Studi Kepadatan Makroalga (Sargassum polycistum) Dan (Padina australis) Berdasarkan karakteristik Sedimen di Perairan Pantai Losari Kabupaten Bone Bolango Provinsi Gorontalo

(Density study of Macroalga (Sargassum polycistum) and (Padina australis) Based on Sediment Characteristics in Losari Beach, Bone Bolango Regency, Gorontalo).

Abstract

Sediment characteristics are an ecological factor that supports the adhesion ability and density level of macroalgae in coastal areas. The study on the density of the macroalgae Sargassum polycystum and Padina Australis based on sediment characteristics was conducted at Losari Beach, Bone Bolango Regency, Gorontalo Province. The determination of the research location is based on the presence of the brown macroalgae species Sargassum polycystum and Padina Australis. There are three stations, each with three sub-stations. The determination of the density of the macroalgae S polycystum and P Australis was conducted using a 1×1 m² transect, and sediment samples were collected using a 2-inch diameter PVC pipe in the transect area. The classification of sediment grain size was done using the Wentworth classification. The research results show that the density of macroalgae is higher at each station on coarse sand (1-2 mm), with an average density of S polycistum 21 ind and P Australis 12 ind. Then, on medium sand (0.25-0.5 mm), S polycistum 18 ind and P Australis 10 ind, and on fine sand (< 0.075 - 0.18), S polycistum 8 ind and P Australis 11. This is because macroalgae tend to live on coarse/large-sized sediments as a place for their holdfasts to attach, and fine-sized sediments will hinder the process of photosynthesis. In addition, the average BOT at the 3 stations was 1.57%, indicating that the nutrient content is sufficient to support the growth of both types of maroalgae.