Water quality and phytoplankton community structure in mangrove streams under different logging regimes in C ameroon

• Published in: African journal of ecology 2016-03, Vol.54 (1), p.39-48
• Main Authors: Fonge, Ambo Beatrice, Tabot, Pascal Tabi, Mumbang, Coleen, Mange, Chop Adeline
• Format: Article
• Language: English
• ISSN: 0141-6707; 1365-2028
• DOI: 10.1111/aje.12256

Mangrove logging is rampant, and its effects on phytoplankton dynamics have not been investigated. Phytoplankton are valuable in biomonitoring pollution in mangrove ecosystems. This study assessed the relationship between physico‐chemical characteristics of the water and observed phytoplankton community structure, in relation to anthropogenic activities. Water samples were collected from seven sites within the mangrove ecosystem that differed in wood harvesting age and proximity to human settlements. Characterization of samples followed standard methods. pH of all water samples indicated acidity. Phytoplankton species richness and soluble P were positively correlated (r = 0.822, P  ≤ 0.023), but no correlations existed with logging age (r = −0.273, P  = 0553). The site with highest soluble phosphorus concentration (Site 4) had highest phytoplankton abundance, diversity and richness. A total of 127 species were identified in 58 families. Euglenaceae was the most abundant family (13 species) and Anacystis sp. the most frequent species (100%). The most common genera were Microcystis and Anacystis, bioindicators of pollution. The site at which harvesting was most recently performed had more eutrophic species, while site harvested earliest (Site 5) had the least. These results are discussed with respect to how anthropogenic activities influence water quality, phytoplankton community structure, mangrove conservation and management. Les coupes d'arbres dans les mangroves sont un phénomène rampant et leurs effets sur la dynamique du phytoplancton n'ont pas été étudiés. Le phytoplancton est intéressant dans le bio‐monitoring de la pollution dans les écosystèmes de mangroves. Cette étude a évalué la relation entre diverses caractéristiques physico‐chimiques de l'eau et observé la structure de la communauté de phytoplancton en lien avec des activités anthropiques. Nous avons collecté des échantillons d'eau sur sept sites de l'écosystème de mangrove qui différaient par l'ancienneté de la collecte et la proximité d'installations humaines. La caractérisation des échantillons suivait les méthodes standard. Le pH de tous les échantillons d'eau indique de l'acidité. La richesse en espèces du phytoplancton et le P soluble étaient liés positivement (r = 0.822, P  ≤ 0.023), mais il n'y avait pas de corrélation entre l'âge à la coupe (r = −0.273, P  = 0.553). Le site avec la plus forte concentration en phosphore soluble (Site 4) avait les plus grandes abondance, diversité et r