scholarly journals DINAMIKA POPULASI LOBSTER PASIR (Panulirus homarus Linnaeus, 1758) DI PERAIRAN PALABUHANRATU, JAWA BARAT

2018 ◽  
Vol 23 (3) ◽  
pp. 215 ◽  
Author(s):  
Zairion Zairion ◽  
Nefi Islamiati ◽  
Yusli Wardiatno ◽  
Ali Mashar ◽  
Rudi Alek Wahyudin ◽  
...  

Dinamika populasi merupakan aspek penting sebagai dasar pengelolaan perikanan dan informasi tentang aspek tersebut pada lobster pasir masih minim di perairan Palabuhanratu. Tujuan penelitian ini adalah mengkaji aspek pertumbuhan, pola rekrutmen, mortalitas dan laju eksploitasi lobster pasir (Panulirus homarus) di perairan Palabuhanratu. Penelitian ini dilakukan periode Juni 2015-Mei 2016 dengan metode sensus. Lobster pasir hasil tangkapan jaring insang dasar dengan jumlah total sampel 483 ekor mempunyai panjang karapas antara 28-100 mm. Pola pertumbuhan berdasarkan hasil regresi linear memperlihatkan allometrik negatif. Hasil analisis menggunakan metode ELEFAN I (Electronic Length Frequency Analysis) menunjukan koefisien pertumbuhan lobster pasir jantan (K = 0,29 per tahun), lebih kecil dibandingkan dengan betina (K = 0,40 per tahun). Rekrutmen terindikasi dua puncak dalam setahun: yaitu pada Februari-Mei dan September-Oktober). Laju mortalitaskarena penangkapan (F) mencapai 1,9-2,2 kali laju mortalitas alami (M). Nilai Lc<Lrmemperlihatkan lobster pasir sudah tertangkap sebelum mencapaiukuran rata-rata mengerami telur atau ukuran kematangan reproduktif. Laju eksploitasi lobster pasir mencapai 32-38% di atas laju eksploitasi optimum, sehingga lobster pasir sudah mengalamieksploitasi yang berlebih.Population dynamics is an important aspect as basic of fisheries management and little information of this aspect for spiny lobster fishery in Pelabuhanratu waters. This research aims to evaluate of growth aspects, recruitment pattern, mortality, and exploitation rate of scalloped spiny lobster (Panulirus homarus) in Palabuhanratu waters. This research was conducted in June 2015 until May 2016 using census method. The size of P. homarus captured using bottom gill-net with total sample 483 specimen was between 28-100 mm carapace lengths (CL). Linear regression showed that growth pattern was negative allometric. The growth coefficient of male (K = 0.29 per year) was found smaller than female (K = 0.40 per year) based on ELEFAN I (Electronic Length Frequency Analysis) method. Recruitment seems to be accrued twice peaks a year (February to May and September to October) and the highest was at February to May. Fishing mortality (F) reached 1.9 to 2.2 times of natural mortality (M). The LcÂLr value showed that female has been caught before reached the average size of bearing eggs or reproductive maturity size. The exploitation rate of spiny lobsters reaches 32-38% above optimum level. This study suggests that the spiny lobster fishery in Palabuhanratu in the state of overexploitation.

2015 ◽  
Vol 7 (3) ◽  
pp. 129
Author(s):  
Tegoeh Noegroho ◽  
Umi Chodrijah

Perikanan neritik tuna di perairan Barat Sumatera berkembang pesat beberapa dekade terakhir ini. Sementara belum banyak diperoleh hasil penelitian tentang populasi ikan tongkol lisong (Auxis rochei). Penelitian tentang parameter populasi dan pola rekruitmen ikan tongkol lisong dilakukan pada bulan Februari-Desember 2013 di beberapa lokasi pendaratan ikan di Barat Sumatera. Tujuan penelitian ini adalah untuk memperoleh laju pertumbuhan, panjang asimptotik, laju kematian, laju eksploitasi, dan pola rekruitmen ikan tongkol lisong (Auxis rochei). Estimasi parameter populasi menggunakan model analitik berdasarkan program “Electronic Length Frequency Analysis (ELEFAN 1)”. Data frekuensi panjang dikumpulkan berkesinambungan di beberapa tempat pendaratan utama. Hasil penelitian menunjukkan panjang cagak ikan tongkol lisong yang tertangkap berada pada kisaran 11-42 cmFL. Parameter pertumbuhan Von Bertalanffy diperoleh nilai laju pertumbuhan (K) sebesar 0,54/tahun, panjang asimptotik (L ) sebesar 43,5 cm FL, dan umur ikan pada saat panjang ke-0 (-t0) sebesar -0,076/tahun. Laju mortalitas total (Z) sebesar 1,96/tahun. Laju kematian karena penangkapan (F) sebesar ,07/tahun, dan laju kematian alami (M) 0,89/tahun. Laju eksploitasi (E) tongkol lisong di Barat Sumatera adalah 0,49/tahun atau berada pada tingkat eksploitasi moderat. Pola rekrutmen tongkol lisong terjadi dua kali dalam setahunnya, yaitu mencapai puncak pada bulan Maret dan Juni.Neritic tuna fishery in theWest Sumatra waters was developed very intensively in the captured.Meanwhile, study population of bullet tuna (Auxis rochei) in those are still limited. Research in population parameters and recruitmen pattern of bullet tuna has been conducted in February-December 2013 based on several landing place inWest Sumatra. The aim of this study is to obtain asymptotic length, mortality rate, exploitation rate, and recruitment pattern of bullet tuna (Auxis rochei). Estimation of population parameters using an analytical model based on the program “Electronic Length Frequency Analysis (ELEFAN 1)”. Length frequency data collected continuously in themain landing places The results showed the fork length of bullet tuna was caught in the range 11-42 cm FL. Von Bertalanffy growth parameters obtained the growth rate value (K) of 0,54/year, asymptotic length (L ) of 43,5 cm FL, and fish age when the length to the-0 (-t0) of -0,076/year. Total mortality was 1,96/year. Fishing mortality rate (F) was 1,07/year and natural mortality rate (M) 0,89/year. The exploitation rate (E) of bullet tiuna in West Sumatra was 0,49 / year or are at a moderate level of exploitation. Recruitment patterns of bullet tuna happen twice in a year, which reached a peak in March and June.


2015 ◽  
Vol 7 (3) ◽  
pp. 165
Author(s):  
Prihatiningsih Prihatiningsih ◽  
Nurainun Mukhlis ◽  
Sri Turni Hartati

Ikan bawal putih (Pampus argenteus) mempunyai nilai ekonomis penting dan sebagai salah satu komoditas unggulan di perairan Tarakan. Informasi tentang biologi perikanan ikan tersebut masih terbatas. Penelitian ini bertujuan untukmengestimasi parameter populasi meliputi pertumbuhan, umur, mortalitas dan tingkat eksploitasi ikan bawal putih. Data frekuensi panjang bulanan dikumpulan pada Februari – Nopember 2013 dengan bantuan enumerator. Sebaran frekuensi panjang ikan dipisahkan kedalam sebaran normal menggunakan metode Bhattacharya pada progran FiSAT (FAO-ICLARM Stock Assessment Tools). Estimasi parameter populasi dengan aplikasi model analitikmenggunakan program ELEFAN-1 (Electronic Length Frequency Analysis). Hasil penelitian menunjukkan ukuran panjang ikan bawal putih berkisar antara 9,0 cm–35,0 cmFL. Hubungan panjangberat ikan bawal putih yang tertangkap dengan jaring insang bersifat allometrik negatif mengikuti persamaan W= 0,187L2,374. Nilai rata-rata panjang ikan pada saat pertama kali tertangkap (Lc) sama dengan ukuran pertama kali matang gonad (Lm). Laju pertumbuhan (K) sebesar 0,52/tahun dan panjang asimptotik (L ) sebesar 37,28 cmFL. Persamaan pertumbuhan dari Von Bertalanffy sebagai Lt = 37,28 (1 – e-0,52(t-+0,07)). Mortalitas alami (M) adalah 1,11/tahun, mortalitas karena penangkapan (F) = ,65/tahun dan mortalitas total (Z) = 1,65/tahun. Laju pengusahaan (E) sebesar 0,60 berarti tingkat eksploitasinya sudah melebihi dari nilai optimal (E=0,5) atau populasi ikan bawal putih dalam keadaan lebih tangkap (over exploited). Untuk itu diperlukan kebijakan pengelolaan secara hati-hati dengan mempertimbangkan aspek biologi dan aspek penangkapan yang sedang berjalan.White pomfret (Pampus argenteus) is one of the economically important fish and includes leading commodity in Tarakan waters. Information of fishing biology of those species were still limited. This study aims to determine the population parameters including growth, age, mortality and exploitation rate of white pomfret. Monthly length frequency data have been collected by enumerator from February to November 2013. Fish lengthfrequency distribution was separated into a normal distribution using the Bhattacharya method with software of FiSAT (FAO-ICLARMStock Assessment Tools). Estimation of population parameters were use analytical model application with ELEFAN-1 (Electronic Length Frequency Analysis) program. The results showed that lengths distribution of white pomfret ranged beetwen 9.0 cm -35.0 cmFL. Length-weight relationship was negatively allometric. Estimating the average length at first captured (Lc) was equal with average length at first maturity (Lm) with growth equation of Lt = 37.28 (1 - e-0, 52 (t +0.07)). Natural mortality (M) was 1.11/year, fishing mortality (F) was 1.65/yearand total mortality (Z) was 1.65/ year. The exploitation rate (E) was 0.60. It is mean that more higher than optimal exploitation so that the white pomfret fish population in a state of over fished. It is necessary to better policy in the management of white pomfret through precaution approach and describing of biologycal and fishing aspect in Tarakan, Kalimantan Timur.


2015 ◽  
Vol 7 (3) ◽  
pp. 121
Author(s):  
Duranta D Kembaren ◽  
Erfind Nurdin

Penelitian tentang distribusi ukuran dan parameter populasi lobster pasir di perairan Aceh Barat dilakukan pada bulanApril sampai November 2013. Penelitian ini bertujuan untukmengkaji status lobster di perairan Aceh Barat dilihat dari aspek distribusi ukuran dan parameter populasinya. Pengamatan dan pengukuran lobster dilakukan di tempat pengumpul lobster dengan sistem sampling acak. Sebaran frekuensi panjang karapas selanjutnya ditabulasikan dan dianalisa dengan metode kurva logistik. Struktur ukuran lobster yang tertangkap menunjukkan bahwa lobster jantan dominan tertangkap dibawah ukuran nilai tengah 72,5 mm dan sebaliknya diatas ukuran nilai tengah 72,5 mm yang didominasi jenis kelamin betina. Lobster terlebih dahulu tertangkap sebelum mencapai ukuran matang gonad (Lc = 65,8mm< Lm= 76,8 mm). Puncak musim pemijahan terjadi pada bulan Mei dan Agustus. Panjang asimtosis (CL∞ ) sebesar 119,5 mm dengan laju pertumbuhan (K) 0,39/tahun serta laju kematian total (Z) 1,44/tahun, laju kematian alamiah (M) 0,67/tahun dan laju keamatian akibat penangkapan (F) 0,77/tahun. Laju eksploitasi sudah mengarah kepada penangkapan yang berlebih (E=0,54), oleh karena itu perlu dilakukan tindakan pengelolaan perikanan lobster yang berkelanjutan. Salah satu upaya yang dapat di tempuh adalah dengan menerapkan sistem penutupan musim penangkapan lobster pada saat terjadinya puncak musim pemijahan.Research on the length distribution and population parameters of scalloped spiny lobster conducted in the Aceh Barat waters during April to November 2013. The aim of this study was to assess lobster fishery status in this waters from the point of view their length size and population parameters. Sampel collected randomly in the lobster landing site. Distribution of carapace length frequency was tabulated and analysed using logistic curve method. Length composition of male lobster was dominated under 72,5 mm midlenght, while female lobster was dominated above 72,5 mm midlength. This study found that the scalloped spiny lobster was caught before their reach the size of maturity (Lc = 65,8 mm < Lm = 76,8 mm). The peak season of spawning was indicated on May and August. Asimtotic length (CL∞) of scalloped spiny lobster was 119,5 mm with the growth rate (K) 0,39/year, total mortality (Z) 1,44/year, natural mortality (M) 0,67/year, and fishing mortality (F) 0,77/year. Exploitation rate was leading to the overfishing condition (E=0,54). Thus, it is needed to manage the lobster fishery in this area to gain the sustainability. We suggest that closing system season should be applied, especially in the peak spawning season.


2014 ◽  
Vol 80 (4) ◽  
pp. 665-678 ◽  
Author(s):  
Hiroshi Yamaguchi ◽  
Yoko Goto ◽  
Noboru Hoshino ◽  
Kazushi Miyashita

1954 ◽  
Vol 5 (3) ◽  
pp. 513 ◽  
Author(s):  
RM Cassie

Methods are described by which the component groups may be extracted from polymodal size frequency samples by the use of probability graph paper. Four examples are given illustrating: the solution of a distribution with more than two modes and with only one exposed flank; the coordination of fish age determinations by the two methods, length frequency analysis and scale reading; a bivariate sample where the two means coincide though the standard deviations are different; a method of correcting for truncation.


2020 ◽  
Vol 225 ◽  
pp. 105474 ◽  
Author(s):  
Kun Wang ◽  
Chongliang Zhang ◽  
Binduo Xu ◽  
Ying Xue ◽  
Yiping Ren

1990 ◽  
Vol 47 (7) ◽  
pp. 1330-1338 ◽  
Author(s):  
Bruce F. Phillips

Studies of juvenile rock lobsters (Panulirus cygnus) in the nursery reefs of Western Australia indicated that density-dependent processes on the reefs were the major determinant of year-class strengths of recruitment to the fishery. Reassessment of early data, plus additional information, indicates that these estimates may have been inaccurate. Alternative methods of estimating juvenile densities were examined; application of length–frequency analysis to calculate the age-classes; visual estimates, and single-night trapping. Length–frequency analysis indicated that either immigration onto the test reefs had occurred, or the data were inaccurate. Visual estimates and single-night trapping were more rapid and used less manpower and resources than mark–recapture methods, but the estimates were of unknown accuracy. No truly satisfactory method of making reliable estimates of either the density of natural mortality rate of juveniles in the nursery reefs is yet available. Nevertheless, the data on the levels of larval settlement and subsequent catches, suggest that density dependent processes probably have a significant effect on the levels of recruitment to the fishery, although the upper level to this recruitment has not been reached over the past 20 yrs.


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