Presentation on theme: "Lobsters in Northumberland Jessica Duffill Telsnig (McLoughney, 2013)"— Presentation transcript:
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
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.
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
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 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 system Consists 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 sites Lobster 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