COMMUNITY STRUCTURE AND DIVERSITY OF PHYTOPLANKTON IN LEMUKUTAN ISLAND WATERS, WEST KALIMANTAN

Phytoplankton plays an important role in marine ecosystems as primary producer, as the basis of food chains and the food web, and are widely used as bioindicators to monitor water condition. The study of phytoplankton is the primary interest to explore aquatic resources for blue biotechnology applications in conditions as a live feed, antibacterial, antiviral, antioxidant, pharmaceutical, cosmetics, possibly food and health industry. The study aims to assess the composition, abundance and diversity of phytoplankton community in Lemukutan Island waters of West Kalimantan. The present study found 31 genera of phytoplankton, consisted of Bacillariophyceae (28 genera) and Dinophyceae (3 genera). In term of contribution, Bacillariophyceae were found to be dominant (93.035%) than dinophyceae (6.965%). The abundance of phytoplankton varied between 636.91 to 2034.48 cell.L-1. The diversity index (H’), the evenness (E) index, and the dominance (C) index ranged from 1.959–2.579, 0.582–0.868, 0.094–0.283, respectively. The result showed that the diversity index was moderate, the evenness index was high, and the dominance index was low.

AKTIVITAS ANTIOKSIDAN BERBAGAI JENIS MAKROALGA DI PANTAI SEPANJANG, KABUPATEN GUNUNGKIDUL, YOGYAKARTA (Antioxidant Activities in Various Types of Macroalgae at Sepanjang Beach, Gunungkidul District, Yogyakarta)

Penelitian ini bertujuan untuk mengetahui aktivitas antioksidan berbagai jenis makroalga di Pantai Sepanjang, Kabupaten Gunungkidul, Yogyakarta. Penelitian ini dilaksanakan di Pantai Sepanjang, Kabupaten Gunungkidul, Yogyakarta pada bulan Agustus 2020. Jenis makroalga yang ditemukan pada saat penelitian antara lain Ulva lactuca, Palmaria palmata, Sargassum crassifolium, Gelidium spinosum, Gelidiella acerosa, dan Gracilaria verrucosa. Metode yang digunakan dalam penelitian ini adalah deskriptif eksploratif. Pengambilan sampel makroalga dilakukan secara purposive sampling meliputi bagian timur, tengah dan barat Pantai Sepanjang. Analisis aktivitas antioksidan menggunakan metode DPPH (1,1-diphenyl-2-picrylhydrazyl). Hasil analisis menunjukan bahwa potensi aktivitas antioksidan tertinggi terdapat pada Gelidiella acerosa yang berada di bagian tengah Pantai Sepanjang dengan nilai IC50 sebesar 22,407 g/ml. This research aimed to analyze antioxidant activities from various types of macroalgae. Sample collection was taken at Sepanjang Beach, Gunungkidul District, Yogyakarta in August 2020. Various types of macroalgae were found are: Ulva lactuca, Palmaria palmata, Sargassum crassifolium, Gelidium spinosum, Gelidiella acerosa, and Gracilaria verrucosa. A method of descriptive exploratory was used in this research. Macroalgae samples were collected by purposive sampling from the eastern, central and western area of Sepanjang Beach. Antioxidant activities were carried out using DPPH method. The results showed that fresh Gelidiella acerosa which is located in the middle of Sepanjang Beach, has the highest antioxidant activities with IC50 value 22.407 g ml-1.

CHARACTERISTICS OF TUNA, SMALL TUNA AND SKIPJACK (TTS) FISHERY IN KUTARAJA OCEAN FISHING PORT, ACEH

Kutaraja Ocean Fishery Port is the oldest port in Banda Aceh City, Lampulo. Fishery resources are a new potential in the regional economic development of Aceh province. Fish resources that have great potential are from the large pelagic fish groups, including Tuna, Small Tuna and Skipjack (TTS) . Fishery characteristics are used to carry out sustainable fishing. This research was conducted at PPS Kuta Raja, Aceh for one year. Data collection was carried out directly through site surveys and interviews with related fisheries actors. Biological data and capturing aspects were carried out using a stratifield random sampling system by placing enumerators. The results showed that the production of TCT at PPS Kutaraja was dominated by 2 fishing gears, purse seine and hand lines. Based on the results of enumeration in 2020, the estimated total production of tuna skipjack and small tuna at PPS Kuta Raja reaches 11,520 tons. The highest total estimated fish catch is skipjack tuna (Katsuwonus pelamis) (SKJ) 5,802 tons, Bullet tuna (Auxis rochei)(BLT) 2814 tons, Yellow fin (Thunnus albacares) (YFT) 2,452 tons, Krai Tongkol (Auxis thazard) (FRI) 448 tons, and Eastern little tuna (Euthynnus affinis) (KAW) 1,745 tonnes. All of the fish caught were dominated by immature fish. So it is very necessary to evaluate the use of fishing gear or the licensing of FADs. The monthly CPUE distribution pattern is the same, where in August it reaches the highest CPUE and in October it reaches the lowest CPUE value.