Lobsters in Northumberland

Jessica Duffill Telsnig

(McLoughney, 2013)

An assessment of the impact of v-notching European lobsters in the Northumberland district

Jessica Duffill Telsnig Northumberland Inshore Fisheries and Conservation Authority

Newcastle University

Introduction

• V-notching: removing a triangular piece of exoskeleton and somatic tissue from females

• Aim of v-notching: to increase the abundance of females and egg output

• Why investigate v-notching?• No assessment has been completed• The Northumberland and Durham stock may be

declining (Cefas, 2011)• This project used: Landings data, a model of the v-

notched population and Fishers’ views

2000 2002 2004 2006 2008 2010 2012 20140

1000

2000

3000

4000

5000

0

0.2

0.4

0.6

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1

1.2

Year

CPU

E (k

g/ve

ssel

num

bers

)

CPU

E (k

g/po

t num

bers

)

m=0.063

m=179

m=0.155

m=472

m=592

m=0.096

Lobster landings: temporal trends

Results

2000 2002 2004 2006 2008 2010 2012 20140

20

40

60

80

100

Area 1

Area 2

Area 3

Area 4

Area 5

Area 6

Area 7Year

Num

ber o

f v-n

otch

ed lo

bste

rs

per k

m2

• Number of v-notched lobsters recaptured between areas did vary significantly (F=3.77; P<0.004)

• The percentage of hard substrate in the different areas (Turner et al,. 2009) was negatively correlated with the number of v-notched lobsters recaptured per unit of area (r = -0.59).

Lobster landings: spatial trends

Turner, R.A., Hardy, M.H., Green, J. and Polunin, N.V.C. (2009) 'Defining the Northumberland Lobster Fishery.', Report to the Marine and Fisheries Agency, London.

2000 2002 2004 2006 2008 2010 2012 2014500

1500

2500

3500

4500

5500

4 year notch 3 year notch2 year notch

Year

Num

ber o

f v-n

otch

ed lo

bste

rs

• 11,000 to 27,000 lobster larvae could be produced per year • 3000 to 32,000 lobsters could grow to recruitment stage

Modelling v-notched populations

2006 2007 2008 2009 2010 2011 2012 20130

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9

10

Worst case scenarioBest case scenario

Year

% o

f lob

ster

land

ings

due

to v

-not

chin

g

• However, some larvae from the southern areas may travel beyond the NIFCA limit

Fishers’ views

Reasons why catch might have increased: • V-notching• Increased fishing effort• Improvements in equipment

• A decline in predators• Changes in weather and environmental reasons

Increased Decreased Not changed02468

101214161820

Population changeCatch changeUndersized catch change

Num

ber o

f res

pons

es

Change over 10 years

•90% of fishers thought that v-notching was very effective in protecting the lobster population

• 40% fishers thought most abided by the v-notching regulations• 60% thought all fishers abided by v-notching regulations

•80% think that the number of v-notched lobsters have increased over the past 10 years.

Conclusions

• V-notching may have led to a small increase in local stock and catch and be responsible for 0.3-9% of lobster landings.

• Fishers think v-notching is an effective management measure

Further research: • Continuing collecting lobster landings and fishers’ views • Conduct further research into the biology of the European lobster

The feasibility of a lobster hatchery in Amble

Jessica Duffill Telsnig

Produced for the Amble Development Trust

• A lobster hatchery= grows lobsters from eggs to juveniles. They are then released in the sea to boost the local population

• 3 lobster hatcheries exist in the UK: Padstow, Ornkey and Firth of Forth

Lobster hatchery system: Can be ran using a recirculation or flow through to waste systemConsists of 4 main systems: • Broodstock tanks to house mature females • Larval rearing tanks • Juvenile on-growing tanks • Live food stock production

• Juveniles can become cannibalistic and so need to be housed in separate containers

• There are two types of systems: • Shallow Tray system

Aquahive system

• Due to the low survivorship of lobsters when they are released into the sea an outdoor system can also be used.

Site suitability

• Need to test water quality for potential sites

Lobster hatchery development:

Creating a demonstration unit of a lobster hatchery and visitors centre may be viable based on the small site next to the harbour.

Estimated based on the Firth of Forth lobster hatchery demonstration unit that it may cost under £10,000.

Estimated revenue from ticket sales may be £21,054, potentially increasing to £69,600 in the future.

This revenue and a large grant can be used to build large lobster hatchery based on the site on the industrial estate.

Estimated to cost between £175,950-182,700 and will produce between 34,000-104,000 juveniles per year if the stacking tray system were to be used.

If the aquahive system were to be used this could increase the number of juveniles by a factor of 6-10 at an additional cost of £750-1125 per tank.

The running costs of the facility may be £5637-6337 per year.

If juveniles were to be held in an outdoor caging system than an additional relatively small cost must also be included.

Financing for the large-scale hatchery may be obtained from donations, sale of juvenile lobsters to third parties, revenue from a souvenir shop, sponsorship and an industrial levy.

Conclusions and recommendations

• Site suitability: Test water quality for the sitesLobster hatchery= Viable with a demonstration unit and visitors centre on the small site with a small grant.

If obtain a large grant can build a large-scale hatchery on the industrial site

Thank you!

Any questions?