Springer 2005
Hydrobiologia (2005) 537: 71–80
Factors affecting the distribution, abundance and diversity of fishes of small, soft-substrata tidal pools within Moreton Bay, Australia J. J. Meager1,2, I. Williamson1 & C. R. King1 1 2
School of Natural Resource Sciences, Queensland university of Technology, GPO Box 2434 Brisbane Qld, Australia 4001 Current address: Department of Biology, P.O. Box 7800, Bergen 5020, Norway, E-mail:
[email protected]
Received 24 September 2002; in revised form 4 August 2004; accepted 4 August 2004
Key words: intertidal, tidepools, seagrass, teleost, Australia, east coast
Abstract A survey of fishes in small, soft-substrata tidepools was undertaken between May and September 1996 at two sites in south-east Queensland, Australia. Pools sampled varied in size (0.005–2.8 m2 surface area), location within the intertidal zone, and habitat structure. A total of 680 fish representing 18 species from eight families were caught. Gobiidae was the dominant family and Favonigobius exquisites, Arenigobius frenatus and Favonigobius lateralis were the most abundant species. Most fish caught were juveniles, and only F. lateralis was represented by all life-history stages (from late larval). The mean density of fish was 4.7 m)2 and mean species richness was 2.3 m)2. Both abundance and species richness increased with pool size and decreased with distance up the intertidal zone. The distribution patterns of fish in these softsubstrata tidepools were similar to patterns noted for fish in rocky tidepools.
Introduction Shallow nearshore and estuarine areas can be important habitats for many species of marine teleosts (e.g. Weinstein, 1979; Lenanton, 1982; Robertson & Duke, 1987). Such habitats may provide protection from predators, abundant food and suitable conditions for development (Kneib, 1987; Morton et al., 1987; Lankford & Targett, 1994). Vast expanses of estuarine and sheltered oceanic shore areas are mud and sandflats, characterized by barely perceptible slope and large tidal variations. In most of these areas, the whole substratum is exposed at low tide, with water remaining only in isolated pools and deeper channel areas. As the shallow-water areas of high and low tides are often very long distances apart, small fishes exploiting this zone would need to move long distances to remain in shallow water (Blaber et al., 1985). Alternatively, these fishes may stay in the intertidal zone during low tide by either burying themselves in the substratum,
associating with burrowing invertebrates, withstanding air exposure or inhabiting tidepools (Gibson, 1982, 1988; Martin, 1995). On sandy or muddy shores, tidepools may be naturally occurring depressions or they may be created by elasmobranch rays (Gregory et al., 1979) or human disturbance (such as bait collection). These soft-substrata tidepools may last for several days, months or even years, depending on the flow characteristics of the substrata (Gregory et al., 1979). Fishes present in large (>5 m2), soft-substrata tidepools have been well documented (e.g. Anderson et al., 1977; Crabtree & Dean, 1982; Russell & Garrett, 1983; van der Veer & Bergman, 1986; Blaber et al., 1985, 1992; Crowley & Tibbetts, 1996). However, large areas of intertidal mudflats and sandflats have small tidepools (8 h); Me, medium emersion (4–8 h); Lo, low emersion (8 h); Me, medium emersion (4–8 h); Lo, low emersion (
