TINGKAT KEANEKARAGAMAN, DENSITAS, DAN DOMINANSI GASTROPODA DI PANTAI MIMBO SITUBONDO

Oleh: Harissudin Masrur

Gastropoda is molusca member as benthic animal. The diversity of the animals role as bioindicator of marine ecosystem. The objectives in this research is to identify the species of Gastropoda and to know the diversity, density, and dominancy in three research stations around at Mimbo beach, Situbondo district, and to know the influence of environment factors on diversity, density, and dominancy of the Gastropoda . The data collecting used plot transect method. Plot had size 1 × 1 m². There were 3 transects for every stations, located about 50 m from shoreline horizontaly into the sea. Result of the research revealed that there were five Gastropodas consisted of 277 individuals which spread in three stations. The total of Gastropoda diversity showed a middle category (H’ = 1,0289). Population density of Gastropoda was 6,1 individual/m², dominancy of Gastropoda was very low (C = 0,3154). Environment factors such as temperature, dissolved oxygen, pH, salinity, and light intensity had significant influnce on diversity and dominancy of Gastropoda, but not for its density.   

Struktur Komunitas, Kepadatan dan Pola Distribusi Populasi Lamun (Seagrass) di Pantai Plengkung Taman Nasional Alas Purwo Kabupaten Banyuwangi

Oleh: Heru Prasetyo

Seagrass is a kind of most productive ecosystm in shallow sea water and has strategic role as producers. This aim of this study is to know the community structure, density, and population distribution patterns of seagrass in Plengkung Beach District Banyuwangi. The data was collected on September 2013 using plot transect method. The size of plot that's used is 1×1 m² .The result of research have shown the kind of seagrass that found in plengkung beach, is Thalassia hemprichii, Halodule pinifolia and Cymodocea rotundata. The species have  low dominance with value C < 0,50 and have low diversity with value H’ < 1, and have clumped distribution pattern with value Is > 1. Cymodocea rotundata is a higest density species (16,578 individu/m²) in 2^nd station. The environment factors have correlation with seagrass density, so it has contributed to decide the community structure and seagrass pupulation density.