Keanekaragaman Bivalvia di Pesisir Utara Kabupaten Lamongan

Diversity of Bivalvia in the North Coast of Lamongan

Keanekaragaman hayati di perairan Indonesia sangat melimpah, salah satunya adalah bivalvia. Penelitian ini bertujuan untuk menganalisis keanekaragaman, kelimpahan, keseragaman dan dominansi  bivalvia, serta profil habitat bivalvia di Pesisir Utara Kabupaten Lamongan. Pengambilan sampel bivalvia dilakukan di Pantai Kutang dan Pantai Joko Mursodo. Setiap pantai ditetapkan 3 stasiun yang terdiri atas 3 substasiun. Di setiap substasiun ditetapkan plot 5 m × 5 m. Pada plot tersebut terdapat subplot ukuran 1 m × 1 m di lima titik. Profil habitat yang dikaji adalah suhu, pH, salinitas, kekeruhan dan tipe substrat. Bivalvia diidentifikasi menggunakan buku Dharma (2005), Poutiers (1998), dan website database World Register of Marine Species (WoRMS) (2022). Data hasil penelitian dianalisis secara deskriptif kualitatif. Hasil penelitian menunjukkan bahwa bivalvia yang ditemukan di Pesisir Utara Kabupaten Lamongan meliputi  Marcia hiantina, M. cordata, M. carneola, Meretrix sp., Gafrarium pectinatum, Venerupis aspera, Protapes sp., Pitar erubescens, Donax faba, Anadara antiquata, Psammacoma gubernaculum, Vasticardium elongatum, Heterocardia gibbosula, Gari elongate, dan Asaphis violascens Nilai indeks keanekaragaman bivalvia di Pantai Kutang berkisar 1,13–2,201 dan di Pantai Joko Mursodo sebesar 1,685–1,903. Nilai kepadatan bivalvia di Pesisir Pantai Utara Kabupaten Lamongan sebesar 23,7 dan 2,15. Indeks keseragaman bivalvia di Pesisir Pantai Utara Kabupaten Lamongan sebesar 0,429–0,721. Indeks dominansi bivalvia di Pesisir Pantai Utara Kabupaten Lamongan sebesar 0,274–0,489. Profil habitat bivalvia di Pesisir Utara Lamongan adalah suhu 29,3-31,7 ºC, salinitas 25-32 ppt, pH 7,59-8,18, kekeruhan 10,6-17,3 NTU dan tipe substrat dominan lumpur berpasir. Bivalvia lebih banyak ditemukan di pantai yang bermangrove lebat.

Biodiversity in Indonesian waters is very abundant, one of which is bivalves. This study aimed to analyze the diversity, abundance, uniformity and dominance of bivalves, as well as the habitat profile of bivalves in the North Coast of Lamongan. Bivalves sampling was carried out at Kutang Beach and Joko Mursodo Beach. There were 3 research stations consisting 3 sub-station in each beach. At each substation, It was taken plot of 5 m × 5 m. Each plot contained five subplot of 1 m × 1 m. The habitat profiles studied were temperature, pH, salinity, turbidity and the type of substrate. Bivalves were identified using the book Dharma (2005), Poutiers (1998), and the World Register of Marine Species (WoRMS) database website (2022). The research were analyzed descriptive qualitatively. The results showed that the bivalves found in the North Coast of Lamongan included Marcia hiantina, M. cordata, M. carneola, Meretrix sp., Gafrarium pectinatum, Venerupis aspera, Protapes sp., Pitar erubescens, Donax faba, Anadara antiquata, Psammacoma gubernaculum, Vasticardium elongatum, Heterocardia gibbosula, Gari elongate, dan Asaphis violascens. The index value of bivalves diversity at Kutang Beach was 1,13 – 2,201 and at Joko Mursodo Beach was 1,685 – 1,903. The density of bivalves values on the North Coast of Lamongan are 23,7 and 2,15. Bivalves uniformity index in the North Coast of Lamongan was 0,429–0,721. Bivalves dominance index in the North Coast of Lamongan is 0,274–0,489. The habitat profile of the bivalves in the North Coast of Lamongan is temperature 29,3-31,7 C, salinity 25-32 ppt, pH 7,59-8,18, turbidity 10,6-17,3 NTU and the dominant type of substrate is sandy mud. Bivalves are more commonly found on beaches with dense mangroves.