Larval and juvenile fish assemblages at Ningaloo Reef, Western Australia

Williams, Carolyn (1988) Larval and juvenile fish assemblages at Ningaloo Reef, Western Australia. Honours thesis, Murdoch University.

Abstract

The distribution and abundance of larval and presettlement fishes was monitored in the lagoon, entrance passage and on the seaward side of the reef at Ningaloo Reef, north - western Australia. Larval fishes were sampled with plankton nets on seven occasions between November 1987 and September 1988, while presettlement fishes were sampled with submersible light traps every two months between January 1988 and September 1988.

A total of 1362 larvae and 695 presett1ement fishes representing 42 taxa, mostly families, were caught during this study. The dominant families were the Blenniidae and Gobiidae for plankton nets and light traps respectively. In general, the two sampling methods caught different families and age groups of fishes. However, catches from both methods were dominated by the presettlement stages of small reef fish; these stages of larger fish species were much rarer. While both sampling methods revealed a general peBk in abundance during the warmer months (November to March), the larval assemblage was very patchy in abundance and distribution. A diverse larval fish assemblage was detected on the seaward side of the reef in May, and was composed mostly of larvae from shorefishes with pelagic eggs. In contrast, larvae from shorefishes with demersal eggs dominated the lagoon and channel. The number of families caught by each method generally declined after a high number in summer.

Light traps had not previously been used to sample early life history stages of fishes in Western Australian waters. The results indicate that light traps are a complementary method to the plankton nets and provide data on families and ages of fishes that are not sampled by more traditional techniques.

The results of this study are discussed in relation to similar investigations in other Australian coral reef environments.

Item Type:	Thesis (Honours)
Murdoch Affiliation(s):	School of Biological and Environmental Sciences
Notes:	Note to the author: If you would like to make your thesis openly available on Murdoch University Library's Research Repository, please contact: repository@murdoch.edu.au. Thank you.
Supervisor(s):	Lethbridge, Roger
URI:	http://researchrepository.murdoch.edu.au/id/eprint/41551

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