Electronic Theses and Dissertation

Gastropoda dan bivalvia merupakan biota yang dominan di ekosistem mangrove yang
dapat dijadikan indikator kesuburan suatu perairan. Penelitian ini bertujuan untuk
melihat struktur komunitas gastropoda dan bivalvia meliputi kepadatan,
keanekaragaman, keseragaman, dominansi dan pola sebaran. Penelitian ini dilakukan
dari bulan Mei sampai bulan Juli 2021. Lokasi pengambilan sampel terdiri dari 5 stasiun,
stasiun pertama terletak di gampong Deah Gelumpang, stasiun kedua terletak di
gampong Lampageu, stasiun ketiga terletak di gampong Deah Gelumpang, stasiun
keempat dan kelima terletak di gampong Lamnga. Metode penelitian yang digunakan
adalah metode random stratified sampling. Penelitian ini dilakukan dengan
menggunakan transek kuadrat yang berukuran 1m x 1m dengan tiga plot sebagai
ulangan di setiap stasiunnya. Hasil penelitian menunjukan terdapat 10 spesies
gastropoda dengan rata-rata 30,40 ind/m2
dan 2 spesies bivalvia dengan rata-rata 6
ind/m2
. Kepadatan gastropoda tertinggi terdapat pada stasiun 5 dengan spesies
Cerithidae cingulata 71,33 ind/m2
, sedangkan kepadatan bivalvia hanya terdapat pada
stasiun 2 dan tidak ditemukan pada stasiun lainnya. Indeks biologi gastropoda meliputi
keanekaragaman, keseragaman dan dominansi. Keanekaragaman tertinggi terdapat pada
stasiun 3 dengan nilai 1,99. Keseragaman tertinggi terdapat di stasiun 3 dengan nilai
0,86 dan indeks dominansi terendah terdapat pada stasiun 3 dengan nilai 0,30. Namun,
hal ini berbeda dengan bivalvia, indeks biologis bivalvia hanya terdapat pada stasiun 2
dengan nilai, keanekaragaman 0,99. Indeks keseragaman 0,99 dan indeks dominansi
0,51. Pola sebaran menunjukkan semua spesies yang telah ditemukan termasuk dalam
kategori mengelompok. Nilai C-organik tertinggi terdapat pada stasiun 5 dengan nilai
0,94 % dengan kelas tekstur lempung berpasir. Oleh karena itu, secara keseluruhan
struktur komunitas gastropoda dan bivalvia dikawasan rehabilitasi ekosistem mangrove
termasuk dalam kondisi kurang baik karna tidak banyak jenis yang ditemukan.

Kata kunci: Mangrove, Gastropoda, Bivalvia.

Gastropods and bivalves are the dominant biota in the mangrove ecosystem which can be used as indicators of the fertility of water. This study aims to examine the community structure of gastropods and bivalves including density, diversity, uniformity, dominance and distribution patterns. This research was conducted from May to July 2021. The sampling location consisted of 5 stations, the first station was located in the village of Deah Gelumpang, the second station was located in the village of Lampageu, the third station was located in the village of Deah Gelumpang, the fourth and fifth stations were located in the village of Lamnga. The research method used is a random stratified sampling method. This research was conducted using a quadratic transect measuring 1m x 1m with three plots as replicates at each station. The results showed that there were 10 species of gastropods with an average of 30.40 ind/m2 and 2 species of bivalves with an average of 6 ind/m2 . The highest gastropod density was found at station 5 with Cerithidae cingulata 71.33 ind/m2 , the density of bivalves was only found at station 2 and not found at other stations. The gastropod biology includes index diversity, uniformity and dominance. The highest diversity is found at station 3 with a value of 1.99. The highest uniformity is found at station 3 with a value of 0.86 and the lowest dominance index is found at station 3 with a value of 0.30. However, this is different from bivalves, the biological index of bivalves is only found at station 2 with a diversity value of 0.99. The uniformity index is 0.99 and the dominance index is 0.51. The pattern of distribution shows that all species that have been found is included in the group category. The highest organic C-value was found at station 5 with a value of 0.94% with a sandy clay texture class. Therefore, the overall structure of the gastropod and bivalves community in the rehabilitation area of the mangrove ecosystem is in poor condition because not many species were found. Keywords: Mangroves, Gastropods, Bivalves.