Avaliação da diversidade, abundâncias e biomassa das macroalgas marinhas (Chlorophytas) verdes, no Farol de Inhaca, Ponta de Ouro e Praia da Costa do Sol

Abstract

Marine macroalgae are important resources for most coastal communities in Mozambique, particularly in the southern region. They are a vital component of aquatic ecosystems and play crucial roles in the dynamics and health of marine environments. The aim of this study was to assess the diversity, abundance and biomass of marine macroalgae (Chlorophyta) at Inhaca Lighthouse (Ponta Mazodwé), Ponta de Ouro and Costa do Sol Beach. The systematic sampling method with transects and 25*25cm grids perpendicular to the coastline was used in this study. Sampling was carried out in September and November 2022 at Inhaca Lighthouse, Ponta do Ouro and Costa do Sol Beach. The results revealed significant differences in the diversity, abundance and biomass of green macroalgae between Inhaca Lighthouse, Ponta de Ouro and Costa do Sol Beach, with (P = 0.0085), with a total of 5615 individuals identified, covering 30 species distributed in 10 families. The Caulerpaceae and Ulvaceae families stood out with a greater number of species compared to the other families. When analyzing the diversity indices, specifically the Shannon-Winner index, Inhaca Island presented the highest specific diversity (Shannon's H' Inhaca Island = 3.921), followed by Ponta de Ouro (3.06) and Costa do Sol Beach (Bairro dos Pescadores) (1.976). Furthermore, the distribution of macroalgae species varied among the different study sites. At the Inhaca Island Lighthouse, the species with the highest percentage of cover were Codium extricatum and Ulva rigida, both with 10.7% cover. In the coastal area of ​​Inhaca Island, the species with the highest cover were Caulepa mexicanae and Codium mozambiquense, with 17.4% cover for each. In Bairro dos Pescadores, Caulepa mexicanae and Ulva fasciata were the predominant species, with covers of 30.2% and 27.9%, respectively. In relation to biomass per square meter, Praia da Costa do Sol had a higher average biomass compared to the Inhaca Lighthouse and Ponta de Ouro. These results highlight the diversity, abundance and biomass of macroalgae in the different habitats studied, providing valuable information on the ecology of these organisms in different coastal areas(TRADUÇÃO NOSSA)