Abstract

PASACHE MEDINA, Gerardo Andrés et al. Ecological niche of Anchoa nasus “samasa” in Pisco Bay (Perú). Ecol. apl. [online]. 2023, vol.22, n.2, pp.79-90.  Epub Dec 29, 2023. ISSN 1726-2216.  http://dx.doi.org/10.21704/rea.v22i2.2084.

The objective of the present work was to determine the effects of temperature, salinity, oxygen and chlorophyll a on the relative abundance of Anchoa nasus “samasa” in the Pisco area, during the years 2011-2017. For this, biometrical samplings were carried out, oceanographic surveys and information of catches and fishery effort were collected. Relative abundance data were related to environmental factors data using Generalized Additive Models (GAM), the lower and upper limits of the ecological niche was calculated using the Integrated Nested Laplace Approximation (INLA) method. In order to identify temporal phases during the study period Principal Component Analysis, Classfication Analysis and Ordicluster between dates based on environmental variables were carried out. The ecological niche of samasa in relation to surface temperature was found between 18.15 °C and 21.56 °C, in relation to surface salinity between 34.915 and 35.070, regarding chlorophyll a presented a lower limit of 8.59 mg·m-3, and regarding dissolved oxygen presented a lower limit of 8.02 m·l-1 for surface level. Compared to other species, the ecological niche of was located in mesophilic, marine, normoxic and mesotrophic conditions.

Keywords : Anchoa nasus; samasa; ecological niche; temperature; salinity; oxygen; chlorophyll.

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