Using line transect sampling to detect cetaceans and floating litter during vessel survey in western Black Sea

<p>                The quality of the Black Sea ecosystem is partly but importantly dependent on the survival and sustainability of the top predator populations. It is difficult to foresee all consequences for the regional biodiversity if cetaceans disappear as it had happened with the Mediterranean monk seals in the past. During 7 days, between 30 September and 7 October, 2019, a joint oceanographical survey was made with a multipurpose R/V Mare Nigrum in offshore as well as deep sea locations, within the Romanian (RO), Bulgarian (BG) and western Turkish (TK) national waters of the Black Sea in the frame of ANEMONE project. The total track line was around 700 nautical miles and the sampled area covered 9754,58 km<sup>2</sup>. Observations were made of cetaceans and floating litter, following line transect sampling method, with a single platform (2 observers, on the left and right of the vessel bridge) over 380.44 km of transects. A total of 54 cetacean sightings and 81 floating litter items were recorded. All the three species, short-beaked common dolphin (<em>Delphinus delphis</em> ssp. <em>ponticus</em>), Black Sea bottlenose dolphin (<em>Tursiops truncatus</em> ssp. <em>ponticus</em>), and Black Sea harbour porpoise (<em>Phocoena phocoena </em>ssp. <em>relicta</em>), were registered with a similar density (individuals/km<sup>2</sup>), 0.012 for RO sector and 0.013 for BG-TK sector. The number of debris varied between 1 and 24 items, reaching 5.26± 5.93 items on average. Among the transects, 53% contained less than 5 items and only 13% were with more than 10 items. Based on these results, the average density of floating macro-litter in BG waters was found 2.43 ± 2.4 items/km<sup>2</sup>, 1.73 ± 1.24 items/km<sup>2 </sup>in the RO waters and 2.43±2.17 items/km<sup>2</sup> in TR waters. This study was the first to make a joint and continuous survey effort for both cetaceans and litter simultaneously in the Black Sea.</p><p><strong>Key words:</strong>  Black Sea, cetaceans, marine litter, joint cruise, ANEMONE project.</p>

Performance of Parametric Model for Line Transect Data

One of the most important sides of life is wildlife. There is growing research interest in monitoring wildlife. Line transect sampling is one of the techniques widely used for estimating the density of objects especially for animals and plants. In this research, a parametric estimator for estimation of the population abundance is developed. A new parametric model for perpendicular distances for detection function is utilised to develop the estimator. In this paper, the performance of the parametric model which was developed using a simulation study is presented. The detection function has non-increasing curve and a perfect probability at zero. Theoretically, the parametric model which has been developed is guar-anteed to satisfy the shoulder condition assumption. A simulation study is presented to validate the present model. Relative mean error (RME) and Relative Bias (RB) are used to compare the estimator with well-known existing estimators. The results of the simulation study are discussed, and the performance of the proposed model shows promising statistical properties which outperformed the existing models. Keywords: detection function, line transect data, parametric model

Populasi Monyet Ekor Panjang (Macaca fascicularis) di Kawasan Batuan Kapur Jawa Barat

Abstrak. Monyet ekor panjang (Macaca fascicularis) merupakan satwa primata termasuk ke dalam Genus Macaca. Monyet ekor panjang mempunyai daya adaptasi yang tinggi terhadap lingkungan sehingga populasi yang ada di alam semakin bertambah setiap tahunnya. Penelitian ini bertujuan untuk mengetahui jumlah individu dan kepadatan populasi monyet ekor panjang (M. fascicularis) di Gunung Kapur Cicadas Desa Ciampea. Penelitian ini dilaksanakan pada bulan April sampai Juli 2015. Pengumpulan data menggunakan metode jalur (line transect sampling). Hasil penelitian ini diperoleh total individu monyet ekor panjang sebanyak 245 individu dengan jumlah masing-masing individu jantan dan betina dewasa diperoleh 38 individu (15,51%), remaja 56 individu (22,86%), anak 91 individu (37,14%), dan bayi 22 individu (8,98%), dan kepadatan populasinya sebesar 2,0 individu/Ha.Kata Kunci: Populasi, Monyet Ekor Panjang, Gunung Cicadas, Ciampea, Bogor Abstract. Long-tailed macaque (Macaca fascicularis) is a species of primates into the Genus Macaca. Long-tailed monkeys have high adaptability to the environment so that the population that exists in nature is growing every year. This study aims to determine the number of individuals and the population density of long-tailed macaques (M. fascicularis) in Gunung Kapur Cicadas Ciampea village. This study was conducted from April to July 2015. The datawas collected using a path (line transect sampling). The results of this study obtained individual total long-tailed macaques were 245 individuals with the number of individual males and females adult obtained 38 individuals (15,51%), juvenile 56 individuals (22,86%), children 91 individuals (37,14%), and infants 22 individuals (8,98%), and a population density of 2,0 individual / Ha.Keyword: Population, Long-tailed monkeys, Mount Cicadas, Ciampea, Bogor

An Adaptation of Kernel Density Estimation for Population Abundance using Line Transect Sampling When the Shoulder Condition is Violated

Kernel estimation is a commonly used method to estimate the population density in line transect sampling. In general, the classical kernel estimator of (0) X f , which is the probability density function at perpendicular distance x  0 , inclines to be underestimated. In this study, a power transformation of perpendicular distance is proposed for the kernel estimator when the shoulder condition is violated. The mathematical properties of the proposed estimator are derived. A simulation study is also carried out for comparing the proposed estimator with the classical kernel estimators

Population Density of Kloss’s Gibbon (Hylobates klossii) at Bojakan Resort, Siberut Island, West Sumatra

Bilou (Hylobates klossii) merupakan satwa primata endemik Kepulauan Mentawai, Sumatera Barat dan ditetapkan sebagai satwa primata dengan status terancam/genting (endangered) berdasarkan kategori IUCN (International Union for Conservation of Nature and Natural Resources) tahun 2008. Saat ini, informasi populasi bilou terbaru di Pulau Siberut belum diketahui secara lengkap dan menyeluruh. Penilaian terhadap populasi dijadikan sebagai landasan dalam menentukan strategi konservasi. Penelitian bertujuan mengidentifikasi populasi bilou yang meliputi distribusi populasi, kepadatan individu, kepadatan kelompok, ukuran kelompok, serta komposisi kelompok. Penelitian dilaksanakan di Resort Bojakan, Taman Nasional Siberut, Pulau Siberut, Kepulauan Mentawai, Sumatera Barat pada bulan November 2018 sampai Januari 2019. Pengamatan dan pengukuran parameter populasi bilou dilakukan dengan metode line transect sampling. Total perjumpaan dengan bilou sebanyak 77 individu dengan jumlah 25 kelompok. Nilai kepadatan individu 12,8 individu/km2, dan kepadatan kelompok 4,2 kelompok/km2. Rerata ukuran kelompok bilou di Resort Bojakan 3,08 individu/kelompok. Keberadaan populasi bilou di Resort Bojakan dipengaruhi akibat adanya gangguan aktivitas manusia. Kepadatan populasi bilou di Resort Bojakan lebih tinggi dibandingkan dengan penelitian-penelitian sebelumnya di wilayah Pulau Siberut. Persentase kelompok bilou yang memiliki ukuran kelompok lebih dari dua individu lebih tinggi dibandingkan kelompok dengan jumlah dua individu, yang menandakan kawasan Taman Nasional Siberut terutama di Resort Bojakan mendukung pertumbuhan populasi bilou. Proses regenerasi bilou masih terus berlangsung karena jumlah kelompok yang memiliki minimal satu keturunan atau lebih masih cukup banyak. Pemantauan dan patroli oleh pihak Taman Nasional diperlukan untuk memastikan keberadaan populasi bilou di Resort Bojakan. Kata kunci: primata endemik, bilou, metode garis transek, monogami