Ecophysiological differences between Avicennia germinans and Rhizophora harrisonii Leechm, affected by anthropic pressure, Guayaquil – Ecuador

Abstract

The concentrations of proteins and photosynthetic pigments are considered bio-indicators of the quality of mangrove trees. These are pressured by urban development, discharges from clandestine bodies of water, and atmospheric pollution. The main objective was to determine the concentrations of chlorophylls and proteins as bioindicators of the quality of two species of mangrove Rhizophora harrisonii Leechm. (Leechm, 1918) and Avicennia germinans (L) (Linnaeus 1764), which grow in the Gulf of Guayaquil - Ecuador, influenced by the Estero Salado and the Guayas River. From April 2018 – May 2019, 2,300 leaves were randomly collected from Isla Santay and Estero Salado, protected natural areas of the city. The extraction of the photosynthetic pigments was carried out by macerating the leaves with 80% acetone and proteins the Bradfor method, to later be read by spectrophotometry, at different absorbances between 470 to 664 and 595 nm, respectively. Simple one-way Anova was performed with a confidence level of 95% (p < 0.05). Chlorophyll a and b concentrations in R. harrisonii were lower than 1.0 – 1.2 ug/ml, while for A. germinans they were higher. In both species, the median is between 40-42 ug/ml of protein and the concentration ranges are higher than in A. germinans, whose median is between 40-60 ug/ml, atypical values are predominant in this last species.