The Correlation Between Abundance of Macroalgae and Echinoderms at Sepanjang Beach, Gunung Kidul-Yogyakarta

Abstract

Macroalgae and echinoderms are biological marine resources whosE presence can be found in the intertidal zone. One of the beaches that supports the life of macroalgae and echinoderms is the Sepanjang beach. This beach is generally a rocky coastal water overgrown with various macroalgae and home to various types of echinoderms, such as the Ophiuroidea (snake stars), Echinoidea (sea urchins), and Holothuroidea (sea cucumbers) groups. The existence of tourism activities on the Sepanjang beach which is open to the public indirectly impacts macroalgae and echinoderms. Therefore, this study aims to determine the abundance and correlation between the abundance of macroalgae and echinoderms on the Sepanjang beach. The research method used a descriptive method with direct observation. Data analysis was carried out descriptively through abundance calculations and statistically through Spearman rank correlation. The study's results identified 19 macroalgae species belonging to 4 divisions with the highest abundance value, namely Chaetomorpha linum, and the lowest abundance value, namely Halimeda macroloba, Acrocystis nana, and Gracilaria arcuata. Echinoderms identified as many as nine species that belong to 2 classes, with the highest abundance of Echinometra oblonga and the lowest abundance of Echinothrix calamaris, Echinometra viridis, and Diadema setosum. The correlation between the abundance of macroalgae and echinoderms at the Sepanjang beach is in the weak category.