Rajungan (Portunus pelagicus) merupakan salah satu jenis krustasea laut yang bernilai ekonomis penting yang menjadi target utama tangkapan di perairan Teluk Jakarta. Penelitian ini bertujuan untuk mengkaji dinamika populasi rajungan yang berguna sebagai dasar pengelolaannya. Penelitian dilakukan pada periode Januari sampai dengan November 2015. Hasil penelitian menunjukkan bahwa hubungan panjang berat rajungan bersifat allometrik positif dan rata-rata ukuran pertama kali matang gonad (Lm) sebesar 106,81 mm (lebar karapas), laju pertumbuhan (K) sebesar 1,0 per tahun dan lebar karapas infinitif (CW)  sebesar 157 mm. Laju kematian akibat penangkapan (F) sebesar 1,12 per tahun dan laju mortalitas alami (M) sebesar 1,14 per tahun. Laju eksploitasi (E) sudah berada pada tahapan penuh atau fully exploited, dengan demikian perlu adanya pengendalian upaya penangkapan.Blue swimming crabs (Portunus pelagicus) is one of the important marine crustaceans species forming the main target of fishing in the Jakarta Bay. This study aims to assess the population dynamics of crab for the basis e for their management. The study was conducted from January to November 2015. The result showed that carapace width and weigth relationship analysis was isometric and the estimated length at first maturity (Lm) was 106.81 mm (in carapace width), growth rate (K) was 1 mm per year, carapace width infinit (CW) was 157 mm, fishing mortality (F) was 1.12 per year and natural mortality rate (M) at about 1.14 per year. The exploitation rate (E) was predicted at fully exploited level, so that control of fishing effort are needed.

Abstract. Removal methods were used to estimate key fishery parameters, abundance and exploitation rate for five species of tropical sea cucumbers harvested by Indonesian fishers at Scott Reef, north-western Australia. Detailed catch records were kept by the traditional fishers over a period of 58 days as needed for this method, whereas effort was estimated from aerial surveillance. Concurrently, ,1007 artificial sea cucumber surrogates, were distributed and rewards were paid for recovered surrogates. Both datasets were analysed using the Huggins closed-population procedure in program MARK to obtain maximum-likelihood estimates. This procedure allowed inclusion of effort and tide covariates and an initial search phase followed by an exploitation phase. We accounted for extreme over-dispersion which is a common problem in fishery removal data. Our results strongly suggested that some surrogates became unavailable to the fishers. However, results from both datasets demonstrated strong evidence of extreme rates of exploitation on the shallow, drying reef-top habitat. Closed-removal or depletion methods are shown to be a viable method to estimate abundance and exploitation rate for sea cucumbers harvested with intense fishing pressure during a short fishing season.

Sebagai alat bantu penangkapan ikan, penggunaan rumpon sekarang ini semakin meningkat dan tidak terkendali. Ketidak pastian waktu penangkapan membuat operasi penangkapan tidak efisien dengan biaya yang tinggi. Informasi musim penangkapan ikan dapat membantu untuk melakukan penangkapan ikan secara terencana dan efisien. Tujuan penelitian ini untuk menganalisis musim penangkapan ikan cakalang di perairan Palabuhanratu sehingga pemanfaatan ikan cakalang dapat dilakukan lebih efektif berdasarkan musim penangkapan dan ukuran panjang ikan yang tertangkap. Pengumpulan data ukuran panjang dan bobot cakalang dilakukan terhadap 2.580 individu. Analisa musim penangkapan dilakukan dengan metode persentase rata-rata, pola pertumbuhan berdasarkan hubungan panjang dengan berat, kapasitas fisik ikan dengan faktor kondisi (Kf). Hasil penelitian menunjukkan musim penangkapan berlangsung September sampai dengan Desember, struktur ukuran panjang antara 24 sampa dengan 60 cmFL dengan ukuran panjang pertama kali tertangkap (Lc) sebesar 40 cmFL. Hubungan panjang dengan berat bersifat allometrik positif dan nilai rata-rata faktor kondisi (KF) sebesar 1,7. As a fishing tool, the use of FADs is now increasing and uncontrollable. Uncertainty of fishing season makes fishing operations inefficient at high cost. Season fishing information can help to catch a fish in a planned and efficient manner. The purpose of this research is to analyze the skipjack fishing season in Palabuhanratu waters so that the utilization of skipjack can be done more effectively based on the catching season with the length of fish caught. The purpose of this study is to analyze the skipjack fishing season in Palabuhanratu waters so that the utilization of skipjack fish can be done more effectively based on the catching season and the length of the fish caught. Length and width of skipjack data collection were conducted on 2,580 individuals.The analysis of the fishing season was performed by means of average percentage method, growth pattern based on length and weidth relationship, physical capacity of fish with condition factor (Kf). The results showed that the fishing season begin from September until to December, the size structure of the length between 24 until 60 cmFL with the size of length first capture  (Lc) is 40 cmFL..The long relationship with the weight is allometrically positive and the value of mean condition (KF) is 1.7.

Tingginya permintaan pasar terhadap lobster mengakibatkan aktivitas penangkapannya di perairan Gunung Kidul dan sekitarnya berlangsung terus-menerus sepanjang tahun sehingga mengancam kelestariannya. Penelitian tentang status stok merupakan salah satu dasar utama dalam merumuskan pengelolaan menuju pemanfaatannya secara berkelanjutan. Tujuan penelitian ini adalah untuk mengetahui dinamika penangkapan, parameter populasi serta tingkat pemanfaatan lobster pasir (Panulirus homarus) dan lobster batu (Panulirus penicillatus) di perairan Gunung Kidul. Pengumpulan data bulanan dilakukan dengan bantuan enumerator dari bulan Januari sampai dengan Oktober 2016 menggunakan metode survey. Parameter populasi dianalisis dengan program FISAT. Hasil penelitian menunjukkan bahwa alat tangkap yang digunakan untuk menangkap lobster adalah jaring lobster dan jaring krendet. Musim penangkapan berlangsung sepanjang tahun dengan puncaknya antara bulan Oktober sampai dengan Desember. Struktur ukuran lobster pasir berkisar antara 35-100 mm (panjang karapas) dan untuk lobster batu berkisar antara 30-110 mm (panjang karapas). Ukuran rata-rata pertama kali tertangkap (Lc) kedua jenis lobster tersebut umumnya lebih kecil dari ukuran rata-rata pertama kali matang kelamin (Lm). Laju pertumbuhan (K) lobster tergolong rendah dan laju kematian karena penangkapan (F) lebih besar dari laju kematian almiah (M). Laju eksploitasi (E) lobster pasir adalah 0,66 per tahun dan untuk lobster batu adalah 0,52 per tahun, dengan demikian status stok lobster sudah berada pada penangkapan berlebih (overfishing). Agar sumber daya lobster terjamin kelestariannya, maka harus dilakukan pengurangan upaya dari jumlah upaya yang ada saat ini.The high market demand for the spiny lobster cause an intensive fishing for its resources efforts in Gunung Kidul and adjacent waters and tend to threatening their sustainability. Studies for spiny lobster stock status are the main foundations for formulating a management for sustainable utilization. The purpose of this study was to determine the fishing dynamic, population parameters and exploitation rate of scalopped spiny lobster (Panulirus homarus) and pronghorn spiny lobster (Panulirus penicillatus) in Gunung Kidul and adjacent waters. Monthly data were collected by enumerators. Study was conducted in Gunung Kidul and adjacent waters from January to October 2016 using a survey method. The results showed that the main fishing gears for spiny lobster were lobster net (bottom gillnet monofilament) and krendet net (hoop net). Fishing season of this lobster occur throughout the yearly with the peak season at October to December. The carapace length range for scalopped and pronghorn spiny lobsters were in the range of 35-100 mm and 30-110 mm, respectively. The length at first capture (Lc) of those spiny lobster were smallert han the length at first maturity (Lm). The growth rate (K) of spiny lobster was low and the fishing mortality rate (F) was higher than natural mortality rate (M). The exploitation rate (E) of scalopped and pronghorn spiny lobster was 0.66 per year and 0.52 per year, respectively. It showed that the exploitation rate of spiny lobster were overfishing. In order to ensure the sustainability of the spiny lobster, there is needed to apply the precautionary approach such as reducing fishing effort by 32 % for scalopped spiny lobster and 4 % for pronghorn spiny lobster from the current situation.

The sustainability of the exploitation of the Indonesian fishes depends heavily on many of fish's basic information including both larvae distribution and dispersal. However, the identification of fish larvae and juvenile to species is very limited. In this study, we employed DNA barcoding techniques to identify marine fish larvae to a species level in Jakarta Bay and Banda Sea by comparing the querries with sequences from adult stage as reference library to contribute on biodiversity information on that particular area. The result revealed that in Jakarta Bay, the molecular marker of a 471 bp region of the mitchondrial cyctochrome c oxidase I gene (COI) has been successfully found to be species-specific, genetic distance within species (0.0 -1.30 percent). There are total of 8 families, 5 genera and 5 species from a total 15 successful PCR that could be used to calculate the accuracy of larval fish identification in three taxonomic categories. Meanwhile in Banda Sea, for the adult specimens, after some of PCR experiment, we have successfully amplified 27 individuals, only 8 sequences available. There are a total 326 eggs and larvae which been collected from 19 stations, of the 28 successfully amplified PCR samples, 11 sequences were available for DNA analysis and at least 10 species used Banda Sea and surrounding area as their spawning ground. We prove the ability of COI barcodes to identify species level resolution from query sequences and to classify species from distinct geographical origins and determine of how the data retrieved give important information for proposing plans for conserving and managing of fisheries in the sea waters.