Effects of Open Circuit SCUBA Exhaust on Reef Fish Surveys in the Main Hawaiian Islands

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dc.contributor.advisorAdolf, Jason E.
dc.contributor.authorLopes Jr, Keolohilani H.
dc.contributor.departmentTropical Conservation Biology & Environmental Science
dc.date.accessioned2017-06-22T19:01:55Z
dc.date.available2017-06-22T19:01:55Z
dc.date.issued2017-05
dc.description.abstractThe predominant method to quantify reef fish populations is the Open Circuit SCUBA (OC) in-situ fish survey. However, there are many biases associated with these surveys including the expelled OC exhaust which can cause visual and audible disturbances. This study aims to evaluate the bias created by OC exhaust utilizing closed-circuit rebreather (CCR) surveys, along surveys were conducted in protected areas and fished areas. The three sites in the main Hawaiian Islands were Kealakekua Bay (KK), Old Kona Airport (OA), and Pūpūkea (PK) marine life conservation district. This study found that the total fish biomass and species richness from all sites pooled showed no significant differences between gear types. However, there was a significant interaction between the gear type and the protection status (Pr(>|t|) = 0.025), indicating that there are greater differences between OC and CCR in the fished areas than the protected areas. The difference between the gear types showed a greater magnitude of OC having a higher biomass in the fished areas opposed to the protected areas where that difference was smaller. When fished species (Table 4 – a, b) were examined, significant differences between gear types were shown (Pr(>|t|) = 0.010). The OC surveys showed more fished biomass than the CCR surveys which could mean that the attraction to the exhaust within the protected areas were greater than the repulsion of the exhaust in the fished areas. Differences in the fished species biomass while having no difference in the all fish biomass supports the previous studies findings that fishing pressure is very influential on the magnitude of difference between the gear types. For researchers, estimating fishing pressure is of high importance in order to assess the level of bias associated with OC exhaust on surveys. These biases need to be accounted for in population estimations for protected areas and non-protected areas in order to get more accurate biological fish data.
dc.description.degreeM.S.
dc.description.institutionUniversity of Hawaii at Hilo
dc.format.extent37 pages
dc.identifier.urihttp://hdl.handle.net/10790/3230
dc.language.isoeng
dc.subjectConservation biology
dc.subjectBiology
dc.subjectEnvironmental science
dc.subjectClosed-Circuit Rebreather
dc.subjectFish Management
dc.subjectMarine Protected Areas
dc.subjectNear Shore Fisheries
dc.titleEffects of Open Circuit SCUBA Exhaust on Reef Fish Surveys in the Main Hawaiian Islands
dcterms.rightsAll UHH dissertations and theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission from the copyright owner.
local.identifier.alturihttp://dissertations.umi.com/hilo.hawaii:10139

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