Abstract. Coastal regions and small islands are areas that will be adversely affected by the phenomenon of sea level rise globally. In general, Sea Level Rise (SLR) will result in coastal impacts as follows: increased frequency and intensity of floods, changes in ocean currents and widespread intrusion of sea water. This research was conducted in Gili Raja Island of Sumenep Madura. Objectives of this research were to demonstrate the ability of combining remote sensing and GIS method to determine the impact of SLR on a small island and to model its scale using different scenario. GIS based run-up model were performed to estimate and predict the impact of SLR to the island's area. Three water level scenario (0.5 m, 1.0 m and 1.5 m) were applied. The results showed that in the first scenario 8.73% of the island was flooded by sea water, furthermore in two other scenario the flooded area was increase significantly (15.88% and 22.38%).

Mangrove ecosystems are resources of landscapes, flora, fauna, and local communities that interact with each other. Mangrove ecosystems have important ecological, economic and social functions for coastal development. Conservation is a means of involving the community in mangrove recovery and management activities as a preservation effort. This paper examines the potential of mangrove ecosystems in the southern coast of Bangkalan as a conservation area. The fact, mangrove ecosystems have a pressure that decreased area significantly. Data collection used the quadratic transect method and satellite image analysis. Mangroves on the southern coast of Bangkalan have increased area over the past 10 years. Mangrove vegetation found consisted of 4 families and 8 species. There are also found fauna i.e. insects, snakes, primates and birds. The observations indicated that conservation of mangrove forests on the southern coast of Bangkalan needs to be done. This effort can be supported by ecotourism activities which are expected to improve the community welfare.

Pemilihan lokasi merupakan langkah awal untuk penentuan kegiatan perikanan budidaya laut yang berkelanjutan. Dokumen Rencana Zonasi Wilayah Pesisir dan Pulau-Pulau Kecil (RZWP3K) Provinsi Jawa Timur menyebutkan bahwa kawasan pesisir dan laut yang berada di perairan Selat Madura dan Selat Bali, terutama pesisir Kabupaten Situbondo dan Banyuwangi dialokasikan sebagai wilayah pengembangan budidaya laut. Penelitian ini bertujuan untuk menganalisa karakteristik kondisi perairan Kabupaten Situbondo dan Banyuwangi, khususnya mengenai kelayakan sebagai lokasi budidaya laut. Penelitian ini dilaksanakan pada bulan Juni sampai dengan Juli tahun 2020. Pengambilan data sample air laut dilakukan di titik pengamatan yang tersebar di 15 kecamatan pesisir di Kabupaten Situbondo (Selat Madura) dan Banyuwangi (Selat Bali dan Samudera Hindia). Metode yang digunakan adalah dengan menganalisis parameter kualitas perairan dan menghitung nilai indeks kesesuaian. Selain itu dilakukan pula pendugaan besarnya beban limbah dan analisis komponen utama. Hasil penelitian dapat disimpulkan bahwa lokasi yang sesuai untuk pengembangan budidaya laut di Kabupaten Situbondo terletak di Kecamatan Suboh, Kendit, Arjasa dan Jangkar dengan nilai indeks kesesuaian berkisar antara 63,5-67,5. Sementara untuk Kabupaten Banyuwangi, kawasan yang sesuai untuk pengembangan budidaya laut terletak di Kecamatan Wongsorejo dan Muncar dengan nilai indeks antara 64 -68.5. Estimasi beban limbah menunjukkan bahwa potensi limbah yang terjadi akibat budidaya laut dengan KJA adalah sekitar 0,24 ton N/10 unit karamba. Hasil perhitungan analisis komponen utama menunjukkan stasiun pengamatan memiliki karakteristik nilai parameter kualitas air yang beragam.

Implementasi UU No 1 tahun 2014 dan UU No 23 tahun 2014 terlihat dalam pengelolaan kawasan hutan mangrove berada di bawah kewenangan Provinsi Jawa Timur. Namun demikian, masyarakat pesisir selatan Kabupaten Bangkalan dapat memanfaatkan sesuai dengan peraturan dan perundangan yang berlaku. Penerapan Perpres No 80 tahun 2019 dapat menjadi pendorong terbangunnya kawasan wisata di pesisir Kecamatan Modung melalui pemanfaatan sumberdaya alamnya. Pesisir Selatan Kabupaten Bangkalan berupaya membangun desa pesisir dengan zona-zona wisata. Perencanaan pengelolaan kawasan mangrove di pesisir selatan Kabupaten Bangkalan dalam revisi  RTRW tahun 2020 ini diharapkan dapat dilakukan kolaborasi antara pemerintah kabupaten dan pemerintah propinsi sebagai bentuk implementasi UU No 1 tahun 2014 dan UU No 23 tahun 2014 dengan konsep pembangunan yang berkelanjutan dan terintegrasi.

Ujung Pangkah merupakan muara dari Sungai Bengawan Solo yang merupakan salah satu sungai terpanjang di Indonesia. Secara administrasi, daerah ini masuk kedalam wilayah Kecamatan Ujung Pangkah Kabupaten Gresik. Aliran Sungai Bengawan Solo yang bermuara di perairan estuari ini membawa sedimen yang terlarut dalam bentuk Muatan Padatan Tersuspensi (MPT) yang persebarannya dipengaruhi oleh pergerakan arus.   Penelitian ini bertujuan untuk mengetahui pola sirkulasi arus di perairan estuari Ujung Pangkah Gresik dan menganalisis pengaruh pergerakan arus dan pasang surut terhadap sebaran MPT. Simulasi model hidrodinamika digunakan pada penelitian ini dengan input data utama adalah pasang surut dan batimetri. Hasil penelitian menjelaskan bahwa model hidrodinamika yang diperoleh untuk menjelaskan pergerakan arus pasang surut dengan kecepatan berkisar antara 0,12 -0,38 m/s. Pola sebaran menunjukkan bahwa konsentrasi MPT yang tinggi umumnya terjadi pada saat kondisi perairan surut, sedangkan pada saat kondisi pasang, nilai konsentrasi MPT cenderung rendah. Pada saat kondisi surut terendah, hasil simulasi menunjukkan konsentrasi MPT yang tinggi (360 - >440 mg/l) tepat di mulut sungai dan menyebar ke bagian utara muara. Sementara itu, di bagian timur dan selatan muara, konsentrasi MPT relatif lebih rendah, berkisar antara 80–240 mg/l. Model hidrodinamika yang diperoleh cukup baik untuk menjelaskan pergerakan arus dan MPT (MAPE <20%).   Ujung Pangkah is the estuary of the Bengawan Solo River which is one of the longest rivers in Indonesia. Administratively, this area is included in the Ujung Pangkah District, Gresik Regency. The flow of the Bengawan Solo River into the estuary carries dissolved sediments in the form of suspended solids which distribution is influenced by current movements. This study aims to determine the pattern of current circulation in the Ujung Pangkah estuary and analyze the effect of current and tidal movements on the distribution of suspended solids. Hydrodynamic model simulation is used in this study with the main data inputs are tides and bathymetry. The results of the study explain that the hydrodynamic model explain the movement of tidal currents with velocities ranging from 0,12 to 0,38 m/s. The distribution pattern shows that high suspended solids concentrations generally occur during low tide conditions, whereas during high tide conditions, suspended solids concentrations tend to be low. At the lowest low tide, the simulation results show high suspended solids concentrations (360 to >440 mg/l) at the estuary and distributed to the northern part of the estuary. Meanwhile, in the eastern and southern parts of the estuary, suspended solids concentrations were relatively lower, ranging from 80–240 mg/l. The hydrodynamic model obtained in this study was sufficient to explain the current movement and MPT (MAPE <20%).

Collisions or harsh shifting of earth plates accompanied by an earthquake in the ocean would pose a potential tsunami. The coastal area in Pacitan Bay East Java faces directly to the Indian Ocean and is prone to tsunami disasters. This study aims to determine the vulnerability level of the area and the resilience of coastal communities against tsunamis. The geographic Information System (GIS) method was used in this study. This study applied weighted overlay calculation with four components: elevation, slope, and distance from the beach and the river to measure the vulnerability level. Moreover, Coastal Community Resilience (CCR) method was applied to measure the predictive response of the communities. The results indicated that most of the area in Pacitan Bay (79,70%) was categorised into high to very high vulnerable against tsunamis. The CCR results showed the low index structure design and post-disaster recovery elements.

Bawean Island is located in the middle of the Java Sea, approximately 80 km north of Gresik Regency, East Java Province. The coastal area of Bawean Island is famous for its potential as a marine tourism area because it has a well-preserved coral reef ecosystem. The potential for tourism development on this island requires the support of environmental suitability. The dynamics of ocean currents as an important parameter for small island development is important to be analyzed. This study aims to determine the characteristics of currents in the eastern coast of Bawean Island through the hydro-oceanographic model. The data used in this modelling was hourly wind and tide data from the period of 2020-2021. The results showed that the velocity of surface current speed in the study area was weak (<0,5 m/s). There was a significant difference of current direction during the west monsoon season and the first transitional season. Validation of model simulation and ADCP measurements produce MAE values 0,014 and 0,035 as well as MAPE values 12,75% and 27,48%.

<p><strong>ABSTRAK</strong></p><p><em>Kondisi perairan laut yang fluktuatif dan cenderung ekstrim menyebabkan rumput laut mudah terserang penyakit ice-ice. Munculnya bercak putih pada thallus rumput laut Eucheuma cottonii yang terinfeksi penyakit ice-ice diduga disebabkan oleh bakteri patogen yaitu Pseudomonas spp.  Tujuan yang ingin dicapai dalam pelaksanaan penelitian ini adalah untuk mengetahui pengaruh perbedaan salinitas terhadap viabilitas bakteri Pseudomonas spp dan untuk mengetahui pada salinitas berapakah bakteri Pseudomonas spp tidak dapat tumbuh. Bakteri diidentifikasi melalui uji biokimia, dan viabilitas diamati dengan menanam bakteri pada media TSA plate dengan salinitas 30, 32, dan 34 ppt dengan 3 kali pengulangan, dan untuk uji konfirmasi bakteri di tanam pada media TSA miring dengan kadar salinitas 0, 20, 40, 60, 80, dan 100 ppt. Hasil yang diperoleh menunjukan bakteri tumbuh dengan normal pada hampir semua media uji kecuali pada media 100 ppt, hal ini menunjukan bahwa bakteri Pseudomonas spp merupakan bakteri yang bersifat halofilik atau dapat tumbuh baik pada kadar salinitas yang tinggi. </em></p><p><em>Kata Kunci: Eucheuma cottonii, ice-ice, Pseudomonosa spp,Viabilitas.  </em></p><p align="center">The Influence of Salinity Difference to Viability of Pseudomonas spp. Bacteria<strong></strong></p><p><strong>ABSTRACT</strong></p><p><em>The conditions of marine waters that fluctuate and tend to extremes can cause seaweed susceptible to ice-ice disease. The appearance of white patches on infected Eucheuma cottonii seaweed thallus is estimated as ice-ice disease which is caused by pathogenic bacteria of Pseudomonas spp  The objectives of this research is to determine the effect of salinity difference to viability of bacteria Pseudomonas spp and to know on what salinity is the bacterium Pseudomonas spp that can’t grow. Bacteria were identified by biochemical tests. Viability was observed by planting bacteria on TSA plate medium with salinity 30 ppt, 32 ppt, and 34 ppt with 3 repetitions, and for bacterial confirmation test in planting on TSA tilting with salinity 0 ppt, 20 ppt, 40 ppt, 60 ppt, 80 ppt, And 100 ppt. The results showed that bacteria grew normally in almost all test media except in 100 ppt media, this showed that Pseudomonas spp bacteria were halophilic bacteria or could grow well at high salinity levels.</em></p><p><em>Keywords: Eucheuma cottonii, ice-ice, Pseudomonosa spp, Viability.</em></p>