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dc.contributor.supervisor Palace, Vince (Biological Science) Hanson, Mark (Environment and Geography) en
dc.contributor.author Godard, Danielle R
dc.date.accessioned 2010-08-23T14:37:39Z
dc.date.available 2010-08-23T14:37:39Z
dc.date.issued 2010-08-23T14:37:39Z
dc.identifier.citation Godard DR, Peters L, Evans R, Wautier K, Cott PA., Hanna B. and Palace V. 2009. Development of histopathology tools to assess instantaneous pressure change-induced effects in rainbow trout (Oncorhynchus mykiss) early life stages. Environmental Studies Research Funds Report. 164: iv + 88 p. en
dc.identifier.uri http://hdl.handle.net/1993/4056
dc.description.abstract Oil and gas exploration in Northern Canada uses explosive-based seismic techniques to locate hydrocarbon reserves beneath waterbodies not frozen to the bottom. The use of explosives in, or near, waterbodies has the potential to harm fishes, primarily through instantaneous pressure changes (IPCs) generated from the detonations. These IPCs can damage soft tissues through the rapid compression and expansion of the swimbladder as the pressure wave passes. In Canada, a document entitled Guidelines for the Use of Explosives In or Near Canadian Fisheries Waters recommends that peak pressures not exceed 100 kPa for the protection of fish, however damage has been reported below this level. To simulate seismic exploration and examine potential pathological changes surrounding the current Guideline, fish across different developmental stages and with varying degrees of swimbladder presence were exposed to a variety of explosive based IPC levels in field experiments. Early life stages of rainbow trout (Oncorhynchus mykiss) including eyed eggs, sac fry, and juveniles were caged and exposed to discrete detonations from 0 to 280 kPa in the Mackenzie Delta, NWT. These fish were subsequently examined for both gross pathological and histological changes to cranial structures as well as swimbladder, kidney, liver and gill tissue. Results showed changes in both the area and circumference of the cranial region of eyed eggs, as well as swimbladder, ocular and kidney damage in juveniles. Additionally, caged adult swimbladder bearing lake trout (Salvelinus namaycush) and non-swimbladder bearing slimy sculpin (Cottus cognatus) were exposed to explosive based IPCs ranging in peak pressure from 0 to 127 kPa at the Experimental Lakes Area, Ontario. Fish were later examined grossly and blood, liver, kidney, intestine, and spleen were examined to determine the presence of any traumatic based pathological changes. Results indicated the occurrence of swimbladder hemorrhage in lake trout exposed to IPCs near the current Guideline level. Finally, a risk assessment for lake trout of the Mackenzie Delta exposed to IPCs was undertaken; to examine the potential for adverse risk to individuals and populations, and the likelihood of populations being unable to recover. Based on the findings of the aforementioned studies, the recommended Guideline level is not protective of early life stages of rainbow trout and furthermore represents the threshold at which damage to the swimbladder in adult lake trout does not occur, as such, a re-examination of the recommended Guideline level is warranted. en
dc.format.extent 2924314 bytes
dc.format.mimetype application/pdf
dc.language.iso en_US
dc.subject pathology en
dc.subject explosive en
dc.subject seismic en
dc.subject fish en
dc.title Pathological examination of fish exposed to explosive based instantaneous pressure change en
dc.degree.discipline Environment and Geography en
dc.contributor.examiningcommittee Baydack, Rick (Environment and Geography) Smits, Judit (University of Calgary) en
dc.degree.level Master of Science (M.Sc.) en
dc.description.note October 2010 en


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