Publication - Consultation paper

2014 Consultation on the Management of Inshore Special Areas of Conservation and Marine Protected Areas Approaches.

Published: 11 Nov 2014
Part of:
Marine and fisheries
ISBN:
9781784128913

2014 Public Consultation on the Management of Inshore Special Areas of Conservation and Marine Protected Areas Approaches.

77 page PDF

570.7 kB

77 page PDF

570.7 kB

Contents
2014 Consultation on the Management of Inshore Special Areas of Conservation and Marine Protected Areas Approaches.
Protected Area E - Loch Sween MPA

77 page PDF

570.7 kB

Protected Area E - Loch Sween MPA

This section sets out 2 possible management approaches for this protected area.

Approach 2 is preferred because it would deliver all the management requirements in one batch. If approach 1 was implemented then further measures would be required in the 2 nd batch.

A description of this protected area can be found in the main consultation document is Annex A, Protected Area E.

Maps to support understanding of the approaches can be found under Protected Area E in the technical maps document. Figure E1 shows Loch Sween in context with other protected areas.

Measures for Loch Sween would be delivered by Statutory Instrument using powers under the Marine (Scotland) Act 2010.

Questions 13 to 15 refer to Loch Sween.

The site features and conservation objectives

Protected Feature

Conservation objective

Native Oyster

Conserve

Maerl Beds

Conserve

Burrowed mud

Conserve

Sublittoral mud and mixed sediment communities

Conserve

Summary of the management advice

Feature

Mobile gear

Static gear

Other gear

Native Oyster

Remove / avoid pressure from demersal trawl, mechanical dredges, or suction dredges.

Consider reduce / limit pressure

Remove / avoid pressure from diver operated suction dredging or hand gathering

Maerl beds

Remove / avoid pressure from demersal trawl, mechanical dredges, or suction dredges.

Consider reduce / limit pressure

Remove / avoid pressure from diver operated suction dredging

Burrowed mud

Remove / avoid pressure from demersal trawl, mechanical dredges, or suction dredges.

Consider reduce / limit pressure

Sublittoral mud and mixed sediment communities

Remove / avoid pressure from demersal trawl, mechanical dredges, or suction dredges.

Consider reduce / limit pressure

Native oysters and maerl beds are highly sensitive to physical disturbance caused by mobile gears which can cause surface and sub-surface abrasion/penetration. These pressures can cause damage to the native oyster shells and remove a proportion of the population.

Additionally, mobile gear such as mechanical dredges may remove the underlying sediment, cobbles and shell material thereby resulting in substratum loss for the feature to grow on. Native oysters are also considered to be highly sensitive to fisheries which specifically target this species, e.g. through hand gathering.

For maerl beds, the three dimensional structure, quality and associated communities can be substantially affected by mobile demersal gear fishing from crushing, burial of live maerl and disruption of the surface and underlying sediment. Maerl beds have a low rate of recovery due to their very slow growth rate. In addition to direct impacts, maerl beds are sensitive to increased levels of sedimentation.

The approaches to management

Static gear assessment

Static gear activity is relatively low in Loch Sween according to Scotmap. It is unlikely to be used in locations with maerl beds, or the majority of locations with native oysters. The current levels are not considered to be impacting on the sedimentary habitats. Consequently no static gear management is proposed. However if future studies found there to be a negative effect then this would be addressed then.

Measures common to both approaches

The use of suction dredges (boat or diver operated) would be prohibited throughout the MPA. The hand collection of shellfish would be prohibited within Loch Sween itself but not the outer part of the MPA where scallop divers may be active. The size of vessel which can fish in the MPA would be restricted to 75 Gross Registered Tonnage ( GRT).

Approach 1

This approach would apply specific zonal measures, but would not deliver all the management requirements. Further consideration of the sublittoral mud and mixed sediment communities would be required in the 2 nd batch of measures.

The proposed measures

The following activities would be prohibited all year round;

In addition to the common measures, there would be no demersal trawling or mechanical dredging in Linne Mhurrich or at the head of the Loch Sween. Figure E2 shows a map of the measures under approach 1

The benefit

Not permitting any hand gathering of shellfish in effect removes the risk of Native Oysters being removed. The spatial measures will ensure that the main maerl beds are fully protected. In addition the area at the head of Loch Sween is an exceptional example of burrowed mud and worthy of the same level of protection as a "remove / avoid" pressure feature.

The capacity restriction would go some way to delivering the conservation objectives for the sedimentary habitats throughout the rest of the MPA.

The costs

The amount of fishing effort is relatively low in Loch Sween when compared with the surrounding waters. This can be clearly seen in figures E4 and E5. The impact of the measures under approach 1 is very low. However this approach requires further measures to be taken later. Trawl and dredge data has been amalgamated to avoid disclosure issues.

Method

Average annual MPA value

Average annual value affected

% of value affected

Average annual effort hours in MPA

Average annual effort hours affected

% of effort affected

Trawl /

Dredge

£28.5

£2

7%

319

25

8%

Table E1: Average annual impact of approach 1 based on 2007 to 2013 data for over 15 metre vessels (rounded to nearest £000s)

Loch Sween covers part of ICES rectangles 40E4, and 41E4. According to the analysis of Scotmap data for trawl and dredge fisheries approximately 0.7% of the total value of these ICES Rectangles is taken from the MPA. For 2013 this equates to approximately 3 effort days and £2,500. If the same proportion of activity (8%) was affected by the measures this would equate to 0.2 effort days and £200 for the year.

The displacement effects

SCOTMAP data shows little under 15m trawl or dredge effort inside the body of Loch Sween (see figures E6 and E7). Loch Sween is reportedly used during poorer weather when fishing would be restricted or curtailed in the wider Sound of Jura / Gigha area. This means that the vessels would be unlikely to fish on such days if the head of Loch Sween was not available but could still operate in the rest of the loch. Consequently there would be no significant environmental consequences of this displacement. The capacity restriction would affect the periodic visiting scallop dredgers. There are significant scallop grounds within 20 nm of Loch Sween MPA as shown in figure E5. Therefore any effort displaced is likely to be dispersed over a broad area.

Approach 2 (preferred approach)

This approach would apply management specific zonal measures and a curfew on mechanical dredging. This approach would deliver all of the management requirements.

The proposed measures

In addition to the common measures, there would be no demersal trawling or mechanical dredging in the body of Loch Sween itself. In the rest of the MPA a curfew on scallop dredging would be implemented to reduce / limit pressure on the sublittoral mud and mixed sediment communities. Fishing operations would only be permitted between 0700 - 2100 Monday to Friday each week. See Figure E3.

The benefit

Not permitting any hand gathering of shellfish in effect removes the risk of Native Oysters being removed. The spatial measures will ensure that the main maerl beds are fully protected. In addition the area at the head of Loch Sween is an exceptional example of burrowed mud and worthy of the same level of protection as a "remove / avoid" pressure feature. In addition the sedimentary habitats within the main body of the loch would have a high level of protection.

The capacity restriction would help reduce / limit pressure on the sedimentary habitats throughout the rest of the MPA.

The costs

For over 15m vessels which have VMS the following data can be derived using a dataset from 2007 to 2013.

Method

Average annual MPA value

Average annual value affected

% of value affected

Average annual effort hours in MPA

Average annual effort hours affected

% of effort affected

Trawl /

Dredge

£28.5

£5

17.5%

319

58

18%

Table E2: Average annual impact of approach 2 based on 2007 to 2013 data for over 15 metre vessels (rounded to nearest £000s)

Loch Sween covers part of ICES rectangles 40E4, and 41E4. According to the analysis of Scotmap data for trawl and dredge fisheries approximately 0.07% of the total value of these ICES Rectangles is taken from the MPA. For 2013 this equates to approximately 3 effort days and £2,500. If the same proportion of activity (18%) was affected by the measures this would equate to 0.5 effort days and £450 for the year.

The displacement effects

SCOTMAP data shows little under 15m trawl effort inside the body of Loch Sween (see figure E6). However during the displacement study skippers reported trying it during 2012 and 2013. It was indicated that it is mostly used during poorer weather when fishing would be restricted or curtailed in the wider Sound of Jura / Gigha area. This means that the vessels would be unlikely to fish on such days if Loch Sween was not available. Consequently there would be no significant environmental consequences of this displacement.

Vessel Monitoring System data shows very low amounts of presence in body of the loch itself by vessels who use trawl or mechanical dredge gears. Therefore displacing this activity is unlikely to have a negative effect on the environment or the earnings of any vessel concerned.

The capacity restriction would affect the periodic visiting scallop dredgers. There are significant scallop grounds within 20 nm of Loch Sween MPA as shown in figure E5. Therefore any effort displaced is likely to be dispersed over a broad area.


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