MB0142 Final Report Spurdog By-catch Avoidance Programme Aligning spurdog with the Common Fisheries Policy landing obligation by reducing spurdog by-catch and subsequent dead discards, whilst minimising the risk of creating a ‘choke’ species. Stuart J Hetherington, Rose E Nicholson and Carl M O’Brien 27 th July 2016
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MB0142 Final Report
Spurdog By-catch Avoidance
Programme
Aligning spurdog with the Common Fisheries Policy landing obligation by
reducing spurdog by-catch and subsequent dead discards, whilst minimising the
risk of creating a ‘choke’ species.
Stuart J Hetherington, Rose E Nicholson and Carl M O’Brien
Society, North Devon Fisherman Association, Falfish, Scottish Association of Marine Science, Sea
Mammal Research Unit, Zoological Society of London, New England Aquarium and Seafish.
In addition to meetings and workshops, the fishing industry have been engaged through one-to-one
meetings, and articles in the fishing press. The article in the Fishing News on 11th February 2016 http://fishingnews.co.uk/2016/02/fishermen-buy-in-to-shark-by-watch/ (Annex 2) was used to raise
awareness and provide a progress update of the Defra-led initiative to the fishing industry.
Defra has undertaken engagement with other EU Member States through the North Western Waters,
and North Sea, Advisory Councils, Technical Groups and High Level Groups. The pilot project has also
been shared directly with EU Member States to encourage discussion on the approach. Cefas and
Defra have presented the project to:
- the North Western Waters Advisory Council (NWWAC) in Edinburgh on 7th July 2015 and
subsequently received strong endorsement (Annex 3).
- The European Commission at the Directorate-General for Maritime Affairs and Fisheries,
Brussels on 29th February 2016 to present the UK proposal for establishing a precautionary by-
catch allowance for spurdog to enable a more comprehensive trial of the pilot project in the
NEA.
The stakeholder engagement and outreach programme for this pilot project has been extensive and far
reaching, yet targeted to the project’s objective of forming working partnerships to deliver the Spurdog
By-catch Avoidance Programme by keeping all partners engaged, both for this pilot project, and for a
potential follow-on.
3.2. Select up to 10 suitable commercial fishing vessels operating in the Celtic Sea fisheries to participate in the Spurdog By-catch Avoidance Programme
The pilot project relies on participating fishing vessel skippers to self-report their spurdog by-catch and
make informed decisions to avoid ‘hot spot’ areas to reduce spurdog by-catch, reducing fishing mortality
and prevent ‘choking’ the fishery. Simply put, to avoid areas of high incidence of spurdog by-catch,
possibly moving to less productive fishing grounds.
This additional requirement of ‘avoidance’ by the fishing vessel skippers is seen as an additional burden,
both in time and loss of earnings (if displaced to less productive grounds). To offset this burden to
fishing vessel skippers, an incentive is required. This was identified in the original proposal to STECF
and the EC for a UK Pilot Project to develop a real-time Spurdog By-catch Avoidance Programme
(Bendall et al., 2014). This proposed a provision of a small (50 tonnes) marketable dead spurdog by-
catch allowance to account for unavoidable by-catch and to incentivise participation in the pilot project.
Before initiating this pilot project in 2015, a dead spurdog by-catch allowance was sought at the
December Fisheries Council 2014, so as to incentivise participation in the Spurdog By-catch Avoidance
Programme. Unfortunately, the dead spurdog by-catch allowance was not secured before the
commencement of this pilot project. As a result, an alternative incentive was offered, limited additional
quota for commercial species to the equivalent value of a hypothetical spurdog by-catch allowance of
50 tonnes.
Dispensation from the Provision of Council Regulation 2007/41 (Article 2) quota restrictions allowed
vessels in the pilot project to be allocated limited additional quota if the fishing vessel skipper adhered
to the pilot projects requirements of reporting their spurdog by-catch in real-time.
The incentive of additional quota was insufficient to obtain the necessary ‘buy-in’ of fishermen at the
level first envisaged of up to 10 vessels. The incentive for participation is not an economic one (i.e. the
provision of additional quota), but a moral principle of reducing spurdog by-catch and subsequent dead
discards. Many fishermen were unwilling to voluntarily participate in the pilot project, reporting in real-
time, avoiding spurdog to potentially fish less productive grounds, yet continue discarding dead
spurdog. That said, through support of the CFPO, 3 commercial offshore netting vessels were
identified. Two of the three vessels provided limited, ad hoc reports of spurdog by-catch for a limited
number of fishing trips at project start-up, but not to the standard required. The limited reports of
spurdog by-catch from these vessels have not been included in this report. The third vessel provided
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real-time reports of spurdog by-catch to the standard and frequency required. The vessel was a 22.65
m offshore netter operating from a port in the south-west of England.
3.3. Investigate, develop, source and implement a real-time by-catch avoidance tool
A desk based review of real-time reporting systems for reporting elasmobranch by-catch was
undertaken (Hunter et al., 2016). Following the example of the US scallop fishery (O'Keefe and
DeCelles, 2013), a relatively low tech option involving email and fax, as opposed to the more high-tech
options using e-logbook, was chosen, principally as a low-cost, reliable option for a short-term pilot
project, with many offshore vessels having these systems in place already. The real-time channels of
communication are schematised in Figure 3.
The CFPO took a proactive role in the pilot project. Using email, the participating skipper reported his
spurdog by-catch by total approximate weight per grid cell (see section 3.3.1 and Annex 7) to the CFPO
by midnight for that days fishing activity (Figure 4).
Figure 3: Schematic of the real-time spurdog by-catch reporting tool.
The following morning, the CFPO entered the data into the real-time spurdog reporting tool via the Defra
ArcGIS on-line reporting portal (Annex 4). The data were transferred to the Cefas network where the
automated advisory tool that runs within ArcGIS for Desktop 10.1 (ESRI, Redlands) processed the data
(Figure 5). The weight of spurdog by-catch in each grid cell was classified to predetermined thresholds
(see section 3.3.3), using a traffic light system. The cells of the reporting grid are coloured to the level
of spurdog by-catch, green (low risk of significant by-catch), amber (medium risk of significant by-catch)
and red (high risk of spurdog by-catch) to produce an advisory notice that can be sent back in near real-
time (before mid-day) to the CFPO. These can be forwarded by the CFPO to the participating vessel.
This advises fishermen of the by-catch “hotspots”, enabling them to make informed decisions on their
fishing behaviours, reducing spurdog by-catch, reducing fishing mortality and prevent ‘choking’ the
fishery. All spatial data and advisory maps generated by the real-time reporting tool are accessible for
further analysis within the Cefas network.
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Figure 4: Example of 24 hour spurdog by-catch real-time report. Personal data anonymised.
Figure 5: The advisory tool in ArcGIS for Desktop 10.1.
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3.3.1. Reporting grid
The size of the reporting grid cells must be of a spatial resolution to allow participating fishermen in the
pilot project to accurately report the spurdog by-catch from a days fishing activity, and should it be
necessary, avoid by-catch “hotspots” for relatively small areas, rather than curtail fishing activity over
large areas. For this reason, the size of an ICES statistical rectangle (approximately 30 nautical miles
by 30 nautical miles, dependent on the curvature of the Earth) is too great for an amalgamation of ICES
statistical rectangles be an effective reporting grid. Instead, daily movements of 12 electronically tagged
spurdog were used to inform the appropriate size of the reporting grid cell in relation to the spatial extent
for a grid-based 'move on' rule (Bendall et al., 2014). Based on that data, ‘128th’ of an ICES rectangle
(approximately 4.5 km by 3.5 km) was deemed an appropriate size for each cell within the reporting
grid (Annex 7).
3.3.2. Spurdog by-catch allowance allocation
The pilot project is designed around the provision of a hypothetical dead spurdog by-catch allowance
of 5 tonnes per vessel. This was considered a sufficient allocation for a continuation of this pilot project
in the future but not substantial enough to incentivise any targeting of spurdog or the retention of live
specimens. Survivability of spurdog caught by the UK netting fleet in the Celtic Sea region (ICES
Divisions VIIe-j) is estimated to be around 60% (Bendall et al., 2014), therefore the spurdog catch
allowance per vessel is set at 12.5 tonnes, with an expected 7.5 tonnes to be returned alive. The
hypothetical allowance is distributed across a 12-month period as follows: 80% between October to
April, where spurdog is a frequent by-catch species, and 20% between May to September where
spurdog by-catch is less frequent in the Celtic Sea gill-net fishery (Ellis et al., 2014).
3.3.3. Traffic light system thresholds
Using a traffic light system, the amount of spurdog by-catch in each grid cell, reported by the vessel, is
set to predetermined thresholds and coloured to the level of spurdog by-catch, as follows:
Green: low risk of significant spurdog by-catch
Amber: medium risk of significant spurdog by-catch
Red: high risk of significant spurdog by-catch and choking the fishery
To identify the thresholds, firstly for the participating vessel, generalised fishing grounds were identified
based on Vessel Monitoring System (VMS) data for the 2-year period from 1st January 2013 to 31st
December 2014. Ping locations for the vessel were processed as described in Lee et al. (2010) using
a simple speed rule whereby vessels travelling at 1-6 knots were assumed to be fishing, and allocated
to the grid cells used for real-time reporting. This rule works less well for fishing vessels fishing static
gear, as during hauling operations that often last >10 hours in every 24-hour period, they travel at <1
knot. That said the participating fishing vessel steams to and from the fishing grounds at 8 knots,
therefore speeds <6 knots indicate that the vessel is operating on the fishing ground, moving between,
and hauling static gear.
The commercial fishing vessel involved in this pilot project also participated in the Defra funded, fishery-
dependent programme; NEPTUNE Shark, Skate and Ray Scientific By-Catch Fishery (NEPTUNE) (Ellis
et al., 2015), providing self-sampling data on levels of spurdog by-catch during typical commercial
fishing activity. Historic spurdog by-catch “hotspots” have been identified from this data. Fishing events
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where spurdog by-catch accounted for over 95% of the total spurdog by-catch reported were allocated
to the reporting grid cells. 8 grid cells were identified as historic “hotspots” (Figure 6).
For the gill-net fishery in the Celtic Sea, thresholds for medium risk of spurdog by-catch (designated
amber) have been determined by assigning 80% of the hypothetical spurdog by-catch allowance
allocated to the 7 months from October to April and the remaining 20% to the 5 months from May to
September. The monthly allocated hypothetical spurdog by-catch allowance is split between the
average number of grid cells fished over one month from January 2013 to December 2014. Thus the
threshold for medium risk of spurdog by-catch at grid cell level for October is:
𝑇ℎ𝑟𝑒𝑠ℎ𝑜𝑙𝑑 = 𝑇𝑜𝑡𝑎𝑙 𝑄𝑢𝑜𝑡𝑎 ×
80100
×17
𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑔𝑟𝑖𝑑 𝑐𝑒𝑙𝑙𝑠
Cells are assigned low risk status (designated green) where spurdog by-catch is reported, but the total
weight of by-catch over the month remains below the medium risk threshold (designated amber). Based
on the distribution of the spurdog by-catch weights and numbers reported by this vessel in NEPTUNE,
the threshold for high risk of spurdog by-catch (designated red) is set to the same as the threshold for
medium risk for historic hotspots and 5 times the threshold for medium risk for other cells. Additionally,
historic “hotspots” are given an influence over the 24 neighbouring cells, so that spurdog by-catch within
these cells results in high risk being attributed to neighbouring cells as shown below:
Illustration: The dark red cell in the centre is a historic “hotspot”. It has an influence over the neighbouring grid cells, shown in light red. High spurdog by-catch events in the dark red grid cell results in an advisory notice of high risk status (red: high risk of significant spurdog by-catch and choking the fishery) being issued for this cell and all adjacent light red grid cells.
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For cells where the risk is not influenced by the proximity of hotspots from the same month in a previous
year, the baseline risk of spurdog by-catch on the first day of the month is determined by reducing the
risk from the previous month by one level. Thus, high risk cells become medium risk the following month,
medium risk cells become low risk, and low risk cells remain low risk.
Outside the main fishing grounds, a threshold of zero is applied for medium risk of spurdog by-catch.
This is to alert the fact that the fishing vessel is fishing outside its typical ground, for which we have little
spurdog by-catch data. The threshold for high-risk of spurdog by-catch is unchanged from the threshold
within the main fishing grounds.
3.3.4. Baseline reporting of voluntary avoidance behaviour
Real-time reporting began in October 2015 following the initial identification of 3 potential vessels.
Advisory notices consisting of the level of spurdog by-catch, green (low risk of significant by-catch),
amber (medium risk of significant by-catch) and red (high risk of spurdog by-catch), for each reporting
grid cell were not issued to the fishing vessel. This was a deliberate action to collate three months of
baseline data of voluntary avoidance. Due to the limited nature of this pilot project (one vessel reporting
over 3 months), evaluation of avoidance behaviour by one vessel resulting from the advisory notice
would have been inconclusive. Instead, should a spurdog by-catch allowance be secured for a more
comprehensive future project, including more vessels, then the baseline data collected in this pilot
project will be of more value in the evaluation process of any follow-on project.
3.4. Record the activity of up to 10 fishing vessels participating in the Spurdog By-catch Avoidance
Programme in the Celtic sea
The pilot project was undertaken in the commercial fixed net fishery in the Celtic Sea (ICES Divisions
VIIe-h). The participating vessel fishes predominately with gill-nets, typically 120 – 150 mm mesh size,
ranging from 7.5 – 10.5 nm in length, soaked for 16 – 34 hours, targeting hake (Merluccius merluccius)
and pollack (Pollachius pollachius), between October- April, where spurdog is a frequent by-catch
species (Ellis et al., 2014). For the summer months, May – September, tangle nets of 250-300 mm
mesh size are more typically used, targeting larger commercial species such as anglerfish and turbot.
Spurdog are only an occasional by-catch in this gear type. This seasonal fishing pattern of gear use is
typical of the majority of UK offshore gill-netters fishing in the Celtic sea, therefore spurdog is a frequent
by-catch species for the UK offshore gill-net fleet from October – April.
The real-time by-catch avoidance tool was developed, tested and in-place by the end of July 2015.
However, due to the seasonality of spurdog by-catch in this fishery, real-time reporting did not begin
until October 2015.
Working in partnership with the CFPO, the 3 vessels identified at the outset of the project were engaged
with on a one-to-one basis. The skippers were supplied with (i) Background information to skippers
(Annex 5), (ii) 24-h reporting sheet template (Annex 6), and (iii) Reporting Grid Reference Booklet
(Annex 7). A member of the Cefas project team met with the fishing vessel skipper to provide further
background to the project and explain what was required from them in terms of their real-time reports
of spurdog by-catch. As mentioned in section 3.2, only one of the vessels provided real-time reports of
spurdog by-catch to the standard and frequency required and only these data are included in this report.
Given other national priorities, a UK proposal for establishing a precautionary by-catch allowance for
spurdog to enable a more comprehensive trial of the pilot project in 2016 was not sought at the
December Fisheries Council 2015. As a result, the support of the participating fishing vessel waned.
Due to a lack of incentive to participate, real-time reports of spurdog by-catch by the participating vessel
stopped in January 2016.
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3.5. Evaluate the outcomes and success of the Spurdog By-catch Avoidance Programme.
The pilot project has been evaluated against clearly measurable objectives: (i) engagement, (ii) data
quality, and (iii) the uptake of a hypothetical by-catch allowance for dead spurdog. In addition, historic
baseline fishery dependant spurdog by-catch and discard data, e-logbook data and VMS data, at vessel
and fleet level, have been used to evaluate voluntary avoidance of spurdog by-catch by the participating
vessel.
3.5.1. Engagement
There was a baseline level of engagement from the participating vessel, providing 17 daily spurdog by-
catch reports, for the 33 days that the vessel was at sea in the same period. The measure of
engagement was the timely provision of data. Spurdog by-catch was reported on 9 days in October-
November 2015, the lag time between emails from the skipper of the participating vessel and data entry
onto the on-line reporting tool ranged from 4 days to 22 days. The mean lag time was 11 days; the
median 9 days.
Timeliness of data entry into the online reporting tool, therefore engagement, improved markedly in
December 2015, with 6 out of 9 reports entered within 1 day of the email from the skipper. The remaining
3 reports were entered within 3-5 days and were emailed on a Thursday or a Friday. The additional
delay over weekends highlights the need for more streamlined reporting systems in order for the tool to
be effective. This increase in engagement during December 2015 appears directly related to increased
levels of spurdog by-catch in that month, with 9 daily spurdog by-catch reports, including 3 reports of
very high weights of by-catch, for 15 days at sea.
To promote good working practice as part of the pilot project, the fishing vessel’s skipper and crew
engaged with a voluntary Code of Conduct for zero TAC, and prohibited species of sharks and skates
within Celtic Sea fisheries. Previously developed between Cefas and fishermen, the Code of Conduct
promotes good practical handling and discard practices, to further aid the long-term survival of live
spurdog, post discard (Figure 7).
3.5.2. Data quality
To evaluate the spatial and temporal accuracy of the reports of spurdog by-catch submitted during the
pilot project, reports were cross-checked against one another, and also against VMS and e-logbook
catch and landings data for the participating vessel. Dates in VMS and logbooks have been observed
to fluctuate by +/- 1 day when coupling VMS and logbook data (Bastardie et al., 2010). This problem is
likely to be particularly significant for gill-netters due to the long soak times of their fishing gear, often
hauled at least 1 day after shooting. Therefore, reports of spurdog by-catch for a given date were
mapped against VMS data and logbook data for the day before, the same day and the day after. UK
vessels over 12 m in length (over 15 m prior to 2015) are required to submit their location to VMS at 2
hourly intervals, from which shoot and haul locations cannot be reliably identified. Probable shoot or
haul locations were identified based on speeds of <1 knot (see section 3.3.3).
Reports entered in October 2015 included two suspected duplicates. For two grid cells, identical weights
of spurdog by-catch were entered on 8th October and 13th October 2015. The weights entered
correspond to 6 and 7 boxes of dead spurdog. Whilst it cannot be ruled out that the identical reports 5
days apart are coincidental, this seems unlikely for two reasons. Firstly, whereas weights of 0.5, 1, 2,
or 3 boxes per grid cell were reported frequently throughout the pilot project, specific larger weights
were only reported once or twice. There was one other report of 7 boxes in one grid cell on 3rd December
2015 and no other reports of 6 boxes in one grid cell. Secondly, VMS locations for the participating
vessel for 7th – 9th October 2015 indicate that the vessel was fishing to the South or South-West of the
cells where by-catch was reported (Figure 8a). In contrast, VMS data for 12th – 14th October 2015 are
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consistent with reports of spurdog by-catch (Figure 8b). There was no duplication of reporting in
November or December 2015.
Reports for November and December 2015 were consistent with VMS locations, with the exception of
one grid cell, where relatively low spurdog by-catch was reported on 10th December (Figure 8c). It is
assumed that an erroneous grid cell reference was entered. Occasional errors of this type were to be
expected under the reporting set-up used in the pilot project. However, such errors were easily
traceable, primarily through cross-checking with other grid cells with reports from the same vessel on
the same day.
VMS data provided a secondary form of validation, as long as a tolerance of +/- 1 day is allowed.
Because of the low spatial resolution of e-logbook data (i.e. ICES rectangle), it could not be used to
reliably validate the higher resolution spurdog by-catch reports from the reporting tool.
Figure 7: Voluntary Code of Conduct
3.5.3. Uptake of a hypothetical by-catch allowance for dead spurdog With a hypothetical annual dead spurdog by-catch allowance of 5 tonnes, equating to a spurdog catch allowance of 12.5 tonnes for the one participating vessel, the monthly allowance in October-April was 1,428.5 kg. Figure 9 shows the weight of spurdog by-catch reported by the participating vessel each day in relation to this monthly allowance, hereafter referred to as threshold weight of spurdog by-catch. Figure 10 shows the cumulative spurdog by-catch for each month during the pilot project. The weight of spurdog by-catch reported exceeded the threshold in a single day on four occasions during the pilot project: on 9th October 2015, 9th December 2015, 14th December 2015 and 17th
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December 2015. Additionally, the weight of spurdog by-catch reported on 8th October was marginally below the threshold.
Figure 8: Location of reported spurdog by-catch by the participating vessel in relation to its VMS
location and landing on the day before, the same day, and day after the report date. (a) Inconsistency
with VMS suggests that either the date or the grid cell references were incorrect for the report dated 8th
October 2015. (b) Consistency with VMS confirms the accuracy of the date and the grid cell references
for the report dated 13th October 2015. (c) Comparison with VMS suggests that two grid cell references
from 10th December 2015 are correct, while the third, located approximately 50 km to the south of the
other two cells and the VMS locations is erroneous.
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Figure 9: Daily reports of spurdog by-catch from one vessel from October-December 2015, in relation to a threshold weight of spurdog by-catch based on a hypothetical allowance.
Figure 10: Monthly cumulative Spurdog by-catch from October-December 2015, in relation to a threshold weight of spurdog by-catch based on a hypothetical allowance.
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3.5.4. Analysis and evaluation of voluntary avoidance behaviour
Using a sub-set of the real-time spurdog by-catch data provided by the participating vessel, an analysis
and evaluation of the vessels voluntary avoidance of spurdog by-catch has been conducted. The
analysis focussed on two fishing trips in December 2015. Reports for October 2015 were not included
due to concerns over spatial and temporal accuracy. In November 2015, the participating vessel was
fishing in different areas to the other two months and reporting very low by-catch of spurdog, meaning
avoidance would not have been necessary.
The series of maps in Figure 11 shows reported spurdog by-catch, the risk of spurdog by-catch, and
probable fishing activity by the participating vessel and by 7 similar vessels not involved in the pilot
project. Maps for the first and last days of October and November 2015 are included to provide context
to the risk of spurdog by-catch status attributed to cells in December 2015 (Figures 11a-d), in addition
to a time series from 1st December to 18th December 2015, covering 3 fishing trips by the participating
vessel (Figures 11e-v).
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Figure 11: Risk of spurdog by-catch, fishing activity (gill-nets) and actual spurdog by-catch during the
pilot project.
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Limited information on the location of areas at high risk of spurdog by-catch were built into the spurdog
by-catch reporting tool at the start of the pilot project. One or two historic “spurdog” by-catch hotspots
in each month were attributed a high risk of by-catch status at the start of each month (Figures 11a, c
and e). These “hotspots” were identified from data provided by the participating vessel during the
NEPTUNE project (see section 3.3.3). During this pilot project, 5 additional “hotspots” were incorporated
into the tool for October 2015, and 13 for December 2015. These “hotspots” would theoretically be
attributed a high risk of by-catch status at the start of the same month, the following year. Spatial
clustering of “hotspot”s could also be used to identify larger high risk areas, by grouping grid cells
together, whilst maintaining a much finer spatial resolution than that of an entire ICES rectangle.
The advisory information on maps towards the end of the month (Figures 11b, d and v) is more
comprehensive. The advisory information on the maps in Figure 11 is reactive rather than preventative:
areas are flagged as high risk of spurdog by-catch only after spurdog by-catch is recorded. The
effectiveness of the advisory tool during the pilot project was limited by the fact that (i) only one vessel
was involved in the pilot project, (ii) the lack of historic information on spurdog by-catch location at a
fine spatial resolution, and (ii) the lack of evidence-based predictions based within the tool.
From 1st – 4th December 2015, on the first of 3 fishing trips during the month, the participating vessel
fished in an area where it had also fished in October 2015, resulting in relatively very low spurdog by-
catch (1 x 33 kg box or less per grid cell). This area was located to the North-east of all areas where
high levels of spurdog by-catch were reported in the previous two months, adjacent to the nearest of
those areas. Despite unresolved questions relating to the accuracy of the some of the data submitted
in October 2015, it could be put that the participating vessel was avoiding the areas where it had caught
high weights of spurdog in October 2015 and December 2013. The tool attributed a status of low risk
of spurdog by-catch or unknown risk to all cells fished by the participating vessel during this fishing trip.
Following reports of 429 kg of spurdog by-catch across 3 cells over 2 days, 1 of those cells was turned
amber (medium risk of significant spurdog by-catch) and the other 2 cells turned red (high risk of
significant spurdog by-catch).
On its second fishing trip of the month, from 8th – 10th December 2015, the participating vessel fished
grounds located over 35 nautical miles away from any known areas of high-risk of spurdog by-catch.
Based on the data available within the tool at the time, this is assumed to be voluntary avoidance
behaviour. However, the participating vessel reported very high spurdog by-catch in this area on 9th
December 2015. It appears that voluntary avoidance behaviour was, in this instance, unsuccessful.
From 9th – 11th December 2015, there was fishing activity by one or more non-participating vessels in
the area where cells had acquired high risk status following reports from the participating vessel on 3rd
and 4th December 2015. Had other vessels been involved in the pilot, they would have been expected
to avoid the high risk or red cells. As none of the non-participating vessels were reporting spurdog by-
catch via e-logbook catch data, there is no means of knowing how much spurdog by-catch (if any)
resulted from fishing in the high risk area.
On its third fishing trip of the month, from 11th and 16th December 2015, the participating vessel returned
to the grounds where it had fished at the beginning of the month. It fished mainly to the North-west of
the cells where it had reported 100 – 200 kg of spurdog by-catch, although it also appears that fishing
in one cell with high ris’ status resulted in low spurdog by-catch (1 x 33 kg box) on 11th – 12th December
2015.
On 14th December 2015, the participating vessel caught 2.5 tonnes of spurdog whilst fishing 10 nautical
miles or more to the North-west of the nearest cells attributed high risk of spurdog by-catch by the tool.
The skipper on the participating vessel provided an additional comment on his daily spurdog by-catch
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report, stating that two other fishing vessels were East-north-east of them and also caught large
amounts of spurdog on the same day. Fishing activity derived from VMS is consistent with the
information provided by the skipper.
The following day, 15th December 2015, the participating vessel moved 10 miles south, resulting in low
spurdog by-catch (1 x 33 kg box or less per grid cell). The vessel then moved 10 miles or more East-
south-east, resulting in high spurdog by-catch on 16th – 17th December 2015.
3.5.5. Comparison of e-logbook catch data
The participating vessel’s e-logbook catch data reports have been used to evaluate whether the vessels
avoidance of an area of high spurdog by-catch, was the sole motivation or whether catch rates of the
vessel’s target species was an influencing factor.
The vessel reported weight of spurdog by-catch on its e-logbook along with the weight of other species
caught. A lag of 1-2 days between the dates on the two systems was common. This is similar to the
difference of +/- 1 day between VMS and e-logbook data that has been observed previously in the
context of coupling datasets. Reports entered on the online reporting tool were consistent with probable
haul locations identified from VMS (with the exception of the report dated 17th December 2015, for which
the correct date is believed to be 16th December 2015). It seems likely that the dates on the e-logbook
may correspond to the date the net was set, whereas the dates on the online portal correspond to the
haul date. If this is taken into account, the weights of spurdog by-catch recorded on the two systems
are broadly consistent, as shown in Figure 12. However, the disparity between dates on the two systems
presents a challenge in terms of allocating catch of target species to location.
Figure 12: Spurdog by-catch reported via two systems by the participating vessel in December 2015.
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Within the e-logbook, spurdog by-catch is reliably linked to catch of target species. The e-logbook
weights are compared for spurdog, hake, pollack, saithe (Pollachius virens), cod (Gadus morhua) and
haddock (Melanograminus aeglefinus). It is important to be cautious about drawing conclusions from
such a small dataset, but Figure 13 indicates that immediately following a high by-catch event the weight
of spurdog by-catch deceases in subsequent fishing operations. Generally, the catch of other target
species (e.g. hake, the main target species) also appears to decrease. The limited data available
support the suggestion that any altered activity by the participating vessel is aimed to reduce spurdog
by-catch, rather than increase the catch of target species, where high levels of spurdog by-catch will be
tolerated for increased financial gain from the commercial species.
Figure 13: Spurdog by-catch and catch of target species by the participating vessel in December 2015.
3.5.6. Comparison to spurdog by-catch and discards from the southwest fleet in 2013
Between October 2013 – December 2014, the NEPTUNE project involved three UK offshore
commercial netting vessels collecting self-sampling data on shark, skate and ray by-catch and discards
in the Celtic Sea, in effect acting as a ‘reference fleet’ to this pilot project.
The NEPTUNE project dataset has provided a baseline of the level of spurdog by-catch within the fixed
net commercial fishery in the Celtic Sea, prior to the implementation of the pilot project. The fishing
vessel participating in this pilot project, also took part in the NEPTUNE project. For the period October
2013 – May 2014 the vessel self-reported levels of spurdog by-catch during 14 fishing trips.
For this exercise, the reported levels of spurdog by-catch in relation to the reported retained catch of
the main target species (hake and pollack) for the period October to December 2015 for this pilot project
have been compared to those in the NEPTUNE project, for the same vessel, for the period October –
December 2013.
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Table 1 shows the reported levels of spurdog by-catch, catch of hake and pollack and the ratio of
spurdog by-catch to the two main target species (kg of by-catch / tonnes of target catch) for 7 fishing
trips by the participating vessel in October – December 2013 and October – December 2015. In both
years, there is considerable variability between trips. There are no notable differences between the two
years.
Project Year Trip Month Hake Pollack Spurdog
Kg Kg Kg Kg/t
NEPTUNE 2013 1 Oct 8976 214.5 23.9
2 Oct 1056 429 1914 1288.9
3 Nov 11121 99 8.9
4 Nov 11022 3348 303.8
5 Nov 6072 1848 396 50.0
6 Dec 3201 198 1980 582.5
7 Dec 165 1782 709.5 364.4
Pilot
project
2015 1 Oct 5932 1004 3003 433.0
2 Oct 4830 485 578 108.8
3 Oct 5282 516 381 65.7
4 Nov 278 99 356.1
5 Dec 4572 1502 495 81.5
6 Dec 2887 134 2013 666.3
7 Dec 6075 1673 4818 621.3
Table 1: Weight of spurdog, hake and pollack caught per trip by the participating vessel. 2013 data
from Ellis et al., 2015.
3.5.7. Fishing activity compared to prior behaviour
The participating fishing vessels VMS data prior to, and during the pilot project has been used as a
baseline to compare their fishing activity prior to, and during their involvement with the pilot project. For
the same 3-month period of the pilot project (October - December) in 2015, the distribution of fishing
activity has been compared to the same period in 2013 (when the vessel was reporting spurdog by-
catch levels for the NEPTUNE project). Equivalent information for 2014 were not included as the vessel
was fishing a different gear type (trammel nets) for a part of the 3-month period.
Fishing activity and spurdog by-catch are shown in Figures 14 and 15, by month and year. Patterns of
fishing activity commonly vary considerably year on year for a variety of reasons, including economics,
quota, weather and, at individual vessel level, behaviour of other vessels. The main grounds fished in
October – December by the participating vessel were similar in 2013 and 2015, although some grounds
were not fished in the same months. Also, the vessel fished more in October and December and less
in November in 2015, compared to 2013.
In November and December 2015, the participating vessel did not fish grounds in and around the South-
east quarter of ICES rectangle 29E1 (including around the boundary with 29E2), where it had reported
high weights of spurdog by-catch in the same months in 2013. In November 2015, the vessel remained
around the 12 nautical miles fishing limit to the South of Lizard, in the North-east quarter of ICES
rectangle 28E4. In December 2015, the participating vessel fished around 50°N, 7°W, where it had not
fished in October – December 2013, and to the North and to the East of grounds where fishing in 2013
had resulted in high spurdog by-catch.
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VMS data for the participating vessel in November and December 2015 suggest that the vessel may
have been voluntarily avoiding areas where it had reported high spurdog by-catch previously, although
there may also have been other reasons for differences in fishing activity. Assuming voluntary
avoidance did occur, spurdog by-catch remained well below the hypothetical monthly allowance in
November, although the catch of target species was also low (see Table 1). In December 2015, spurdog
by-catch was high despite of possible voluntary avoidance.
Figure 14: Probable fishing activity by the participating vessel in October, November and December
2013, prior to its involvement in the pilot project.
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Figure 15: Probable fishing activity by the participating vessel in October, November and December
2015, during its involvement in the pilot project.
3.5.8. Comparison of fishing activity of non-participating vessels
Commercial offshore netting vessels from the UK southwest fleet operating during, but not involved in
the pilot project can in effect act as a ‘control’ to the participating vessel. VMS data from 7 similar
regional vessels not involved in the pilot project, of a similar size, operating the same gear type (gill-
nets) during the period October to December 2015, have been used to compare their spatial activity
with the fishing vessel directly involved in the pilot project.
Figures 16 and 17 provide a direct comparison between the spatial distribution of probable fishing
activity by the participating vessel and by the 7 vessels selected for comparison, for each month of the
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pilot project. The main areas fished by the participating vessel were broadly similar or near to areas
targeted by other vessels.
Figure 16: Probable fishing activity by the participating vessel in October, November and December
2015.
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Figure 17: Probable fishing activity by 7 regional vessels not involved in the pilot project in October,
November and December 2015.
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4. Discussion
The pilot project has successfully demonstrated that a simple, low-cost, functioning, real-time
spurdog by-catch reporting tool is in place, allowing a commercial fishing vessel skipper to report
spurdog by-catch in real-time.
The real-time spurdog by-catch data can be successfully collated with the amount of spurdog by-
catch in each grid cell classified to predetermined thresholds, using a traffic light system. The cells
of the reporting grid can be coloured to denote the level of spurdog by-catch thresholds, green (low
risk of significant spurdog by-catch), amber (medium risk of significant spurdog by-catch) and red
(high risk of significant spurdog by-catch). There is the capability to send an advisory notice in near
real-time to the vessel, alerting fishermen of spurdog aggregations to avoid, potentially reducing
wasteful dead discarding and overall fishing induced mortality of spurdog.
The pilot project relies on fishing vessel skippers to participate voluntarily, avoiding spurdog
aggregations, possibly moving to less productive fishing grounds. This additional requirement by
the fishing vessel skippers is seen as an additional burden, both in time and loss of earnings (if
displaced to less productive grounds). To offset this burden to fishing vessel skippers, an incentive
is required.
The provision of a small (50 tonnes) marketable dead spurdog by-catch allowance to account for
unavoidable by-catch to incentivise participation in the pilot project was not secured at December
Fisheries Council 2014. Instead, to incentivise participation in the pilot project, limited additional
quota for commercial species to the equivalent value of the spurdog by-catch allowance was
offered. This was not sufficient to obtain the necessary ‘buy-in’ of fishermen at the level first
envisaged (up to 10 vessels) as the incentive for participation is not an economic one (i.e. the
provision of additional quota), but a moral principle of reducing spurdog by-catch and subsequent
dead discards. Fishermen are unwilling to voluntarily participate in the pilot project, reporting in
real-time, adhering to move-on rules, yet continue discarding dead spurdog.
Real-time reporting by one participating vessel began in October 2015. Due to the limited
participation in the pilot project, advisory notices consisting of the level of spurdog by-catch, using
the ‘traffic-light’ system were not issued as an evaluation of avoidance behaviour by one vessel
resulting from the advisory notice would have been inconclusive. Instead, the baseline data
collected in this pilot project will be of more value in the evaluation of a more comprehensive pilot
project, including more vessels, should there be a follow-on study.
The pilot project has begun to provide real-time mapping of seasonal spurdog by-catch. Such data
on seasonal distribution and abundance of spurdog are currently lacking and will help underpin
future decisions on avoiding by-catches in key “hotspot” areas.
The pilot project has been evaluated against the level of engagement and data quality by those
involved and the uptake of a hypothetical by-catch allowance for dead spurdog. Engagement by
the participating fishing skipper improved markedly with increased levels of spurdog by-catch. Data
quality improved with timely data entry, reducing error through duplication or omission.
The pilot project has demonstrated that a dead spurdog by-catch allowance of 5 tonnes per annum
per vessel (1.43 tonnes per month, October – April) can be exceeded by high by-catch events
(approx. 1-2.5 tonnes within 24 hours), before an advisory notice can be sent. To allow advisories
notices to be effective, it will be necessary to increase the annual dead spurdog by-catch allowance
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beyond 5 tonnes per annum, per vessel in order to ensure that single fishing events do not exceed
the thresholds derived for the spurdog by-catch allowance. Although the spurdog by-catch
allowance needs to be increased to allow the traffic light system to be fully effective, it is anticipated
that the increase would not be directly proportional to the number of participating vessels. The
increase in spurdog by-catch reports associated with increased participation is expected to improve
the accuracy of advisory notices, better informing avoidance.
Analysis of three fishing trips by the participating vessel in December 2015 demonstrates the
analytical methods that can be undertaken to evaluate the effectiveness of spurdog by-catch
avoidance behaviour, using historic baseline fishery dependant spurdog by-catch and discard data,
e-logbook data and Vessel Monitoring System (VMS) data.
The pilot project has shown that albeit with limited data, the participating vessel does appear to
demonstrate voluntary spurdog by-catch avoidance, sometimes unsuccessfully. A follow-on pilot
project, with more participating vessels and advisory notices being issued, could potentially improve
this uninformed voluntary avoidance to informed more effective voluntary avoidance.
Without the appropriate incentive, the Spurdog By-catch Avoidance Programme is neither viable in
the long-term nor self-financing.
5. Concluding remarks
As a small allowance to land dead spurdog was not available to the pilot project, there was a low uptake
by vessels to participate, which limited implementation and complete evaluation of the pilot project, in
particular the real-time spurdog by-catch reporting tool. However, the Spurdog By-catch Avoidance
Programme pilot project has successfully:
i) developed and put in place a functional, low-cost, real-time spurdog by-catch reporting tool,
allowing a commercial fishing vessel skipper to report spurdog by-catch in real-time.
ii) demonstrated and proven the approach of using historic fishery-dependant spurdog by-catch
and discards data, VMS data and e-logbook data, at both an individual vessel and fleet level to
evaluate spurdog by-catch avoidance behaviour from using the real-time reporting tool.
The findings from this pilot project demonstrate the real-time spurdog by-catch reporting tool, together
with a small dead spurdog by-catch allowance, offers a real and probable alternative to an immediate
‘Prohibited Species listing’ for spurdog, providing a pragmatic solution to align spurdog with the CFP
C.M., Rijnsdorp, A.D., Sayer, C., Scott, J., Serena, F., Smith-Vaniz, W.F., Soldo, A., Stump, E. and
Williams, J.T. 2015. European Red List of marine fishes. Luxembourg: Publications Office of the
European Union.
Lee, J., South, A. B., and Jennings, S. 2010. Developing reliable, repeatable, and accessible methods
to provide high-resolution estimates of fishing-effort distributions from vessel monitoring system (VMS)
data. – ICES Journal of Marine Science, 67: 1260–1271.
O'Keefe C. E and DeCelles G. R. 2013. Forming a partnership to avoid by-catch. American Fisheries
Society. Vol 38 No 10: 434- 444.
Vince, M. R. (1991). Stock identity in spurdog (Squalus acanthias L.) around the British Isles. Fisheries
Research, 12: 341–354
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Annex 1: Press release by the Cornish Fish Producers Organisation (CFPO).
News & Updates
Cornish Fishermen Leading the Way to Change Nonsensical EU Spurdog Management
There have been an increasing number of sporadic but significant hauls of spurdog (Squalus acanthias) encountered by Cornish fishermen in recent months. Just last week a Newlyn based trawler accidently caught over 10 tonnes of spurdog while fishing for John Dory around the Isles of Scilly. This meant damaged fishing gear, lost fishing time and a great deal of frustration for the skipper involved. To make it even worse under current EU fishing rules not one of the spurdog could be landed for human consumption or sold.
Cornish fishermen are no longer able to land spurdog because of stock status fears that led to a zero Total Allowable Catch (TAC) being introduced in 2010, since when no landings of spurdog have been allowed in the European Union (EU). It would be logical to think that a zero TAC for spurdog means a zero take or zero fishing mortality on the stock, but as spurdog are widespread and locally abundant throughout the Western Approaches and other areas of the North East Atlantic this is
simply not the case.
The reality is that there are accidental by-catches of spurdog in many mixed-fisheries not just in Cornwall but around the UK, this inevitably leads to a level of fishing mortality of spurdog. Under the current EU management regime these perfectly good fish must be discarded whether they are dead or alive. There is no real benefit for the stock, fishermen or wider society under the current regime of discarding dead spurdog. This is a waste of a perfectly good food resource and is clearly not in line with the principles of the recently reformed Common Fisheries Policy (CFP) and in particular the much heralded Landings Obligation (“discard ban”). In an effort to end this madness Cornish fishermen have been at the forefront of working in partnership with scientists from CEFAS and policy makers from DEFRA since 2010 in a genuine effort to assist scientists, managers and policy makers to better understand that the current management measures for spurdog are not in tune with what they encounter on a daily basis at sea, as well as giving a valuable insight into spurdog behaviour and interactions with fishing gears in the South West. At the heart of this ongoing working relationship is a desire to improve genuine, rather than cosmetic, management of spurdog whilst providing legitimate flexibility within the future landings obligation to account for unpredictable and unavoidable spurdog catches, i.e. allowing the landing of dead spurdog.
The Cornish Fish Producer’s Organisation (CFPO) is now taking part in an important part of the ongoing work. In conjunction with CEFAS and DEFRA it is developing a pilot project using a real time reporting system, similar to that used for the cod recovery programme in the North Sea. The project will be carried out in the Western Approaches/Celtic Sea (ICES Divisions VIIe-j). Fishermen are asked to report any spurdog catches within pre-defined reporting grids and that information can then be fed back
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to other skippers. It is envisaged that the project will assist skippers by giving them up-to-date information on spurdog movements and allow skippers to make informed decisions about potential interactions. This will hopefully reduce the occurrence of significant spurdog catch events and contribute to the perceived stock improvement being witnessed by fishermen. It will not result in a complete avoidance of spurdog catches. The CFPO is therefore calling for an ability to land a marketable dead spurdog bycatch with a nominal landing allowance that does not incentivise targeting of the stock.
This proposed solution allows for the ongoing recovery of spurdog in the North East Atlantic by reducing fishing induced mortality, further improving scientific understanding of spurdog and its interactions with fishermen, whilst allowing incidental dead spurdog by-catch to be landed and marketed. This would appear be the most logical option for a way forward and of course would be in the interests of fishermen, scientists, managers and conservation. International support for this initiative was clearly given at the most recent North Western Waters Advisory Council (NWW AC) in July, with backing from all present at the meeting and a willingness from other member states to be actively involved. For the project to work effectively, there needs to be a high level of industry-science collaboration and cooperation. Paul Trebilcock Chief Executive of the CFPO said “Progress has been frustratingly slow on this issue. But credit must go to the skippers and crews who have remained engaged and continue to work with scientists and policy makers. There is no question in my mind that spurdog populations are increasing throughout the Western Approaches and beyond. This perception is being echoed by fishermen across Europe. I genuinely believe that DEFRA and CEFAS understand that the current EU management regime for spurdog isn’t compatible with the Landing Obligation and are committed to changing it. George Eustice and his DEFRA team have clearly stated that the UK position will be to seek a landing allowance to stop the unnecessary waste of dead by-caught spurdog as part of the pilot project we are involved in.”
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Annex 2: Fishing News article on Shark By-Watch UK 2, including the Spurdog By-catch Avoidance
Programme
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Annex 3: Letter from the North Western Waters Advisory Council (NWWAC) High-Level Group in
relation to the Spurdog By-catch Avoidance programme
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Annex 4: The ArcGIS on-line reporting portal
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Annex 5: Background project information for fishing skippers
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Annex 6: 24 hour reporting sheet template for skippers
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Annex 7: Reporting grid reference booklet for skippers
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