Distribution patterns of Vibrionaceae abundance on the landing stages in coastal area: Understanding the influence of physicochemical variables by using multiple linear regression models and corrgram for matrix correlation

The present work used multiple linear regression (MLR) models and corrgram to assess the importance of environmental parameters on diversity and abundance dynamics of Vibrio sp. in waters of few landing stages in the city of Douala (Cameroon). It was recorded in all the five selected stations, the presence of four species of Vibrio namely, Vibrio parahaemolyticus, Vibrio cholerae, Vibrio fluvialis and Vibrio alginolyticus whose highest abundance reached 5.65, 6.26, 4.9 and 4.83 log CFU/100 ml respectively. Vibrio cholerae was the most isolated during the study with a frequency of 65%. The abundance dynamics of these germs is strongly influenced by nitrates, salinity, dissolved carbon dioxyde (CO2) and ammonium ions (NH4+). The visualization of corrgram shows high degree of association between studied parameters. We note a coefficient of determination r2 = 0.50 for the multiple linear regression model for Heterotrophic Aerobic Bacteria (HAB) and a coefficient of determination r2 = 0.58 for the MLR model for V. cholerae. The physicochemical parameters explain at 43% (r2 = 0.43) the distribution of the abundances of V. parahaemolyticus, at 45% (r2 = 0.45) the distribution of abundances of V. alginolyticus and at 26% (r2 = 0.26) for V. fluvialis.   Keywords: Multiple linear regression, visualization of corrgram, environmental parameters, distribution patterns, Vibrionaceae.