Data from: Breaking out of the comfort zone: El Niño-Southern Oscillation as a driver of trophic flows in a benthic consumer of the Humboldt Current ecosystem
Riascos, José M., University of Antofagasta
Solís, Marco A., University of Barcelona
Pacheco, Aldo S., University of Antofagasta
Ballesteros, Manuel, University of Barcelona
Published May 25, 2017 on Dryad.
Cite this dataset
Riascos, José M.; Solís, Marco A.; Pacheco, Aldo S.; Ballesteros, Manuel (2017). Data from: Breaking out of the comfort zone: El Niño-Southern Oscillation as a driver of trophic flows in a benthic consumer of the Humboldt Current ecosystem [Dataset]. Dryad. https://doi.org/10.5061/dryad.1436s
The trophic flow of a species is considered a characteristic trait reflecting its trophic position and function in the ecosystem and its interaction with the environment. However, climate patterns are changing and we ignore how patterns of trophic flow are being affected. In the Humboldt Current ecosystem, arguably one of the most productive marine systems, El Niño-Southern Oscillation is the main source of interannual and longer-term variability. To assess the effect of this variability on trophic flow we built a 16-year series of mass-specific somatic production rate (P/B) of the Peruvian scallop (Argopecten purpuratus), a species belonging to a former tropical fauna that thrived in this cold ecosystem. A strong increase of the P/B ratio of this species was observed during nutrient-poor, warmer water conditions typical of El Niño, owing to the massive recruitment of fast-growing juvenile scallops. Trophic ecology theory predicts that when primary production is nutrient limited, the trophic flow of organisms occupying low trophic levels should be constrained (bottom-up control). For former tropical fauna thriving in cold, productive upwelling coastal zones, a short time of low food conditions but warm waters during El Niño could be sufficient to waken their ancestral biological features and display massive proliferations.
Growth parameters of Argopecten purpuratus and associated statistics
Estimation of growth parameters of Argopecten purpuratus using the ELEFAN_SA optimization procedure implemented in TropFishR. Ncohort: is the number of yearly repeating cohorts; Agemax: maximum age of the population; L∞ L asymptotic total length; K: von Bertalanffy growth constant; t_anchor: is the fraction of the year (ranging between 0 and 1) where yearly repeating growth curves cross length equal to zero; C: is a constant indicating the amplitude of the growth oscillation; ts is the fraction of a year where the sine wave oscillation begins; Φ´: growth performance index (see eq. 3); Rn_max: maximum possible score obtained during the fitness maximization process; ASP: available sum of peaks (for details see Mildenberger et al. 2017 ). CI: confidence intervals for growth parameters calculated with the jack knife technique 
P/B ratio of Argopecten purpuratus and environmental factors
Annual changes in the production to biomass ratio of Argopecten purpuratus and environmental factors potentially affecting them
Population parameters of Argopecten purpuratus
Monthly estimation of population parameters of Argopecten purpuratus in Bahia independencia: Mean abundance (number of individuals per square meter); Individual mass (g ash-free dry mass estimated for a standard individual of 65 mm in shell length); body size (mm, mean, minimum, Q1 percentil, Q2 percentil and maximum)