Details of Award
NERC Reference : NE/J016896/1
[AGRIFOOD] Advancing the quantitative basis for sustainable management of inshore crab fisheries: case study for edible crabs in Northumberland.
Training Grant Award
- Lead Supervisor:
- Professor C Fitzsimmons, Newcastle University, Sch of Natural & Environmental Sciences
- Grant held at:
- Newcastle University, Sch of Natural & Environmental Sciences
- Science Area:
- Marine
- Overall Classification:
- Marine
- ENRIs:
- Global Change
- Natural Resource Management
- Science Topics:
- None
- Abstract:
- Rationale With the general decline in finfish yields shellfisheries now play an important socio-economic role in fishing communities. UK catch has increased by 34% since 1994, with 28 thousand tonnes worth #37 million landed in 2010 (MMO 2010). Current levels of crab fishing are at or beyond biologically sensible levels and UK stocks are 'over exploited' (Bannister 2009). The newly formed Inshore Fisheries and Conservation Authorities (IFCAs) have been tasked with the sustainable management of sea fisheries resources in their local areas out to 6 nautical miles. However, knowledge of edible crab population dynamics is limited and given the absence of age data and the inadequacy of abundance estimates current scientific stock assessments are imprecise. The study site is the district governed by the Northumberland Inshore Fisheries and Conservation Authority (NIFCA) which covers 130 km of coast from Tynemouth to Berwick, where artisanal inshore fisheries help sustain several coastal communities. Building on existing collaborations between Newcastle University, Northumberland Inshore Fisheries and Conservation Authority (NIFCA) and Natural England, this study will improve the evidence-base and analytical methodologies to support management decisions on sustainable resource use. Objectives 1.Estimate age and growth rates for the local edible crab population to provide an unbiased and geographically relevant quantitative underpinning for stock assessments. 2.Define spatial and temporal patterns in directed fishing effort and catch rates of edible crabs across the study area. 3.Quantify the stock in terms of recent and historical abundance and mortality levels and determine status in relation to potential reference points for yield and spawning potential. Methods 1.Crustaceans grow by moulting the exoskeleton, so their skeletal hard parts do not have annuli suitable for age reading. Growth rates are also highly variable such that size is not a good proxy for age. This inability to determine age for edible crab has severely limited stock assessment modelling. Lipofuscin ageing techniques based on histological analysis of the eyestalk terminal medulla (MT-A) will be used to calibrate lipofuscin concentrations to chronological age. Approximately 8,000 animals will be tagged and released across the district and local fishers incentivised to collect and return re-captures. Size-at-age modal progression will be derived for the recapture sample and other size-stratified samples taken from the wild via lipofuscin histology and compared with observed growth rates under natural conditions. Age and growth parameters will be estimated and taken forward into stock assessments (3). Recaptures made during the tagging programme itself will also feed into the mark-recapture population analysis (3c). 2.a) By employing GIS spatial analysis techniques vessel sightings and landings data will be combined to estimate the distribution of fishing effort and catch across the district. b) Using Generalised Linear Models (GLM) and Generalised Additive Models (GAM) spatial and temporal patterns in the fishery and spatial discontinuities indicating separate stock units will be characterised. A catch rate index will be derived and taken forward into stock assessment models (3). 3.a) Alternative stock assessment methods will be explored utilising annual age- and length-frequency data and growth parameters estimated in (1) and catch rate indices from (2b). b) Population and fishing mortality parameters estimated from (3a) will be projected forward under a range of relevant management scenarios and in yield and spawner per recruit analyses to estimate reference points indicative of stock and fishery status. c) Mark-recapture data modelled to estimate crab density (Bell et al. 2003) will be augmented with new mark-recapture data (1). Density estimates will be scaled to district level by estimating suitable edible crab habitat using GIS spatial anal
- NERC Reference:
- NE/J016896/1
- Grant Stage:
- Completed
- Scheme:
- DTG - directed
- Grant Status:
- Closed
- Programme:
- Open CASE
This training grant award has a total value of £95,214
FDAB - Financial Details (Award breakdown by headings)
| Total - Other Costs | Total - Fees | Total - RTSG | Total - Student Stipend |
|---|---|---|---|
| £5,868 | £13,812 | £27,250 | £48,285 |
If you need further help, please read the user guide.