Distribution of the soft-bottom macroinfauna in an estuary of Southern Chile

Changes to the benthic assemblage associated with mollusc and seaweed cultivation in the Quempillén estuary, north patagonia, Chile

“…The first group formed by the stations nearest to the mouth (1 and 2) was dominated by coarse sediments (< -1 Φ) (Folk 1980) with low organic content, the second group (stations 4 and 5) covered the middle reaches of the estuary and was dominated by sand (between -1 and 4 Φ), finally the third group (3, 6 and 7 stations) at the head of the estuary dominated by sand-muddy sediments (> 4 Φ). The distribution of sediment type and organic matter within the estuary concur with that reported by Bertrán (1984Bertrán ( , 1989, Jaramillo et al (1985) and Richter (1985) for the Queule and Lingüe estuaries (Southern Chile). In those estuaries the sand fraction decreased while the mud fraction increases across the transition from marine waters to the limnetic waters.…”

“…The Cluster and the MDS analyses indicate 2 groups, with stations 1, 2 and 4 in the first group and the remaining stations in the second group (3, 5, 6 and 7 stations), representing the change in the diversity in the middle zone of the estuary. The higher Diversities and Species Richness values were found in the first group (stations 1, 2 and 4), towards the mouth of the estuary, as has been found previously by Bertrán et al 2001, Hughes & Gerdol 1997, Richter 1985, Jaramillo et al 1985, Bravo 1984. The conclusion of this study is that different anthropogenic activities change the characteristics of the macrofaunal benthos, and particularly the sediment structure and organic matter content.…”

“…Richter (1985) reported 20 species, and the BioBío estuary where, depending on the seasons of the year, between 16 and 42 species were recorded (Bertrán et al 2001). Diverse studies made in estuarine areas (Bertrán et al 2001, Hughes & Gerdol 1997, Jaramillo et al 1985, Richter 1985, Bravo 1984 have concluded that a decrease species diversity moving upstream correlates with an increase in the density of those species present. The results obtained in the present study concur with this hypotheses, there was a gradual decrease in the number of species moving from the most marine station upstream (from 20 to 12 different species).…”

“…current velocity and salinity gradient), which are generated mainly by the action of the tides (Bertrán et al 2001, Jaramillo et al 1984. The fauna inhabiting these estuaries are subjected to considerable variation in environmental factors that determine their distribution, these physical-chemical factors include temperature and salinity (Beukema 1990, Holland et al 1987, gradients in the interstitial water (Meadows & Tait 1989) and the characteristics of the sediment, including texture and organic matter content (Nichols et al 1986, Richter 1985. The aim of this study was to determine the composition and distribution patterns of subtidal macrobenthic communities inhabiting the sediment in the Quempillén estuary, and the effects of two anthropogenic sources of perturbation, mollusc and seaweed cultivation.…”

Benthic food distribution as a predictor of the spatial distribution for shorebirds in a wetland of central Chile

“…The coastal wetlands of central Chile are characterized by smooth gradients both in terms of physical properties, such as sediment grain size distributions, and biological properties, such as density of meio-and macrozoobenthic species (Kraan et al 2009, Ge et al 2011, Suazo et al 2012. Oligochaetes, polychaetes, ostracods, amphipods, and chironomids are the main taxa found in these environments (Jaramillo et al 1985, Richter 1985, Quijón & Jaramillo 1993, Torres et al 2012.…”