Biodiversitas Gastropoda dan Pengaruh Parameter Lingkungan terhadap Kelimpahan Gastropoda di Lahan Mangrove Silvofishery Desa Eyat Mayang, Lombok Barat

Abstract

Gastropoda merupakan hewan bertubuh lunak yang menggunakan otot perutnya untuk berjalan. Tekanan ekologis dan kondisi lingkungan seperti vegetasi mangrove dapat mempengaruhi kelimpahan gastropoda pada suatu kawasan. Desa Eyat Mayang adalah salah satu desa yang berada di Kecamatan Lembar, Kabupaten Lombok Barat yang memiliki kawasan hutan mangrove yang cukup luas, yang kemudian banyak dialihfungsikan menjadi lahan tambak intensif. Penelitian ini dilakukan untuk mengetahui biodiversitas gastropoda, kelimpahan gastropoda, dan pengaruh beberapa parameter lingkungan terhadap kelimpahan gastropoda di lahan mangrove silvofishery Desa Eyat Mayang, Kecamatan Lembar, Lombok Barat. Pengambilan sampel gastropoda dilakukan dengan metode transek kuadran pada 3 plot sampling dengan 4 kali pengulangan. Kerapatan ekosistem mangrove di lahan mangrove silvofishery Desa Eyat Mayang, Kecamatan Lembar termasuk kedalam kategori padat (>1500 ind/ha). Terdapat 7 (tujuh) famili,10 genus, dan 14 spesies, dengan kelimpahan tertinggi terdapat pada spesies Cerithidea quadrata (12 ind/m²). Sedangkan spesies Littorina brevicula, Nerita picea, dan Faunus ater memiliki nilai kelimpahan terendah, sebanyak 0,25 ind/m². Nilai indeks keanekaragaman pada ke 3 plot sampling termasuk ke dalam kategori sedang, indeks keseragaman termasuk ke dalam kategori tinggi, dan tidak terdapat spesies yang mendominasi. Parameter lingkungan berupa suhu, kerapatan mangrove, dan fraksi pasir halus memiliki pengaruh yang kuat terhadap kelimpahan gastropoda dengan nilai korelasi berkisar antara 0,5278 - 0,9999.

Gastropods are soft-bodied animals that use their abdominal muscles to walk. Ecological pressures and environmental conditions such as mangrove vegetation can affect the abundance of gastropods in an area. Eyat Mayang Village is one of the villages in Lembar Sub-district, West Lombok Regency which has a fairly large mangrove forest area, which was later converted into intensive ponds. This study was conducted to determine the biodiversity of gastropods, gastropod abundance, and the influence of several environmental parameters on gastropod abundance in mangrove silvofishery in Eyat Mayang Village, Lembar District, West Lombok. Gastropod sampling was conducted using the quadrant transect method on 3 sampling plots with 4 repetitions. The density of mangrove ecosystems in the silvofishery mangrove land of Eyat Mayang Village, Lembar District is included in the dense category (>1500 ind/ha). There are 7 (seven) families, 10 genera, and 14 species, with the highest abundance found in Cerithidea quadrata species (12 ind/m²). While the species Littorina brevicula, Nerita picea, and Faunus ater had the lowest abundance value, as much as 0.25 ind/m². The diversity index value in the 3 sampling plots is included in the medium category, the uniformity index is included in the high category, and there is no dominating species. Environmental parameters such as temperature, mangrove density, and fine sand fraction have a strong influence on gastropod abundance with correlation values ranging from 0.5278 - 0.9999.