Aims and objectives

These studies show that the impact of MPAs on fisheries permitted within their boundaries are mixed and dependent on location and management measures.

Studies conducted to date have mostly focussed on fish rather than shellfish species, but in the UK, shellfish landings (predominantly edible crab (Cancer pagurus), European lobster (Homarus gammarus), Norway lobster (Nephrops norvegicus), squid, cuttlefish, king scallop (Pecten maximus) and whelk (Buccinum undatum)) account for more than one third of total landings, and had a value of

£278.8 million in 2014 (Marine Management Organisation 2015). Of these, N.

norvegicus and P. maximus are targeted primarily by bottom towed fishing gear accounting for 56 % of shellfish landings into the UK in 2014, and H. gammarus, C.

pagurus and B. undatum, are key species targeted by static gear vessels and accounting for 34 % of landings in 2014 (Marine Management Organisation 2015).

Static gear fishers targeting these species may benefit from the designation of MPAs in the UK through a reduction in competition, an increase in available ground and a reduction in gear conflicts. UK MPAs are likely to encompass preferred habitats for H. gammarus, C. pagurus and B. undatum. C. pagurus and H.

gammarus favour rocky reef habitats, and reef is a listed feature for which both MCZs and SACs are designated, and is a qualifying feature in 59 of the 99 SAC sites in the UK (JNCC 2016). B. undatum are known to favour softer sediment habitats, but may occur on areas between rocky reefs which provide important habitat for

146

them as well as juvenile H. gammarus (Howard and Bennett 1979; Martel et al.).

There is likely to be considerable overlap therefore, between MPAs and ground targeted by H. gammarus, C. pagurus and B. undatum fishers, potentially leading to economic benefits for these vessels. Multiuse MPAs may therefore bring economic benefits to fishers targeting these species, and quantification of the benefits may enhance understanding of the role of MPAs in fisheries management. Increasing understanding may also aid interpretation and communication of the benefits of MPAs to fishers, an aspect which is crucial to promoting compliance with management measures and acceptance of MPA designations (Arias et al. 2015;

Rossiter and Levine 2014).

Using the Lyme Bay MPA, this study therefore built on the work of Mangi et al.

(2012) to determine the impact of multi-use MPA designation on landings of C.

pagurus, H. gammarus and B. undatum; species that are of key importance to the livelihoods of fishers operating in the area. Using the metrics: number of active vessels (mean number of active vessels per month), CPUE (mean number of tonnes per vessel per month) and value of landings (mean £ per vessel per month), the study aimed to determine whether multi-use MPAs provide economic benefit for fishers whose activities are permitted within them.

Following the cessation of the initial MPA monitoring project, in October 2011 the Blue Marine Foundation established the Lyme Bay Working Group which aimed to

‘develop, promote and implement best practise in fishery and conservation management…in order to maximise socio-economic benefits for local coastal communities’ (Lyme Bay Fisheries and Conservation Reserve). The working group comprised regulators, fishers, conservationists and scientists and a voluntary code

147

of conduct for fishers operating within the MPA was developed. The code of conduct included a cap on the number of pots per vessel, limiting this to 250, although all vessels were thought to be fishing well within this limit (Lyme Bay Fisheries and Conservation Reserve). The work of Mangi et al. (2012); (2011) and the discussions of the working group suggested that use of static gear had increased within the MPA since designation. This was thought to be a result of the reduction in conflict between fishers using static gear and those using bottom towed fishing gear, with economic benefits expected for fishers targeting C.

pagurus, H. gammarus and B. undatum.

To provide a control site enabling exclusion of confounding variables external to the MPA, data were compared to vessels fishing within the Inshore Potting Agreement (IPA) area in South Devon. The IPA was established as a voluntary zoned fisheries management system in 1978 primarily to reduce conflict between mobile and static gear types and the agreement was incorporated into legislation in 2002 (Hart et al. 2003). It covers an area approximately 500 km² and as well as zones where static gear (pots and static nets) is exclusively allowed and areas where towed gear is exclusively allowed there are also areas where gear types are managed seasonally (Figure 4.1), and is managed by the Devon & Severn IFCA (D&SIFCA). This site provides an appropriate control for Lyme Bay as any changes seen in landings can be expected to be the result of external factors and market fluctuations rather than site specific factors. Fluctuations in landings from boats fishing for C. pagurus, H. gammarus and B. undatum are unlikely to result from management measures as these have been static for so long. Furthermore, static gear fishers operate independently in set areas that are historic in origin and the ground is perceived to be fished to capacity (D&SIFCA, pers. comm.).

148

The study therefore examined the hypotheses that:

H1 = numbers of active vessels statistically significantly increased with time in the Lyme Bay MPA whilst remaining static in the IPA

H2 = CPUE statistically significantly increased with time in the Lyme Bay MPA whilst remaining static in the IPA

H3 = the value of landings statistically significantly increased with time in the Lyme Bay MPA whilst remaining static in the IPA

These were tested over nine years, covering the period from two years before the Lyme Bay MPA came into effect until seven years after.

4.2 Methods

To determine whether a change in the metrics: number of active vessels (mean number of active vessels per month), CPUE (mean number of tonnes per vessel per month) and value of landings (mean £ per vessel per month) occurred following the implementation of an MPA in Lyme Bay, UK, landings data were analysed. Data were provided by the Marine Management Organisation and covered the period from two years before the Lyme Bay MPA was implemented until seven years after it came into effect. Data were provided per vessel for ICES rectangles 30E6 and 30E7 for Lyme Bay, and 29E5 and 29E6 for the IPA (Figure 4.1).

149

Data were refined using the following criteria: 1) vessels must fish within the Lyme Bay MPA/IPA, determined through consultation with D&SIFCA, Southern IFCA and the Blue Marine Foundation (identified using Port Letters and Numbers), 2) data must only include landings of target species; C. pagurus, H. gammarus and B.

undatum. Consultation with D&SIFCA, Southern IFCA and the Blue Marine Foundation also confirmed that the assumption that landings from all vessels came from within the Lyme Bay MPA or IPA could be made, based on their known fishing patterns. Landings were plotted using a July to June year, reflecting the implementation of the Lyme Bay MPA in July 2008. Due to availability of data at the time of writing, data for 2015 was only available until May.

Figure 4.1: Location of the Lyme Bay MPA and Inshore Potting Agreement, showing the Lyme Bay & Torbay and Start Point to Plymouth Sound &

Eddystone Special Areas of Conservation and relevant ICES rectangles. Map created using ArcGIS, 2016

150

Differences before and after MPA designation in Lyme Bay were calculated for each metric by subtracting the average before designation (2006/2007 – 2007/2008) from the average measure after designation (2008/2009 – 2014/2015) to give a positive (increase following designation) or negative (decrease following designation) value. These differences were also calculated as a percentage to enable direct comparison between case study sites.

4.2.1 Data analysis

Analysis of Variance (ANOVA) was conducted to test for differences for each metric between Years (fixed: 2006/2007 – 2014/2015) using PRIMER 6 (Clarke and Warwick 2001) with PERMANOVA+ for PRIMER, chosen as it is robust to unbalanced designs and makes no assumptions about underlying data distributions (Walters and Coen 2006). Data were untransformed and Euclidean distance similarity indices were used to conduct resemblance matrices (Clarke and Warwick 2001). Each term in the analyses used 9999 permutations of the appropriate units (Anderson and Braak 2003). Differences were considered significant where P < 0.05.

4.3 Results

Over the period of study, 43 active vessels were known to be fishing within the MPA in Lyme Bay. Of these, 41 targeted C. pagurus, 42 H. gammarus, and 29 B.

undatum, with all except two vessels targeting two or more species (Table 4.1).

Landings were greatest for B. undatum (mean = 65.49 tonnes per month ± 5.15), followed by C. pagurus (mean = 10.48 tonnes per month ± 0.93) and H. gammarus

151

(mean = 0.71 tonnes per month ± 0.05) and combined totals were greatest in the year 2013/2014 averaging 137.16 tonnes per month ± 24.10 and lowest in 2007/2008 averaging 42.63 tonnes per month ± 9.50.

Table 4.1: Number of active vessels targeting Cancer pagurus, Hommarus gammarus and Buccinum undatum in the Lyme Bay MPA and the IPA

Over the same period 34 vessels were actively fishing within the IPA, 32 targeting C. pagurus, 33 H. gammarus and five B. undatum (Table 4.1). Landings were greatest for C. pagurus (mean = 98.66 tonnes per month ± 6.97) followed by B.

undatum (7.58 tonnes per month ± 0.75) and H. gammarus (0.73 tonnes per month

± 0.06) and combined totals were greatest in the year 2014/2015, averaging 159.12 tonnes per month ± 26.33 and lowest in 2009/2010 averaging 77.50 tonnes per month ± 15.13.