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FEDERICO BETTI Distav - Università degli Studi di Genova Climate and Ecosystem change under the COP 25 perspective in Patagonia, Chile Coyhaique, 21-22 October 2019
Transcript of FEDERICO BETTI Distav - Università degli Studi di Genova · FEDERICO BETTI Distav - Università...
FEDERICO BETTIDistav - Università degli Studi di Genova
Climate and Ecosystem change under the COP 25 perspective in Patagonia, ChileCoyhaique, 21-22 October 2019
- High biomasses due to nutrient rich waters
- Complex trophic nets
- Gigantism
- Many endemic species
- Antarctic species
- Deep water emergence
CHILEAN FJORDS BENTHIC COMMUNITIES
CHILEAN FJORDS BENTHIC COMMUNITIES
Various zoological studies have been conducted on many fjord benthic taxa
(i.e. Canete et al., 1999; Mutschke & Gorny, 1999; Schmidt & Brandt, 2001;
Forsterra & Haussermann, 2003; Hromic et al., 2006; Melzer et al., 2006;Schwabe et al., 2006; Haussermann & Forsterra, 2007; Cardeans et al., 2008;Sinniger & Haussermann, 2009; Bertolino et al., 2019)
Nevertheless, a global picture of the benthic biodiversity ofthe Chilean fjords and the zonation and ecologicalrequirements of the benthic communities, is still quite missing
THE PUYUHUAPI – JACAF SYSTEM
Identify and Describe Benthic Assemblages in the Puyuhuapi – Jacaf FjordSystem, Their Geographical Variations and Their Ecological Role
THE PUYUHUAPI – JACAF SYSTEM
Schneider et al., 2012
THE PUYUHUAPI – JACAF SYSTEM
- Understand the dynamics of the fjord ecosystems
- Obtain useful information for management and conservation of these ecosystems
- Establish a BASE LINE in an age of global change
- 59 spots explored by SCUBA diving- 0 – 30 m depth- Visual census, photographic transects,
frame photography, sampling
THE PUYUHUAPI – JACAF SYSTEM
- 220 megabenthic taxa
- Algal communities extremely poor, but Corallinalesrepresenting up to 70% of the hard bottom coverage
- 12 main biocoenoses, 9 typical of hard bottoms
IMPORTANCE OF A BASE LINE
IMPORTANCE OF A BASE LINE
JACAF
NORTH PUYUHUAPI
SOUTH PUYUHUAPI
JACAF NORTH PUYUHUAPI SOUTH PUYUHUAPI
HARD SUBSTRATES ANIMAL COVERAGE75 OTUs
126 OTUs
106 OTUs
IMPORTANCE OF A BASE LINE
Passive zooplankton filter-feeders
IMPORTANCE OF A BASE LINE
Active filter-feeders
IMPORTANCE OF A BASE LINE
Passive filter-feeders
IMPORTANCE OF A BASE LINE
Large particles passive filter-feeders
WHAT TO EXPECT
i) Climate changes are proved to alter the freshwater discharge of large riversRecent studies highlighted a historical declining trend in precipitation and streamflows in northern fjords
(up to 48° S)(i.e. Lara et al., 2008; Iriarte et al., 2016; Garreaud, 2018)
Depth reduction of surface layer Decrease in nutrient input
- Homogenization of shallow and deep communities
- Shrinkage of bathymetric range of species typical of surface layer, and emergence of deeper species
- Reduction of PP
- Increase in non-Corallinales macroalgae
- Breakage of the fresh water / oceanic water balance
Benthic shift of Jacaf communities towards«North Puyuhuapi communities»:
WHAT TO EXPECT
Reduction of large particles passive filter feeders(i.e. Holothuroidea)
Increase of medium particles active filter feeders (i.e. Bivalvia) and their predators (i.e. Asteroidea)
Puyuhuapi – Jacaf as sentinel area
WHAT TO EXPECTTARGET SPECIES
WHAT TO EXPECT
ii) The Chilean fjords host many Antarctic species, at the northern reach of their geographical distribution , and species adapted to cold waters
Global warming may have severe impact on many Antarctic species;CWCs are known to be threatened by water warming and subsequent oxygen reduction
(i.e. Jantzen et al., 2013)
TARGET SPECIES
Northern species might take advantage of the more suitable conditions and the lack of colder water species: ecosystem repercussions
WHAT TO EXPECT
Since the effects of global warming are threatening the Chilean fjords benthic communities, is important to
reduce the stress levels on the organisms, by an accurate management of the other sources of anthropic
impacts, such ad fishery and aquaculture
