Library Open Repository

Attenuation coefficients of ultraviolet and photosynthetically active wavelengths in the waters of Heron Reef, Great Barrier Reef, Australia

Downloads

Downloads per month over past year

Nunez, M and Michael, KJ and Veal, C (2011) Attenuation coefficients of ultraviolet and photosynthetically active wavelengths in the waters of Heron Reef, Great Barrier Reef, Australia. Marine and Freshwater Research, 63 (2). pp. 142-149. ISSN 1323-1650

[img] PDF
Marine_Freshwater_Res.pdf | Request a copy
Full text restricted
Available under University of Tasmania Standard License.

Abstract

Variation in subsurface solar radiation has been identified as a second-order factor in coral bleaching. This study examines transmission of radiation at Heron Reef (southern Great Barrier Reef, Australia) testing the hypotheses that spectral transmission is independent of location, season and solar zenith angle. In June and December 2004, 132 underwater irradiance profiles were collected at six ultraviolet wavelengths (305, 313, 320, 340, 380, 395 nm) and photosynthetically-active radiation (PAR) to estimate spectral diffuse attenuation coefficients Kd(l). Mean Kd(l) decreased through the ultraviolet spectrum (0.435m 1 at 305 nm to 0.115m 1 at 395 nm) whereas mean Kd(PAR) was 0.129m 1. Ultraviolet Kd(l) values were highly correlated with each other, but less well correlated with Kd(PAR). Kd(l) values were larger inside than outside Heron Lagoon, both across all wavelengths and at individual wavelengths. Similarly, Kd(l) values were significantly larger in December than June. These results are consistent with greater resuspension and transport of particulates in Heron Lagoon at higher wind speeds. Kd(l) values were not dependent on solar zenith angle. The implications are that location and season must be accounted for when setting Kd(l) values to calculate spectral irradiances affecting corals at Heron Reef

Item Type: Article
Journal or Publication Title: Marine and Freshwater Research
Page Range: pp. 142-149
ISSN: 1323-1650
Identification Number - DOI: 10.1071/MF11106
Additional Information: Copyright 2011 CSIRO
Date Deposited: 17 May 2012 04:31
Last Modified: 18 Nov 2014 04:32
URI: http://eprints.utas.edu.au/id/eprint/13325
Item Statistics: View statistics for this item

Repository Staff Only (login required)

Item Control Page Item Control Page