scholarly journals Population dynamics of pronghorn spiny lobster (Panulirus penicillatus) in Palabuhanratu Bay, Sukabumi, West Java

Author(s):  
Mennofatria Boer ◽  
Rudi Alek Wahyudin ◽  
Yusli Wardiatno ◽  
Achmad Farajallah ◽  
Agus Alim Hakim

Pronghorn spiny lobster (Panulirus penicillatus) is one of the dominant lobsters and has high economic value. The fishing activities are conducted continuously and put aside the preservation of these resources. This study purposed to analyze the population dynamics of pronghorn spiny lobster (Panulirus penicillatus) in Pelabuhanratu Bay, Sukabumi, West Java. The data were collected from January until December 2016 with samples from local fisherman. Lobsters were measured carapace length and total weight. Data analysis included the relationship between length and weight, growth parameters, recruitment patterns, mortality, exploitation rate, length at first maturity or incubating eggs (Lr), and length for first capture (Lc). Panulirus penicillatus from the Palabuhanratu Bay has growth pattern of a negative allometric in both males and females. The asymptotic carapace length (CL∞) of males is higher than females while the growth coefficient (K) of males is lower than females. The peak recruitment for males is expected to be in April and July, while for females in May and August. The total mortality rate of males is higher than the natural mortality rate and vice versa for females. The male lobsters have occurred overexploitation, while females have not occurred overexploitation. The female lobsters have an Lr <Lc value which indicates that the female lobsters are caught after incubating the eggs.

2013 ◽  
Vol 19 (2) ◽  
pp. 99 ◽  
Author(s):  
Duranta D. Kembaren ◽  
Ali Suman

Study of biology and population dynamic of banana shrimp (<em>Penaeus merguiensis</em>) in Tarakan waters, East Borneo was carried out from January to November 2012. The aim of this research was to identify the biological aspects and population dynamics of banana shrimp. For estimating dynamic population, data were analysed using FiSAT II. The result showed that length at first capture (Lc) of banana shrimp by mini trawl (pukat hela) was 35 mm and the size at first maturity (Lm) was 33,86 mm in carapace length. Spawning occured all year around and reached it’s peak in March. The growth coefficient (K) of banana shrimp was 1,45/year with carapace asymptotic length (CL”) of 80 mm. Total mortality rate (Z) and natural mortality rate (M) were 4,85/year and 1,76/year. While fishing mortality rate (F) and exploitation rate (E) were 3,09/year and 0,64, respectively. The exploitation rate of banana shrimp in Tarakan waters tended to be overexploited so that it needed to be managed wisely and carefully by reducing the fishing effort and fishing season especially on spawning season. The recruitment peak of banana shrimp occured in May.


2019 ◽  
Vol 23 (4) ◽  
pp. 207
Author(s):  
Suradi Wijaya Saputra ◽  
Anhar Solichin ◽  
Wiwiet Teguh Taufani

One of the most-caught shrimp in north coast of Central Java is Penaeus merguiensis. However, little is known on the population biology of the organisms. This study was aimed to investigate length-weight relationship, growth, length at first capture (Lc50), mortality rate, and exploitation rate of P. merguiensis in Western part of Central Java’s northern coastal waters. The study was conducted from May 2016 to July 2017 using survey method. Samples were taken for 15 times (month) from 9 coastal fishing ports. The result shows that the relationship of the carapace length and weight is negative allometry. The growth parameters of CL∞ and K were 52.5mm and 1.3 y-1 (male) and 57.25mm and 1.2 y-1 (female). Total mortality rate (Z), natural mortality rate (M), and fishing mortality rate (F) were 4.51 y-1, 1.86 y-1 and 2.65 y-1 (male), and 5.36 y-1, 1.72 y-1, and 3.64 y-1 (female), respectively. The exploitation rate (E) of male banana shrimp was 0.59, and for female shrimp was 0.68. The result shows that the exploitation level has exceeded the optimum level (E>0.5). Recruitment of P. merguiensis may occur the whole year, but it peaks were in March and August (male), April and August (female). Carapace length of first captured (CLc50) was 20.63mm (male) and 18.28mm (female). It means that the sized of captured P. merguiensis is less than the size of first mature (CLm50) or growth overfishing and as a result, disrupting the availability of adult shrimp. The condition occurs due to the size of cod-end mesh measured 0.75inc.


2020 ◽  
Vol 7 (3) ◽  
pp. 517-531
Author(s):  
Komba Jossie Konoyima ◽  
Lahai Duramany Seisay

The study evaluated aspects of population dynamics of Pagruscaeruleostictus and the implications for management in Sierra Leone, needed to support efficient management plans of its fishery. 12, 729 specimens of Pagruscaeruleostictus were collected off Sierra Leone from January-November, 2016 using randomized sampling techniques on-board demersal trawler. Analysis of population dynamics employed methods fitted in FiSAT II software using pooled length-frequencies. Estimated growth parameters were asymptotic length (L∞ = 34.48cm) and weight (W∞ = 4693.6g), growth rate (K = 0.29yr-1), growth performance index (ɸ = 2.54), growth exponent (b = 3.09), theoretical age (to = -0.8years) and life-span (tmax = 9.50years). The instantaneous fishing mortality rate (F = 0.40yr-1) climaxed the optimum fishing mortality rate (Fopt = 0.30yr-1) and slightly below the limiting fishing mortality (Flimit = 0.51yr-1) whereas natural mortality rate (M) gave 0.76yr-1. Besides, the estimated current exploitation rate (Ecurrent) exceeded the estimated sustainable level of exploitation (E50 = 0.39yr-1) but below the estimated maximum allowable exploitation point (Emax = 1.10yr-1). Further, the length (Lm50 = 23.00cm) and age (tm50 = 4.60years) at first maturity climaxed the length and age at first capture (Lc50 = 21.64cm, tc50 = 3.8years,), length and age at first recruitment (Lr = 13.00cm, tr = 2.4years). Results portrayed slow and isometric growth, median life-span and high survival of a continuously recruited spawning stock of Pagruscaeruleostictus. Also, the stock suffered growth overfishing, moderate fishing pressure and overexploition, implying the need for management to recalibrate measures for rational exploitation. Res. Agric., Livest. Fish.7(3): 517-531,  December 2020


2018 ◽  
Vol 24 (2) ◽  
pp. 125
Author(s):  
Sevi Sawetri ◽  
Subagdja Subagdja ◽  
Dina Muthmainnah

The Malayan leaf fish or locally named as kepor (Pristolepis grooti) is one of important biotic components in Ranau Lake ecosystems. This study aimed to estimate population dynamic and exploitation rate of kepor in Ranau Lake, South Sumatera. The population parameters are estimated based on length frequency data which were collected in March to October 2013. Growth parameters and fishing mortality rates were calculated using FiSAT software package. The results showed that kepor’s growth was negative allometric, which tended to gain length faster than weight. Kepor population was dominated (42%) by individual length of 10.0 to 11.0 cm. Predicted length infinity (L) was 17.28 cm with high value of growth rates (K) of 1.4 year-1. The natural mortality rate (M) is 2.57 year-1, the fishing mortality rate (F) is 5.36 year-1 and total mortality rate (Z) is 7.93 year-1. The exploitation rate of Malayan leaf fish in Ranau Lake (E = 0.68 year-1) has passed the optimum score.  


Author(s):  
Elaine Espino Barr ◽  
Manuel Gallardo Cabello ◽  
Fernando González Orozco ◽  
Arturo Garcia Boa

This paper deals with the growth and mortality analysis of the burrito grunt A n i s o t remus interru p t u s on the coast of Colima, México. The estimated growth parameters are: L¥ = 50.59 cm; W¥ = 5,051.04 g; k = 0.147 years- 1; to = -0.916 years; A0 . 9 5 = 19.46 years. Most of the growth occurred during the first year of life, when the grunt grows 12.52 cm, the second year it grows 4.95 cm and the third, 4.60 cm. The highest value of the condition index took place between February and September. The total mortality rate (Z) was calculated as 0.53 years- 1. These values are basic for the plan of administration of the fishery of this species.


2019 ◽  
Vol 32 ◽  
pp. 9
Author(s):  
Theparambil Mohamed Najmudeen ◽  
Pallangattu Kochukandan Seetha ◽  
Payiyappanal Ulahannan Zacharia

The brushtooth lizardfish Saurida undosquamis (Richardson, 1848) is a high trophic level benthic predator and is one among the most exploited demersal finfish species from eastern Arabian Sea by Indian trawlers. However, in recent years, the landings of many top predator fishes including S. undosquamis showed a declining trend resulting in a steady decline in the mean trophic levels of the fishes caught commercially in the region. We investigated the growth, mortality and stock dynamics of S. undosquamis harvested by mechanised trawls in the southeastern Arabian Sea, using length-based methods for the data collected during 2012–2016. Besides, Bayesian state-space implementation of the Schaefer model (BSM) and catch-based MSY (CMSY) estimation were also made using the data for the period 1985–2016. Total length of the fish ranged from 5.5 to 34.5 cm with average annual mean length of 22.0 cm during 2012–2016. The growth parameters L∞ and K were 37.3 cm and 0.41 year−1, respectively. The natural, fishing and total mortality coefficients were 0.92, 2.58 and 3.5, respectively and exploitation ratio was 0.82. The length at first maturity was estimated at 21.4 cm for females. The mean size in the catch is lower than the optimum length for exploitation. Fisheries reference points (MSY, Fmsy, Bmsy) as well as relative stock size (B/Bmsy) and exploitation (F/Fmsy) estimated from catch data and broad priors for resilience (r), implies an exploitation of 30% below Bmsy level. Results from the length-based Thompson and Bell prediction model indicates that reducing the present level of fishing effort by 40% would lead to a harvest of the species at a sustainable level. As “fishing down food web” is reported in recent years from eastern Arabian Sea, the exploitation of top predators need to be maintained at sustainable levels to prevent ecosystem changes along the region.


2019 ◽  
Vol 5 (2) ◽  
pp. 211
Author(s):  
I Gusti Ayu Febiana Putri Wardeni ◽  
Pande Gde Sasmita Julyantoro ◽  
Rani Ekawaty

Skipjack Tuna (Katsuwonus Pelamis) is one of the big pelagic fish in fishery resources that has high economic value and plays an important role in export activity in Indonesia. Catch activities for consumption needs for people could threatened of Skipjack Tuna availability. The growth pattern of Skipjack Tuna is needed to used as references for the appropriate management plan to protect Skipjack Tuna. The research was conducted from February to April 2017 at PPI Kedonganan, Kuta District, Badung, Bali. The fish were collected by simple random sampling method. This study showed that gillnet and handline were used as fishing gears. The length frequency distributions were in the long-range of 315-337 mm means the catch fish is still young. The growth pattern of Skipjack Tuna was negative allometric means length growth was faster than weight growth. The growth parameters of Skipjack Tuna were obtained by the asymptotic length (Linf) of 875.2 mm, growth coefficient (K) of 0.09, and theoretical age (t0) of -0.78. Skipjack Tuna have small body size with condition factors were ranged from 0.8783-1.7269. It can be concluded that these methods can be used to determine the appropriate management efforts.


2020 ◽  
Vol 49 (1) ◽  
pp. 13-22 ◽  
Author(s):  
Ismail Burak Daban ◽  
Ali Ismen ◽  
Mukadder Arslan Ihsanoglu ◽  
Koray Cabbar

AbstractThis study determines the length distribution, length– weight relationship, age, growth parameters, mortality rate, sex ratios, length at first maturity and reproduction of saddled seabream (Oblada melanura) collected monthly by fishermen around the Northern Aegean Sea between November 2017 and October 2018. The length–weight relationship was calculated as W=0.0091×L3.11 (R2=0.95) and positive allometric growth was found. The condition factor and GSI varied between 0.81–1.58 and 0.01–9.61, respectively. The spawning season extended from May to July and peaked in June. Total lengths at 50% maturity were 18.97 cm for males and 18.83 cm for females. Parameters of the von Bertalanffy growth equation were: L∞ =29.91 cm, K =0.27 per year, t0 =−0.82 year and age varied between 1 and 8. The instantaneous rates of total mortality (Z) and natural mortality (M) were 1.36 and 0.58 per year, respectively. Rates for fishing mortality F and exploitation E were 0.78 and 0.57 per year, respectively. The mean absolute fecundity (F) was 117 075±23 243 oocytes, ranging from 19130 to 470 132.


1998 ◽  
Vol 10 (2) ◽  
pp. 153-160 ◽  
Author(s):  
H.-Jörg Urban ◽  
Guillermo Mercuri

Body size, geographical distribution and biomass make Laternula elliptica one of the most important bivalve species of the Antarctic. A complete study on the population dynamics (reproduction cycle, growth, mortality and productivity) of this species from King George Island gave growth parameters for the von-Bertalanffy-growth-function of: L∞ = 112.2 mm, K = 0.160 yr 1, t0 = 0.000 yr. Total mortality was estimated as Z = 0.392 yr−1. Somatic production and mean biomass of two distinct sub-populations were 8.7 and 67.3 g AFDW m−2 yr−1 at Beach & Glacier and 20.0 and 88.6 g AFDW m−2 yr−1 at Punta Elefante. The following P / B values were calculated; Beach & Glacier = 0.129, Punta Elefante = 0.226. It is suggested that these differences are linked to mortality caused by icebergs which is expected to be higher at the shallower Punta Elefante site.


2019 ◽  
Vol 25 (1) ◽  
pp. 19
Author(s):  
Ali Suman ◽  
Prihatiningsih Prihatiningsih ◽  
Pratiwi Lestari ◽  
Andina Ramadhani Putri Pane

Study on the population dynamic of endeavour shrimp (Metapenaus ensis) was conducted in Binuangeun waters based on data collected during period of survey, January to November 2016. The purpose of the study was to identify population parameters of the endeavour shrimp. Result showed that the endeavor shrimp growth pattern in Binuangeun waters was negative allometric and sex ratio of males and females was 1.0 : 2.7. The chi square test indicated that comparison of male and female of the endeavour shrimp was significantly different. It mean that there was imbalance in number between males and females. The length at first capture (Lc) of endeavour shrimp was 28.9 mm (carapace length),smaller than the length at first maturity (Lm) at 37.7 mm (carapace length). The growth parameter of endeavour shrimp was 1.33/year with maximum carapace length (Loo) of 51.45 mm. Instantenous total mortality (Z) and natural mortality (M) were 7.74/year and 1.88/year, respectively. While fishing mortality (F) and exploitation rate (E) respectively were 5.86/year and 0.76/year. The exploitation rate of endeavour shrimp in Binuangeun and adjacent waters was high. It was, therefore, recommended that fishing effort of the endeavour shrimp in that waters should be reduced about 52 % in the next year.


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