Subtidal macrozoobenthos communities from northern Chile during and post El Niño 1997–1998

Abstract

Despite a large amount of climatic and oceanographic information dealing with the recurring climate phenomenon El Niño (EN) and its well known impact on diversity of marine benthic communities, most published data are rather descriptive and consequently our understanding of the underlying mechanisms and processes that drive community structure during EN are still very scarce. In this study, we address two questions on the effects of EN on macrozoobenthic communities: (1) how does EN affect species diversity of the communities in northern Chile? and (2) is EN a phenomenon that restarts community assembling processes by affecting species interactions in northern Chile? To answer these questions, we compared species diversity and co-occurrence patterns of soft-bottoms macrozoobenthos communities from the continental shelf off northern Chile during (March 1998) and after (September 1998) the strong EN event 1997-1998. The methods used varied from species diversity and species cooccurrence analyses to multivariate ordination methods. Our results indicate that EN positively affects diversity of macrozoobenthos communities in the study area, increasing the species richness and diversity and decreasing the species dominance. EN represents a strong disturbance that affects species interactions that rule the species assembling processes in shallow-water, sea-bottom environments.

Functional diversity of marine macrobenthic communities from sublittoral soft-sediment habitats off northern Chile

“…A very similar community composition has been reported at different locations within the bay (e.g., Laudien et al 2007) and elsewhere in the northern of Chile coast (e.g., Quiroga et al 1999;Carrasco 1997;Carrasco and Moreno 2006;Moreno et al 2008); thus, our study can be considered representative of sublittoral sediments of this geographic region. Thirty-six species from all phyla were recorded in the shallow normoxic habitat, while in the deep hypoxic habitat eleven species were registered, representing mainly Polychaeta (Table 3).…”

“…The Humboldt Current system is subject to the occurrence of El Niño Southern Oscillation, which can induce either drastic or subtle changes in soft-bottom benthic diversity and community structure (Arntz et al 2006). For hypoxic habitats off central Peru and northern Chile taxa, diversity tends to increase during El Niño events, as a result of improved conditions brought about by increments of dissolved oxygen and temperature (Tarazona et al 1988a(Tarazona et al , b, 1996Moreno et al 2008). These diversity changes are thought to be a consequence of ecological succession to more mature stages (Tarazona et al 1988a(Tarazona et al , b, 1996Thatje et al 2008).…”

Seasonal variability of emerging invertebrate assemblages in a sheltered soft-bottom sublittoral habitat

“…For example, time series studies reveal significant increases in species richness, biomass, and abundance of dominant pelagic (defined broadly here to include all water column environments) copepods coupled with the seasonal intensification of upwelling during the transition from spring-summer to autumn-winter months (Escribano et al, 2012;Hidalgo et al, 2010). In contrast to the pelagic realm, timeseries analyses and experimental studies of soft-bottom macrobenthic invertebrate assemblages suggest that fluctuations in diversity, biomass, and structure are not necessarily in phase with the seasonal variation and/or upwelling intensity (Carrasco, 1997;Carrasco and Moreno, 2006;Laudien et al, 2007;Moreno et al, 2008;Pacheco et al, 2010). In fact, inter-annual fluctuations drive the strongest temporal variation in benthos, notably El Niño-Southern Oscillation and inter-decadal oscillations (Gutiérrez et al, 2008;Pacheco et al, 2012a).…”

Climate variability and El Niño Southern Oscillation: implications for natural coastal resources and management

“…Information from recent moderate and strong EN events (e.g. 1982/1983, 1987/1988, 1991-1993, 1997/1998) as well as LN events (like the strong and longer than usual 1998-2001 event) demonstrated diVerences in the resilience potential of coastal communities Moreno et al 2008). Owing to the high concentration of nutrients, the Humboldt Current upwelling system is the most productive marine ecosystem of the world.…”