The existence of mackerel scad in Ambon waters, Moluccas Indonesia has decreased from year to year mainly due to the over exploitation. This research aimed to study the biological aspects, in particular were sex ratio, age group and length at first maturity of mackerel scad (Decapterus macarellus) from this area. Sampling was done on September 2016 to July 2017 at the southern waters of Ambon Island. Samples collected were dissected to determine their sex and their gonad maturity level then measured. Bhattacharya method was used to determine age group while Spearman- Kaber method was used to identify length at the first maturity of this species. It was found that mackerel scad in the southern waters of Ambon Island had an equal number of male and female that consists of four age groups with length at first maturity for male and female were 24.9 cm and 24.8 cm, respectively.

─Mackerel scad (Decapterusmacarellus) is one of the small pelagic fish that has important economic value and caught throughout the year around the waters of Ambon. Utilization of these fish is not only profitable economically but also can have a negative impact if not pay attention to aspects of sustainability. The purpose of this research is to know the distribution of long frequency and growth pattern. This research was conducted for six months (September 2016-February 2017 around Ambon waters. Samples of fish analyzed amounted to 1548 individuals. The average length of the minimum fish caught is 9.5 cm and the average size of the maximum length of fish caught is 31.8 cm. Fish growth patterns obtained are isometric.

This research aims are to determine the potential fishing grounds of yellowfin tuna based on the approach of sea surface temperature, chlorophyll-a and catches in the Ceram Sea. Overall catches of 407 Individuals. In January the total catches were 66 individuals (14.44%), in February 67 individuals (14.66%), in March 84 individuals (18.38%), in April 116 individuals (25.38%) and in May 124 individuals (27.13%). The distribution of sea surface temperature and chlorophyll-a in the Ceram Sea in January-May 2019 looks varied. In January the average sea surface temperature was 29.13 oC, in February sea surface temperature was 29.54 oC, in March sea surface temperature was 30.12 oC, in April sea surface temperature was 30.12 oC, in May sea surface temperature was 29.77 oC. Chlorophyll-a concentration in January and February was 0.21 mg/m3, March was 0.20 mg/m3, April was 0.16 mg/m3, and May was 0.25 mg/m3. The results of the t-test analysis showed the P-value of sea surface temperature was 0.009<0.05, chlorophyll-a P-value 0.00048<0.05. Determination of potential fishing areas based on sea surface temperature, chlorophyll-a, and CPUE indicators shows that potential fishing areas are found in January, February, March, and May, while in April are in the medium potential category. Penelitian ini dilaksanakan dengan tujuan menentukan daerah penangkapan potensial Tuna madidihang berdasarkan pendekatan suhu permukaan laut, klorofil-a dan hasil tangkapan di Laut Seram.  Secara keseluruhan hasil tangkapan ikan tuna madidihang sebanyak 407 Individu. Bulan Januari total hasil tangkapan sebanyak 66 individu (14.44%), bulan Februari 67 individu (14.66%), bulan Maret 84 individu (18.38%), bulan April 116 individu (25.38%) dan bulan Mei 124 individu (27.13%). Sebaran suhu permukaan laut dan klorofil-a di Laut Seram pada bulan Januari-Mei 2019 terlihat bervariasi. Bulan Januari rata-rata suhu permukaan laut sebesar 29.13 oC, bulan Februari suhu permukaan laut 29.54 o, bulan Maret suhu permukaan laut 30.12 oC, bulan April suhu permukaan laut 30.12 oC, bulan Mei suhu permukaan laut 29.77 oC. Konsentrasi klorofil-a pada bulan Januari dan Februari sebesar 0.21 mg/m3, bulan Maret sebesar 0.20 mg/m3, bulan April sebesar 0.16 mg/m3, dan bulan Mei sebesar 0.25 mg/m3.  Hasil analisis uji t menunjukan nilai P-value suhu permukaan laut sebesar 0,009<0,05, klorofil-a P-value 0,00048<0,05. Penentuan daerah penangkapan ikan potensial berdasarkan indikator suhu permukaan laut, klorofil-a dan CPUE menunjukkan daerah penangkapan ikan potensial terdapat pada bulan Januari, Februari, Maret, dan Mei, sedangkan pada bulan April berada dalam kategori potensial sedang.

Ambon Bay is one of the centers of economic activity held by the Ambon City community and is vicinity area. The fishing sector is one of the activities found in this area. The kind of fishing activity and its related problem faced by the fishermen of this area is the content of this study. This study was aimed to investigate the kind of fishing gear operated in this area and to identify problems faced by the fishermen in conducting their activity. Data were obtained from 91 fishermen fishing in this area with various types of fishing gear and conducted through interviews and field observation. Data obtained were then analyzed descriptively. Kind of fishing gears found to operate in Ambon Bay consists of gill net, hand line, beach seine, bottom longline, lift net, purse seine, and trap net. The common problem face by the fishermen is plenty of floating debris, high turbidity caused by flooding. All these problems hampering the fishing activity that leads to a decline in fish production and fishermen’s income. Another problem that occurs is the increase of fishing gear operated in the area with relatively a small fishing area apart from fish resources that already decrease compared to 15 – 20 years before. From field observation and interviews with the local fisher, it was found that fish production has declined up to 50%.

Yellowfin tuna is an important economic commodity that is widely exploited with various fishing tools and methods and catches of various sizes. This study aims to describe yellowfin tuna fishing units and analyze the size distribution and productivity of yellowfin tuna resources based on seasons in the waters of the Tanimbar Islands. This research was carried out in the waters of the Tanimbar Islands from August 2021-March 2022. Data were collected through interviews, observations and measurements of the length and weight of the catch and analyzed descriptively and CPUE analysis. The results showed that catching yellowfin tuna in the waters of the Tanimbar Islands was classified as a small-scale fishery, using hand fishing gear with boat sizes under 10 GT. Yellowfin tuna caught in the waters of the Tanimbar Islands throughout the year are dominated by small size fish that are still classified as juveniles. The presence of large-sized tuna was more in the first transitional season with an attendance percentage of 21.98%. The abundance of yellowfin tuna resources in the waters of the Tanimbar Islands fluctuated according to the seasons, and the highest abundance was found in the transitional season one.   ABSTRAK Ikan tuna madidihang merupakan komoditas ekonomis penting yang banyak dieksploitasi dengan berbagai alat dan metode penangkapan serta hasil tangkapan yang beragam ukurannya. Penelitian ini betujuan untuk mendeskripsi unit penangkapan tuna madidihang dan menganalisis distribusi ukuran serta produktivitas sumberdaya ikan tuna madidihang berdasarkan musim di perairan Kepulauan Tanimbar. Penelitian ini dilaksanakan di perairan Kepulauan Tanimbar sejak Agustus 2021-Maret 2022. Data dikumpulkan melalui wawancara, observasi dan pengukuran panjang dan berat hasil tangkapan, kemudian dianalisis secara deskriptif serta analisis CPUE. Hasil penelitian menunjukkan bahwa penangkapan ikan tuna madidihang di perairan Kepulauan Tanimbar tergolong perikanan skala kecil, menggunakan alat tangkap pancing tangan dengan ukuran kapal di bawah 10 GT. Ikan tuna madidihang yang tertangkap di perairan Kepulauan Tanimbar sepanjang tahun didominasi ikan ukuran kecil yang masih tergolong juvenile. Kehadiran ikan tuna ukuran besar lebih banyak pada musim peralihan satu dengan persentasi kehadiran sebesar 21,98%. Kelimpahan sumberdaya ikan tuna madidihang di perairan Kepulauan Tanimbar berflutuksi menurut musim, dan kelimpahan tertinggi didapati pada musim peralihan satu Kata kunci: Distibusi ukuran, kelimpahan, musim, pancing tangan, tuna madidihang

Changes in internal and external factors during operation of bottom gill net will affect to catch ability of bottom gill net. The presence of marine debris in the ocean is predicted to influence the internal factors of gill nets which leads to reduction of catch ability. This study aimed to identify the factors that lead to decreasing of catch ability of bottom gill nets and to calculate the reduction of catch ability due to changes in hanging ratio caused by marine debris. Fishing activity using bottom gill net for 10 replications was conducted to identify the factors that affect the bottom gill net’s catch ability, while the reduced catch ability is calculated through the percentage of net area covered by garbage, changes in the hanging ratio and tension of the net body due to the entangled and twisted garbage in the net. The results showed that there were three factors that led to a reduction in the catch ability of bottom gill nets due to marine debris, namely: garbage stuck to the body of the net, trash entangled in net webs and trash wrapped around the body of the net. The closure of the mesh, changes in openings of mesh and net tension result in a decrease in the catch ability of bottom gill nets by 20-50%.

Distribution of small pelagis fish in FADs, and produktivity of FADs in AmFADs are usually used by fishermen to concentrate fish for an efficient catching activity. However, the number, distance, and distribution in the waters need to be assessed in relation to the productivity of the FADs in order to maintain the sustainability. This study was aimed to map the distribution of FADs; to analyze the distribution of species, number and size of fish associated with FADs; and to calculate FAD productivity based on distribution in the Outer Ambon Bay waters. Data was obtained by observation and interview. Field observation, including: coordinates and number of FADs, species, number and size of fish. The distance and distribution of FADs, was mapped using software (Argis web), while the productivity of FADs was analyzed base on catch per unit effort (CPUE). The result, FAD in Outer Ambon Bay waters was found 25 unit and the average distance of FAD was obtained 0.47 nautical miles, and the placement of the device was irregular. The placement pattern of FADs were generally straight to coastline. Small pelagic fish was found 7 species and the 5 of the dominant species were obtained Decapterus sp, Selar crumenophthalmus, Rastreliger sp, Sardinella sp and Selaroides sp. The species were unevenly spread at each FAD with quite varied sizes. FAD productivity showed that the highest productivity was found in the middle group FAD at Ambon Bay waters.Keywords: Distance, size, small pelagis, productivitybon Bay

Exploitation of squid by fisher’s on the southern coast of Ambon Island uses simple fishing technology with modifications based on fisher's experience. This study aims to describe tools and fishing methods, fishing seasons and areas, as well as analysis of production and income of squid fishing in the southern waters of Ambon Island. Data was collected through experimental fishing for 21 trips for each fishing gear and analysis was carried out descriptively and analysis of costs and income. The results showed that the use of a scoop net is one of the fishing gear that is not found elsewhere, while the jigger used has been modified by using underwater lights. Fishing areas in coastal areas with a distance of about 1 nautical mile. Data collection was carried out during the fishing season in September-December. Scoop net productivity is 49.5 kg/trip, and labor productivity is 16.5 kg/person/trip. Jigger production is 509.88 kg and labor productivity is 24.28 kg/person/trip. The net profit of each fisher’s per month from scoop and jigger are Rp.3,025,250 and Rp.2,665,000, respectively