Struktur Komunitas Lamun di Perairan Pantai Prawean dan Pantai Blebak Jepara

Abstract

Kondisi lingkungan padang lamun dipengaruhi oleh salinitas, suhu, pasang surut dan substrat. Ekosistem lamun memiliki peranan penting terhadap kehidupan dan perkembangan biota lain pada laut dangkal. Pantai Prawean dan Pantai Blebak Jepara merupakan kawasan wisata yang lokasinya dekat dengan tambak dan pemukiman warga. Aktivitas yang ada di kedua lokasi dapat mempengaruhi kondisi lamun di perairan tersebut. Penelitian ini dilakukan pada tanggal 21 - 25 September 2023. Tujuan dari penelitian ini yaitu menghitung struktur komunitas lamun dengan mengkaji komposisi jenis, kerapatan, presentase tutupan, indeks keanekaragaman, indeks keseragaman, dan indeks dominasi. Lokasi penelitian dipilih menggunakan metode purposive sampling yaitu terletak pada 2 lokasi dan 2 stasiun pada setiap lokasinya. Penelitian dilakukan menggunakan metode penelitian deskriptif dengan pendekatan kuantitatif. Pengambilan data dilakukan menggunakan metode line transect quadrant. Seluruh pengamatan yang dilakukan diukur dan diamati secara langsung di lapangan secara visual. Hasil penelitian menunjukkan terdapat lima jenis lamun yang ditemukan di perairan Pantai Prawean yaitu Cymodocea rotundata, Thalassia hemprichii, Enhalus acoroides, Halodule uninervis, dan Oceana serrulata. Pantai Blebak ditemukan tiga jenis lamun yaitu C. rotundata, T. hemprichii, dan O. serrulata. Perbedaan kondisi lamun pada kedua lokasi dipengaruhi oleh parameter perairan, jenis substrat, nutrien nitrat dan fosfat. 

The environmental conditions of seagrass meadows are influenced by salinity, temperature, tides and substrate. Seagrass ecosystems have an important role in the life and development of other biota in shallow seas. Prawean Beach and Jepara Blebak Beach are tourist areas which are located close to ponds and residential areas. Activities in both locations can affect the condition of seagrasses in these waters. This research was conducted on 21 - 25 September 2023. The purpose of this study was to calculate the structure of the seagrass community by examining species composition, density, percentage cover, diversity index, uniformity index, and dominance index. The research location was selected using the method purposive sampling that is located at 2 locations and 2 stations at each location. The research was conducted using descriptive research methods with a quantitative approach. Data collection is done using the method line transect quadrant. All observations made were measured and observed directly in the field visually. The results showed that there were five types of seagrass found in the waters of Prawean Beach namely Cymodocea rotundata, Thalassia hemprichii, Enhalus acoroides, Halodule  uninervis, and Oceana serrulata. Blebak Beach found three types of seagrass there were C. rotundata, T. hemprichii, and O. serrulata. Differences in seagrass conditions at the two locations were influenced by water parameters, type of substrate, and the nutrients nitrate and phosphate found in the waters.