Publications

Ralph, PJ, Brown, K, Wearing, SL & Nudd, B 1998, 'GIS - A tool for integrating tourism and mariculture in Wallis Lakes' in Wearing Stephen (ed), Planning Recreation and Tourism with Australian Communities, HM Leisure Planning Pty Ltd, Melbourne, pp. 95-102.

Jones, RJ, Hoegh‐Guldberg, O, Larkum, AWD & Schreiber, U 1998, 'Temperature‐induced bleaching of corals begins with impairment of the CO₂ fixation mechanism in zooxanthellae', Plant, Cell & Environment, vol. 21, no. 12, pp. 1219-1230.
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The early effects of heat stress on the photosynthesis of symbiotic dinoflagellates (zooxanthellae) within the tissues of a reef‐building coral were examined using pulse‐amplitude‐modulated (PAM) chlorophyll fluorescence and photorespirometry. Exposure of Stylophora pistillata to 33 and 34 °C for 4 h resulted in (1) the development of strong non‐photochemical quenching (qN) of the chlorophyll fluorescence signal, (2) marked decreases in photosynthetic oxygen evolution, and (3) decreases in optimal quantum yield (Fv/Fm) of photosystem II (PSII). Quantum yield decreased to a greater extent on the illuminated surfaces of coral branches than on lower (shaded) surfaces, and also when high irradiance intensities were combined with elevated temperature (33 °C as opposed to 28 °C). qN collapsed in heat‐stressed samples when quenching analysis was conducted in the absence of oxygen. Collectively, these observations are interpreted as the initiation of photoprotective dissipation of excess absorbed energy as heat (qN) and O2‐dependent electron flow through the Mehler‐Ascorbate‐Peroxidase cycle (MAP‐cycle) following the point at which the rate of light‐driven electron transport exceeds the capacity of the Calvin cycle. A model for coral bleaching is proposed whereby the primary site of heat damage in S. pistillata is carboxylation within the Calvin cycle, as has been observed during heat damage in higher plants. Damage to PSII and a reduction in Fv/Fm (i.e. photoinhibition) are secondary effects following the overwhelming of photoprotective mechanisms by light. This secondary factor increases the effect of the primary variable, temperature. Potential restrictions of electron flow in heat‐stress...

O'Meara, TJ, Lucca, SD, Sporik, R, Graham, A & Tovey, E 1998, 'Detection of inhaled cat allergen', The Lancet, vol. 351, no. 9114, pp. 1488-1489.
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Ralph, PJ 1998, 'Photosynthetic response of laboratory-cultured Halophila ovalis to thermal stress', MARINE ECOLOGY PROGRESS SERIES, vol. 171, pp. 123-130.
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Chlorophyll a fluorescence was able to rapidly detect responses of laboratory-cultured Halophila ovalis to acute changes in temperature. Six heating (27.5, 30.0, 32.5, 35.0, 37.5 and 40.0 degrees C) and 6 chilling (10.0, 12.5, 15.0, 17.5, 20.0 and 22.5 d

Ralph, PJ 1998, 'Photosynthetic responses of Halophila ovalis (R. Br.) Hook. f. to osmotic stress', JOURNAL OF EXPERIMENTAL MARINE BIOLOGY AND ECOLOGY, vol. 227, no. 2, pp. 203-220.
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Chlorophyll fluorescence was used to monitor the onset, development and recovery from hyper- and hypo-osmotic stress effects of the seagrass, Halophila ovalis (R. Br.) Hook. f. H. ovalis was able to tolerate rapid transfer from normal (35 ppt) seawater t

Ralph, PJ & Burchett, MD 1998, 'Impact of petrochemicals on the photosynthesis of Halophila ovalis using chlorophyll fluorescence', MARINE POLLUTION BULLETIN, vol. 36, no. 6, pp. 429-436.
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Laboratory-cultured Halophila ovalis showed tolerance to petrochemical exposure up to 1% (w/v) solution of Bass Strait crude oil, an oil dispersant (Corexit 9527) and a mixture of crude oil and dispersant, Quantum yield, as measured by chlorophyll fluore

Ralph, PJ & Burchett, MD 1998, 'Photosynthetic response of Halophila ovalis to heavy metal stress', ENVIRONMENTAL POLLUTION, vol. 103, no. 1, pp. 91-101.
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This paper deals with the photosynthetic effects of a range of heavy metals on the seagrass Halophila ovalis. In this study, the photosynthetic response of laboratory-cultured II. ovalis to four heavy metals (Cu, Cd, Pb, Zn) was investigated. The results

Ralph, PJ, Gademann, R & Dennison, WC 1998, 'In situ seagrass photosynthesis measured using a submersible, pulse-amplitude modulated fluorometer', MARINE BIOLOGY, vol. 132, no. 3, pp. 367-373.
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Assessments of photosynthetic activity in marine plants can now be made in situ using a newly developed, submersible, pulse-amplitude modulated (PAM) fluorometer: Diving-PAM. PAM fluorometry provides a measure of chlorophyll a fluorescence using rapid-li

Ralph, PJ, Morrison, DA & Addison, A 1998, 'A quantitative study of the patterns of morphological variation within Hormosira banksii (Turner) Decaisne (Fucales : Phaeophyta) in south-eastern Australia', JOURNAL OF EXPERIMENTAL MARINE BIOLOGY AND ECOLOGY, vol. 225, no. 2, pp. 285-300.
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Homzosira banksii shows a considerable degree of morphological variability throughout its range in south-eastern Australia, apparently in relation to the local habitat, and there have been several previous qualitative attempts to categorize this variatio

Razmovski, V, O'meara, T, Hjelmroos, M, Marks, G & Tovey, E 1998, 'Adhesive tapes as capturing surfaces in Burkard sampling', Grana, vol. 37, no. 5, pp. 305-310.
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