Opening up about using Closed Areas to

Manage Scallop Fisheries

Bryce Stewart, Leigh Howarth, Marija Sciberras, Katherine Yates & Miles Hoskin

Howard Wood

Sustainability of Global Scallop Fisheries

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UN FAO Fisheries & Aquaculture Department (2013)

The Effect of Fishing on Scallops

Catch per unit effort for scallops

Bradda Inshore

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30

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1950 1960 1970 1980 1990 2000

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UE

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Age composition of scallops Bradda Inshore

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Age (years)

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osi

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1937

2004

The Effect of Fishing on Scallops

Ecosystem Effects of Scallop Fisheries

Biodiversity Settlement Habitat

Public Pressure

http://www.youtube.com/watch?v=nkfz5fOPSck

Principles for Improving the Management of

Scallop Inshore Fisheries 1. Encourage industry stewardship of the resource (spatial or catch

based ownership) – reduce the “race for fish”

2. Allow stocks to recover towards more natural size / age structures – improve yield per recruit & reproductive output

3. Provide spawning refuges – high densities of large individuals

4. Minimise the effects of the fishery on juveniles – improve future yields

5. Reduce by-catch & conflicts with other fisheries

6. Reduce the effect of fisheries on benthic habitats – maintain / recover biodiversity & improve recruitment

Beukers-Stewart & Beukers-Stewart (2009)

Are Closed Areas

The Solution? Georges Bank

/ NE USA

Case Study: UK Scallop Fisheries

Great or King

scallops

Pecten maximus

Queen scallops

Aequipecten

opercularis

UN FAO Fisheries & Aquaculture Department (2013)

Arran

(NTZ)

Port Erin (CA)

Cardigan Bay

(SAC)

Skomer

Island (MNR)

Lundy Island

(NTZ) Devon (IPA)

Llyn Peninsula

(SAC)

IRELAND UNITED

KINGDOM

Scotland

Northern

Ireland

England Wales

Isle of Man Scallop Fishery

• Scallops dominate fisheries

landings into the Isle of Man

• Fishery appears sustainable

but is much less productive

than in the past

• Dredging for scallops has

reduced biodiversity & habitat

complexity on the main fishing

grounds

• IoM have set up a network of

marine protected areas to

improve fisheries sustainability

Closed Area

Scallop Recovery in Port Erin Closed Area

Density (1989-2006)

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1989 1991 1993 1995 1997 1999 2001 2003 2005

Den

sit

y (

no

./100m

2)

Closed Area

Fished Area

10 TIMES HIGHER!!

Beukers-Stewart et al. (2005) MEPS

Scallop Recovery in Port Erin Closed Area

Density (2008)

Murray, Hinz & Kaiser (2009)

Scallop Recovery in Port Erin Closed Area

9 TIMES HIGHER!

Biomass (2006)

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Shell length (mm)

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sit

y (

no

./100m

2) Fished area

Closed area

20 TIMES HIGHER!!

Scallop Biomass & Reproduction

• Large scallops

Egg production

(33 x fished area)

• High densities

Fertilisation

• Combination

Larval production

(100 x fished area?)

Closed area Fished area

(2006)

Fisheries Benefits?

Larval Export?

Spill-over?

Neill & Kaiser 2008

Pascal Dubois

Fisheries Benefits?

Commercial Catch Rates

Beukers-Stewart et al. (2003) ICES J Mar Sci; Beukers-Stewart et al. (2006) J Shellfish Res

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SW Coast

East Coast

Conservation Benefits Closed Area

- Increased biodiversity

- More long-lived and

fragile animals

- Increased habitat

complexity (upright

hydroids, bryozoans

etc)

- Feedback to

commercial species

Bradshaw et al. (2001; 2003)

NTZ

Arran No-Take Zone (NTZ)

• Scotland’s first No-take Zone (October 2008)

• Passed by Scottish parliament after years of campaigning by

COAST

• Designed to benefit both fisheries and conservation

University of York Research (2010-13)

Leigh Howarth Howard Wood

Angus Robson

Habitat - Photoquadrats

Tim Cross

Last three years - macroalgae within the NTZ was

found to contain hundreds of juvenile scallops

Leigh Howarth

Juvenile Scallop Density

• Abundance of scallop settlement was significantly greater

inside the reserve

Howarth et al., (2011)

Adult Scallops

*Error bars represent ±1 SE.

Kings Queens

Over 3 years

• Scallop density higher in

reserve for 3 years year

running

• Kings 1.5 times greater

inside reserve

• Queens over 3 times

greater inside reserve

Den

sit

y (

No

/100m

)

Reserve

Fishing

grounds

Scallops older and larger within reserve

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sit

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(%

) Queen scallops NTZO…

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(%

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Size range (mm)

King scallops NTZ

OUT

Reserve

Fishing

grounds

Reserve

Fishing

grounds

Scallops & Closed Areas in the UK

Area Species Response Factors

Arran NTZ P. maximus Moderately higher

densities, size and age

inside

Variable settlement,

moderate fishing pressure

outside, some illegal

fishing, short duration of

protection.

Arran NTZ A. opercularis Moderately higher

densities, size & age

inside

As above

Port Erin CA P. maximus Much higher densities,

size and age inside

Regular settlement, high

natural densities, high

fishing pressure outside,

well enforced, long history

of protection

Port Erin CA A. opercularis Higher densities outside Variable settlement, low

natural densities, low

fishing pressure.

Llyn Peninsula SAC P. maximus Higher densities inside Moderate fishing pressure

outside, some illegal

fishing, long duration of

protection

Llyn Peninsula SAC A. opercularis Higher densities outside As above

Continued…

Area Species Response Factors

Cardigan Bay SAC P. maximus Similar densities inside &

outside

High natural disturbance,

short duration of

protection.

Cardigan Bay SAC A. opercularis Similar densities inside &

outside, highly variable

As above

Skomer MNR P. maximus Higher densities inside Negligible fishing for

scallops outside, long

duration of protection

Skomer MNR A. opercularis Similar densities inside &

outside

As above

Lundy NTZ P. maximus Similar densities and

population structure inside

& outside

Very low natural densities,

low settlement, low fishing

pressure outside, some

illegal fishing.

Devon IPA P. maximus Much higher densities,

size and age inside

High natural densities,

well enforced, long

duration of protection.

Key Messages… So Far

• Species biology is important

- permanent closures for long lived species

- flexible closures for short lived species

• Location is important – you need to understand

- distribution of suitable habitat

- larval dispersal and settlement patterns

- patterns of fishing pressure

• Recovery may be a lengthy process

• Levels of natural disturbance are important

• Enforcement is important

- industry and stakeholder buy-in is key

Implementation & Management The Real Challenge

The English Experience Marine Conservation Zones (MCZs)

127 MCZs recommended – but now only 31 being consulted on

The Northern Ireland Experience

Access priorities of the

Northern Ireland Scallop Fleet

Yates (2012)

The Northern Ireland Experience

Areas

suggested for

protection from

dredging

Closed areas

suggested for

scallop fishery

management

Are Closed Areas the Solution?

• Scallop fisheries appear ideally suited to management with networks of closed areas

• BUT… effective management outside MPAs is also essential

• A suite of tools are often needed (e.g. minimum sizes, gear modifications, effort restriction, stock enhancement)

• Mapping of benthic habitats, larval dispersal, fishing activity and resources is key to developing effective networks of closed areas

• Closed areas should be set up to benefit both fisheries & conservation wherever possible

• Industry and stakeholder involvement will improve effectiveness and reduce management costs

We All Want Sustainable Seafood

Obrigado!

Science without Borders

http://sciencewithoutborders.international.ac.uk