Browsing by Author "Adolf, Jason E."

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    Effects of Open Circuit SCUBA Exhaust on Reef Fish Surveys in the Main Hawaiian Islands
    (2017-05) Lopes Jr, Keolohilani H.; Adolf, Jason E.; Tropical Conservation Biology & Environmental Science
    The 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.
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    Evaluating techniques of quantifying lipid yield and cell density of Chlorella protothecoides (Kruger) grown on waste glycerol
    (2015-12) Collins, Topaz Palakika; Adolf, Jason E.; Tropical Conservation Biology & Environmental Science
    Chlorella protothecoides (Krüger) is ubiquitous as a research organism for biofuels. The genus consists of species that are photosynthetic, heterotrophic, and mixotrophic, and cellular lipid yield can be relatively high compared to other algal species. The research presented here addressed the differences between conventional and novel methods of quantifying lipid yield and cell density of C. protothecoides produced on various glycerol media. Conventional methods of light microscopy, gravimetric lipid analysis, and colony forming units, were compared with BODIPY 505/515 lipid-stained cells and NucRed Live 647 nucleic acid stained cells analyzed by flow cytometer. This is the first report of using a dual stain technique to simultaneously quantify cell density and lipid yield of an algal species for biofuel production. Results indicated that there is no significant difference (p > 0.05) between BODIPY 505/515 and NucRed Live 647 for cell density. There is no significance between the dyes and hemocytometer counts (p>0.05). Lipid analysis indicated no significant difference between flow cytometer lipid per cell and %oil/vol (p>0.05), especially for UTEX B25. This indicates that the novel method of utilizing BODIPY 505/515 or NucRed Live 647, singularly or in concert, is comparable to conventional methods of lipid and cell density analyses. Because all three strains of C. protothecoides obtained cell densities of between 107 and 109 cells/mL and highest oil yield was about 45% per cell, waste glycerol has the potential to become a viable feedstock for Hawaii’s growing biofuel industry.