Contrasting effects of microhabitat use on large-scale adult abundance in two families of Caribbean reef fishes

The degree to which species partition resources often depends on the spatial scale of the study. To investigate this, we examined the distribution and abundance patterns of 3 relatively rare pygmy angelfishes (family Pomacanthidae: Centropyge) among reef locations, depths and microhabitats at Lizard Island on the Great Barrier Reef. A strong association among species and between species and their habitat was found at some scales, but not others. On a broad scale, the abundances of the 3 species were highest at the same 4 sites (kilometres apart). These sites were all located at headlands, suggesting that the patterns of abundance may be in response to the topographic features of the island at this scale. Differences among species occurred at intermediate scales (10s to 100s of metres), where species were associated with different depth zones or reef locations. Centropyge vroliki occurred shallower than C. bicolor, while the depth distribution of C. bispinosa overlapped with both of these species. Laterally along the fringing reef, C. vroliki were more abundant in areas where both C. bicolor and C. bispinosa were also abundant, but these 2 latter species were not correlated with each other. The proportions of substratum types present in home patches differed among species, to some extent reflecting the benthic composition of the reef area where each occurred. However on a fine scale (metres), all 3 species appeared to use the same substratum type, which consisted of dead branching coral covered in algae, and occasionally formed multi-species groups. Species abundances were not correlated with this commonly used microhabitat, but rather the availability of the substrata characterizing the reef areas in which they were most abundant. Here, although Centropyge species use the same type of microhabitat, they may be an example of species that partition space on the basis of non-preferred resources. For example, all 3 species used home patches containing high proportions of overgrown corals; however where this habitat was not available, C. bicolor used sand and rubble habitat at the reef base, while C. vroliki used coral habitat on the reef crest. Most importantly, this study emphasizes that a multi-scale approach is necessary to determine appropriate scales for examining species associations and resource partitioning in reef fishes.

Section: Discussioncontrasting

confidence: 50%

A multi-scale study of the relationships between habitat use and the distribution and abundance patterns of three coral reef angelfishes (Pomacanthidae)

Eagle¹,

Jones²,

McCormick³

2001

“…For example, Tolimieri (1998a) showed that large-scale patterns of adult abundance in a parrotfish and 4 damselfishes were related to patterns of microhabitat availability. For the damselfish Stegastes dorsopunicans, 84% of the among-reef variance was explained by availability of preferred microhabitats.…”

Section: Discussionmentioning

confidence: 99%

“…While the literature is replete with studies of fish-habitat associations, most of these studies are conducted at a single spatial scale. Thus the degree to which among-reef patterns of abundance are predicted by among-reef variability in the amount of appropriate microhabitat is largely unknown (but see Tolimieri 1995, 1998a,b, Caselle & Warner 1996.…”

Section: Introductionmentioning

confidence: 99%

Fish-seaweed association on temperate reefs: do small-scale experiments predict large-scale patterns?

Levin¹,

Hay²

2002

Processes affecting reef fish populations are likely to vary with spatial scale, but there have been few attempts to determine whether predictions generated by small-scale experiments are manifested at larger spatial scales. Our goal in this study was to determine if patterns of microhabitat use measured in small-scale experimental manipulations scaled-up and allowed predictions of among-reef patterns of abundance across larger spatial scales. Manipulations of algal biomass in artificially created 1.5 m 2 plots indicated that patches of Sargassum filipendula supported greater numbers of slippery dick Halichoeres bivittatus than those with an equal biomass of Zonaria tournefortii, or than patches with an equal mix of S. filipendula and Z. tournefortii. Scaling up and manipulating S. filipendula and Z. tournefortii abundance in 100 m 2 sections of reef produced results qualitatively similar to the small-scale experiments; fish densities varied as a function of S. filipendula mass. Larger scale surveys of fish densities and algal biomass on large reefs separated by 1 to 30 km showed positive associations between fish density and S. filipendula biomass. For the reefs that we studied, our small-scale experiments scaled up and predicted large-scale patterns of abundance on reefs in the South Atlantic Bight.KEY WORDS: Reef fish · Temperate reef · Habitat structure · Macroalgae · Scale · RecruitmentResale or republication not permitted without written consent of the publisher

“…Note that this study does not attempt to provide insights into the detailed mechanisms causing the variations in fish abundances, which will be a complex combination of factors such as settlement and post-settlement habitat choices and subsequent survival (e.g. Tolimieri 1998, Schmitt et al 1999, White & Warner 2007, Shima et al 2008. We link habitat quality to adult and juvenile fishes separately because different life-phases within an ecological community may have different habitat requirements (Almany 2004a).…”

mentioning

confidence: 99%

Biotic and multi-scale abiotic controls of habitat quality: their effect on coral-reef fishes

Harborne¹,

Mumby²,

Kennedy³

et al. 2011

The influence of habitat quality on a species' demographics is critical for understanding its ecology and effective conservation. However, quantifying habitat quality is problematic because it may comprise of abiotic components at different spatial scales and also be influenced by biotic processes. This study investigated the relationship between reef-associated Caribbean fishes and habitat quality at 2 spatial scales: (1) multiple characteristics of Montastraea annularis coral colonies (<1 m 2 ) and (2) coral density in a 5 × 5 m plot around each microhabitat. Furthermore, the influence on habitat quality of 2 biotic factors (predation pressure and interactions between competitively superior territorial damselfishes and other species) was considered. A total of 102 M. annularis colonies within thirty 25 m 2 plots were surveyed on a Belizean forereef. Generalised linear mixed-effect models demonstrated that both damselfishes and other reefassociated species were correlated with colony-scale habitat quality (more abundant on taller, refuge-rich colonies). Adult reef-associated species were also correlated with larger-scale habitat quality, being more abundant on colonies with high densities of other Montastraea colonies within 25 m 2 (probably higher quality home ranges). However, the presence of damselfishes was associated with reduced abundances of other reef-associated species on M. annularis colonies, reflecting the importance of both biotic and abiotic controls of habitat quality. On reefs, coral mortality will reduce the density of optimal colonies and potentially increase the proportion occupied by damselfishes. This may lead to smaller populations of inferior competitors as they are increasingly displaced onto sub-optimal microhabitats. KEY WORDS:Anthropogenic stress · Community ecology · Ecosystem degradation · Fish behaviour · Fish recruitment 437: 201-214, 2011 202 est threat to the survival of species worldwide (Barbault & Sastrapradja 1995). Resale or republication not permitted without written consent of the publisherMar Ecol Prog SerCoral-reef fishes represent an excellent model system for investigating the controls of habitat quality. Reef fishes are diverse, relatively easy to census, and many species are closely associated with benthic communities that provide them with spatially variable resources at a range of scales. For example, coral growth and bioerosion creates small-scale crevices that are critical for most reef-associated fishes (Hixon & Beets 1993), and corals providing such refuges support higher abundances of fishes (Holbrook et al. 2002). These refuges provide foraging, spawning, and nesting sites (Robertson & Sheldon 1979), can help fishes maintain themselves in high-flow environments (Johansen et al. 2008), and sheltering in refuges reduces the high risk of predation on reefs (Hixon 1991). Loss of this scale of complexity, from stressors such as bleaching and hurricanes, has been demonstrated to have dramatic effects on reef-associated species (Jones & Syms 1998, Wil...