Species Diversity and Distribution of Macroalgae at Ao Yang Bay, Chanthaburi Province

Abstract

Diversity and distribution research of seaweed at Ao Yang Bay, Chanthaburi Province was conducted 6 times in June, August and October 2018 and January, February and March 2019. The physical factor such as temperature, pH, dissolved oxygen, light intensity, salinity and depth was also measured. Sampling design was divided into 3 stations in left hand side near the coral reef, in the middle of Nomsao Island near the rocky shore and right hand side near the rocky shore and sand beach. Sample collection of seaweed was conducted and studied percentage of cover area was recorded by photos of seaweed in the field study by using quadrate 1x1 m. Samples were identified by book guide and key of seaweed. The result found that seaweed was belonged to 10 family 15 genera and 22 species. The composition of seaweed was comprised 11 Rhodophyta, 10 Phaeophyta and 3 Chlorophyta. At high tide only one type of seaweed was found, Enteromorphaprolofera. Thirteen generas and seventeen species were found at intertidal zone. The dominance species was Gelidiumpusilum. While at low tide was found 2 generas and 5 species of seaweed. Furthermore, the result also found that density of seaweed was difference in each season (P<0.05). The density of seaweed was higher in dry season than wet season. The dominance species was Sargassumcrassifolium. The relationship between the density of seaweed with physical factor was correlated with salinity and depth (P<0.05).