Karimunjawa National Park (KNP) is a marine protected area established to preserve ecosystems and natural resources. Scomberomorus commerson (tenggiri) and Euthynnus affinis (tongkol) arethe two species of pelagic fish which are the main catches for artisanal fishery in KNP. This study was aimed to analyze the exploitation rate of S. commerson and E. affinis. Field survey was conducted in KNP District of Jepara, Central Java, in June-September 2016. The exploitation rate is measured by analytical method based on fish’s growth and mortality, through measuring the length of the fish for three months. Totally, as many as 314 individuals of S. Commersonand 499 individuals of E. Affinis were measured. The data were analyzed using Fish Stock Assessment Tools (FISAT II) statistical program. The results indicated that S. Commerson have a body-size trend that tends to increase, with the rate of exploitation (E) was 0,29 (under-exploited), which means there is anopportunity to increase it’s utilization. At the other hand, the size of E. Affinis tends to decrease, with the rate of exploitation (E) = 0,5. It means that the condition of utilizationof E. Affinis was at alarming position. It is necessary to control the tongkol fishing by regulating fishing gear, in order to avoid overfishing situation.
Taman Nasional Karimunjawa (TNKJ) merupakan salah satu kawasan konservasi yang bertujuan melindungi kelestarian ekosistem dan sumber daya alam. Ikan tenggiri (Scomberomorus commerson)dan tongkol (Euthynnus affinis) adalah ikan pelagis yang merupakan tangkapan utama di TNKJ. Tujuan studi ini adalah menganalisis laju eksploitasi ikan tenggiri dan tongkol. Penelitian dilakukan pada bulan Juni-September 2016. Pengukuran laju eksploitasi menggunakan metode analitik didasarkan pada pertumbuhan dan mortalitas ikan, dengan mengukur panjang ikan hasil tangkapan selama tiga bulan. Jumlah ikan tenggiri yang diukur adalah 314 ekor, dan ikan tongkol adalah 499 ekor. Analisis data menggunakan program Fish Stock Assessment Tools (FISAT II). Hasil penelitian menunjukkan tren ukuran ikan tenggiri cenderung meningkat, dengan laju eksploitasi (E) = 0,29 (under exploited), sehingga pemanfaatannya dapat ditingkatkan. Sementara ukuran ikan tongkol cenderung menurun, dengan laju eksploitasi (E) = 0,5. Kondisi pemanfaatan ikan tongkol berada pada posisi mengkhawatirkan. Sehingga perlu dilakukan pengelolaan terhadap penangkapan ikan tongkol agar tidak mengarah ke penangkapan berlebih, dengan mengatur alat tangkap nelayan.
 
