<![CDATA[Tongkol abu-abu atau longtail tuna (Thunnus tonggol) salah satu jenis ikan tuna neritik sebagai target penangkapan armada pukat cincin, jaring isang, dan pancing di Laut Jawa. Penelitian ini bertujuan untuk mengetahui parameter pertumbuhan, umur dan mortalitas ikan tongkol abu-abu untuk penyusunan strategi pengelolaannya. Pengumpulan data frekuensi panjang dan bobot ikan dilakukan di Pelabuhan Perikanan Nusantara (PPN) Pekalongan pada Januari – Nopember 2014. Hasil penelitian menunjukkan hubungan panjang-bobot ikan tongkol abu-abu bersifat isometrik dan indek kecepatan pertumbuhan 3,46/tahun. Ikan dapat tumbuh hingga mencapai panjang asimtotik (L) = 85 cm dengan laju pertumbuhan (K) sebesar 0,4/tahun. Umur teoritis pada saat panjang ikan sama dengan nol (t0) adalah 0,046 tahun. Umur maksimal diduga 15 tahun. Mortalitas alami (M) sebesar 0,61/tahun, mortalitas karena penangkapan (F) 1,01/tahun, mortalitas total (Z) 1,62/tahun. Tingkat eksploitasi (E) sebesar 0,59 berarti bahwa pemanfaatan ikan tongkol abu-abu di Laut Jawa cenderung sudah penuh (fully exploited).Longtail tuna as one of neritic tuna species are commonly caught by purse seine, gill net and hand line in java sea.. This research activity aims to determine population parameters i.e. growth, mortality and its exploitation rate that can contribute to strengthen database on preparation its harvest strategy. The Collecting of length and weight data were conducted at Pekalongan fishing port during period of January to November 2014. The Long-weigth relationship was isometric and growth performance index was 3.46/year. The asymptotic length rate (L) was 85 cmFL, growth rate (K) was 0.4/year and zero age (t0) was 0.046 year. This length is reached allegedly at the 15 years age. Natural mortality (M) was 0.6/year, fishing mortality (F) was 1.01/year, total mortality (Z) was 1.62/yera. The exploitation rate (E) was 0.59, it means exploitation of longtail tuna in the Java Sea tend to highly exploited.]]>
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