Community structure of temperate reef fishes in kelp-dominated subtidal habitats of northern Chile

Abstract

An important aim of fish ecology is to understand and predict patterns of distribution and abundance in marine communities. Such patterns were examined at four kelp-dominated sites along the northern coast of Chile (19° through 30° S) over 1 year. Fish species richness, diversity and abundance estimates obtained via observational and destructive sampling methods were compared among sites as were habitat and environmental variables that characterised the sites; including sea water temperature below the surface, nutrients, productivity, visibility, density of macroalgae stands, and percentage cover of observed microhabitats (including understorey algae and faunal assemblages). In total, 19 fish species belonging to 14 families were observed from all sites. Species richness and diversity were highest in sites where kelp canopy was composed of two species and where kelp was densest, although only species diversity was significantly different among sites. The sites with high kelp density, in turn, sustained abundant habitat-forming species in the kelp understorey. Principal coordinate analysis indicated that the composition and structure of the fish assemblages varied significantly with depth at all study sites. The depth distribution of fishes was correlated with the arrangement of site-specific biological microhabitats, defined by the algae or invertebrate species that form the microhabitat. Temperature, productivity, and nutrients did not vary consistently across study sites, but did vary within individual sites. We suggest that kelp cover and composition strongly affects the diversity and distribution of fishes at shallow coastal habitats in northern Chile through the availability of microhabitats.

Subtidal reef fish and macrobenthic community structure at the temperate Juan Fernandez Archipelago, Chile

“…In northern (~18-30ºS) Chile (only 650 km east of our study sites), pomacentrids, haemulids, and cheilodactylids dominate the fish assemblages (Angel & Ojeda, 2001;Pérez-Matus et al, 2007), and similar families dominate the Peruvian coasts (~12ºS) (Gárate & Pacheco, 2004), while notothenids dominate the southern Chilean (~50ºS) fish faunas (Moreno & Jara, 1984). At the Galápagos Archipelago (Jennings et al, 1994), three western Pacific temperate families (Pomacentridae, Labridae, and Serranidae) dominate the assemblages, although biogeographical differences occur within the archipelago (Edgar et al, 2004).…”

“…The ability of Dictyota to deter herbivores (Clerck et al, 2006) may explain the high abundance of this genus at our study sites. Additionally benthic algae may host numerous amphipods, isopods and gastropods, providing a trophic link to predatory fishes (Pérez-Matus et al, 2007). As with many coastal reef fish assemblages, invertebrate consumers of this epifauna dominate the fish assemblage at Juan Fernández.…”

Nest building and description of parental care behavior in a temperate reef fish, Chromis crusma (Pisces: Pomacentridae)

“…To our knowledge, this is the first study which describes parental care carried out by a pomacentrid temperate reef fish in the southeastern Pacific. C. crusma is abundant within the reef system (Pérez-Matus et al 2007). Modes of parental care have co-evolved in many taxa, and comparative information about young survivorship from different modes of reproduction is needed.…”

“…Along the central Chilean coast, individuals are usually found in rock outcrops within depths of between 5 and 35 m and reef areas dominated by large brown macroalgae where they recruit (i.e., Lessonia trabeculata). Adults can reach up to 25 cm in total length (TL) and are often seen in large schools (up to 100 individuals) (Pérez-Matus et al 2007). The diet of C. crusma is comprised mainly of planktonic species (Angel and Ojeda 2001).…”

Initial assessment of coastal benthic communities in the Marine Parks at Robinson Crusoe Island

“…Coastal fish richness and abundances were measured through visual and photographic samples following a methodology previously used on Robinson Crusoe (see Ramírez et al, 2013) and continental Chile (see Pérez-Matus et al, 2007). Identification and size structure of fish species were carried out in 2 m on each side of the 50 m transects and 5 m in front of the diver.…”