017)
Figure 1: Northwest Atlantic Fisheries Organization (NAFO) Divisions 5Z (DFO 2017).
Description

Figure 1: Northwest Atlantic Fisheries Organization (NAFO) Divisions 5Z (DFO 2017).

Habitat requirements

Hare et al. (2016) completed a climate vulnerability assessment on 82 fish and invertebrate species in the Northeast US Shelf and concluded that yellowtail flounder has high potential for a change in species distribution and high certainty that climate change will have a negative directional effect.  A risk analysis completed by (NEFSC 2017) provides qualitative information on Northeast groundfish species vulnerability and the probable response to ecosystem indicators. They found that increasing mean fall bottom temperatures, increasing sea surface temperatures, decreasing cool thermal habitats, and species distribution changes are expected to have a negative impact on Georges Bank yellowtail flounder.  

The spatial distribution of this stock is mapped each year in a collaboration between the US and Canada and is based on the 3 most recent fishery-independent research surveys conducted in the area. As of 2018, these surveys show that there have been no recent changes in yellowtail flounder distribution on Georges Bank (Legault and McCurdy In prep.);  however, there is evidence of increasing temperature on Georges Bank in long-term sea surface records as well as bottom measurements from surveys. Warming waters have impacts on the ecosystem that can be complex and can include changes in productivity as thermal habitats shift (NEFSC 2018). It is not known how these changes in thermal habitat will impact the recovery of yellowtail flounder in this area.

DFO’s Maritimes Region delivers regional programs and services in support of the national mandate for Fish Habitat Management  and Oceans Management .

II. Overview of the fishery

The Georges Bank (5Z) yellowtail flounder stock is a transboundary resource in Canadian and US jurisdictions. Historically, 5Z yellowtail flounder were caught as part of a mixed species fishery that includes haddock, pollock, winter flounder, redfish and other species (DFO 2017). Currently, as a result of declines in stock biomass and consequent low quota levels, it is used strictly as a bycatch species with the majority being caught by the offshore scallop fleet. The 2017 Canadian catch of 3 mt was well below the Canadian quota of 93 mt, with landings of <1 mt from the groundfish fishery and estimated discards of 2 mt from the scallop dredge fishery. In the past 5 years, Canadian landings have averaged 16 mt from all sources.

Recognizing that groundfish discards by the offshore scallop fishery were a significant source of fishery removals in 2006, Canada has set aside bycatch reserves from its share of the TAC to cover their bycatch on Georges Bank.  The reserve is established at 30% of Canada’s share of the TAC for yellowtail flounder. Discarding of Cod is required in the offshore scallop fishery but prohibited in groundfish fisheries.  Mortality of discards for groundfish species in the offshore scallop fishery are expected to be 100% and therefore are treated as catch.  An estimate is calculated for the entire fleet based on observed trips.  A breakdown of fleet shares can be found below in Table 1.

Table 1: Fleet shares for 5Z yellowtail flounder. Mobile gear refers mainly to otter trawls and each fleet is described by the vessel lengths historically permitted for that fleet.
Fleet Percent Share
Aboriginal 0.700
Mobile gear  < 65’ 64.400
Vessels >100’ 4.900
Bycatch reserve 30.000

Since the initial implementation of the bycatch reserves, modifications to fishing practices and gear have helped to reduce the estimated discards in the offshore scallop fleet, though discard levels are also affected by the spatial distribution of the fishery each season.  As a result, there have been end-of-year surpluses remaining in the reserve. As of 2012, DFO implemented a midseason temporary reallocation through a Bycatch Reserve Redistribution Process, which allows unused bycatch reserve amounts to be transferred among fleets. The process is undertaken in most years for cod and haddock, however it has not been used in recent years for yellowtail flounder due to the fact that the quotas have not been exceeded by any fleet.

The offshore lobster fishery has the potential to catch yellowtail flounder as bycatch in 5Z but is not permitted to land it.  For more information please refer to Section 6.3.1 of the Offshore lobster and jonah crab IFMP (DFO 2016a). There is also the potential for recreational or Aboriginal Food, Social and Ceremonial fisheries to encounter yellowtail flounder, however there is not currently a comprehensive reporting structure for these fisheries so it is not known if there are any interactions.  Recreational fishing on Georges Bank is thought to be a very rare occurrence due to the long distance from shore. Additional information on the 5Z yellowtail flounder fishery can be found below in Section IV, Socio-Economic and Cultural Importance.

III. Stock status

Stock assessment

Transboundary assessment

After 1977, the US and Canada used national institutions for stock evaluation of Georges Bank stocks. The analyses were supported by exchanges of respective fishery and scientific information, as well as complementary participation in the review processes.  This cooperation culminated in the formation of the Transboundary Management Guidance Committee (TMGC) in 2000 to provide non-binding guidance to the 2 parties.  The Transboundary Resources Assessment Committee (TRAC) which was formed in 1998, is the scientific arm of the TMGC; the TRAC is the forum for joint science advice and conducts the peer review of the status of transboundary resources considered by the TMGC (eastern Georges Bank cod, eastern Georges Bank haddock, and Georges Bank yellowtail flounder).  The most recent information is available at the TRAC website.

A decision was made at the June 2014 TRAC assessment meeting to no longer use the virtual population analysis model which had previously provided stock status and catch advice.  The 2014 Diagnostic Benchmark recommended an empirical (ie, index-based) approach to providing catch advice based on the 3 bottom trawl surveys and an assumed exploitation rate.

In 2017, TRAC recommended an exploitation rate of 2% to 16% for Georges Bank yellowtail flounder, resulting in catch advice of 31 mt to 245 mt for 2018.  TMGC recommended a combined US-Canada quota for 2017 of 300 mt (TMGC 2017).  In 2018, the TRAC recommended an upper bound of 6% for the exploitation rate, which corresponded to catch advice of no more than 68 mt for 2019.  TMGC recommended a combined US-Canada catch quota of 140 mt. TMGC did not follow the TRAC recommendation, because the stock assessment states that current levels of catch are not the primary factor impacting stock rebuilding and due to bycatch quota needs for other fisheries. While the 2019 quota is above the recommendation from TRAC, it is a 53% reduction relative to 2018 and the lowest quota on record.  Despite the total US-Canada quota exceeding the upper bound of 6% exploitation rate, Canada intends to maintain its total 2019 catch at or below the level recommended by TRAC.

The current biomass index for 2018 was the lowest in the 32-year time series for the DFO survey, and the lowest in the 51-year time series for the NMFS surveys (Figure 2).

Bottom trawl survey catch rates (in biomass) for Georges Bank yellowtail flounder (filled circles) with 90% confidence intervals (gray area).
Figure 2: Bottom trawl survey catch rates (in biomass) for Georges Bank yellowtail flounder (filled circles) with 90% confidence intervals (gray area).
Description

Figure 2: Bottom trawl survey catch rates (in biomass) for Georges Bank yellowtail flounder (filled circles) with 90% confidence intervals (gray area). The declining trend in survey biomass to low levels, despite reductions in catch to historically low amounts, indicates a poor state of the resource.

The declining trend in survey biomass to low levels, despite reductions in catch to historically low amounts, indicates a poor state of the resource (Figure 2). Recent catch (Figure 3) is low relative to the biomass estimated from the surveys, but the total mortality rate (Z) remains high (Figure 4) indicating other sources of mortality are contributing to the decline (TRAC 2018).

Relative F (catch in mt divided by survey catch in kg per tow) scaled to the mean value during 1987-2007 for the 3 surveys.
Figure 3: Relative F (catch in mt divided by survey catch in kg per tow) scaled to the mean value during 1987-2007 for the 3 surveys.
Description

Figure 3: Relative F (catch in mt divided by survey catch in kg per tow) scaled to the mean value during 1987-2007 for the 3 surveys.

Total mortality (Z) from the 3 surveys using the Sinclair (2001) method with a 4-year moving window for ages 3 to 8.
Figure 4: Total mortality (Z) from the 3 surveys using the Sinclair (2001) method with a 4-year moving window for ages 3 to 8.
Description

Figure 4: Total mortality (Z) from the 3 surveys using the Sinclair (2001) method with a 4-year moving window for ages 3 to 8.

Stock scenarios

Over the past 2 decades, trends in yellowtail flounder survey biomass have been consistent between the Canadian and US surveys. Currently there is no assessment model, so the fishing mortality for 5Z yellowtail flounder cannot be assessed against the FREF of 0.25 (established in 2002 by TMGC) but relative fishing mortality (fishery catch biomass divided by survey biomass)  has been at a low level since 1995 while total mortality (Z) remains high (DFO 2018).

The 5Z yellowtail flounder stock is primarily distributed on the US side of Georges Bank and there is an indication of depensation (a reduction in per-capita stock productivity at small population sizes) in recent years. This could have strong negative implications for the ability of the stock to rebuild even under a no fishing scenario (TRAC 2017).

Although the US did calculate a rebuilding target and publish a rebuilding plan for the stock as part of their domestic process in 2008, this was done at a time when there was an accepted model for the stock.  In the absence of a model, progress towards this target can no longer be assessed.

Precautionary approach

The United Nations Agreement on Straddling and Highly Migratory Fish Stocks (UNFA), which came into force in 2001, commits Canada to use the precautionary approach in managing straddling stocks as well as domestic stocks.  In 2003, the Privy Council Office, on behalf of the Government of Canada, published a framework applicable to all federal government departments that sets out guiding principles for the application of precaution to decision making about risks of serious or irreversible harm where there is a lack of full scientific certainty.

In 2009, subsequent to these commitments, DFO developed a fishery decision-making framework incorporating the precautionary approach  (, which applies where decisions on harvest strategies or harvest rates for a stock must be taken to determine total allowable catch (TAC) or other measures to control harvests.  The framework applies to key harvested stocks managed by DFO: those stocks that are the specific and intended targets of a fishery, whether in a commercial, recreational or subsistence fishery.  While the framework in this case is designed for directed fisheries, the general principle of the precautionary approach (making cautious decisions that support positive fish stock outcomes, especially in the absence of information) should be applied to all management decisions.  In applying the framework, all removals of these stocks from all types of fishing must be taken into account.

The following are the primary components of the generalized framework:

Reference points

In 2002, TMGC adopted a strategy to maintain a low to neutral risk of exceeding the fishing mortality limit reference for yellowtail. In addition, when stock conditions are poor the TMGC strategy is to further reduce fishing mortality rates to promote rebuilding (DFO 2018). Since an empirical approach is now used for assessing this stock, an estimate of fishing mortality rate can no longer be calculated and therefore status determination relative to this reference is not possible.  Biomass reference points consistent with the precautionary approach framework have not been developed for this stock but all 3 survey indices are at their lowest point in the time series and well below historical values (TRAC 2018).  This would indicate that the stock is in the Critical Zone. To give some historical context for stock size, the last reference point calculated for this stock was SSBMSY = 43,200 mt (TRAC 2013).

Developing reference points consistent with the precautionary approach framework is challenging under the current empirical (ie, index-based) approach to the stock assessment. It may be possible to develop proxy reference points that would serve as an interim target for rebuilding. Currently, the stock is being managed in a precautionary way consistent with being in the Critical Zone.

COSEWIC assessment/ SARA considerations

This stock has not been assessed by COSEWIC and is therefore not currently under consideration for listing under SARA.

Indigenous knowledge

DFO aims to incorporate traditional knowledge into fisheries management planning.  This will be completed through consultations with First Nations and other Indigenous organizations. Please refer to Section 3.1 of the 4VWX5 Groundfish IFMP for additional information.

IV. Socio-economic and cultural importance

Exploitation of the Georges Bank yellowtail flounder stock began in the mid-1930s by the US trawler fleet.  Catch (including discards) increased from 400 mt in 1935 to the highest annual catches during 1963-1976 (average: 17,500 mt) and included modest catches by distant water fleets (Figure 5).  A directed Canadian fishery began on Georges Bank in 1993, pursued mainly by small otter trawlers (< 20 m), and in 2001 the decision was made to manage the stock as a transboundary resource in Canadian and US jurisdictions (TMGC 2002).  Since 2004, decreasing quotas, and catches below these quotas, have resulted in a declining trend in catches through 2016 (Figure 5).  In 2017, the Canadian catch, including discards, was 3 mt, the lowest in the time series (1935-2017); the total Canadian and US combined catch was 95 mt, the second lowest value in the time series (DFO 2018).

Canadian fishermen initiated a directed fishery for yellowtail flounder on Georges Bank in 1993, but landings have been less than 100 mt every year since 2004, and less than 3 mt in each of the last five years.  Since 2004, with the exception of 2011 and 2012, there has been no directed Canadian yellowtail flounder fishery (the groundfish fishery is not permitted to target yellowtail flounder, nor use gear appropriate for targeting this species); the Canadian quota has been reserved to cover bycatch in the commercial groundfish and scallop fisheries.  From 2004 to 2011 and from 2013 to 2017, most of the reported yellowtail flounder landings in the groundfish fishery were from trips directed for haddock. The Canadian 5Z groundfish fleet landed 13,400 mt of haddock in 2017, representing by far the largest portion of fish caught by this fleet on Georges Bank.

The Canadian offshore scallop fishery is the only significant source of Canadian yellowtail flounder discards on Georges Bank.  Discards are estimated from at-sea observer deployments using the methodology documented in Van Eeckhaute et al. (2005).  Since August 2004, there has been routine observer coverage on vessels in the Canadian scallop fishery on Georges Bank.  The result of these calculations for 2017 is a discard estimate of 2 mt, the lowest in the time series (Figure 5 and Table 2).  For 2017, the total Canadian catch, including discards, was 3 mt, which is 3.2% of the 2017 quota of 93 mt (TRAC 2017). The Canadian offshore scallop fleet in 5Z landed 30,796 mt of scallop in 2017; this is more than twice that landed by the inshore scallop fleet for the same year. Given the small Canadian quota for yellowtail flounder in 5Z, it has been reserved for bycatch by all fleets since 2013.

Annual catch (landings plus discards) of Georges Bank yellowtail flounder by nation
Figure 5: Annual catch (landings plus discards) of Georges Bank yellowtail flounder by nation.
Description

Figure 5: Annual catch (landings plus discards) of Georges Bank yellowtail flounder by nation.

Table 2: Georges Bank yellowtail flounder catches and discards in metric tonnes (mt).
    2012 2013 2014 2015 2016 2017 2018 Avg¹ Min¹ Max¹
Canada² Quota 586 285 72 106 85 93 87      
  Landed 46 1 1 3 1  <1    430  <1 2,913
  Discard 48 39 14 11 10 2   428 10 815
USA² Quota³ 564 215 328 248 269 207 213      
  Catch³ 379 93 122 68 26 844        
  Landed 443 130 70 63 26 35   3,792 26 15,899
  Discard 188 49 74 41 7 57   519 7 3,021
Total² Quota5 1,150 500 400 354 354 300 300      
  Catch5 473 132 136 82 36 874        
  Catch6 725 218 159 118 44 95   5,192 44 17,211

¹1973 – 2017
²unless otherwise noted, all values reported are for calendar year
³for fishing year May 1 – April 30
4preliminary estimate 
5for Canadian calendar year and USA fishing year May 1 – April 30
6sum of Canadian landed, Canadian discarded, and USA catch (includes discards)

Please refer to section 4 of the 4VWX5 Groundfish IFMP for additional details on the socio-economic and cultural importance of the commercial groundfish fishery within the Maritimes Region fishery.

V. Management issues

Due to the lack of an analytical assessment model, an estimate of fishing mortality rate can no longer be calculated. Status determination relative to reference points is not possible because reference points cannot be defined.

This is a transboundary stock managed jointly with the US. The 2017 Canadian catch of 3 mt was well below the Canadian quota of 93 mt, with landings of <1 mt and estimated discards of 2 mt from the scallop dredge fishery. US catches in calendar year 2017 were 92 mt, with landings of 35 mt and discards of 57 mt. The US landings in calendar year 2017 were predominantly from the trawl fishery, while discards were predominantly from the scallop dredge fishery. Preliminary estimates of the US catch (landings plus discards) for fishing year 2017 were 44% of the 207 mt quota.

Both the US and Canada have caught less than their respective quotas since at least 2011 (TMGC 2017), with the total quota being approximately 3.1 times higher than the actual catch in the period of 2010 to 2017 (TRAC 2018).

As there is currently no directed Canadian fishery for yellowtail flounder and bycatch is low, any further actions taken by Canada are unlikely to greatly impact the rebuilding of this stock. No actions other than reductions in fishing mortality have been identified that would be expected to contribute to stock rebuilding.

VI. Objectives

There are 5 overarching objectives identified in the 4VWX5 Groundfish IFMP , and these are guided by the principle that the fishery is a common property resource to be managed for the benefit of all Canadians, consistent with conservation objectives, the constitutional protection afforded Aboriginal and treaty rights, and the relative contributions that various uses of the resource make to Canadian society, including socio-economic benefits to communities.

Conservation-based objectives

  1. Productivity: Do not cause unacceptable reduction in productivity so that components can play their role in the functioning of the ecosystem.
  2. Biodiversity: Do not cause unacceptable reduction in biodiversity in order to preserve the structure and natural resilience of the ecosystem.
  3. Habitat: Do not cause unacceptable modification to the habitat in order to safeguard both physical and chemical properties of the ecosystem.

Social, cultural and economic objectives

  1. Cultural and sustenance: respect Aboriginal and treaty rights to fish.
  2. Prosperity: Create the circumstances for economically prosperous fisheries.

As outlined in the precautionary approach framework, the primary objective of this rebuilding plan is to promote stock growth out of the Critical Zone (e.g. grow the stock beyond the LRP), by ensuring removals from all fishing sources are kept to the lowest possible level until the stock has cleared this zone. Within the Critical Zone, this objective remains the same whether the stock is declining, stable or increasing.

Short-term objectives (3-5 years)

Under current conditions of high natural mortality, it is not possible to set timelines for rebuilding the 5Z yellowtail flounder stock. Canadian catches have been in line with previous TRAC recommendations and Canada plans to continue to maintain catches at a level that is consistent with science advice. Canada will aim to maintain bycatch of 5Z yellowtail flounder at the lowest practicable levels.

Mid-term objectives (5-15 years)

According to the precautionary approach framework , when a stock is in the Critical Zone, rebuilding to a level above the LRP should be achieved in a reasonable timeframe (1.5 to 2 generations) with a high degree of probability (greater than 75%). For the 5Z yellowtail flounder stock, this equates to approximately 12-16 years; however, given the low productivity and high natural mortality of the stock and the lack of response to reduced fishing to date, rebuilding of this stock is not expected unless stock productivity improves.

Long-term objective (15 + years)

The long-term objective for 5Z yellowtail flounder is for the stock to grow out of the Critical Zone, and eventually to achieve and maintain the spawning stock biomass in the Healthy Zone for the benefit of all Canadians, including harvesters, industry workers and other people in coastal communities who depend on the resource for their livelihood, and to provide reasonable fishing opportunities during the rebuilding period. 

VII. Management measures

Catch reductions and controls (groundfish fisheries)

The primary control on fishery removals for 5Z yellowtail flounder is the TAC.  All groundfish landings are counted towards the quota, and no discarding of 5Z yellowtail flounder is permitted in groundfish fisheries.

The season for the 3 transboundary stocks on Georges Bank (Georges Bank yellowtail flounder and Georges Bank cod and haddock) runs from January 1 to December 31, with a closure between the fifth week of the year and May 31. The Georges Bank fishery is separated into US and Canadian management regimes.  When fishing on Georges Bank, all Canadian vessels are required to hail out prior to departing on a fishing trip, to hail in upon return, and to carry Vessel Monitoring Systems (VMS) onboard.  All Canadian Georges Bank landings are monitored at the point of offloading via the third-party dockside monitoring program.  These monitors verify the weight and species of fish offloaded.  Detailed catch and effort information for every trip must be recorded in logbooks and submitted to DFO (via a dockside monitoring company).  At-sea observers are also used to monitor catches of all species, including yellowtail flounder, in the Georges Bank groundfish fisheries. For Georges Bank, from 2015-2017, at-sea observers monitored an average of 66.3% of the directed haddock trips using mobile gear and 18.6% of the directed haddock trips using longlines.  

Catch reductions and controls (other fisheries)

DFO has developed a Policy for Managing Bycatch . The policy will be implemented through IFMPs over time, according to national and regional priorities and resource availability. This policy has 2 objectives:

The Conservation Harvesting Plan (CHP) for the 5Z groundfish fishery allows for a 10% bycatch of flatfish (yellowtail flounder, witch flounder, winter flounder, and American plaice) when directing for haddock or pollock using mobile gear; yellowtail flounder bycatch alone can only constitute up to 5% of the total catch.

Lobster fishing on Georges Bank falls within Lobster Fishing Area 41 and is open year-round.  The fishery currently has 8 licences, which are owned by a single corporation, fished from a single vessel, with no trap limit because the fishery is managed under a TAC. Six at-sea observer trips are conducted each year which provide information on bycatch profiles.  No yellowtail flounder were identified in observations of bycatch for LFA 41 from 2006 to 2015 with at-sea observer coverage of 15% by trip since 2012 (Cook et al. 2017).

Seal predation

Beck et al. (2007) identified that an increase in seal populations may contribute to the high natural mortality for 5Z yellowtail flounder, but stated that the degree to which seals contribute to natural mortality has yet to be quantified. Therefore, it is not known to what extent management of the seal population would assist in the rebuilding of the stock.

Gear modification and restrictions

Since 2005, there has been a reduction in estimated bycatch amounts by the Canadian offshore scallop fishery on Georges Bank (Table 5).  This may indicate the industry’s ability to reduce bycatch using avoidance protocols and gear modifications (i.e., ring sizes and rope backs); however, total bycatch may also be affected by decreased effort, spatial changes in fishing, changes in the scallop TAC or by the abundance of the bycatch species (DFO 2016b).

The use of a horizontal separator panel when fishing for groundfish with mobile gear became mandatory in 1999, unless an at-sea observer is on board the vessel.  Since 2009, the separator panel has been mandatory at all times in the Georges Bank (5Z) mobile gear haddock fishery to reduce bycatch of cod, and also reduces the potential for catch of yellowtail and other flounders.

Closed areas

In addition to quota-based management, DFO regularly employs measures intended to reduce catch of juvenile fish and increase their chances of surviving to maturity and contributing to stock productivity, including both ad hoc and permanent small-fish closures.

There is an annual spawning closure affecting the offshore scallop fishery on Georges Bank for the month of June.  The intent of the closure is to minimize disturbance during yellowtail flounder spawning in case such disturbance might negatively affect spawning success. The area/time closure is effective in a portion of NAFO area 5Zjm, part of which is colloquially named the Yellowtail Hole. There is also a closure of this same fishery on Georges Bank for 7 weeks in February and March to protect spawning cod.

Small fish area closures

Small fish area closures may be enacted for specified fleet sectors when the number of undersized fish (species lengths vary) reaches or exceeds 15% of the catch. These closures are enacted for cod and haddock in area 5Z and so would not be relevant to yellowtail flounder lengths, but would impact the fishing effort and resulting bycatch in the given area. A small fish size has been determined for yellowtail flounder (30cm), but due to the extremely low catch rates, size sampling is not currently being done for this stock.

For additional information, please refer to Section 5.4.2 of the 4VWX5 Groundfish IFMP.

Monitoring

Monitoring tools in use vary by fleet and include hails, dockside monitoring of landings, at-sea observer coverage, logbooks, and vessel monitoring systems. Please refer to Section 5.1 of the 4VWX5 Groundfish IFMP for additional details.

Habitat protection

The Corsair and Georges Canyon Conservation Area  can be found on the southeast corner of Georges Bank and was developed to protect cold-water corals. This area is closed to bottom-contact fishing gears.

The Northeast Channel Coral Conservation Area  is found at the northeastern corner of NAFO area 5Ze. It was also created to protect cold-water corals, and as such is closed to bottom-contact fishing gears.

Please refer to section 5.1 of the 4VWX5 Groundfish IFMP for further details on Oceans and Ecosystem Management Considerations in the Maritimes Region, and section 5.5  for details on existing measures within 5Zjm to limit benthic impacts.

Harvest strategies and tactics

This section presents the current harvest strategies and tactics being used for 5Z yellowtail flounder to achieve the objectives outlined below.  Table 3 outlines the current harvest strategies and tactics, incorporating the relevant reference points, which are applied to achieve the objectives for the stock.  

In 2018 the TRAC external reviewers and science members recommended an exploitation rate of 2% to 6% for catch advice. The average exploitation rate associated with the quota for years 2010 to 2017 is 6% (the upper bound) while the average exploitation rate associated with the catch for years 2010 to 2017 is 2%. Applying this range of exploitation rates to this year’s updated surveys resulted in catch advice of 23 mt to 68 mt for 2019. The TRAC noted that increasing the exploitation rate above the average from 2010 to 2017, a period when the stock declined substantially, is risky and reduces the chances of rebuilding.

Considering 5Z is included in the US-Canada Transboundary Resource Sharing Understanding, it is recognized that TAC-setting is a collaborative process.  As such, the objectives and strategies described below apply explicitly to the management of the stock within Canada.  They may also be used to guide Canadian members who will advance positions consistent with these objectives during negotiations at the TMGC; however, it is acknowledged that, as with any international body, differing legislative frameworks may prevent the perfect implementation of the domestic strategies advanced by a particular country.

Table 3: Current Canadian harvest strategies and tactics for 5Z yellowtail flounder.
Strategies Tactics
Productivity

Manage fishing mortality in the groundfish fishery by using the following references and risk tolerances:

  • exploitation rate for Canadian portion of fishery kept as low as possible below the upper bound of 6%.
  • TAC (which may be introduced through fleet quota caps or trip limits)
  • Small fish protocol
  • Gear modifications (e.g. mandatory use of a cod separator panel when fishing with mobile gear in 5Z)
  • Size selectivity through gear restrictions (e.g. mesh and hook size constraints)
  • Bycatch limits when directing for other groundfish
Keep fishing mortality of yellowtail flounder in the offshore scallop fishery to the lowest possible level.
  • Mandatory release of yellowtail flounder bycatch
  • Encourage the offshore scallop fleet to continue using voluntary, industry-led avoidance protocols and gear modifications
  • Continue the June spawning closure of the offshore scallop fishery

VIII. Access and allocation

The 5Z yellowtail flounder TAC is fully allocated to fleet sectors according to established percentage shares (Table 1).  Please see Section 7 of the 4VWX5 Groundfish IFMP for further details.

IX. Shared stewardship

Shared stewardship is achieved through the involvement of stakeholders and rights-holders in advisory committees and regional science advisory processes.  Please see Section 2.6 of the 4VWX5 Groundfish IFMP  for further details.

X. Compliance

Compliance monitoring involves the deployment of fishery officers to air, sea and land patrols, observer coverage on fishing vessels, the dockside monitoring program (DMP) and remote electronic monitoring (VMS).  For details on regional compliance program delivery, current compliance issues and the compliance strategy, see section 8 of the 4VWX5 Groundfish IFMP 

XI. Plan enhancement, evaluation and performance review

Outcomes from the application of this plan will be reviewed periodically through the GOMAC as required to determine if changes to the plan are warranted.  There is an annual scientific assessment for 5Z yellowtail flounder through the TRAC, and this rebuilding plan will be reviewed and revised as needed following each assessment.

DFO will also ensure that all significant sources of fishing mortality can be estimated and accounted for.  For groundfish fisheries, unreported (and illegal) discards would be the main source of unaccounted fishing mortality.  DFO will review the current strategy used to estimate illegal discards, which could include exploring other forms of catch monitoring, such as electronic video monitoring.

A full accounting of 5Z yellowtail flounder fishing mortality should also include catches in Aboriginal food, social, and ceremonial fisheries and recreational fisheries, if these fisheries are taking place in 5Z.  DFO is considering the implementation of a marine recreational licence for Atlantic Canada, which would improve data collection from recreational groundfish fisheries.  DFO is also working with First Nations and other Indigenous organizations to improve reporting of catches in food, social, and ceremonial fisheries.

An overview of action items to support the rebuilding of 5Z yellowtail flounder can be found in Table 4.

Table 4: Action items to support rebuilding of 5Z yellowtail flounder.
Issue Action Timeline Lead
No reference points Establish a proxy limit reference point or other rebuilding target. 2020/21 Science, Resource Management and GOMAC
Commercial fishing

Review TAC and rebuilding plan following annual TRAC Assessment

(e.g. revisit existing bycatch rules).
2019/20 Resource Management and GOMAC
Maintain yellowtail flounder spawning area closure on Georges Bank (scallop fishery only). Annually in June Resource Management  
Recreational fishing Pending a Ministerial decision, the implementation of a marine recreational licence for Atlantic Canada would greatly improve data collection from recreational groundfish fisheries, including yellowtail flounder catches. Unknown Resource Management
Bycatch management Consult with the offshore scallop fishery to better understand the bycatch avoidance techniques they voluntarily employ to reduce yellowtail flounder bycatch. 2019 Resource Management and offshore scallop fishing industry
Remove yellowtail flounder as a species that is eligible for bycatch redistribution under the Bycatch Reserve Redistribution Process. 2019 Resource Management  
Illegal discarding Review the current strategy used to estimate illegal discards of yellowtail flounder in the groundfish industry. 2019-22 Resource Management, Science and Conservation and Protection
Seasonal distribution Map the distribution of yellowtail flounder on Georges Bank using the RV and NMFS Spring and Fall surveys. Ongoing via annual assessments Science

XII. References

Beck, C. A., Iverson, S. J., Bowen, W. D., and Blanchard, W. 2007. Sex differences in grey seal diet reflect seasonal variation in foraging behaviour and reproductive expenditure: evidence from quantitative fatty acid signature analysis. J Animal Ecol, 76(3), 490-502.

Cadrin, S.X. and Westwood, A.D. 2004. The Use of Electronic Tags to Study Fish Movement: A Case Study with Yellowtail Flounder off New England. ICES C.M. 2004/K:81.

Cook, A.M., Cassista-DaRos, M., and Denton, C. 2017. Framework Assessment of the Offshore American Lobster (Homarus americanus) in Lobster Fishing Area (LFA) 41. Can Sci Assess Sec Res Doc 2017/065.

DFO. 2016a. Offshore Lobster and Jonah Crab - Maritimes Region IFMP - September 2016.

DFO. 2016b. Offshore Scallop – Maritimes Region IFMP.

DFO. 2018. 4VWX5 Groundfish – Maritimes Region IFMP.

Hare J.A., Morrison W.E., Nelson M.W., Stachura M.M., Teeters E.J., et al. (2016) A Vulnerability Assessment of Fish and Invertebrates to Climate Change on the Northeast U.S. Continental Shelf. PLOS ONE 11(2): e0146756. https://doi.org/10.1371/journal.pone.0146756

Legault, C.M. and McCurdy, Q.M. In prep. Stock assessment of Georges Bank Yellowtail Flounder for 2018. TRAC Reference Document 2019/xxx.

Northeast Fisheries Science Center. 2017. Operational Assessment of 19 Northeast Groundfish Stocks, Updated Through 2016. US Dept Commer, Northeast Fish Sci Cent Ref Doc. 17-17; 259 p.

Northeast Fisheries Science Center. 2018. State of the Ecosystem - Gulf of Maine and Georges Bank. (Accessed Dec 21, 2018).

Sameoto, J.A and Glass, A. 2012. An Overview of Discards from the Canadian Inshore Scallop Fishery in SFA 28 and SFA 29 West for 2002 to 2009. Can Tech Rep Fish Aquat Sci 2979:vi+39 p.

TRAC. 2013. Georges Bank Yellowtail Flounder. TRAC Status Report 2013/01.

TRAC. 2014. Proceedings of the Transboundary Resources Assessment Committee for Georges Bank Yellowtail Flounder Diagnostic and Empirical Approach Benchmark. TRAC Proceedings 2014/01.

TRAC. 2017. Georges Bank Yellowtail Flounder. TRAC Status Report 2017/03.

TRAC. 2018. Georges Bank Yellowtail Flounder. TRAC Status Report 2018/03.

Van Eeckhaute L.V., Gavaris S. and Stone H.H. 2005. Estimation of Cod, Haddock and Yellowtail Flounder Discards from the Canadian Georges Bank Scallop Fishery for 1960 to 2004