The ecology of the plaice Pleuronectes platessa L. and other flatfish in the Clyde Sea Area have been described by M.G.Poxton for the award of the degree of PhD (1976). The dates and duration of spawning have been deduced and the maximum concentrations of eggs and larvae given. Information on the distribution of the eggs and larvae in the plankton is presented. The ecology of O-group plaice on their nursery grounds has been examined in particular detail. Every sandy bay in the Clyde Sea Area has been sampled in order to determine the most important nursery areas. Population estimates have been calculated by making right-angled tows off the beaches with a 2-metre beam trawl. Estimates of mortality and growth rates have been obtained and a length/wet-weight relationship and a wet/dry weight ratio have been calculated. Particular attention has been paid to the food of the plaice, samples of stomachs being taken from the trawl caught fish. Comparisons have been made between plaice taken from different areas (including Firemore Bay, Loch Ewe) and between plaice and the dab Limanda limanda L. which shares the same nursery environment. The main nursery area, Irvine Bay, has been described and details of the bottom fauna given. Offshore sampling for juvenile flatfish has also been carried out using an 18ft. beam trawl in conjunction with F.R.V. Mara. Details concerning the adult plaice stock have been obtained by sampling at Ayr fishmarket where most of the catches are landed. The commercial fishery for plaice has been described and data on the landings have been compiled. The age and length composition of the plaice stocks have been given and assessments of their population dynamics have been made. Research has also been conducted using commercial boats from which samples of adult flatfish have been taken and details of the food eaten have been obtained.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:469370 |
| Date | January 1976 |
| Creators | Poxton, Michael Gerald |
| Publisher | University of Aberdeen |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU432442 |
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