Seasonal Variability of Upwelling off Central-Southern Chile

Pinochet, Andre; Garces-Vargas, José; Lara, Carlos; Olguín, Francisco

doi:10.3390/rs11151737

Cited by 17 publications

(8 citation statements)

References 26 publications

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“…Sea Surface Temperature anomalies during 2015/2016 ENSO event reached˜3.5 • C (Paek et al, 2017), which suggests that temporal stability in haplotype frequencies was significantly affected by these anomalies. Changes in upwelling intensity (Aravena et al, 2014;Pinochet et al, 2019) may also influence temporal patterns of genetic structure in P. chilensis, as reported for other species such as Balanus glandula in the northwest Atlantic coast (Barshis et al, 2011).…”

Section: Discussionmentioning

confidence: 70%

Time or Space? Relative Importance of Geographic Distribution and Interannual Variation in Three Lineages of the Ascidian Pyura chilensis in the Southeast Pacific Coast

2021

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Spatial and temporal variation of environmental parameters can affect dispersal, recruitment and population persistence of marine benthic species. Studies including inter-annual comparisons of genetic structure often indicate high/moderate temporal heterogeneity in marine invertebrates, which may be a prevailing pattern. This suggests that temporal studies are necessary to understand the dynamics of marine metapopulations. In this study, we analyzed the spatio-temporal genetic structure of the ascidian Pyura chilensis, a low dispersal sessile marine species endemic from the Southeast Pacific coast and highly demanded for human consumption. We sequenced a fragment of the mitochondrial gene Cytochrome Oxidase I (COI) from 1,005 individuals of six locations (30–40 individuals per site and year) spanning a wide latitudinal range (24°–42°S) and sampled over 5 years (2012, 2014, 2015, 2016, and 2017). The genetic structure of COI indicates the presence of three monophyletic lineages (haplogroups 1–3) previously described for the species, being one of them highly divergent and geographically restricted (~39°S, Los Molinos). Considering the whole dataset, a picture of strong spatial differentiation but temporal stability emerged in Pyura chilensis. However, detailed studies of the two main lineages revealed important differences in the extent of spatio-temporal variation. Analyses using haplotype frequencies sorted by site and year showed that, for haplogroup 1, genetic variation was explained mainly by differences between sites, while for haplogroup 2 differences between years were prevailing. Haplogroup 3 was restricted to the most southern sites, and also showed inter-annual variability in its frequency. These results point to disparate patterns of genetic differentiation, which may reflect different adaptive scope or variation in reproductive and dispersal features and could be a response to extreme events such as El Niño (2015–2016). This work calls for caution when obtaining general trends in species clearly differentiated in lineages, and prompts instead for separate analyses of sub-specific genetic lineages whenever possible.

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Section: Discussionmentioning

confidence: 70%

Time or Space? Relative Importance of Geographic Distribution and Interannual Variation in Three Lineages of the Ascidian Pyura chilensis in the Southeast Pacific Coast

2021

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“…There is however a seasonal variation in the production of photosynthesizing organisms. The maximum of the production occurs during the austral spring, whereas the minimum during the austral autumn (e.g., Pinochet et al, 2019).…”

Section: Surface Hydrographymentioning

confidence: 99%

Ventilation and Expansion of Intermediate and Deep Waters in the Southeast Pacific During the Last Termination

Haddam

Michel

Siani

et al. 2020

Paleoceanog and Paleoclimatol

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We investigate the geometry and ventilation of the water masses within bathyal depths (~1,500 to~2,500 m) of the Southeast Pacific (SEP), inferring the lower depth limit variations of the Antarctic Intermediate Water (AAIW) since~22 kyr cal. BP. We use three cores collected at the upper limit of the Pacific deep waters, between 41°S and 49°S, and one core at a greater depth within this same water mass, at 46°S. The benthic foraminiferal assemblages and carbon and oxygen isotopes are used to show strong linkages between the timing of the deglacial Southern Ocean upwelling events and changes in the vertical extension and ventilation of the AAIW. In accordance with local/sublocal oxygen reconstructions, we propose at least three states of ventilation-AAIW vertical extension: (i) the late glacial and the Antarctic Cold Reversal (ACR): AAIW depth-limit shoals, as its formation zone moves northward; (ii) the deglaciation (excluding the ACR): the [O 2 ] enrichment of the AAIW and the dominance of benthic species Trifarina angulosa indicate ventilated AAIW, along with a deepening of its lower limit; and (iii) the Holocene: enhanced influence of the Pacific deep water at bathyal depths (1,500-2,500 m) in the SEP north of~46°S and the circumpolar deep water south of~46°S.

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“…In this region, upwelling activity is weaker and more intermittent than the sector equatorward from Concepción, which is dominated by strong seasonal upwelling (ca. 37S; Atkinson et al, 2002;Letelier et al, 2009;Pinochet et al, 2019).…”

Section: Study Regionmentioning

confidence: 99%

High dimensionality of the stability of a marine benthic ecosystem

Valdivia

Aguilera

Broitman

2020

Preprint

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Stability is a central property of complex systems and encompasses multiple dimensions such as resistance, resilience, recovery, and invariability. How these dimensions correlate among them is focus of recent ecological research; yet, empirical evidence at regional scales, at which conservation decisions are usually made, remains absent. Using a field-based manipulative experiment conducted in two marine intertidal regions, we analyse the correlations among different aspects of stability in functioning (community cover) and composition of local communities facing a press disturbance. The experiment involved the removal of the local space-dominant species for 35 months in eight sites under different environmental regimes in northern- and southern-central Chile (ca. 30°S and 40°S, respectively). After the disturbance, the magnitude of the initial responses and the recovery patterns were similar among communities dominated by different species, but varied between the functional and compositional response variables, and among four dimensions of stability. The recovery trajectories in function and composition remained mostly uncorrelated across the system. Yet, larger initial functional responses were associated with faster recovery trajectories−high functional resilience, in turn, was associated with both, high and low variability in the pattern of recovery. Finally, the compositional stability dimensions were independent from each other. The results suggest that varying community compositions can perform similar levels of functioning, which might be the result of strong compensatory dynamics among species competing for space in these communities. Knowledge of several, and sometimes orthogonal, aspects of stability is mandatory to fully describe the stability of complex ecological systems.

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Seasonal Variability of Upwelling off Central-Southern Chile

Cited by 17 publications

References 26 publications

Time or Space? Relative Importance of Geographic Distribution and Interannual Variation in Three Lineages of the Ascidian Pyura chilensis in the Southeast Pacific Coast

Time or Space? Relative Importance of Geographic Distribution and Interannual Variation in Three Lineages of the Ascidian Pyura chilensis in the Southeast Pacific Coast

Ventilation and Expansion of Intermediate and Deep Waters in the Southeast Pacific During the Last Termination

High dimensionality of the stability of a marine benthic ecosystem

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