Kualitas Penetasan Kista Artemia yang Dibudidaya pada Berbagai Tingkat Perubahan Salinitas

Kualitas kista artemia tergantung tingginya nilai derajat dan efisiensi penetasan. Tujuan dari penelitian ini untuk mengetahui kapan (waktu) Perubahan salinitas dan berapa besarnya Perubahan salinitas tersebut yang dicirikan nilai derajat dan efisiensi penetasan sebagai indikator kualitas artemia. Penelitian ini menggunakan Rancangan Acak Kelompok. Faktor pertama terdiri dari dua, yaitu A (menaikkan salinitas pada hari ke 9) dan B (menaikkan salinitas pada hari ke 15). Faktor kedua terdiri dari empat, yaitu peningkatan salinitas I (100; 100; 100;140 g/kg), II (100; 100; 140; 140 g/kg), III (100; 140; 140; 140 g/kg) dan IV (100; 110; 125; 140 g/kg), dan dengan 3 kelompok warna yaitu biru, merah dan hijau. Data yang diperoleh dianalisis dengan sidik ragam dan bila memberikan pengaruh yang berbeda nyata dilanjutkan dengan uji Duncan. Hasil penelitian menunjukkan bahwa perlakuan B II menghasilkan derajat penetasan paling tinggi, sedangkan efisiensi penetasan paling tinggi terdapat pada perlakuan AIII

Struktur Komunitas Lamun Di Perairan Pesisir Manokwari

The study was done from July to October 2007 by line transect method, plots, and exploration survey. There were eight species found in this study were grouped into pioneer group (Cymodocea rotundata, Halodule pinifolia, Halodule uninervis, Halophila ovalis, Syringodium isoetifolium) and climax (Cymodocea serrulata, Enhalus acoroides, Thalassia hemprichii), with mixed vegetations. Density, covering percentage and biomass in Andai and Wosi were dominated by H. pinifolia; Rendani and Tj. Mangewa were dominated by T. hemprichii; and Briosi were dominated by C. rotundata and T. hemprichii. INP in Andai and Wosi (dominated by H. pinifolia) were 290.005 and 243.767, respectively; Rendani and Tj. Mangewa (dominated by T. hemprichii) were 101.725 and 135.139, respectively; and Briosi (dominated by C. rotundata) was 120.146. The highest ratio of above and below biomass was found in Andai (7.831) and the lowest was found in Briosi (2.103). Seagrass community in Rendani, Tj. Mangewa and Briosi had higher biodiversity index than Wosi and Andai (0.109 and 0.015). On the other hand, Rendani, Tj. Mangewa, and Briosi had lower dominance index (0.262, 0.421 and 0.338, respectively), compared to Andai (0.989) and Wosi (0.889). Level of similarity among seagrass community in Rendani, Briosi and Tj. Mangewa was categorized as very high (92.31 %), while Andai and Wosi was high (66.67 %)

Kualitas Penetasan Kista Artemia yang Dibudidaya pada Berbagai Tingkat Perubahan Salinitas

Kualitas kista artemia tergantung tingginya nilai derajat dan efisiensi penetasan. Tujuan dari penelitian ini untuk mengetahui kapan (waktu) Perubahan salinitas dan berapa besarnya Perubahan salinitas tersebut yang dicirikan nilai derajat dan efisiensi penetasan sebagai indikator kualitas artemia.penelitian ini menggunakan Rancangan Acak Kelompok. Faktor pertama terdiri dari dua, yaitu A (menaikkan salinitas pada hari ke9) dan B (menaikkan salinitas pada hari ke 15). Faktor kedua terdiri dari empat, yaitu peningkatan salinitas I (100; 100; 100;140 g/kg), II (100; 100; 140; 140 g/kg), III (100; 140; 140; 140 g/kg) dan IV (100; 110; 125;140 g/kg), dan dengan 3 kelompok warna yaitu biru, merah dan hijau. Data yang diperoleh dianalisis dengan sidik ragam dan bila memberikan pengaruh yang berbeda nyata dilanjutkan dengan uji Duncan. Hasil penelitian menunjukkan bahwa perlakuan B II menghasilkan derajat penetasan paling tinggi, sedangkan efisiensi penetasan paling tinggi terdapat pada perlakuan AIII

Model of Ecotourism Management in Small Islands of Bunaken National Park, North Sulawesi

The Bunaken National Park is one of the famous national park for tourism in North Sulawesi, Indonesia. The abundance natural resources is one of the crucial natural attraction for tourism in Bunaken. Tourism in Bunaken contributes significantly in local economic development. In the same situation, however, tourism contributes negatively to environment. Tourist activities contributes significantly in coral reef covers. Utilization of natural resources as an object and attraction needs to be done carefully, taking into account the balance of ecological, socio-economic and socio-cultural. The concept of ecotourism with three aspects of development were important in aspect in Bunaken National Park tourism development. The management of the park tour needs to be done based on the concept and principles of ecotourism. The Bunaken National Park tourist management model simulated by the dynamic system with the Powersim Constructor software show the number of tourist 2035 reached 27,152.98, extensive coral cover 447.87ha, the local community incomes Rp 15,834,861,419.63 and government revenues Rp 1,751,770,691.04. Keywords: conservation area, ecotourism, powersim model, sustainable management

Changes of Ammonia, Nitrite and Nitrate at Recirculation System of Red Tilapia (Oreochromis sp.) Rearing

High rearing density of fish in an intensive culture system require  high amount of feed which may result in the accumulation of organic materials in the water to a higher level. The accumulation of organic materials can  be toxic for fish, generate mineralization of nutrient from organic materials and cause high oxygen expenditure.  Recirculation system is an aquaculture system which aimed to maintain water quality at an appropriate level for fish to survive and grow,   Theammonia concentration in recirculation system with biofilter tended to decrease sharply while there was only a slightly decrease in that without biofilter. Conversion efficacy of ammonia nitrogen (NH3-N)  and nitrite nitrogen (NO2-N) of   biofilter compiled with aeration system was 46.20% and 30.68%, while in an unaerated system was 39.31% and 8.53%, respectively.  The use of aquatic plant was found to be an effective way to reduce nitrate nitrogen (NO3-N).  A higher conversion efficacy of nitrate (50.15%) in the tank containing aquatic plant was observed by using aeration before biofilter. Keywords: ammonia, nitrite, nitrate, recirculation system, red tilapia, Oreochromis sp.   ABSTRAK Padat penebaran tinggi pada sistem budidaya intensif menuntut tingginya jumlah pakan yang diberikan kepada ikan sehingga mengakibatkan penumpukan bahan organik dalam wadah. Akumulasi bahan organik akan menyebabkan terjadinya pembentukan senyawa-senyawa yang beracun bagi ikan, mineralisasi nutrien dari bahan organik dan penyerapan oksigen yang tinggi. Untuk mempertahankan kualitas air sehingga tetap layak bagi ikan, digunakan sistem resirkulasi dalam proses pemeliharaannya. Kecenderungan penurunan konsentrasi ammonia terlihat tajam pada filter biologis pada unit yang menggunakan filter biologis, sedangkan tanpa filter biologis hanya terjadi penurunan konsentrasi ammonia yang kecil sehingga efektifitas pengubahannya menjadi kecil.  Efektivitas pengubahan ammonia (NH3-N) pada filter biologis pada unit tanpa perlakuan aerasi hanya sebesar 39,31% dengan efektivitas pengubahan nitrit (NO2-N) sebesar 8,53%. Sedangkan pada unit yang meggunakan proses aerasi sebelum filter biologis, efektivitas pengubahan ammonia dan nitrit masing-masing mencapai 46,20% dan 30,68%. Penggunaan tanaman akuatik efektif untuk menurunkan konsentrasi nitrat (NO3-N). Efektifitas pengubahan nitrat pada wadah tanaman akuatik tertinggi sebesar 50,15% dicapai oleh unit yang menggunakan sistem aerasi sebelum filter biologis. Kata kunci: ammonia, nitrit, nitrat, resirkulasi, nila merah,  Oreochromis sp

Analisis Strategi Pengelolaan Dan Peran Lembaga Dalam Rangka Konservasi Danau Sentani Jayapura (Analyze of Management Strategy and Institution Participation in Concervation of Sentani Lake, Jayapura)

The Sentani Lake located at Jayapura regency which covered : east Sentani District, Sentani District, and West Sentani district. Other area located in Jayapura city. Sentani lake has 9630 ha area with 52 m depth and 72 m mean surface level. Some problem on Sentani lake are erotion, domestic waste and industrial waste which due to Cu and Zn concentration in these lake over standard of water quality. The strategy consist of management and institution responsibility, and lake institution is needed to develop lake sustainability . Analyze method by ISM (interpretative structural modeling) with institution fellowship, goal in lake management and management model programe as some input . According to expert judgment, the institution elements responsed to develop management model of Sentani lake are marine and fishing institution, Housing institution, local leader and local institution, environmental institution, landscape intitution, university, and tourisme institution. That elements is the fourth level. The fourth elements level become the main driver power and to effect on next sub element. Co-Management institution is proposed in this research

Effect of Heating at Various Temperatures for 30 Minutes on Pathogenicity of White Spot Syndrome Virus (WSSV) in Tiger Prawn (Penaeus monodon Fabr.)

White spot syndrome virus (WSSV) is a strong pathogenic virus which spread very rapidly and can cause tiger shrimp mass mortality within a short period.  Enhancement of shrimp immunity by infecting inactivated WSSV is one of the efforts to overcome WSSV infection in shrimp.  In this study, inactivated WSSV were prepared by heating them with various temperatures namely 45, 50, 55 and 60oC for 30 minutes. The results shows that infection with  heating inactivated WSSV at 45°C and 60°C for 30 min on PL-15 could increase their immunities.  The survival rate of inactivated WSSV-infected shrimp after challenge test with  WSSV virulent  reached 77%, while  no survive shrimp was observed in control.  This suggests that shrimp immunity could be improved by vaccination using  WSSV virus inactivated by heating. Keywords: WSSV virus, pathogen, tiger shrimp, heating   ABSTRAK White Spot Syndrome Virus (WSSV) merupakan virus yang sangat ganas bagi udang windu, dengan penularan yang sangat cepat dan menyebabkan kematian dalam waktu yang cepat. Peningkatan imunitas udang dengan meenginfeksikan WSSV inaktif merupakan salah satu upaya untuk menanggulangi infeksi WSSV pada udang. Pada penelitian ini, inaktivasi WSSV dilakukan menggunakan pemanasan pada suhu berbeda, yaitu 45, 50, 55 dan 60oC selama 30 menit.  Hasil penelitian menunjukkan bahwa infeksi PL-15 menggunakan virus WSSV yang telah diinaktivasi dengan pemanasan pada suhu 45oC dan 60oC dapat meningkatkan daya tahan udang.  Kelangsungan hidup udang yang telah diinfeksi dengan WSSV hasil inaktivasi sebelum uji tantang dengan WSSV virulen mencapai 77%, sementara udang yang tidak diinfeksi dengan WSSV hasil inaktivasi adalah semua mati.  Dengan demikian dapat disimpulkan bahwa daya tahan udang dapat ditingkatkan melalui vaksinasi menggunakan WSSV yang telah diinaktivasi dengan pemanasan. Kata kunci: virus WSSV, patogen, udang windu, pemanasa