Modeling Mackerel Tuna (Euthynnus affinis) Habitat in Southern Coast of Java: Influence of Seasonal Upwelling and Negative IOD

We used fishery catch data from Cilacap Fishing Port and Copernicus data set in July 2016-December 2017 to investigate the impacts of Indian Ocean Dipole (IOD) on upwelling and mackerel tuna distribution in the southern coast of Java. This study implemented a Generalized Additive Model (GAM) for habitat prediction of mackerel tuna in the waters. The present study showed that the extreme negative IOD in 2016 caused a weaker southeasterly wind and even a reversal to the northwesterly wind, as seen off Sumatra in September 2016. The situation produced vertically mixed layer thickening and no upwelling during the southeast monsoon event 2016, consequently resulted in warmer temperature and fewer Chlorophyll-a (Chl-a) compared to the southeast monsoon event 2017. The mackerel tuna production significantly dropped in 2016 and rose in 2017, particularly during the upwelling event. The high Habitat Suitability Index (HSI) was found in southern Central Java in July 2017, expanded bigger in August 2017, and decreased in September 2017. During July and August 2016, the high HSI covered only a less area in the region and disappeared in September 2017. The high HSI indicates that the oceanographic factor is consistent with the catch probability of mackerel tuna

Poverty and livelihood analysis of Former Enclave (Chitmahal) people in a selected area of Bangladesh

With the aim of creating development programs for the residents of the former enclave (Chitmahal), a survey of their poverty and livelihoods is essential. In this study, socioeconomic factors, poverty levels, changes in livelihood assets, and respondent satisfaction levels with social institutions in the study area were all assessed. A total of 100 respondents were randomly selected from Debiganj Upazila in the Panchagarh district of Bangladesh. A survey approach was employed to obtain the data. Respondents were able to respond quickly to questions and indicate their level of agreement with five points using a five-point Likert scale. The data were analyzed using the Direct Caloric Intake (DCI) approach and DFID's Sustainable Livelihoods Framework. The main finding of the study was that the average age of the head of family was within the working age range. The average size of a household was medium. The head of family has only completed nearly five years of school. Three-fifths of those surveyed had high household incomes. The majority of households had poverty. After becoming a citizen of Bangladesh, the five asset classes- human assets, social assets, natural assets, physical assets and financial assets were positively changed. Satisfaction with social institutions has been moderate. In order to reduce poverty and improve the standard of living of households in the research area, social institutions need to be more efficient

SEBARAN DAERAH TANGKAP IKAN TONGKOL (Euthynnus sp.) DI PERAIRAN SELATAN JAWA

The high utilization of the community towards mackerel is contradicted by the majority of the fleet owned by fishermen in South Java in the form of gill net and long line which are the specifications for capturing other large tuna and pelagic. Maps of mackerel fishing areas are needed by fishermen, especially when the fish famine season takes place as the backbone of the fishermen’s catch. Raw data of the catch is obtained from the log book of Cilacap  Oceanic Fishing Port catch throughout 2017. This research aimed to (1) analyze the distribution of mackerel fishing for gill net and long line fishing gear in the coastal of South Java and (2) analyze the distribution of the average layer thickness of the optimum water temperature and salinity for mackerel. The result of this study shows that the number of mackerel fishing areas (Euthynnus sp.) for gill net fishing equipment is 105,56⁰-110,78⁰ E and 7,48⁰-11,57⁰ S and for long line fishing gear is 106,69⁰-109,46⁰ E and 7,84⁰-9,37⁰ S. The distribution of mackerel fishing areas using the highest gill net in August with the acquisition of 76.634 kg of catch, while using the long line in July with the acquisition of catch results of 18.741 kg. The upright distribution of the average water temperature for mackerel is optimal in July, August, September for gill net and July and November for the long line, 26-27⁰ C. The upright distribution of monthly average water salinity for mackerel is also optimum in July, August, September for gill net and long line throughout the year except January is the optimum range which ranges from 34,0 to 43,3 %o.Tingginya pemanfaatan masyarakat terhadap ikan tongkol kontradiksi dengan mayoritas armada kapal yang dimiliki nelayan di Selatan Jawa berupa gill net dan long line yang spesifikasi untuk menangkap tuna dan pelagis besar lainya. Peta daerah penangkapan ikan tongkol sangat dibutuhkan oleh nelayan, terutama ketika musim paceklik ikan berlangsung menjadi tulang punggung hasil tangkap nelayan. Raw data penangkapan diperoleh dari logbook penangkapan Pelabuhan Perikanan Samudera Cilacap (PPS Cilacap) sepanjang tahun 2017. Penelitian ini bertujuan (1) menganalisis sebaran daerah penangkapan ikan tongkol (Euthynnus sp.) untuk alat tangkap gill net dan long line di perairan selatan Jawa dan (2) menganalisis sebaran menegak lapisan rata-rata bulanan suhu dan salinitas perairan yang optimum untuk ikan tongkol. Hasil penelitian ini menunjukkan sebaran daerah penangkapan ikan tongkol (Euthynnus sp.) untuk alat tangkap gill net adalah 105,56⁰-110,78⁰ BT dan 7,48⁰-11,57⁰ LS serta untuk alat tangkap long line adalah 106,69⁰-109,46⁰ BT dan 7,84⁰-9,37⁰ LS. Sebaran daerah penangkapan ikan tongkol menggunakan gill net tertinggi pada bulan Agustus dengan perolehan hasil tangkap 76.634 kg, sedangkan menggunakan long line pada bulan Juli dengan perolehan hasil tangkap 18.741 kg. Sebaran menegak lapisan rata-rata bulanan suhu perairan untuk ikan tongkol optimum pada bulan Juli, Agustus, September untuk gill net dan bulan Juli serta November untuk long line yaitu 26-27⁰ C. Sebaran menegak rata-rata bulanan salinitas perairan untuk ikan tongkol juga optimum bulan Juli, Agustus, September untuk gill net dan long line sepanjang tahun kecuali bulan Januari merupakan kisaran optimum yaitu berkisar 34,0-43,3 %o

EFEKTIVITAS ATRAKTOR CUMI-CUMI DI LOMBOK TIMUR, NUSA TENGGARA BARAT

Salah satu teknologi yang dapat mendukung peningkatan populasi cumi-cumi di alam adalah teknologi atraktor cumi-cumi. Atraktor cumi-cumi dapat berfungsi sebagai suatu ekosistem baru dan dapat mengumpulkan cumi-cumi. Tujuan penelitian ini adalah menentukan karakteristik perairan tempat pemasangan atraktor cumi-cumi, menentukan desain kontruksi atraktor cumi-cumi, dan menentukan efektivitas pemasangan atraktor terhadap hasil tangkapan cumi-cumi. Metode penelitian berupa eksperimental fishing dan studi literatur digunakan dalam penelitian ini. Hasil penelitian menunjukkan suhu permukaan laut di periaran Labuhan Haji dan Tajung Luar secara berurutan berkisar 27,10-28,29°C dan 28,15-28,79°C, kondisi dasar perairan Labuhan Haji pasir berlumpur dan Tanjung Luar pasir berbatu. Desain atraktor berbentuk tabung dengan diameter 60 cm, panjang 120 cm, dan berwarna hitam. Pemasangan atraktor efektif mengumpulkan cumi-cumi.One of the technologies that can support an increase in the population of squid in nature is squid attractor technology. Squid attractors can function as a new ecosystem and can collect the squid. The purpose of this study is to determine a characteristics of the waters where the squid attractor was installed, to determine the construction design of the squid attractor, and to determine the effectiveness of the attractor installation on squid catches. Fishing experimental research methods and literature studies were used in this study. The results shows that the sea surface temperature in the waters of Labuhan Haji and Tajung Luar ranged from 27.10-28.29°C and 28.15-28.79°C, respectively, the bottom conditions of the Labuhan Haji waters were muddy sand and Tanjung Luar was rocky sand. Design of the attractor was in the form of a tube with a diameter of 60 cm, a length of 120 cm, and black in color. Installing an attractor effectively collected the squid

Arahan Pengembangan Kawasan Konservasi Padang Lamun Berbasis Manfaat Penggunaan Langsung dan Tidak Langsung/ Direct and Indirect Use Values sebagai Bagian dari Wilayah Pesisir di Pulau Bawean

Wilayah pesisir dan laut Indonesia mempunyai kekayaan dan keanekaragaman hayati (biodiversity) terbesar di dunia, yang tercermin pada keberadaan ekosistem pesisir seperti hutan mangroove, terumbu karang, padang lamun dan berjenis-jenis ikan, baik ikan hias maupun ikan konsumsi. Secara fisik, ekosistem mangrove berfungsi sebagai penahan laju sedimentasi dari daratan, sehingga menjaga kejernihan air yang masuk ke ekosistem lamun dan terumbu karang. Demikian pula dengan ekosistem lamun yang berfungsi sebagai pemerangkap sedimen, sehingga menjaga kejernihan air, serta berfungsi sebagai habitat dari hewan laut yang bernilai ekonomis, seperti rajungan dan ikan baronang. Padang lamun cukup penting keberadaannya, khususnya di perairan laut dangkal. Lamun yang membentuk padang lamun kemudian menjadi suatu ekosistem yang merupakan salah satu ekosistem laut terkaya dan paling produktif, bila dibandingkan dengan produktifitas dari hasil usaha pertanian tropis (Den HARTOG, 1976). Banyak jenis tumbuhan dan hewan mengggunakan lamun sebagai tempat tinggal dan berlindung dari hewan-hewan pemangsa (KIKUCHI & PERES, 1977). Menurut LIPI (2018), kondisi padang lamun saat ini dapat dikatakan sudah tidak sehat akibat dominasi aktifitas manusia yang merusak ekosistem. Ekosistem padang lamun sendiri masih belum terlalu diperhatikan oleh masyarakat jika dibandingkan oleh terumbu karang dan mangrove. Masih sedikit pula studi yang membahas terkait pentingnya ekosistem ini. Pulau Bawean merupakan salah satu wilayah yang memiliki ekosistem pesisr yang lengkap. Dengan adanya hutan mangrove, padang lamun, dan terumbuj karang menajdikan daya tarik sendiri, sehingga sering dijadikan sebagai destinasi wisata bagi banyak orang. Akan tetapi hal ini dapat menajdi ancaman bagi keberlangsungan ekosistem. Tujuan dari penelitian ini yaitu merumuskan arahan konservasi bagi ekosistem padang lamun di Pulau Bawean dengan berdasarkan manfaat penggunaan atau use value. dengan tahapan yang pertama adalah pemetaan persebaran padang lamun di wilayah penelitian, kemudian menentukan manfaat penggunaan secara langsung dan tidak langsung pada ekosistem padang lamun dan selanjutnya merumuskan arahan kosnervasi berdasarkan manfaat penggunaan langsung dan tidak langsung Adapun hasil penelitian ini yaitu diketahuinya manfaat penggunaan ssecara langsung dan tidak langsung pada ekosistem padang lamun menurut jenisnya di wilayah penelitian. Dari manfaat tersebut, kemudian dirumuskan arahan konservasi berdasarkan teori dan kebijakan terkait dengan menggunakan metode triangulasi data. ============================================ The coastal and marine areas of Indonesia have the largest biodiversity and wealth in the world, which is reflected in the existence of coastal ecosystems such as mangrove forests, coral reefs, seagrass beds and various types of fish, both ornamental and consumption fish. Physically, the mangrove ecosystem functions as a barrier to the sedimentation rate from the land, thereby maintaining the clarity of the water that enters the seagrass and coral reef ecosystems. Likewise with the seagrass ecosystem which functions as a sediment trap, thus maintaining the clarity of the water, as well as functioning as a habitat for economically valuable marine animals, such as crabs and baronang fish. Seagrass beds are quite important, especially in shallow sea waters. The seagrass that forms seagrass beds then becomes an ecosystem which is one of the richest and most productive marine ecosystems, when compared to the productivity of tropical agricultural enterprises (Den HARTOG, 1976). Many types of plants and animals use seagrass as a place to live and shelter from predators (KIKUCHI & PERES, 1977). According to LIPI (2018), the current condition of the seagrass beds can be said to be unhealthy due to the dominance of human activities that damage the ecosystem. The community has not paid much attention to the seagrass ecosystem when compared to coral reefs and mangroves. There are still few studies that discuss the importance of this ecosystem. Bawean Island is one of the areas that has a complete coastal ecosystem. With the presence of mangrove forests, seagrass beds, and coral reefs, they are their own attraction, so they are often used as tourist destinations for many people. However, this can be a threat to the sustainability of the ecosystem. The purpose of this research is to formulate conservation directions for the seagrass ecosystem on Bawean Island based on the use value. This goal can be achieved through the research stages with the first stage is mapping the distribution of the seagrass beds in the research area, then determining the value of the benefits of direct and indirect use of the seagrass ecosystem and then formulating conservation directions based on the value of benefits of direct and indirect use. The results of this study are the direct and indirect benefit values of the use of the seagrass ecosystem according to its type in the study area. From the value of these benefits, conservation directions are then formulated based on related theories and policies using the data triangulation method