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Papers by campbell davies

Fisheries Research, Mar 1, 2005

Journal of Fish Biology, Jun 1, 2002

Canadian Journal of Fisheries and Aquatic Sciences, Mar 1, 2005

Journal of Fish Biology, Mar 18, 2014

Marine and Freshwater Research, 2005

Marginal increment analysis was used to validate the periodicity of opaque increment formation in... more Marginal increment analysis was used to validate the periodicity of opaque increment formation in red throat emperor (Lethrinus miniatus) otoliths and to test for variation in the periodicity and timing of increment formation across age classes, years and regions of the Great Barrier Reef (GBR). Marginal increment analysis demonstrated that opaque increments were deposited on an annual basis, a result supported by a preliminary experiment on a chemically tagged captive fish, although significant regional and temporal variation in the timing of increment formation was observed. Marginal increment analysis revealed a clear annual periodicity in increment formation for all age classes in the southern region but a more ambiguous pattern for most age classes in the northern region of the species distribution on the GBR. Opaque increments appeared to form 1 month earlier in the southern region than in the northern region and, in the southern region, formed 2 months earlier in 1999 than in 2000. No significant variation was observed in the timing of increment formation between age classes. Based on knowledge of the timing of otolith increment formation and spawning season of L. miniatus, an algorithm was developed for the estimation of age in months, irrespective of the time or location of capture.

Marine Ecology Progress Series, Aug 3, 2006

Ecological Modelling, Feb 1, 2005

Canadian Journal of Fisheries and Aquatic Sciences, Aug 1, 2001

Canadian Journal of Fisheries and Aquatic Sciences, Jul 1, 2000

Variation in reproductive parameters of Plectropomus leopardus populations between coral reefs op... more Variation in reproductive parameters of Plectropomus leopardus populations between coral reefs open and closed to fishing was examined in two geographic regions (off Townsville (19°S) and in the Swains (22°S)) of the Great Barrier Reef, Australia. The reproductive parameters that were examined included the operational (reproductive) sex ratio and size and age structure of mature females, sex-changing individuals (transitionals), and mature males. There was a greater proportion of males above the minimum size and age of harvest on reefs closed to fishing for 8-10 years than on reefs open to fishing, although the effect varied with geographic region. Nevertheless, neither the sex ratio, mean age, nor mean size of males or transitionals varied significantly with reef closure status. Females, however, were significantly older and larger on closed than on open reefs in both regions. Marked regional variations in the sex ratio and average age of transitionals were found independent of reef closure status, suggesting regional variation in reproductive strategies. Controlled manipulations, inclusion of broad spatial scales, and detailed studies of intra- and inter-specific variation in serranid reproductive biology are necessary to resolve such complexities in the responses of protogynous serranids to fishing pressure and management strategies.

Marine and Freshwater Research, 2010

Deep-sea Research Part Ii-topical Studies in Oceanography, Nov 1, 2018

Scientific Reports, Aug 29, 2017

Marine Research in Indonesia, 2007

The blue spot rock cod, Cephalopholis cyanostigma, is a small common coral reef serranid that for... more The blue spot rock cod, Cephalopholis cyanostigma, is a small common coral reef serranid that forms a significant proportion of the discarded by-catch in the Great Barrier line fishery. Samples were obtained by spear and line fishing at Orpheus Island (range 114- 294 mm FL, mean = 226 mm, n = 137) and from Pelorus Island (range 120-285 mm FL, mean = 214 mm, n = 125). Sagittal otoliths were used to obtain age-based parameter estimates for the populations at each island. Analysis of marginal increments on monthly samples suggested that a single opaque band was deposited annually during November - December. Recaptures of three fishes (9,18, and 24 years old) in July and November 1997, five years after injection of oxytetracycline, further corroborated our conclusion that band formation was annual. The maximum age in our samples of 31 years suggested that the blue spotted rock cod was one of the longest lived serranids documented to date. The von Bertalanffy growth function provided the...