Fal Oyster and Queen Scallop Effort Trends Report Seasons 2015/16, 2016/17 and 2017/18

Completed by: Cornwall Inshore Fisheries and Conservation Authority (Cornwall IFCA) Authors: Hilary Naylor, Annie Jenkin, Kate Owen, Colin Trundle and Steph Sturgeon

Document History Version Date Author Change 0.1 11/06/2018 H Naylor Initial draft 0.2 15/06/2018 H Naylor Addition of graphs, results and discussion 0.3 19/06/2018 H Naylor Additions to graphs and discussion 0.4 29/06/2018 H Naylor Additions to graphs and tables 0.5 30/07/2018 H Naylor Addition of statistics and amendments 0.6 10/09/2018 S Sturgeon QA 0.7 12/10/2018 H Naylor Amendments 0.8 18/10/2018 A Jenkin QA 0.9 30/10/2018 H Naylor Amendments CIFCA Fal Oyster and Queen Scallop Fishing Effort Trends Report This report may be cited as:

Naylor, H., Jenkin, A., Owen, K., Trundle, C. and Sturgeon, S. 2018. Fal Oyster and Queen Scallop Effort Trends Report Seasons 2015/16, 2016/17 and 2017/18. Cornwall Inshore Fisheries and Conservation Authority (Cornwall IFCA), Hayle.

This document has been produced by Cornwall Inshore Fisheries and Conservation Authority (Cornwall IFCA)

Cornwall IFCA Chi Gallos Hayle Marine Renewables Business Park North Quay Hayle Cornwall TR27 4DD

Tel: 01736 336842 Email: [email protected]

i CIFCA Fal Oyster and Queen Scallop Fishing Effort Trends Report Contents

List of Figures ...... iii List of Tables ...... iii 1 Introduction ...... 1 2 Aims and Objectives ...... 1 2.1 Aims ...... 1 2.2 Objectives ...... 2 3 Methodology ...... 2 3.1 Data Collection and Data Management ...... 2 3.2 Analysis Methodology ...... 2 3.2.1 Dredging ...... 3 3.2.2 Average/Expected Dredge Hours ...... 3 3.2.3 Landed Shellfish ...... 4 4 Results ...... 4 4.1 Effort...... 4 4.2 Oyster and Queen Scallop Removal ...... 8 5 Discussion ...... 13 5.1 Effort...... 13 5.2 Queen Scallops ...... 14 5.3 Oysters ...... 15 6 Limitations ...... 16 7 Recommendations ...... 16 8 References ...... 17 9 Appendix ...... 18

ii CIFCA Fal Oyster and Queen Scallop Fishing Effort Trends Report List of Figures

Figure 1: Fal Oyster Fishery Management Areas...... 2 Figure 2: Oyster and queen scallop LPUE, season 2017-18 for combined Areas A, B and C...... 5 Figure 3: Expected vs actual dredge hours per tonne of oyster of season 2017-18 and 2014-16 average for combined Areas A, B & C...... 6 Figure 4: Management Area A dredge hours (hundreds) for seasons 2015-16, 2016-17 and 2017-18 (October to March). 7 Figure 5: Management Area B dredge hours (hundreds) for seasons 2015-16, 2016-17 and 2017-18 (October to March). 7 Figure 6: Management Area C dredge hours (hundreds) for seasons 2015-16, 2016-17 and 2017-18 (October to March). 7 Figure 7: Dredge hours and oyster removal (thousand kg’s) from Management Area A during season 2015-16 (October to March)...... 8 Figure 8: Dredge hours and oyster removal (thousand kg’s) from Management Area B during season 2015-16 (October to March)...... 8 Figure 9: Dredge hours and oyster removal (thousand kg’s) from Management Area C during season 2015-16 (October to March)...... 9 Figure 10: Dredge hours, Oyster and Queen scallop removal (thousand kg’s) from Management Area A during season 2016-17 (October to March)...... 10 Figure 11: Dredge hours, Oyster and Queen scallop removal (thousand kg’s) from Management Area B during season 2016-17 (October to March)...... 10 Figure 12: Dredge hours, Oyster and Queen scallop removal (thousand kg’s) from Management Area C during season 2016-17 (October to March)...... 10 Figure 13: Dredge hours, Oyster and Queen scallop removal (thousand kg’s) from Management Area A during season 2017-18 (October to March)...... 12 Figure 14: Dredge hours, Oyster and Queen scallop removal (thousand kg’s) from Management Area B during season 2017-18 (October to March)...... 12 Figure 15: Dredge hours, Oyster and Queen scallop removal (thousand kg’s) from Management Area C during season 2017-18 (October to March)...... 12

List of Tables

Table 1: Season totals of the entire Fal Oyster Fishery including fishing hours, dredge hours, number of dredges, oysters (kg’s) and queen scallops (kg’s)...... 4

iii CIFCA Fal Oyster and Queen Scallop Fishing Effort Trends Report 1 Introduction

Cornwall Council (Port of Truro), as the grantee under the Truro Port Fishery Order 1936 (as amended), was responsible for the Management of the oyster Fishery in the River Fal. The Order was due to expire in July 2014 and as Truro Harbour was not seeking to renew the Order, in 2013 Cornwall IFCA began the process of applying to Defra for a replacement Regulating Order to manage the Fishery. Due to the length of time it took to have the replacement Order confirmed, Cornwall Inshore Fisheries and Conservation Authority (Cornwall IFCA) took over the management of the Fal Oyster Fishery from the start of the 2014 season using existing byelaw powers.

The Fal Oyster Fishery is one of three remaining wild capture oyster fisheries in England (Fal, Solent and Thames Estuary) (Long et al., 2017). The Fishery is exploited by hand gathering, and dredging from non-powered vessels; haul tow punts or sailing boats, and it is thought to be the last commercial sailing fleet in Europe (Long et al., 2017).

As grantee of the Regulating Order, Cornwall IFCA has a responsibility for monitoring and managing the stocks of oysters within the Fishery. Monitoring is achieved through annual dredge surveys (Jenkin et al., 2018) and monthly catch statistics submitted by all licence holders. Annual dredge surveys are conducted by Cornwall IFCA in January and describe the catch rates and distribution of native oysters (Ostrea edulis) within the Fishery. Monthly catch statistics are completed by every licence holder operating within the Fishery, as stipulated in The Regulations. Analysis of this data can be used to estimate the quantity of shellfish being removed from the Fishery each season, and to provide an indication of fishing effort.

In the 2016-17 season fishermen developed a market for queen scallops, sometimes referred to as queenies. Previously, in the Fal Fishery Order 2016, a person that retained on board or landed native species of bivalve or gastropod shellfish had to ensure that the combined weight of species other than oysters (Ostrea edulis) and mussels (Mytilus edulis) did not exceed 20% of the weight of all the native species retained on board or landed. This regulation was removed in the Fal Fishery order prior to the start of the 2017-18 season which changed queenies to a target species. Cornwall IFCA officers believe the species to be primarily the variegated scallop (Mimachlamys varia) as opposed to the more commonly referred to queen scallop (Aequipecten opercularis) (Jenkin et al., 2017). For simplicity the term ‘queen scallop’ has been used to describe this species for the entirety of the report.

This report summarises the trends in fishing effort and reported weight of native oysters (O. edulis) and queen scallops (M. varia) removed from the Fishery over the seasons 2015-16, 2016-17 & 2017-18.

2 Aims and Objectives

2.1 Aims

 To describe trends in fishing effort and the removal of native oysters (O. edulis) and queen scallop (M. varia) from the Fal Oyster Fishery during seasons 2015-16, 2016-17 and 2017-18,

 To assess any impact to the overall fishing effort with the inclusion of queen scallops as a target species.

1 CIFCA Fal Oyster and Queen Scallop Fishing Effort Trends Report 2.2 Objectives

 Analyse Fal Oyster Fishery effort data for seasons 2015-16, 2016-17 and 2017-18 via permit returns data, calculated by Fal Fishery Management Areas A, B and C.

3 Methodology

3.1 Data Collection and Data Management

All licence holders in the Fal Oyster Fishery must complete and submit a monthly statistical returns form to Cornwall IFCA, as previously described in Section 1. Over the period of this report two forms were used, one between 2014 and 2017 then an updated form was used for the 2017-18 season. Examples of the forms can be seen in Annex 1 and 2. Fishery data entered onto the forms includes daily totals of fishing hours, proportion of time spent fishing in each of the Fal Fishery Management Areas, (Figure 1), and the weight of each species of shellfish removed from the Fishery per day.

Figure 1: Fal Oyster Fishery Management Areas.

Upon receipt of the returns forms Cornwall IFCA Admin Officers input the data into a purpose built Microsoft Excel 2010 spreadsheet which follows the same format of the 2017–18 season monthly statistical returns form (Annex 2).

3.2 Analysis Methodology

The total weight (kg) of each shellfish type removed from the Fishery per season was summed. The total weight of shellfish estimated to have been removed from the fishery includes records which have been omitted from further analysis due to lack of attribute data, for example hours fished, or number of dredges used.

2 CIFCA Fal Oyster and Queen Scallop Fishing Effort Trends Report Fishing hours were summed for all Areas, throughout the entire season with no differentiation between fishing methods, differentiation only by Fishery Management Areas (Figure 1). In this study only the oysters reported to have been removed from the Fishery during the Fishery season, not lay Areas, have been analysed.

Due to the differences in the format of the data storage, the methodology for analysis varied slightly between seasons, as described below.

3.2.1 Dredging For each daily record from a licence holder, dredge hours (Dh) were calculated by Area as:

Dhxd = Fhxd x Prxd x Dd

Where Fhxd is fishing hours in Area x on day d, Prxd is the proportion of time spent fishing in Area x on day d and Dd is the number of dredges used on day d. These values were then summed by month for total dredge hours (Dh) in each Area.

For 2015-16 season data is recorded in the database with a calculated total hours fishing (Fh) in each area by month by permit holder. This was summed for all permit holders by month. The dredge hours (Dh) by month is calculated as:

Dhxm = ∑ (FhxmH x DmH)

Where Fhxm is the total fishing hours in area x in month m, by permit holder H, and D is the average number of dredges used in month m, by permit holder H.

3.2.2 Average/Expected Dredge Hours Dredge hours per tonne of oysters per month for seasons 2014-15 and 2015-16 were calculated to determine the average dredge hours over the two seasons, to compare against expected and actual dredge hours of season 2017- 18, in order to show the difference in effort with the addition of queen scallops. Calculated as;

Dhm = Dhm / (Om/1000)

Where Dhm is dredge hours in month m, Om is kilograms of Oysters in month m, divided by 1000 to obtain tonnage of oysters.

Expected dredge hours for season 2017-18 calculated as;

2017-18 Dhm = 2014-16 Dhm x (2017-18 Om/1000)

Where Dhm is dredge hours in month m and Om is kilograms of Oysters landed in month m divided by 1000 to obtain tonnage of oysters.

3 CIFCA Fal Oyster and Queen Scallop Fishing Effort Trends Report 3.2.3 Landed Shellfish For each daily record from a licence holder, total shellfish landed (SH) per Area were calculated as:

SHxds = SHsd x Prxd

Where SHsd is shellfish landed of species on day d, and Prxd is the proportion of time spent in Area x on day d. These values were then summed by month for total shellfish removed from the Fishery by Area By month.

For 2015-16 season total shellfish landed by each permit holder in each area, by month can be described as:

SHsxm

Where SHsxm is the monthly (m) shellfish landed of species s in area x.

4 Results

4.1 Effort

The 2015-16 season data provided a baseline for effort as well as oyster removal, before the change in regulations in January of the 2016-17 season. The baseline season (2015-16) had the highest landings of oysters, however for each successive season the landings of oysters has reduced while effort (dredge hours) has increased, as seen in the landing per unit effort (LPUE) of oysters which has reduced whereas the LPUE of queen scallops has increased with each season (Table 1).

Following the change in regulations in January 2017 there was a 7.8% increase in effort in season 2016-17 compared to 2015-16. The 2017-18 season saw an even greater amount of effort in comparison to the previous season (2016- 17), with a further increase of 13.6% in effort (Table 1). Most notably the landing of queen scallops increased in the 2017-18 season, from 4,040kg in 2016-17 to 72,133kg in 2017-18 (Table 1).

Additionally there has been an increase of 5.5% from seasons 2015-16 to 2016-17 and a further increase of 12% from season 2016-17 to 2017-18 in the total number of license holders operating within the Fal Oyster Fishery (Table 1). However, the numbers of dredges used in each season indicate no increase in the number of dredges through an increase in license holders; (2,866 in 2016-17 and 2,862 in 2017-18).

Table 1: Season totals of the entire Fal Oyster Fishery including fishing hours, dredge hours, number of dredges, oysters (kg’s) and queen scallops (kg’s). A, B & C Total Entire Fishery Oyster Queen scallop Total Number of Total Total LPUE (kg's Queens LPUE (kg's Oysters Season Dredges/License Fishing Dredge oysters/ Scallop queen (kg’s) Holders Hours Hours dredge s (kg) scallops/ hour) dredge hour) 2015-2016 54 7,638 14,068 67,595 4.8 180 0.0 2016-2017 57 8,239 15,170 56,792 3.7 4,040 0.2 2017-2018 64 7,785 17,248 50,031 2.9 72,133 4.1

Figure 2 shows the LPUE data for both oysters and queen scallops during the first season where they were both a target species for the entire season (2017-18). Previously, fishing effort would normally disperse during the latter part 4 CIFCA Fal Oyster and Queen Scallop Fishing Effort Trends Report of the season, as observed in the 2015-16 season (Figure 4, Figure 5 and Figure 6). However this trend has altered with a continuation of effort later in the season.

Queen Scallops Totals Oyster Totals

6 hours)

4 18 18 season LPUE(kg's/ dredge - 2

2017 0 Oct Nov Dec Jan Feb Mar

Figure 2: Oyster and queen scallop LPUE, season 2017-18 for combined Areas A, B and C.

Figure 3 shows the combined average dredge hours per tonne of oysters from seasons 2014-15 and 2015-16. Providing an estimation of a unit of oyster fishing effort from which further analysis could be made. This is plotted against the expected dredge hours per tonne of oyster of season 2017-18, calculated by incorporating the average dredge hours per tonne of oyster in seasons 2014-16 and actual tonnage of oysters removed in 2017-18, with the addition of season 2017-18 actual dredge hours per tonne of oyster for comparison.

Season 2017-18 expected dredge hours shows the amount of predicted dredge hours required to remove the reported quantity of oysters. Whereas season 2017-18 actual dredge hours shows all of the reported effort based on removing both oysters and queen scallops (Figure 3). It can be seen that the expected dredge hours per tonne of oyster are lower than the actual, with a 77% percentage difference.

Furthermore, it should be noted that the expected dredge hours per tonne of oysters for season 2017-18 are noticeably reduced in comparison to the average dredge hours per tonne of oyster of seasons 2014-16 with the exemption of November. Demonstrating the actual dredge hours were expected to decline reflecting the reduction in oyster removal with each successive season. However this has not occurred and season 2017-18 actual effort has differed greatly, as displayed in Figure 3.

5 CIFCA Fal Oyster and Queen Scallop Fishing Effort Trends Report

2014-16 Average 2017-2018 Expected 2017-2018 Actual

10 Dredge Dredge Hours(hundreds)

0 Oct Nov Dec Jan Feb Mar

Figure 3: Expected vs actual dredge hours per tonne of oyster of season 2017-18 and 2014-16 average for combined Areas A, B & C.

There was a larger amount of effort carried out in Management Areas A and B in comparison to Area C in all three Fal Oyster Fishery seasons 2015-16, 2016-17 and 2017-18 (Figure 4, Figure 5 and Figure 6).

Management Area A during season 2017-18, saw a greater amount of dredge hours in October in comparison to the previous two seasons. Seasons 2016-17 and 2017-18 followed a similar trend throughout the season. Notably the 2016-17 season was consistently higher in effort with the exemption of October (Figure 4).

Management Area B showed that similarly both seasons 2016-17 and 2017-18 followed a similar trend line both increasing from October to December, reducing in February before an increase in March. Season 2015-16 differed from the two subsequent seasons displaying no clear trend, decreasing between October and November before a sharp increase through to February, followed by a decrease in March (Figure 5).

Management Area C demonstrated a similar effort trend in all three seasons with the exemption of January in 2016- 17 and March in 2015-16. Declining from October through to December before 2016-17 differed with an increase in January, effort in 2016-17 and 2017-18 then continued on a similar trend line for the remainder of the season whereas 2015-16 displayed a small increase in March (Figure 6).

The results from all three seasons indicates that effort in Management Area C remained steadier throughout the season in comparison to Areas A and B which displayed more fluctuations throughout the season.

6 CIFCA Fal Oyster and Queen Scallop Fishing Effort Trends Report

Dredge hours 15-16 Dredge hours 16-17 Dredge hours 17-18

- 30

18 18 (hundreds) -

15 17 17 17 & - 10

5 16, 16, 2016

Area A dredge hours for seasons dredge A Area hoursseasons for 2015 0 Oct Nov Dec Jan Feb Mar

Figure 4: Management Area A dredge hours (hundreds) for seasons 2015-16, 2016-17 and 2017-18 (October to March).

Dredge hours 16-17 Dredge hours 15-16 Dredge hours 17-18

18 18 (hundreds) - 15

17 17 2017 & 10 -

16, 16, 2016 Area Area B hours dredge for seasons 2015 0 Oct Nov Dec Jan Feb Mar

Figure 5: Management Area B dredge hours (hundreds) for seasons 2015-16, 2016-17 and 2017-18 (October to March). Dredge hours 16-17 Dredge hours 17-18 Dredge hours 15-16

18 18 -

17 17 &2017 -

(hundreds) 16, 16, 2016

- 10 2015

Area Area C hours dredge for seasons 5

0 Oct Nov Dec Jan Feb Mar Figure 6: Management Area C dredge hours (hundreds) for seasons 2015-16, 2016-17 and 2017-18 (October to March).

7 CIFCA Fal Oyster and Queen Scallop Fishing Effort Trends Report 4.2 Oyster and Queen Scallop Removal

Effort and oyster removal followed similar trends throughout the 2015-16 season. Management Areas A and C display a progressive decrease in both effort and oyster removal throughout the season, followed by a small increase during March (Figure 7 and Figure 9), whereas Management Area B effort and oyster removal increases earlier in the season (Figure 8).

During the 2015-16 season both effort and oyster removal followed a similar trend in Management Area A, decreasing from October through to December, remained steady from December to February followed by a small increase in March (Figure 7).

Similarly to Management Area A, both effort and oyster removal in Management Area B followed a similar trend initially declining from October to November then differed with a gradual increase from November through to February before a decline in March (Figure 8).

Similar to Management Area A, Management Area C progressively declined, gradually decreasing from October through to February before a small increase in March (Figure 9).

Oysters (kg) Dredge hours (hrs)

9 9

8 8

7 7 6 6 5 5 4 4 3 3

2 2 fishery (thousnadfishery kg's)

1 1 Area Area oysters A removed from the 0 0 Area dredge A hours(thousands) Oct Nov Dec Jan Feb Mar

Figure 7: Dredge hours and oyster removal (thousand kg’s) from Management Area A during season 2015-16 (October to March).

Oysters (kg) Dredge hours (hrs)

9 9

8 8 7 7 6 6 5 5 4 4 3 3

fishery fishery (thousandkg's) 2 2

1 1 Area Area B oysters removed from the

0 0 Area B hours dredge (thousands) Oct Nov Dec Jan Feb Mar

Figure 8: Dredge hours and oyster removal (thousand kg’s) from Management Area B during season 2015-16 (October to March).

8 CIFCA Fal Oyster and Queen Scallop Fishing Effort Trends Report

Oysters (kg) Dredge hours (hrs)

9 9

8 8 7 7 6 6 5 5 4 4 3 3

fishery fishery (thousandkg's) 2 2

1 1 Area Area C oysters removed the from

0 0 Area C hours dredge (thousands) Oct Nov Dec Jan Feb Mar

Figure 9: Dredge hours and oyster removal (thousand kg’s) from Management Area C during season 2015-16 (October to March).

Figure 10Figure 11Figure 12 display the Fishery season where regulations changed allowing the removal of queen scallops as a target species in January 2017.

For the 2016-17 season (Figure 10) the removal of oysters in Management Area A was high from October to November, decreased largely during December with a subsequent increase in January before decreasing again for the remainder of the season. Queen scallop removal remained low throughout the season in comparison, with small but noticeable increases during November and March. Effort in Management Area A followed a similar trend as oyster and queen scallop removal, with increases in both November and January and a decrease in December (Figure 10).

Oyster removal in Management Area B increased monthly from October to December followed by a decline for the remainder of the season. In contrast, queen scallop removal was very low between October and December, with an increase later in the season from January to March. Effort in Management Area B remained steady throughout the season from October to March (Figure 11).

Management Area C showed a gradual decrease in the removal of oysters throughout the season with the exemption of January, whereas queen scallop removal remained very low for the entire season (Figure 12). Effort in Management Area C maintained a low level of effort throughout the season but followed a similar trend to oyster removal with small decreases in December and February and an increase in January.

Queen scallop removal from the Fishery remained lower than oyster removal within each Management Area for the entire 2016-17 season (Figure 10, Figure 11 and Figure 12). Effort during the 2016-2017 season followed similar trends to both oyster and queen scallop removal in both Management Areas A and C (Figure 10Figure 12) whereas Management Area B showed no clear trend (Figure 11).

9 CIFCA Fal Oyster and Queen Scallop Fishing Effort Trends Report

Oysters (kg) Queens (kg) Dredge hours (hrs)

9 9

8 8 7 7 6 6 5 5 4 4 3 3

2 2 from from thefishery (thousandkg's)

Area Area oysters A queens & removed 1 1 Area Area dredge A hours(thousands) 0 0 Oct Nov Dec Jan Feb Mar

Figure 10: Dredge hours, Oyster and Queen scallop removal (thousand kg’s) from Management Area A during season 2016-17 (October to March).

Oysters (kg) Queens (kg) Dredge hours (hrs)

9 9

8 8 7 7 6 6 5 5 4 4 3 3 2 2

from from thefishery (thousandkg's) 1 1

Area B oysters & queens removed B queens Area removed oysters & Area Area B hours dredge (thousands) 0 0 Oct Nov Dec Jan Feb Mar

Figure 11: Dredge hours, Oyster and Queen scallop removal (thousand kg’s) from Management Area B during season 2016-17 (October to March).

Oysters (kg) Queens (kg) Dredge hours (hrs)

9 9

8 8 7 7 6 6 5 5 4 4 3 3 2 2

from from thefishery (thousandkg's) 1 1

Area Area C oysters queens & removed Area Area C hours dredge (thousands) 0 0 Oct Nov Dec Jan Feb Mar

Figure 12: Dredge hours, Oyster and Queen scallop removal (thousand kg’s) from Management Area C during season 2016-17 (October to March).

10 CIFCA Fal Oyster and Queen Scallop Fishing Effort Trends Report Figure 13Figure 14Figure 15 display the first Fishery season where both oysters’ queen scallops were target species for the entire season.

The 2017-18 season saw a similar trend in the removal of oysters and queen scallops in Management Area A (Figure 13). The removal of oysters decreased from October through to December before small increases during January and March, similarly queen scallop removal also decreased between October and December, followed by a large increase in January before a smaller increase in March. Effort in Management Area A displayed a similar trend to both oyster and queen scallop removal with a gradual decline from October through to December followed by an increase in both January and March (Figure 13).

It can be seen that season 2017-18 oyster and queen scallop removal displayed different trends in Management Area B (Figure 14). Oyster removal in Management Area B increased from October through to November before decreasing for the remainder of the season, queen scallop removal differed and remained stable from October to November with an increase in both January and March. Effort in Management Area B followed a similar trend to that of the oyster removal, however notably there is also a small increase in effort during January when queen scallop removal also increased (Figure 14).

Both oyster and queen scallop removal in Management Area C followed similar trend lines, remaining steady from October to November before declining simultaneously for the remainder of the season (Figure 15). Effort in Management Area C also displayed a similar trend, remaining steady from October to December before declining for the remainder of the season.

In contrast to the previous season (2016-17), which saw the removal of oysters to be higher than queen scallops (Figure 10, Figure 11 and Figure 12), the 2017-18 season showed queen scallop removal was higher than oyster removal in Management Area A for all months when queen scallops were removed from the Fishery, as well as January to March in Management Area B (Figure 13 and Figure 14). Oyster removal remained greater than queen scallop removal within Management Area C for both seasons (Figure 12 and Figure 15). Effort throughout the 2017-18 season displayed similar trends to both oyster and queen scallop removal in Management Areas A and C whereas effort in Management B differed from queen scallop removal (Figure 13, Figure 14 and Figure 15).

11 CIFCA Fal Oyster and Queen Scallop Fishing Effort Trends Report

Oysters (kg) Queens (kg) Dredge hours (hrs)

9 9

8 8 7 7 6 6 5 5 4 4 3 3

2 2 the fishery thefishery (thousnadkg's)

1 1 Area Area dredge A hours(thousands)

Area Area oysters A queens & removed from 0 0 Oct Nov Dec Jan Feb Mar

Figure 13: Dredge hours, Oyster and Queen scallop removal (thousand kg’s) from Management Area A during season 2017-18 (October to March).

Oysters (kg) Queens (kg) Dredge hours (hrs)

9 9

8 8

7 7 6 6 5 5 4 4 3 3

2 2 the fishery thefishery (thousands kg's)

1 1 Area B hours dredge (thousands)

Area Area B oysters queens & removed from 0 0 Oct Nov Dec Jan Feb Mar

Figure 14: Dredge hours, Oyster and Queen scallop removal (thousand kg’s) from Management Area B during season 2017-18 (October to March).

Oysters (kg) Queens (kg) Dredge hours (hrs)

9 9

8 8

7 7 6 6 5 5 4 4 3 3

2 2 the fishery thefishery (thousandskg's)

1 1 Area C hours dredge (thousands) Area Area C oyster& queens sremoved from 0 0 Oct Nov Dec Jan Feb Mar

Figure 15: Dredge hours, Oyster and Queen scallop removal (thousand kg’s) from Management Area C during season 2017-18 (October to March).

12 CIFCA Fal Oyster and Queen Scallop Fishing Effort Trends Report 5 Discussion

5.1 Effort

It was noted that the effort within the Fal Oyster Fishery has been affected since the change in regulations allowing queen scallops as a target species in January 2017. This report’s aim was to investigate whether the change in regulations to queen scallops from a 20% of total catch restriction to an unlimited target species has caused fishing effort to change.

Previously it was expected for effort to reduce through the season as Oyster removal reduced. However this trend has altered and the addition of queen scallops as a target species has caused a visible increase in effort. As a result, Fishery data from season 2015-16 was incorporated into the report to produce a baseline in effort and oyster removal before queen scallops were made an additional target species. It can be seen from the levels of oysters and queen scallops removed from the Fishery that roles of the two species may be reversing, with more queen scallops being removed than oysters (Table 1).

In the baseline season (2015-16), effort was highest at the beginning of the season and gradually declined with a corresponding decline in oysters removed (Figure 7, Figure 8 and Figure 9). In comparison, the proceeding seasons 2016-17 and 2017-18 have a shown a continuation of effort later in the year (Figure 4, Figure 5 and Figure 6), most notably in Management Area A, but also in March of Management Area B and January of Management Area C. It is expected that the fishing effort would normally dissipate during the latter part of the Fishery season as the fishable oyster stock is removed, as previously observed in season 2015-16, however this trend has altered and the continuation of added effort later in the season is likely attributed to the introduction of queen scallops as a target species, as seen with the LPUE of both oysters and queen scallops (Figure 2). The change in LPUE with the decrease in oysters and increase in queen scallops indicates an alteration in the fishing dynamics of this Fishery.

Figure 3 showed a difference in the expected and actual dredge hours per tonne of oyster for season 2017-18 with a 77% percentage difference, season 2017-18 being the first season where the two target species were targeted for the entire season. This increase in dredge hours is therefore likely attributed to the secondary target species, queen scallops. This change in dredging effort shows how the dynamics of the Fishery are changing as a result of the unlimited removal of queen scallops, this is also reflected in LPUE of oyster and queen scallops (Figure 2). In addition, the expected dredge hours per tonne of oyster of 2017-18 were lower than the average dredge hours per tonne of oyster of seasons 2014-16 with the exemption of November, demonstrating the correlation of a reduction in effort due to the decline in oysters landed since seasons 2014-15 and 2015-16 which saw the best landings of oysters (90,641 kg’s in 2014-15 and 67,595 kg’s in 2015-16).

There was a larger amount of effort carried out in Areas A and B in comparison to Area C during all three seasons (Figure 4, Figure 5 and Figure 6). This may be due to the greater area size of Management Areas A and B, which can be utilised by both sail boats and haul tow punts whereas Management Area C, which has a much smaller area, can only be used by haul tow punts, therefore restricting the amount of effort. Also it could be presumed that haul punts would have a steady catch rate due to a fairly consistent towing speed, as a result of the nature of the fishing activity.

13 CIFCA Fal Oyster and Queen Scallop Fishing Effort Trends Report Whereas sail boats can be affected by multiple factors such as wind speed which is likely to have considerable impact on towing speeds and efficiency, while wind direction will also dictate the direction of the tow which can have an impact on the amount of time that the dredge is effectively fishing. Therefore care must be taken when interpreting effort in Management Area A, B and C, due to the difference in the amount of effort that can be carried out within each Area due to size of area and method of fishing.

Management Area A has seen the largest increase in effort compared to the baseline season 2015-16. In comparison, the two proceeding seasons in have shown a large effort increase throughout the whole season with the exemption of December (Figure 4). Additionally, in the 2016-17 season, effort in Area A showed a sharp increase during January (Figure 4), it was from January 2017 that the new market emerged for queen scallops causing a change in regulations, and it is likely that the effort in Area A was driven by the demand for ‘queen scallops’ (Street et al., 2018).

It is apparent that different Management Areas (A, B and C) of the Fishery are fished differently, and at different times of the season. The 2015-16 season saw the highest effort in Management Area A at the beginning of the season, then as effort decreased in A, it increased in B, this is reflected in Figure 4 and Figure 5. This was most likely due to the red macroalgae which covers most of Area B, an area known as East Bank in the early part of the fishing season. It leads to inefficient fishing as the dredge quickly fills with the algae preventing shellfish entering the dredge. Most fishermen avoid Area B, remaining fishing in Area A, until the weed dies off (Street et al., 2018). The two proceeding seasons have displayed a different trend, where effort increased in Management Area A and decreased in Management Area B during both the initial and latter stages of the 2016-17 season, shown in Figure 4 and Figure 5. The season of 2017-18 also differed with effort remaining similar in Management Area B throughout the season, whereas Management Area A displayed more fluctuations similar to that of Management Area A in 2016-17. This difference in trends of fishing effort suggests there may have been a change in the red macroalgae distribution and abundance since the 2015-16 season. All three seasons show that Area C is utilised the least, this is likely to be the result of Management Area C only being fished by haul tow punts and therefore reducing the amount of reported effort within that Area.

Additionally results indicated an increase in the total number of license holders operating within the Fal Oyster Fishery year on year since 2015-16 (Table 1). However, the numbers of dredges used in each season indicated no increase in the number of dredges through an increase in license holders therefore the increase in effort can be attributed to an increase in dredge hours, likely attributed to the additional target species.

5.2 Queen Scallops

Most notably queen scallops removal has increased largely from the 2016-17 to 2017-18 season. For previous Fal Oyster Fishery seasons, the Regulations stipulated that as a by-catch species, only 20% of the total weight of target species catch could be retained of non-target species. Queen scallops were previously non-target species and therefore subject to the 20% of total catch restriction. There was an amendment to the Regulations January in 2017 which removed the 20% by-catch limitation for species other than oysters and mussels, meaning that from January of the 2016-17 season queen scallops could be taken without limitation.

14 CIFCA Fal Oyster and Queen Scallop Fishing Effort Trends Report As a result of this, it can be seen that the removal of queen scallops has increased dramatically in just one season, it is assumed that the 2018-19 season may see a further increase in the weight of queen scallops removed from the Fishery with the continually developing market. However it should be noted that the current fishing regulations for this market may need to be altered if queen scallop removal continues to rise. It’s our responsibility as regulators to ensure the Fishery is sustainable which may lead to a harvest control strategy being developed in the future.

5.3 Oysters

All three Management Areas (A, B and C) over all three seasons observed a progressive decrease in the removal of oysters throughout the season with the exemption of Area B during the 2015-16 seasons. This was expected as the available fishable stock was removed.

The quantity of oysters removed from the Fishery decreased by 13.5% from 2016-17 to 2017-18. This reduction is likely attributed to both the oyster fishermen targeting queen scallops and retaining oysters as a by-catch and the cyclical nature of the species abundance.

However, the removal of oysters may have decreased further without the introduction of the new target species (queen scallops), as oyster removal and effort previously reduced in the latter stages of the season as the fishable stock was removed, therefore making the density of oysters too low to be worthwhile to fish. The quantity of oysters removed from the Fishery may have been higher than would normally have been removed at the apparent density. Whereas since the change in regulations fishermen remove oysters while targeting queenies causing effort and oyster removal to continue towards the end of the season, where it would of previously decreased. Therefore the queen scallop as a new target species has skewed the removal of oysters for the two seasons after their introduction (2016-17 and 2017-18).

The change in regulations has already changed the Fishery dynamics. In 2016-17 a total of 4,040 kg’s of queen scallops were taken and 70,941 kg’s taken in 2017-18 (Table 1). This could potentially affect the abundance of oysters which has already seen a reduction in the number of oysters removed from the Fishery over three seasons (Table 1). It is expected that the 13.5% decrease in the amount of oysters removed from season 2016-17 to 2017-18, will continue to decline with subsequent seasons.

However, a combination of settled, warm weather during the spring/summer of 2018 and an increase in effort is likely to have increased the turnover of ground which in turn could have prepared a very suitable substrate for oyster spat to settle. This suggests that the proceeding Fal oyster survey (2018-19) may record a very good larval spat fall.

15 CIFCA Fal Oyster and Queen Scallop Fishing Effort Trends Report 6 Limitations

Care must be taken when interpreting effort data comparisons in Management Areas A, B and C, many factors other than just oyster and queen scallop abundance may have influenced effort within each Area. For instance size differences between the Management Areas and no differentiation between sail boats and haul tow punts when calculating the effort data, however it is known that sail boats fish within Management Areas A and B whereas only haul tow punts utilise Area C.

The increased effort directed towards queen scallops observed when comparing expected and actual dredge hours per tonne of oyster for season 2017-18 (Figure 3), does not take into consideration the density of oysters on the ground in 2017-18 compared to seasons 2014-16. An assumption has been made on a correlation between oysters and dredge hours, with the number of dredge hours decreasing when there are fewer oysters on the ground viable to fish.

Finally, the introduction of queen scallops has skewed the effort data, making it hard to obtain effort data attributed to oysters alone, therefore it is not possible to accurately measure the level of effort for each species.

7 Recommendations

 Monitor and carry out further analysis into effort trends and species landed in subsequent years.  Use data to inform management of the Fal Fishery.  Determine a way to differentiate between the effort directed towards oysters and queen scallops.  Continue to monitor effort (dredge hours) for the Habitat Regulation Assessment of the Fishery.

16 CIFCA Fal Oyster and Queen Scallop Fishing Effort Trends Report 8 References

Jenkin, A., Trundle, C., Street, K., and Naylor, H. 2017. Fal Oyster Survey. Cornwall Inshore Fisheries and Conservation Authority (Cornwall IFCA), Hayle. Jenkin, A., Trundle, C., Street, K., and Naylor, H. 2018. Fal Oyster Survey. Cornwall Inshore Fisheries and Conservation Authority (Cornwall IFCA), Hayle. King, M., 1995. Fisheries Biology, Assessment and Management. Blackwell Science Ltd, Oxford. Long, S., French-Constant, R., Metacalfe, K., and Witt, M.J., 2017. Have Centuries of Inefficient Fishing Sustained a Wild Oyster Fishery: a Case Study. Fisheries and Aquaculture Journal, 8: 2. Street, K., Trundle, C., Jenkin, A. and Naylor, H. 2018. Fal Native Oyster Fishery Seasons 2014-2015, 2015-2016 and 2016-2017 Permit Statistics Report. Cornwall Inshore Fisheries and Conservation Authority (Cornwall IFCA), Hayle.

17 CIFCA Fal Oyster and Queen Scallop Fishing Effort Trends Report 9 Appendix

Annex 1 - 2014-2017 Season Monthly Shellfish Statistics Form (two sides)

18 CIFCA Fal Oyster and Queen Scallop Fishing Effort Trends Report

19 CIFCA Fal Oyster and Queen Scallop Fishing Effort Trends Report Annex 2 - 2017-2018 Season Monthly Shellfish Statistics Form (Single sided)