Pelagic-benthic coupling in organic matter utilization: the contribution of bacterial communities and benthic suspension feeders to carbon cycling in the Puyuhuapi Fjord ecosystem (Chilean Patagonia)
1. Main oceanographic characteristics of Patagonian fjords The Chilean Patagonia (41°-56°S) encompasses one of the most extensive fjord regions in the world (240000 km2) with oceanographic conditions that can sustain unique ecosystems. The region is made up mainly of fjords and channels, characteriz...
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| Other Authors: | , |
| Format: | Doctoral or Postdoctoral Thesis |
| Language: | English |
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Università degli studi di Genova
2020
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| Online Access: | http://hdl.handle.net/11567/1011190 https://doi.org/10.15167/montero-reyes-paulina-andrea_phd2020-05-20 |
| Summary: | 1. Main oceanographic characteristics of Patagonian fjords The Chilean Patagonia (41°-56°S) encompasses one of the most extensive fjord regions in the world (240000 km2) with oceanographic conditions that can sustain unique ecosystems. The region is made up mainly of fjords and channels, characterized by intertangled geomorphologies where water inputs from terrestrial and marine ecosystems overlap and mix (González et al., 2013). Patagonian fjords are characterized by highly complex geomorphology and hydrographic conditions, besides strong seasonal and latitudinal patterns in precipitation, freshwater discharge, glacier coverage, and light regime (Aracena et al., 2011). These systems receive Sub-Antarctic Water (SAAW) with high loads of nitrate and phosphate from the ocean, and freshwater with high loads of silicic acid from land (Silva, 2008). The surface freshwater layer that is formed by river discharges, high precipitation and glacier melting, gradually mixes with the deeper and salty SAAW layer through estuarine circulation (Chaigneau and Pizarro, 2005; Silva et al., 2009; Schneider et al., 2014). The interplay between oceanic waters and freshwater produces a vertical and horizontal gradient in salinity, nutrients and structure of microplanktonic community, making these fjords highly heterogeneous ecosystems. In addition, this interaction allows the transport and exchange of large amounts of organic matter between terrestrial and open-ocean environments (Sievers and Silva, 2009; González et al., 2011). Patagonian fjords play an important role in biological productivity and in coastal carbon cycling (González et al., 2013; Iriarte et al., 2014). These highly productive ecosystems have a great potential in terms of transfer of food to higher trophic levels, and vertical carbon export (González et al., 2010, 2011; Montero et al., 2011, 2017a,b). Previous studies within this region have highlighted the role of light (Jacob et al., 2014), winds, low-pressure systems, and freshwater discharge in driving ... |
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