Keanekaragaman Kerang (Bivalvia) di Perairan Pantai Sei Nipah Indah Kecamatan Pantai Cermin Kabupaten serdang Bedagai Sumatera Utara

Abstract

Sei Nipah Indah beach is an area that has a water zone whose area is located between the lowest and highest tides. Sei Nipah Indah beach has a coastline of ± 6 km. Along the coastline of Sei Nipah Indah various types of benthic organisms from the class Bivalvia are found. Shellfish is one of several aquatic biota in the coastal waters of Sei Nipah Indah. In addition, shells also as source of food and has economic for people around Sei Naga Lawan village. The study aims to analyze the bivalves community structure and the relationship between the structure and physicochemical factors. This research was conducted in Sei Nipah Indah Coastel Waters in June-July 2021. The sampling of location was determined using purposive sampling method at 3 stations. While bivalves were collected at 9 different points per station. The results obtained were 6 species of bivalves, namely Perna viridis, Anadara antiquata, Anadara gubernaculum, Meretris lusoria, Polymesoda erossa and Phapia undulata. Species densities ranged from 5,6-8,8 ind/m². Diversity index ranged from 0,34-0,39 considered as the low category. Uniformity index ranged from 0,18-1,79 which was categorized as relatively uniform. The correlation value between the bivalve diversity index and the physical and chemical factors of depth, salinity and C-Organic was very strong. The correlation analysis value of BOD₅ and phosphate was strong. The analysis value of pH and nitrat was low and the correlation analysis value of water temperature, brightness and DO was lowest.

Pantai Sei Nipah Indah merupakan daerah yang yang memiliki pasang surut terendah dan pasang surut tertinggi. Pantai Sei Nipah Indah memiliki panjang garis pantai ± 6 km. Disepanjang garis Pantai Sei Nipah Indah banyak ditemukan berbagai macam jenis organisme bentik dari kelas Bivalvia. Kerang merupakan satu diantara beberapa biota air yang hidup di Perairan Pantai Sei Nipah Indah. Kerang juga merupakan bagian dari mata pencaharian masyarakat sekitar desa Sei Naga Lawan karena memiliki nilai ekonomi yang tinggi sehingga dilakukan penangkapan oleh masyarakat. Penelitian ini bertujuan untuk menganalisis struktur komunitas bivalvia dan hubungan faktor fisik-kimianya. Penelitian ini dilakukan di Perairan Pantai Sei Nipah Indah pada bulah Juni-Juli 2021. Penentuan lokasi pengambilan sampel menggunakan metode purposive sampling pada 3 stasiun. Pengambilan bivalvia pada 9 titik setiap stasiun. Hasil penelitian yang didapatkan adalah 6 spesies bivalvia yaitu Perna viridis, Anadara antiquata, Anadara gubernaculum, Meretrix lusoria, Polymesoda erosa dan Phapia undulata. Kepadatan berkisar antara 5,6-8,8 ind/m². Indeks keanekaragaman berkisar 0,34-0,39 termasuk kategori rendah. Indeks keseragaman berkisar 0,18- 1,79 dengan kategori setiap spesies relatif merata. Nilai korelasi antara indeks keanekaragaman bivalvia dan faktor fisik-kimia perairan kedalaman, salinitas dan C-Organik tergolong sangat kuat. Nilai analisis korelasi BOD₅ dan fosfat tergolong kuat. Nilai analisis ph dan nitrat tergolong rendah dan nilai analisis korelasi suhu, kecerahan dan DO tergolong sangat rendah.