7.4.23
Advice October 2012
ECOREGION
STOCK
Bay of Biscay and Atlantic Iberian waters
Lesser-spotted dogfish (Scyliorhinus canicula) in Divisions VIIIc and IXa
(Atlantic Iberian waters)
Advice for 2013 and 2014
Based on ICES approach to data-limited stocks, ICES advises that catches should be decreased by 9%. Because the data
for catches of lesser-spotted dogfish are not fully documented (due to the historical use of generic landings categories),
ICES is not in a position to quantify the result. ICES does not advise that an individual TAC be set for this stock.
This is the first year ICES is providing quantitative advice for data-limited stocks (see Quality considerations).
Stock status
F (Fishing Mortality)
2009–2011
MSY (FMSY)
Unknown
Precautionary
approach (Fpa,Flim)
Unknown
Qualitative evaluation
Unknown
SSB (Spawning-Stock Biomass)
2005–2011
MSY (Btrigger)
Unknown
Precautionary
approach (Bpa,Blim)
Unknown
Qualitative evaluation
Decreasing
Figure 7.4.23.1
Lesser-spotted dogfish in Divisions VIIIc and IXa. Left: Reported landings in Divisions VIIIc and IXa
(tonnes). Right: Survey (SpGFS-WIBTS-Q4) abundance index for Division VIIIc (kg per 30 min haul).
Dashed lines indicate the mean annual catch rate ± st. dev. for 2005–2009, red line indicates the mean annual
catch rate for 2010–2011.
Species-specific landings of lesser-spotted dogfish are stable though data are not complete. The average of the stock
size indicator (kg per 30 minutes) in the last two years (2010-2011) is 9% lower than the average of the five previous
years (2005-2009).
Management plans
There are no known management objectives for this stock.
Biology
Lesser-spotted dogfish is a small, productive, oviparous shark. It is one of the most common small sharks in this
ecoregion and has a high discard survival rate.
ICES Advice 2012, Book 7
1
The fisheries
Lesser-spotted dogfish are mainly bycaught in mixed demersal fisheries. They are generally of low-commercial value
and discard rates are high. Discard survivorship is considered to be high. Fisheries for lesser-spotted dogfish may take
place for use as bait in pot fisheries, but this is unquantified.
Effects of the fisheries on the ecosystem
Some demersal sharks, including lesser-spotted dogfish, may benefit from scavenging on trawl-damaged organisms and
discards.
Quality considerations
As there is no obligation to report lesser-spotted dogfish at the species level, they are often included in generic
categories such as “dogfish and hounds”. Therefore, landings data are not considered reliable. High levels of discarding
take place.
Fishery-independent trawl surveys provide the longest time-series of species-specific information.
The methods applied to derive quantitative advice for data-limited stocks are expected to evolve as they are further
developed and validated. The harvest control rules are expected to stabilize stock size, but they may not be suitable if
the stock size is low and/or overfished.
There is no information on stock trends in Division IXa.
Scientific basis
Assessment type
Input data
Discards and bycatch
Indicators
Other information
Working group report
2
Survey- and landings-based trends.
SpGFS-WIBTS-Q4in Division VIIIc
Data not examined. Improved knowledge of discard rates and discard survival is required.
None.
Life history.
WGEF
ICES Advice 2012, Book 7
7.4.23
ECOREGION
STOCK
Supporting information October 2012
Bay of Biscay and Atlantic Iberian waters
Lesser-spotted dogfish (Scyliorhinus canicula) in Divisions VIIIc and IXa
(Atlantic Iberian waters)
Reference points
No reference points have been defined for this stock.
Outlook for 2013 and 2014
No reliable quantitative assessment can be presented for this stock.
ICES approach to data-limited stocks
For data-limited stocks for which an abundance index is available, ICES uses a harvest control rule on an indexadjusted status quo catch. The advice is based on a comparison of the two most recent index values with the five
preceding values, combined with recent catch or landings data. Knowledge about the exploitation status also influences
the advised catch.
For this stock the abundance is estimated to have decreased by 9% between 2005 and 2009 (average of the five years)
and 2010–2011 (average of the two years). This implies a 9% decrease in catches in relation to the last three years’
average. Because the data for catches of lesser-spotted dogfish are not fully documented (due to the historical use of
generic landings categories), ICES is not in a position to quantify the result.
Given that there is a consistent increase in stock size over an extended period of time, no additional precautionary
buffer is needed.
ICES does not advise that an individual TAC be set for this stock, at present.
Additional considerations
Comparison with previous assessment and advice
The advice is based on Category 3 of ICES approach to data-limited stocks. The previous advice was based on ICES
precautionary considerations.
Source
ICES. 2012. Report of the Working Group on Elasmobranch Fishes (WGEF), 19–26 June 2012, Lisbon, Portugal. ICES
CM 2012/ACOM:19.
ICES Advice 2012, Book 7
3
Figure 7.4.23.2
Lesser-spotted dogfish in Divisions VIIIc and IXa. Distribution and relative abundance (kg/30 min
haul) of the Spanish bottom trawl survey in VIIIc (SpGFS-WIBTS-Q4).
Table 7.4.23.1
Lesser-spotted dogfish in Divisions VIIIc and IXa. ICES advice, management, and landings.
Year
ICES
Predicted
catch
Agreed
Official
Advice1
corresp. to
advice
TAC
Landings
No TAC
No TAC
No TAC
No TAC
No TAC
No TAC
0.31
0.39
0.68
0.78
0.90
No advice
No advice
No advice
No advice
Maintain catch at recent level
No new advice, same as for 2011
Decrease catch by 9% + no species-specific
2013
TAC
No new advice, same as for 2013
2014
Weights in thousand tonnes.
1
Before 2013 the advice included Divisions VIIIa, b, d.
2007
2008
2009
2010
2011
2012
Table 7.4.23.2
France
Spain
Portugal
Total
4
<1.8
<1.8
<1.7
<1.7
-
Combined landings (t) of lesser-spotted dogfish (Scyliorhinus canicula) in Iberian waters
(Divisions VIIIc and IXa).
1996
0
431
667
1098
1997 1998 1999 2000 2001 2002 2003 2004 2005 2006
2007 2008 2009 2010
2011
0
1
1
1
4
3
4
5
1
0
1
1
1
0
0
472
403
491
202
236
155
248
237
297
333
147
273
229
336
431
691
689
882
757
734
673
658
677
385
185
157
120
450
444
473
1163 1093 1374
960
974
831
910
920
683
518
305
394
680
780
904
ICES Advice 2012, Book 7