Primary production and plankton dynamics in the Reloncaví Fjord and the Interior Sea of Chiloé, Northern Patagonia, Chile

González, Humberto E.; Calderón, M. J.; Castro, L. R.; Clément, Alejandro; Cuevas, L. Antonio; Daneri, Giovanni; Iriarte, J. L.; Lizárraga, Lorena; Martínez, Rodrigo Andrés; Menschel, Eduardo; Silva, N.; Carrasco, Cristian Alberto Ojeda; Valenzuela, C.; Vargas, Cristian A.; Molinet, Carlos

doi:10.3354/meps08360

Cited by 115 publications

(88 citation statements)

References 65 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Our average POC concentrations in the upper 25 m of the water column (248 mg C m ; González et al 2010). The composition of POC being on average half allochthonous and half autochthonous, the latter predominated by phytoplankton, suggests a classical spring food web in our study area.…”

Section: Particulate and Dissolved Organic Mattermentioning

confidence: 99%

Carbon flow through the pelagic food web in southern Chilean Patagonia: relevance of Euphausia vallentini as a key species

González¹,

Graeve²,

Kattner³

et al. 2016

Mar. Ecol. Prog. Ser.

Self Cite

View full text Add to dashboard Cite

The southernmost Patagonian region constitutes a major glaciered area with a high freshwater input loaded with particulate and dissolved matter. We assessed the relevance of the terrestrial (allochthonous) and marine (autochthonous) matter that permeates into the fjord and channel system and their possible impact on the euphausiid-based food web. A research cruise (CIMAR 16) was conducted from 18 October to 13 November 2010 (austral spring) in the area between Magellan Strait and Drake Passage to study the physical-chemical and biological characteristics of the pelagic food web, as well as the main biological processes linked with the food web. The dominance of phytoplankton within the autochthonous fractions of particulate organic carbon (POC) and the high abundance and bacterivory rate shown by the heterotrophic nanoflagellates suggest an interplay between microbial and classical food webs. Euphausia vallentini showed a moderate grazing impact (3% of the gross primary production) and a daily ration of 18.6%, and the fecal pellet production rate corresponded to 24.5% of the ingestion rate. This species removed heterotrophic prey (67.5%) preferentially over diatoms (32.5%), and the ingested diet was mainly dinoflagellates, tintinnids, crustacean nauplii and centric diatoms. Overall, euphausiids fed preferentially on marine matter, which showed a tight link with the pelagic food web. Congeneric species of the genus Euphausia shared the condition of 'key species' as they constitute a major carbon and energy flow from lower to higher trophic levels and an important part of the POC flux through their active vertical migration and passive fecal-carbon export. KEY WORDS: Chilean Patagonia · Euphausia vallentini · Pelagic carbon flux · Euphausiid dietResale or republication not permitted without written consent of the publisher

show abstract

Section: Particulate and Dissolved Organic Mattermentioning

confidence: 99%

Carbon flow through the pelagic food web in southern Chilean Patagonia: relevance of Euphausia vallentini as a key species

González¹,

Graeve²,

Kattner³

et al. 2016

Mar. Ecol. Prog. Ser.

Self Cite

View full text Add to dashboard Cite

show abstract

“…In Chilean fjords ecosystems, diatoms are known to represent a significant component of the overall phytoplankton biomass (Iriarte et al, 2001;Cassis et al, 2002;Alves-de-Souza et al, 2008;Iriarte & González, 2008). In addition to efficiently transferring energy to higher trophic levels, diatoms make a significant contribution to the downward transfer of organic carbon (Iriarte et al, 2007;González et al, 2010;Montero et al, 2011;Iriarte et al 2013). Diatoms occur in highest abundance during the Patagonian fjord spring bloom, and are generally dominated by Skeletonema spp.…”

Section: __________________mentioning

confidence: 99%

Diatom blooms and primary production in a channel ecosystem of central Patagonia

Montero

Daneri

Tapia

et al. 2017

lajar

View full text Add to dashboard Cite

ABSTRACT.Here we report on the seasonal productivity cycle at a fixed station in the Puyuhuapi Channel (44ºS, 73ºW), Chilean Patagonia. The analysis of in situ water column data and longer-term records of satellitederived surface ocean color (Chl-a) highlighted two contrasting seasons. A more productive period occurred between August and April, where depth-integrated gross primary production (GPP) estimates ranged from 0.1 to 2.9 g C m -2 d -1, and a shorter, less-productive season lasted from May to July with GPP ranging from 0.03 to. Diatoms of the genera Pseudo-nitzschia, Skeletonema and Chaetoceros dominated the phytoplankton, and showed a pronounced seasonality greatly influenced by prevailing environmental conditions. Warmer waters were associated with high concentrations of Pseudo-nitzschia spp., while high abundances of Skeletonema spp. and Chaetoceros spp. were associated with fresher silicate-rich waters. A marked Skeletonema spp. bloom characterized the onset of the productive season in August 2008, and with some exceptions, the highest levels of GPP (1.5 to 2.9 g C m -2 d -1) were measured when Skeletonema dominated the phytoplankton community. Reduced production (low GPP) was observed during periods of increased discharge from the Cisnes River, whereas the "spring" diatom bloom (or late winter bloom in Puyuhuapi Channel) observed during August 2008 coincided with a ~50% drop in the freshwater discharge. We therefore suggest that periods of intensive freshwater Input, that increase the silicic acid concentrations in the upper layers, provide ideal growing conditions for diatoms as the freshwater flow subsequently recedes. Principal component analysis (PCA) suggests that a decrease in salinity, increase in silicic acid concentration, and growth of Skeletonema spp. and Chaetoceros spp., are probably key factors in the annual cycle of GPP in Puyuhuapi Channel.

show abstract

“…This ecosystem is greatly influenced by rivers and the Patagonian Ice Fields (Pickard, 1971) and supports high rates of biological productivity and vertical export fluxes of carbon (Pantoja et al, 2005;González et al, 2010González et al, , 2011González et al, , 2013Montero et al, 2011Montero et al, , 2017a. The Patagonian fjord ecosystem as a whole is considered to represent a net sink of CO 2 (Torres et al, 2011;González et al, 2013) and of enhanced sedimentary burial of organic carbon (Sepúlveda et al, 2011;Smith et al, 2015).…”

Section: Introductionmentioning

confidence: 99%

Linking Seasonal Reduction of Microbial Diversity to Increase in Winter Temperature of Waters of a Chilean Patagonia Fjord

et al. 2018

View full text Add to dashboard Cite

Since microorganisms play a major role in the biogeochemistry of the ocean, understanding structure and dynamics of natural microbial communities is crucial in assessing the impact of environmental changes on marine ecosystems. In order to identify key environmental drivers of microbial community structure in Chilean Patagonian fjords, we analyzed composition of the prokaryotic community over an annual cycle at a single sampling site in Puyuhuapi Fjord. Distinctive communities represented mainly by Actinomycetales, Rhodobacteraceae, Cryomorphaceae, and Flavobacteriaceae were associated with Estuarine Fresh Waters, whereas Cenarchaeaceae and Oceanospirillales were representative of Modified Sub Antarctic Waters present in the fjord. Salinity and oxygen were first-order factors explaining segregation of microbial communities in these contrasting water masses. Positive correlations of members of Flavobacteriaceae, Alteromonadales, and Verrucomicrobiales with diatoms in subsurface waters and of Flavobacteriales (Cryomorphaceae and Flavobacteriaceae), Rhodobacteraceae, and Pelagibacteraceae with dinoflagellates in surface waters suggest that phytoplankton composition could define specific niches for microorganisms in Puyuhuapi fjord waters. A dramatic reduction of richness and individual abundances within Flavobacteriaceae, Rhodobacteraceae, and Cenarchaeaceae families was principally explained by seasonal increase of surface water temperature, with major reduction associated with changes in temperature during winter conditions. Taxa that are sensitive to increased temperature are key components of organic matter and element cycling, and we therefore suggest that potential decrease in diversity associated with rising of surface water temperature could impact current biogeochemical status of Patagonian fjord ecosystems.

show abstract

Primary production and plankton dynamics in the Reloncaví Fjord and the Interior Sea of Chiloé, Northern Patagonia, Chile

Cited by 115 publications

References 65 publications

Carbon flow through the pelagic food web in southern Chilean Patagonia: relevance of Euphausia vallentini as a key species

Carbon flow through the pelagic food web in southern Chilean Patagonia: relevance of Euphausia vallentini as a key species

Diatom blooms and primary production in a channel ecosystem of central Patagonia

Linking Seasonal Reduction of Microbial Diversity to Increase in Winter Temperature of Waters of a Chilean Patagonia Fjord

Contact Info

Product

Resources

About