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Scottish Marine and Freshwater Science Vol 2 No 9: The Scottish Industry-Science Anglerfish Tallybook Scheme

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The Scottish Industry-Science Anglerfish Tallybook Scheme

Summary

The voluntary anglerfish tallybook scheme operated from 2006 to 2010 and was set up following concerns about the lack of information on anglerfish abundance. Skippers completed the tallybooks on a haul-by haul basis, recording the catches of anglerfish (by size category) and other species where possible together with information on haul location, duration and depth. The complete tallybook data set consists of data from over 18,000 hauls contributed by 37 fishing vessels. Hauls have been recorded over a wide spatial distribution with most of the reported fishing activity in the northern North Sea (around Shetland), off the north and west coast of Scotland along the shelf edge and at Rockall. Recent participation levels have declined and data being provided are no longer considered representative of the fishery as a whole. After trying to address the low participation levels MSS has decided to conclude the project. This report describes the data collection scheme, summarises the data collected and provides a discussion of outcomes.

Introduction

Anglerfish, or monkfish as it is commonly referred to by the Scottish fishing industry, was historically an unimportant component of the catch of mixed species demersal fisheries around Scotland and it was often discarded. Only since the decline of the traditional whitefish stocks have anglerfish become increasingly important. The expansion of the anglerfish fishery across the Northern Shelf (the North Sea, West of Scotland and Rockall) began in the late 1980s and continued into the 1990s. Total reported landings from ICES Subareas IV and VI increased from under 10,000 tonnes in 1985 to almost 35,000 tonnes in 1996. In 2009, landings by UK vessels into Scotland were worth £31.2M at first sale (Scottish Government, 2010). Catches primarily consist of Lophius piscatorius (white-bellied anglerfish) with a small proportion of Lophius budegassa (black-bellied) (Laurenson et al., 2008). The two species are landed and processed together.

In the late 1990s, the International Council for the Exploration of the Sea ( ICES) Working Group on the Assessment of Northern Shelf Demersal Stocks ( WGNSDS) attempted for the first time to provide advice in support of a total allowable catch ( TAC) based on an accepted stock assessment and projection. Due to problems associated with anglerfish age determination, methods concentrated on making use of length-structured catch data. In 2002, a modified catch-at-size analysis (Sullivan et al., 1990) which incorporated commercial catch-at-length data, effort data and a recruitment index was used as the basis for advice. Particular life-history characteristics (high age-at-maturity) meant that the proposed precautionary reference point for fishing mortality (F pa), based on the value implied by 35% pristine spawning stock biomass per recruit (Mace and Sissenwine, 1993), was very low. The ICES advice was for a reduction in TAC such that F would be below F pa which implied a significant reduction in fishing mortality.

As a consequence of this advice, anglerfish TACs were reduced in subsequent years. These reductions in TAC occurred at a time when the Scottish fishing industry were widely reporting an apparent increase in stock abundance over a number of years. During 2003 to 2005, the TACs were highly restrictive resulting in an increased incentive for the industry to discard and to under-report landings.

In 2004, the ICESWGNSDS was unable to present an analytical assessment for anglerfish due to the deteriorating quality of the commercial catch and effort data and inadequate survey data. They concluded that stock status should be considered 'unknown' in relation to precautionary limits and ICES advised that effort in the fishery should not be allowed to increase ( ICES, 2004). Both ICES and the European Commission's Scientific, Technical and Economic Committee for Fisheries ( STECF) agreed that the fishery should be accompanied by mandatory programmes to collect catch and effort data of both target fish catch and bycatch.

In an attempt to address this issue, Marine Scotland Science ( MSS) (at that time Fisheries Research Services ( FRS)) began a new scientific programme for improving anglerfish data availability with the aim of improving the assessment and basis for management. The programme consisted of a number of key components: an industry/science dedicated anglerfish survey (Fernandes, et al. 2007), increased observer coverage during 2005 and 2006, and a tallybook scheme for collecting commercial data. Commercial catch per unit effort (cpue) data have frequently been used to obtain indices of abundance for fish stocks. They are particularly useful for stocks with a wide spatial distribution for which fishery independent surveys are difficult or expensive to carry out (Campbell, 2004; Nishida and Chen, 2004). In addition, commercial data provide a much richer dataset than a single annual survey, covering a broad area with continuous high-resolution sampling.

The tallybook scheme was proposed following the use of fishermen's private diary data in the provision of information to ICES ( ICES, 2005) on temporal and spatial trends in anglerfish catch rate and was run for five years. In 2010, participation levels declined and data being provided were no longer considered representative of the fishery as a whole. In addition, the introduction of buyers and sellers legislation in the UK and Ireland (Council Regulation ( EEC) No. 2847/93) has meant that the accuracy of official landings data has improved significantly. Furthermore, there are now six years of abundance data from the MSS joint industry/science anglerfish survey and these have formed the basis of management advice in recent years. For these reasons, MSS decided to conclude the project. This report describes the data collection scheme, summarises the data collected and provides a discussion of outcomes.

Methods

The voluntary anglerfish tallybook scheme was implemented in 2006 after discussions with the industry about the lack of information on anglerfish abundance. At the outset, effort was made to involve the main fishers for anglerfish and also those vessels fishing closer inshore on the continental shelf for which anglerfish is more of a bycatch. The scheme has been operated by MSS in conjunction with the Scottish Fishermen's Federation ( SFF) and the NAFC Marine Centre, Shetland (and to a lesser extent, the Fishermen's Association Limited ( FAL) and Pêcheurs de Manche et Atlantique). These organizations have been responsible for allocating vessel reference codes before the anonymous data are forwarded to MSS. The SFF and NAFC Marine Centre have retained the record of vessel names and allocated codes, to which MSS has no access.

The skippers completed the tallybooks on a haul-by haul basis recording the catches of anglerfish (by size category) and other species where possible, together with information on haul location, duration and depth. A sample tallybook sheet can be found in Annex 1. Catches (typically landings) are variously recorded in kg or boxes. For vessels reporting landings as boxes, each vessel has a nominal 'box weight' associated with it at the data entry stage so box numbers by size category can be converted into total weight. At this stage, a number of data-checking procedures are implemented and 'fill-ins' are also carried out (e.g. missing depth information or gear descriptions are filled in with reference to previous hauls recorded for that vessel). Data are stored in a relational database at MSS. Tallybook returns from vessels based in Shetland were processed by staff at NAFC Marine Centre and then forwarded electronically to MSS, while all other returns were processed by MSS staff.

Feedback to participants in the scheme has been provided on a periodic basis in the form of personalized summary reports and occasional industry presentations, with the aim of retaining interest and support for the scheme. Any discussion or data queries have been carried out through the intermediary organizations, SFF or the NAFC Marine Centre, due to the anonymous nature of the scheme.

During 2009, MSS noted that there had been a considerable reduction in the number of vessels participating in the tallybook scheme. Although the first years of the scheme had provided extensive, detailed data, it was acknowledged that the reduction was of such an extent that the data were unlikely to be representative of the fishery as a whole. In response, MSS prepared a basic questionnaire to investigate the potential for increasing participation in the scheme and to encourage feedback from the industry. Fishermen were contacted through their relevant organizations and a total of 26 questionnaires were sent out to Scottish fishermen who regularly catch anglerfish. The questionnaire consisted of seven questions asking if they were aware of the scheme, had participated in the past and would be willing to participate in the future. All seven questions were short, concise and could be answered by highlighting the relevant box. Six questions could be answered with a simple "yes" or "no" although three of these asked the fishermen to elaborate on their response. The full questionnaire is shown in Annex 2.

Data Summary

The complete tallybook data set consists of data from over 18,000 hauls contributed by 37 fishing vessels. The number of vessels returning data in any one month since the scheme began is shown in Table 1. Twelve vessels were relatively consistent participants of the scheme during 2006 and 2007, and data from these vessels make up over 70% of the total number of hauls. In 2006, the total amount of landings recorded in the tallybooks represented in excess of 30% of the total reported Scottish landings (official landings data), although this fell to just under 20% in 2007 and was under 2% in 2010.

Table 1
Number of vessels returning tallybook sheets by month and year.

2005

2006

2007

2008

2009

2010

Jan

-

29

11

4

1

2

Feb

-

35

12

4

2

2

Mar

-

31

11

4

1

2

Apr

-

27

12

3

2

1

May

-

25

11

4

1

2

Jun

-

23

9

3

1

1

Jul

-

21

8

3

1

0

Aug

-

16

8

2

1

0

Sep

-

14

8

1

1

0

Oct

-

11

7

1

1

0

Nov

-

9

5

2

1

0

Dec

5

9

4

1

2

0

Hauls were recorded over a wide spatial distribution as shown in Figure 1. Most of the reported fishing activity occurs in the northern North Sea (around Shetland), off the north and west coast of Scotland along the shelf edge and at Rockall. A smaller, but nonetheless significant number of hauls were reported from Stanton Bank and the Fladen. The hauls at the southern end of the shelf edge in Division VIa were reported by three French vessels which were involved in the scheme when it was first launched. The data show good spatial coverage of the areas of high reported Scottish landings. Table 2 shows the distribution of recorded fishing activity by ICES division (most important only) by month and year.

Figure 1: Spatial distribution of hauls recorded in anglerfish tallybook data for all vessels. Blue lines show the 200 m, 500 m and 1000 m depth contours.

Figure 1

Table 2
Recorded hauls by ICES Division, month and year. Only the three main ICES areas of fishing activity are included.

IVa

VIa

VIb

2006

2007

2008

2009

2010

2006

2007

2008

2009

2010

2006

2007

2008

2009

2010

Jan

638

340

155

33

62

362

143

53

0

43

60

63

0

0

0

Feb

937

230

145

54

50

426

149

31

3

57

65

80

15

0

3

Mar

643

295

137

13

61

595

182

61

0

42

90

84

0

0

16

Apr

676

313

149

48

20

406

171

37

0

46

76

87

0

0

0

May

703

179

118

26

21

351

104

56

0

16

130

101

13

0

0

Jun

839

326

144

83

44

136

36

67

0

0

105

36

0

0

0

Jul

867

312

95

74

0

95

2

16

0

0

48

56

0

0

0

Aug

706

321

101

55

0

19

8

6

0

0

90

95

0

0

0

Sep

490

316

51

53

0

83

26

0

0

0

79

0

0

0

0

Oct

444

216

54

71

0

32

35

0

0

0

92

69

0

0

0

Nov

208

123

30

68

0

35

48

0

0

0

49

37

0

0

0

Dec

126

81

44

44

0

205

10

0

27

0

0

0

0

0

0

The depth distribution of the reported hauls is shown in Figure 2. Over 90% of the hauls are from depths between 100 and 400 m, with most of the remainder carried out in depths between 600 and 800 m. Although some of the deeper water records are from the French vessels, the majority are from two Scottish vessels which appeared to make regular trips to fish in deep water. Other vessels appeared to fish in deep water on a more sporadic basis.

Figure 2: Depth distribution of hauls for all vessels.

Figure 2

Results

Catch Rates

Although vessels were asked to record discards on the tallybook sheets, very few actually provided quantitative estimates of total weight or number discarded. In many cases the cell for recording discards was left blank and it was not clear whether this meant zero discards or was due to incomplete data recording. The analysis of the data has therefore been confined to landings per unit effort (lpue). Lpue was calculated for each haul and monthly averages ranged from <10 kg h -1 for vessels likely to be targeting Nephrops (in shallower areas on the continental shelf) to > 100 kg h -1 for some whitefish boats during late winter/early spring. An example of trends in monthly lpue for three of the participating vessels is shown in Figure 3. The catch rates from some vessels showed a marked seasonal pattern, with reduced lpue during the summer months and higher average values during November to April (e.g. Boat 3 below).

Figure 3: Median monthly lpue in kg h -1 for a selection of vessels during 2006 and 2007 (10 th and 90 th quantiles in grey). Not all vessels provided returns for every month. (Figure taken from Dobby et al., 2008)

Figure 3

The average catch rates by ICES area are given in Table 3 and a more detailed spatial distribution of lpue by ICES statistical rectangle is shown in Figure 4. Of the three areas with greatest recorded fishing activity in terms of number of hauls recorded in the tallybook database (IVa, VIa and VIb), average catch rates are highest in Division VIa (West of Scotland) and Division VIb (Rockall).

Table 3
Average catch rates (kg h -1) by ICES (Sub-) Division over all years and vessels.

IIa

IVa

IVb

IVc

Vb1

Vb2

VIa

VIb

8.6

31.1

17.3

9.4

30.3

40.8

66.2

60.5

Figure 4 shows that the highest average catch rates are recorded on the shelf edge to the west of Scotland and at the east side of Rockall. Lower catch rates are recorded from vessels fishing at the Fladen and also in the south Minch. Although the spatial variation in catch rate may be related to spatial heterogeneity in population abundance, it should be emphasized that these average catch rates include all vessels and the distribution of fishing activity by vessels of different sizes and gear types has not been accounted for in Figure 4. For example the difference in catch rates between the south Minch (< 20 kg h -1) and east Rockall (~ 150 kg h -1) could be due to different relative abundance but will also be due to the fact that the vessels working in the south Minch are likely to be of smaller size and power than boats fishing at Rockall.

Figure 4: Average 'catch rate' (lpue in kg h -1) by ICES statistical rectangle for all vessels over all years and months.

Figure 4

A robust statistical analysis of the tallybook lpue data from 2006 and 2007 can be found in Dobby et al., (2008). In that paper, catch rates were analysed using a generalized additive modelling approach incorporating seasonal, annual, spatial and vessel dependent effects. The major outcome of the analysis was to show that there had been a significant increase in lpue between 2006 and 2007. The estimated seasonal effects showed marked decreases in catch rate during the summer, with the lowest values occurring in June in the North Sea, July/August at Rockall and in September in Division VIa.

Questionnaires

Twenty six questionnaires were sent out and eleven returned (42% response rate). Ten fishermen who returned the questionnaire were aware of the tallybook scheme and had previously participated in the scheme. Only one skipper was still submitting tally books on a regular basis.

A number of reasons were selected to explain why they were no longer submitting tallybooks. Skippers were asked to select all that applied from a list of six options. Three skippers felt that it was too time consuming to complete the sheets; three thought the sheets were too complicated, one skipper was no longer targeting anglerfish, three thought the scheme had ended and six were disappointed with the outcomes of the scheme. When asked to elaborate on their answers the responses were:

"The data collected from the monkfish tallybook scheme should clearly indicate that there is an abundance of monkfish west of the 4 degree line, yet year after year there is nothing done to increase quota in line with other stocks."

"We were doing the tallybooks for two years, I was off sick for a year and when I returned there was no sign of them, so I assumed they were finished. We are now at single trawl and monkfish are not a main species with us."

"I have yet to see any thing the Scottish fishermen try whether it be conservation measures, providing catch data etc., actually benefit them in the long run, so I am highly disillusioned with the whole thing."

"After years of working with scientists and tallybooks, nothing has improved. The stock has been improving for years but again nothing has been done! Surely a stat box, depth, number of hauls and grade of monk is enough? Rather than every single haul."

Ten out of eleven skippers felt that the anglerfish tally book scheme could provide a valuable source of information to fisheries scientists. When asked to comment there were a number of positive responses:

"Data from fisheries log sheets in the past has been unreliable due to insufficient quotas in certain areas. The monkfish tally scheme is the one and only reliable source of information true to actual catch rates."

"It gives a long term record of each vessel's fishing patterns and the more years the more detailed information."

"Lets them know the truth. I think this should be done with saithe, haddocks, hake and cod."

"Show where monks are actually at."

"If the scientists actually used the data we provided then the TAC could be set at the correct level."

"The scheme improves the science on the monkfish stock. Area IV monk stock has been proven to be more abundant than the TAC tonnage for the last decade. So why has all the recent data not resulted in an increase in the TAC which reflects the actual stock?"

"It lets you see that there are a lot of monkfish west of the 4 deg line, but nobody seems to listen to the data being provided".

"You are getting the information first hand from the men that know the areas, depths and time of year to fish monks. Unlike the areas that the monk survey boats were going to, that was just a joke!"

The only negative comment was:

"Because scientific information is a waste of money and time, the monks will come and go like they always have (as will all whitefish stocks)."

When asked if they thought the scheme should continue, nine skippers agreed that the scheme should continue and that they would be happy to participate. One skipper thought the scheme should end and another declined to answer. When asked if there was anything that would make them reconsider joining the scheme, the comments were:

"Some reward, for example someone actually standing up and admitting quotas for monkfish have been set wrong for years forcing vessels to misreport to stay viable."

"If they promised to leave us and the monks alone."

"Not just for monk as it is not worth it. Yes, to every species."

"For most of 2009 the SFO boats have had no or very little VIa monks to catch/land. I have been forced to fish in Faroe for the past few months with little other options. I am now back in area VI. I will start to fill in the tally books again as I want to co-operate in anyway I can with the FRS, but other skippers seem to be frustrated at the low TAC. Effort has also reduced."

"It has to be taken seriously by everyone taking part- and that means the scientists and politicians."

Discussion

Utility of Tallybook Data

The anglerfish tallybook scheme described here has provided temporal and spatial commercial catch per unit effort (cpue) data which could be used as an index of abundance. The scheme provides a rich dataset, covering a broad area with continuous, high-resolution sampling. It is therefore considered that with appropriate standardization to account for factors influencing catchability, these data could provide useful information on relative stock abundance. The analysis of these data conducted by Dobby, et al. (2008) showed a significant increase in lpue between 2006 and 2007 which is in agreement with other sources of information: catch rates from observer data showed increases around this time ( ICES, 2007) and the Scottish anglerfish survey showed an increase in biomass of ~30% between 2006 and 2007 (Fernandes, 2008).

The analysis of the tallybook data has revealed clear seasonal and spatial patterns in the lpue for different areas around Scotland (Dobby et al., 2008). Both large- and small-scale anglerfish movements have been previously observed (Laurenson et al., 2005) and although migration patterns are not well understood, anglerfish are thought to spawn in deep water along the shelf edge north and west of Scotland (Fulton, 1903; Hislop et al., 2001). The seasonal and spatial changes in lpue may therefore be related to movements to spawning areas. If additional information on size composition and catches of spawning females and the level of discards had been sufficiently well recorded, this may have provided further insight into the spawning location and behaviour of anglerfish.

The fine scale information on the spatial (and depth) distribution of fishing activity which has been obtained could prove useful for monitoring changes in the fishing activity and behaviour of the fishing fleet if it were available over an extended period of time. In addition, the description of gear which is entered in each tally book may provide insight into technological creep and fishing efficiency over time. Although the survey and tally book data have similar spatial coverage, the tally book data represents much higher intensity sampling across the high density areas in particular and therefore survey design could potentially be improved by referring to the tallybook data.

Data Accuracy

The issue of data accuracy has arisen on a number of occasions during the project. The validity of the results and conclusions above are obviously highly dependent on the provision of accurate returns. Since the tallybooks were anonymous, it is assumed that there has been little incentive for fishers' to deliberately record inaccurate information. However, this also means there has been no straightforward means of cross-checking the data. Some data validation was carried out by MSS observers when the scheme was initially launched, although this amounted to < 2% of the trips that were included in the statistical analysis of catch rates. Data have always been scrutinized thoroughly before analysis and checked for internal consistency, with records that included hauls of atypical duration or too many hauls per day, for example, excluded at the outset. In other parts of the world (Starr and Vignaux, 1997), experience suggests that fisher information from voluntary logbook schemes can provide accurate data on catch rate which may be useful for stock assessment.

Concluding Remarks

When the tallybook scheme was first discussed, it was made clear to the industry that the aim was to implement a long term approach to improving the quality of the scientific data available on anglerfish. The scheme has run for five years and participation levels have dropped from the original 37 vessels in 2006 to only two during 2010. Maintaining industry enthusiasm has been difficult and responses from the questionnaire suggest that the fishermen, although generally supportive of the scheme, may have expected more immediate returns for their work, for example, through increased TACs. The increased paperwork associated with current EU regulations may also have contributed to their reduced willingness to additionally complete a voluntary tallybook and a number of skippers cited lack of time as a reason for no longer completing them.

Other schemes of this type have also been affected by dwindling numbers of participants. For example, the 'F-project', implemented in the Netherlands to obtain cpue and discard data for use in flatfish assessment has had some limited success, but currently has just a few participants, resulting in poor coverage of the fishery's distribution (Johnson and van Densen, 2007). The Institute of Marine Research ( IMR), Bergen, Norway, run a relatively successful fisher self-sampling scheme (known as the 'reference fleet') to collect catch data and biological information (Helle and Pennington, 2004). However, in contrast to the Scottish tallybook scheme, fishers receive payment for their involvement. Voluntary schemes that do succeed appear to be operated by the fishing industry rather than scientists (Starr and Vigneaux, 1997).

The ICES Workshop on Using Fishers to Sample Catches ( WKUFS, ICES 2007) suggested a number of ways of incentivising data collection schemes such as through an increased TAC or direct payment, but they also felt that understanding that participation in such schemes is useful for stock management was a motivating factor. In this case, improving the quality of data and consequently the assessment and management advice was clearly not a great enough incentive for most fishers to continue participating in the scheme. The need for good communication in successful cooperative projects is stressed by Johnson and van Densen (2007). A number of questionnaire responses from skippers within the Scottish scheme suggested that they thought that the scheme had already ended. This is clearly a result of lack of communication between the relevant parties. The Scottish scheme was set up in such a way that vessels remained anonymous (to encourage complete and accurate returns) so it has been difficult for the staff at MSS to liaise directly with the skippers. All discussion of the data was carried out through an intermediary such as the SFF or NAFC, Marine Centre. In hindsight, data workshops or discussion groups (for skippers) may have been more successful communication fora.

Despite the fact that many of the skippers responded positively to the questionnaire on the anglerfish tallybook scheme, MSS has decided to conclude the project. At a time when data (both commercial and survey) on this fishery and stock were particularly poor the scheme provided useful data which could be used in support of fishery management advice. Since then, the quality of the commercial data has improved - the introduction of buyers and sellers legislation has meant that the official landings are now reported with substantially increased accuracy. In addition, the time series of abundance data from the MSS joint science-industry anglerfish survey now extends to six years and these data have formed the basis of management advice in recent years.

Working with the fishing industry has proved a useful and positive experience and it is disappointing that the scheme has ended. To ensure the success of such schemes in the future, regular and direct communication is vital between all parties to maintain the momentum and enthusiasm thus keeping participation levels high, as is initially establishing realistic expectations by the participants concerning the outcomes from the scheme.

Acknowledgements

We would like to thank the skippers of the vessels who have taken part in the Scottish anglerfish tallybook scheme. In addition, our thanks goes to Rory Campbell of the SFF and Chevonne Laurenson of NAFC Marine Centre who have helped with the coordination of the scheme.