The European native oyster (Ostrea edulis) was once abundant across Europe; however, due to a combination of overfishing and disease, many of these populations collapsed during the early 1900s and now there are few natural populations left in Britain or Ireland. One such remaining population is located in Loch Ryan, Scotland which supports a small fishery, currently landing up to 25 tonnes of oysters per annum. The Loch Ryan fishery has been privately owned and managed by the Wallace family since 1701, when they were given the rights to fish in a Royal Charter by King William III. Unique access to historical documents enabled an examination of management techniques, landings and population structure since 1874. Assessment of the leases over the last 87 years suggested that the owners are willing to expend resources on regulating tenant behaviour. The current landings data indicated that the fishery has recovered from the lowest historical catch levels in the 1950s, to a catch similar to that observed before the 1913 population crash (at the highest sustainable catch of 20 tonnes p.a.). The pooled annual sex ratio (male: female) was 3:2 for 2013 and 2:1 for 2014, which was significantly different to the presumed ideal 1:1 ratio. However, the sex ratio for individual months was not significantly different to a 1:1 ratio, with only 3 months (over the two years) showing a significantly skewed ratio. This investigation aimed to ensure sustainable fishing practice in Loch Ryan and, by using this site as a case study, inform the management of other fisheries - both public and private - by emphasising the importance of learning from experience. In conclusion, this study presents results which demonstrate that a collapsed fishery can be restored to produce sustainable high catches, if controlled management is applied over a prolonged period of time.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:705912 |
| Date | January 2016 |
| Creators | Eagling, Lawrence Eric |
| Publisher | Queen's University Belfast |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
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