Odour nuisance in Ireland and the potential use of olfactometry for the control of odours

Odour nuisance in other European countries has led to the development of techniques which employ panels of human assessors for the determination of environmental odours. Odour measurement is not widely practised in Ireland, yet local authorities are frequently in receipt of odour derived public complaints. This dissertation examines the fundamentals of odour nuisance in terms of how we perceive odours, common sources of environmental odours, the principles of odour measurement (in particular the Sutch pre-standard on olfactometry) and the extent to which odour nuisance is a problem in Ireland. The intention is to provide a reference document for use by those interested parties in the country who may be variously involved in policy making, legislative development, enforcement of environmental law or any person who has an interest in odours and the public nuisance they can give rise to. In particular the aim was to provide previously undocumented information on the prevalence of odour nuisance in Ireland, the exercision of the available powers to control odours, and the possible value of odour measurement as part of a regulatory process. A questionnaire was circulated to all local authorities in the country and 82% responded with information on their experiences and views on the subject of odours. The results of the survey are presented in summary and detailed form.

Evaluation of fish pots as a feasible fishing method in Irish waters, with specific reference to the physiological effects of common and alternate pots on the lesser spotted dogfish (Scyliorhinus canicula).

Finfish pots have emerged as a “responsible” gear, when used in combination with conservational and technical measures to sustain fisheries. Previous trials in Irish waters have offered no published reported data and so three designs tested in the current study provide new information on this gear. The most successful traps in terms of fish catch were rigid steel framed rectangular pots used to target Conger eel. Although commercial yield was low (0.2 per trap haul), potential existed for a viable pot fishery. Deployment and storage of Norwegian floating pots was conducted with relative ease but performance in the water was poor resulting in loss of gear. Catch returns were notable even though effort was restricted as mega-faunal by-catch was a problem, which lead to ending this trial. From these initial trials it was evident that catch rates were low compared to established Norwegian fisheries (3.6 cod per pot), which resulted in the utilisation of pots, already established in the crustacean fishery, to find species readily accessible to pot capture. Although fished and designed differently, these gears provided an opportunity to establish the benefits of pot fishing to fish quality and to determine the effects on by-catch. The fishing effects of three catching methods (pots, angling and trawl) and the effects of air exposure on the physiological status of a common by-catch, the lesser spotted dogfish Scyliorhinus canícula (L.) were examined using a range of physiological biomarkers (plasma catecholamine, glucose, lactate, muscle pH and muscle lactate). Physiological responses of fish to an emersion stress regime resulted in a significant metabolic disturbance in groups, but may not have weakened the overall health of these fish, as signified in the revival of some metabolites. Plasma glucose and lactate concentrations did not however recovery to baseline levels indicating that to achieve an accurate profile, responses should be determined by a suite of biomarkers. Responses did not demonstrate that samples from the pots were significantly less stressed than for the other two methods; angling and trawling, which are in contrast to many other studies. Employment of finfish potting therefore in Irish waters needs further consideration before further promotion as a more responsible method to supplement or replace established techniques.