Estimation of Growth and Mortality Parameters for Two Penaeid Species of Tanzanian Coastal Waters

Assessment of the growth and mortality parameters of Fenneropenaeus indicus and Metapenaeus monoceros was conducted. Samples for the study were collected during two ship surveys conducted in February and June 2011 and from land-based surveys on two sites at Bagamoyo and Nyamisati, which was conducted between February 2011 and December 2012. Lengthbased stock assessment FiSAT II software package was used for assessment. The growth parameters which were asymptotic size (L∞), growth coefficient (K), total (Z) and natural (M) mortality, exploitation rate (E) and recruitment pattern were estimated. The results of analysis indicate that asymptotic size (L∞) for F. indicus was 44.1 mm CL for zone 1, zone 2 and Bagamoyo while Nyamisati was 48.3 mm CL. The growth coefficient (K) was 0.42, 0.83, 0.3 and 0.65 per year for zone 1, zone 2, Bagamoyo and Nyamisati respectively. The natural mortality (M) value was low in Bagamoyo and high in zone 2 while exploitation rate (E) and was high at Nyamisati area and low at Bagamoyo site. The study observed high exploitation levels on the two land-based sites (Bagamoyo and Nyamisati) despite the existing moratorium on prawn commercial fishing activities since 2008 hence seasonal closure for artisanal fishers was recommended.

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Estimating some population parameters and stock assessment of Dark Sleeper Odontobutis potamophila in the Gaosha River, Wuyuan County, Jiangxi Province, China

Indian Journal of Animal Research ◽

10.18805/ijar.v0iof.9139 ◽

2017 ◽

Author(s):

Wu Bin Wang Haihua ◽

Fu Huiyun Zhang Yanping

Keyword(s):

Growth Parameters ◽

Stock Assessment ◽

Total Mortality ◽

Landing Site ◽

Jiangxi Province ◽

Recruitment Pattern ◽

Growth Coefficient ◽

West Part ◽

Exploitation Rate ◽

Odontobutis Potamophila

A study was conducted to investigate the growth parameters, mortality and recruitment pattern of Odontobutis potamophila collected in the Gaosha river fish landing site, west part of Wuyuan County (Latitude: 29° 14' 29" N, Longitude: 117° 45' 49" E). O.potamophila were collected from November, 2013 to October, 2014. Growth parameters, asymptotic length (L) = 192mm and growth coefficient (k) = 0.22 year-1. Growth performance index(Ø’) =3.91, total mortality (Z) = 0.72 year-1, natural mortality (M) = 0.32 year-1, fishing mortality (F) = 0.40 year-1 and exploitation rate (E) = 0.55year-1.The estimated exploitation rate (E) has slightly exceeded the optimum value of E indicating this species was sustainable exploitation in the study area. The exploitation ratios were computed as Emax= 0.61, E10= 0.52, E50= 0.34. The length at first capture at 50%, (Lc) was 77 mm. The recruitment pattern of the species was found continuous all-round the year with one peak. The observation of the annual recruitment of O.potamophila found to occur from May to July. Steady biomass also increased with length class until 121-125 mm, and the total steady state biomass was found to be 2240 kg.

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Estimation of Population Parameters and Stock Assessment of Mastacembelus armatus in the Taojiang River, Xinfeng County, Jiangxi Province, China

Indian Journal of Animal Research ◽

10.18805/ijar.b-1185 ◽

2019 ◽

Author(s):

Wu Bin ◽

Wang Haihua ◽

Ma Benhe ◽

Xu Xiandong ◽

Zeng Qingxiang

Keyword(s):

Growth Parameters ◽

Stock Assessment ◽

Total Mortality ◽

Landing Site ◽

Jiangxi Province ◽

Recruitment Pattern ◽

Growth Coefficient ◽

Exploitation Rate ◽

Mastacembelus Armatus ◽

River Fish

A study was conducted to investigate the growth parameters, mortality and recruitment pattern of Mastacembelus armatus collected in the Taojiang River fish landing site, Xinfeng County. M. armatus were collected from March, 2018 to February, 2019. Growth parameters, asymptotic length (L¥) = 58.8cm and growth coefficient (k) = 0.13 year-1. Growth performance index(Ø2 ) =2.65, total mortality (Z) = 0.75 year-1, natural mortality (M) = 0.32 year-1, fishing mortality (F) = 0.43 year-1 and exploitation rate (E) = 0.57year-1.The estimated exploitation rate (E) has slightly exceeded the optimum value of E indicating this species was over exploited mainly due to fishing in the study area. The exploitation ratios were computed as Emax= 0.59, E10= 0.45, E50= 0.31. The length at first capture at 50%, (Lc) was 19.51 cm. The Steady biomass also increased with length class until 36.0-36.9 cm and the total steady state biomass was found to be 19.12 tons.

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Population dynamics of Chrysichthys nigrodigitatus (Lacépède, 1803) in Ikere-gorge, Oyo State, Nigeria

Ghana Journal of Agricultural Science ◽

10.4314/gjas.v56i1.6 ◽

2021 ◽

Vol 56 (1) ◽

pp. 79-86

Author(s):

S.O. Ajagbe ◽

D.O. Odulate ◽

R.O. Ajagbe ◽

O.S. Ariwoola ◽

F.I. Abdulazeez ◽

...

Keyword(s):

Assessment Tool ◽

Growth Parameters ◽

Stock Assessment ◽

Total Mortality ◽

Fishing Mortality ◽

Length Frequency ◽

Optimum Length ◽

Growth Coefficient ◽

Exploitation Rate ◽

Length Frequency Data

The growth and mortality parameters of Chrysichthys nigrodigitatus were estimated to assess the sustainability of its exploitation in Ikere-gorge, Oyo State, Nigeria. A total of 1210 of Chrysichthys nigrodigitatus were sampled from fishermen catches between January, 2017 and December, 2018. C. nigrodigitatus were exploited with gillnet, cast net and traps (Malian trap net and bamboo). Total lengths were measured with fish measuring board. The FAO-ICLARM Stock Assessment Tool (FiSAT II) software was used to analyze length-frequency data of the fish. The estimated growth parameters are: asymptotic length is 60.9 cm, growth coefficient is 0.96, optimum length is 38.51 cm; length at maturity is 33.44 cm while length-at-first-capture is 12.62 cm. The estimated mortality parameters are: total mortality is 3.29 per year, natural mortality is 1.43 per year and fishing mortality is 1.86. It was observed that C. nigrodigitatus of Ikere-gorge were more vulnerable to exploitation at sizes less than their length at maturity. Likewise, the exploitation rate (E = 0.57 yr-1) is greater than sustainable exploitation rate (Emax = 0.46 yr-1). This shows that exploitation of C. nigrodigitatus in Ikere-gorge is not sustainable. Therefore, there is need to reduce fishing pressure on C. nigrodigitatus to ensure its sustainability in Ikere-gorge.

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Demographic Structure and Level of Exploitation of the Small Pelagic Pellonula leonensis Boulenger, 1916 (Pisces; Clupeidae) Fishery in the Aghien lagoon, West Africa

Journal of Biology and Life Science ◽

10.5296/jbls.v10i1.13884 ◽

2018 ◽

Vol 10 (1) ◽

pp. 39

Author(s):

Assi Sonan Romuald ◽

Boussou Koffi Charles ◽

Konan Koffi Félix ◽

Aliko N’Guessan Gustave ◽

Bony Kotchi Yves ◽

...

Keyword(s):

Condition Factor ◽

Growth Parameters ◽

Fish Population ◽

Demographic Structure ◽

Recruitment Pattern ◽

Growth Coefficient ◽

Mean Values ◽

Von Bertalanffy Model ◽

Exploitation Rate ◽

One Year

Demographic structure and level of exploitation of Pellonula leonensis in the Aghien lagoon were examined by applying length-weight relationship (LWR), Condition factor, Von Bertalanffy model, Mortality parameters, Exploitation rate, Recruitment pattern and Beverton and Holt analysis. Fish population were sampled monthly during one year between June 2014 and May 2015 from artisanal and experimental captures in the Aghien Lagoon. Except LWR and the condition factor, studied parameters were provided by the FiSAT II package. The negative allometric growth (b = 2.61) was reported for Pellonula leonensis. Mean values of the condition factor (CF) vary significantly from one month to another (Anova, p ˂ 0.05). Concerning growth parameters, results indicated that the asymptotic length (L∞) has been estimated at 126.84 mm SL, growth coefficient (K) was 0.67 year -1 and growth performance index (Φ') was 2.03. Growth modelization revealed 4 cohorts for Pellonula leonensis. The estimates of the total (Z), natural (M) and fishing (F) mortalities were 1.87, 0.92 and 0.95 year -1 respectively. The recruitment pattern was continuous throughout the year with two Gauss curve. The exploitation rate obtained (E = 0.51) was close to E0.1 (E0.1 = 0.55), thus indicating that the P. leonensis stock is in an optimum state of exploitation.

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POPULATION BIOLOGY OF MUD CRAB Scylla serrata - Forsskal, 1775 IN MANGROVE ECOSYSTEM OF SUBANG DISTRICT, WEST JAVA

Jurnal Ilmu dan Teknologi Kelautan Tropis ◽

10.28930/jitkt.v9i1.17928 ◽

2017 ◽

Vol 9 (1) ◽

pp. 173

Author(s):

Ayu Annisa Kumalah ◽

Yusli Wardiatno ◽

Isdradjad Setyobudiandi ◽

Achmad Fahrudin

Keyword(s):

Population Dynamics ◽

Size Distribution ◽

Population Biology ◽

Stock Assessment ◽

Mangrove Ecosystem ◽

Mature Female ◽

Scylla Serrata ◽

Mud Crab ◽

Growth Coefficient ◽

Exploitation Rate

The study of population biology of mud crab Scylla serrata is necessary to analyse the population dynamics, such as growth of crabs, size distribution, mortality and exploitation rates of S. serrata. Population biology data collection was carried out from March to June 2016 at estuary and silvofishery areas of three stations (Mayangan, Tanjung Tiga and Blanakan villages). Data were analyzed using analytical methods of FISAT-II (FAO-ICLARM Stock Assessment Toool II)instruments. The results showed the growth of S. serrata male in Subang distric was positive allometric and the female was negative allometric. Growth coefficient (K) ranged from 0.21 to 0.43 in the estuary and from 0.28 to 0.89 in silvofishery area. Exploitation rate in the silvofishery area has been above the maximum exploitation rate. The size distribution of S. serrata in Subang district has the highest frequency at class interval of 106-110 mm (male) and of 101-105 mm. The highest abundance of mature female crabs is in May.Keywords : population biology, Scylla serrata, Subang District

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Some Aspect on the Biology of Pen Shell Atrina Pectinata (Linneaus, 1767) In Coastal Waters of Maqueda Bay, Philippines

Journal of Marine Science Research and Oceanography ◽

10.33140/jmsro.02.02.02 ◽

2019 ◽

Vol 2 (2) ◽

Keyword(s):

Coastal Waters ◽

Total Mortality ◽

Condition Index ◽

Recruitment Pattern ◽

Spawning Period ◽

Growth Coefficient ◽

Measurement And Analysis ◽

Pen Shell ◽

Atrina Pectinata

A Total of 379 pen shells Atrinapectinata were collected from February 2017 to January 2018 in the coastal waters of Maqueda Bay. Measurement and analysis of length and weight were done using FiSAT software. Population parameters were assessed to evaluate the stock status which includes the asymptotic length (L∞) and growth coefficient (K) to be 34.65 cm, 0.77 year−1 respectively. Specimens of A. pectinata reached a mean length of 20.98 cm. Length-weight relationship resulted to “negative allometric” 0.0462L2.6533 R2 = 0.7823; signifying pen shells growth was faster in length than on weight. The recruitment pattern was continuous over the year with one major peak during rainy season (July). In addition, the highest catch based on collected sampling date catch was during summer, which suggest as the peak season of the species in the area. Furthermore, the average catch annually of hookah diver was 17.69208. Higher condition index was recorded from April to May, September and January, indicating the high quality of pen shell meat and is recommended as the best period to harvest pen shell whereas June to August and October to December can be concluded as the spawning period of the pen shell and the ideal period to institute close season. Further analysis revealed that the pen shell was nearly facing overexploitation with the exploitation rate (E = 0.46) mainly due to lack of a minimum limit size and also due to an increase in the harvesting effort. The estimated total mortality (Z), natural mortality (M) and fishing mortality (F); 1.36 year−1, 1.01year−1 and 0.62 year−1, respectively. Using the mentioned (Z), (M), (F) and (E), the total population resulted to 84725.7 suggesting that half of the population has been exploited due to overfishing

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Population dynamics and stock assessment of Hilsa shad, Tenualosa ilisha (Hamilton, 1822) along the coast of Bangladesh

Bangladesh Journal of Zoology ◽

10.3329/bjz.v48i2.52365 ◽

2021 ◽

Vol 48 (2) ◽

pp. 231-241

Author(s):

Md Khairul Islam ◽

Md Humayun ◽

Manmatha Nath Sarker ◽

Md Sharifuddin ◽

M Niamul Naser

Keyword(s):

Growth Parameters ◽

Stock Assessment ◽

Population Analysis ◽

Total Mortality ◽

Maximum Sustainable Yield ◽

Fishing Mortality ◽

Recruitment Pattern ◽

Weight Relationship ◽

Tenualosa Ilisha ◽

Highly Correlated

Stock Assessment of Tenualosa ilisha (Hamilton, 1822) were estimated using FiSAT-II software with length-frequency data collected from different landing centers. The Southeast Coast of Bay Of Bengal, Cox's Bazar. The Von Bertalanffy growth parameters Land K for the species were asymptotic length (L∞) was 51.41 cm, growth rate (K) was 0.75 year-1 and t0 = -0.2 year respectively. The estimated value of total mortality (Z) based on length converted catch curve using these growth parameters was 2.35 year-1.Natural mortality (M) based on growth parameters and mean environmental temperature (T = 27° C) was 1.00 year-1 and fishing mortality (F) was 1.35 year-1. Optimum length of hilsa at first capture (Lc=L50) was 28.36 cm TL. Growth performance indices (ϕ') was 3.30. The estimated value of the exploitation rate (E) using the length-converted catch curve was 0.57. The recruitment pattern of this species was continuous and two peaks per year. The present investigation clearly showed the over fishing (E > 0.50) condition for T. ilisha in Bangladesh. The estimated length-weight relationship for the combined sex was found to be W = 0.0109 L3. Virtual population analysis (VPA) showed that the maximum fishing mortality occurring in the length between 30 to 35 cm with a maximum value in the length of 32 cm that repeatedly indicate high fishing mortality in the T. ilisha. The generalized length-weight relationship was fitted with the pooled data of all monthly samples were BW = 0.029 TL2.718 (R2= 0.833) respectively. The results revealed that all length-weight relationships were highly correlated (r > 0.993). Maximum sustainable yield (MSY) was estimated as 435,554 t. Bangladesh J. Zool. 48(2): 231-241, 2020

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Growth parameter, mortality, recruitment pattern, and exploitation rate of white shrimp Penaeus indicus in northern coastal waters of Western Central Java, Indonesia

Biodiversitas Journal of Biological Diversity ◽

10.13057/biodiv/d200511 ◽

2019 ◽

Vol 20 (5) ◽

Author(s):

SURADI WIJAYA SAPUTRA ◽

ANHAR SOLICHIN ◽

WIWIET TEGUH TAUFANI ◽

SITI RUDIYANTI ◽

NINIEK WIDYORINI

Keyword(s):

Carapace Length ◽

Growth Parameters ◽

Growth Parameter ◽

White Shrimp ◽

Survey Method ◽

Northern Coast ◽

Recruitment Pattern ◽

Central Java ◽

Exploitation Rate ◽

Penaeus Indicus

Abstract. Saputra SW, Solichin A, Taufani WT, Rudiyanti S, Widyorini N. 2019. Growth parameter, mortality, recruitment pattern, and exploitation rate of white shrimp Penaeus indicus on the northern coast of Central Java, Indonesia. Biodiversitas 20: 1318-1324. The aims of this study were to know the growth parameters, first lenght captured (Lc), mortality, recruitment pattern, and the exploitation rate of white shrimp (Penaeus indicus H.Milne Edwards, 1837) in the Western Coastal North Central Java Sea, Indonesia. Samples were collected from May 2016 to July 2017 using survey method and direct observations on fishing unit areas. The results showed that the relationship of the carapace length and weight is allometric. Based on the estimates of von Bertalanffy growth equation to the carapace length, the growth parameters of CL∞ and K values in male were 37 mm and 0.97, while in female were 38.5 mm and 0.85. While, the rates of total mortality (Z), natural mortality (M), and fishing mortality (F) were 3.5, 1.67, and 1.84 for males, and 5.03, 1.51, and 3.52 for females, respectively. The exploitation rate (E) of male shrimp was 0.52 and of female was 0.7 indicating that female shrimp get higher capture pressure than the males. It also showed that the rate of exploitation has to exceed the optimum sustainable yield (E>0.5). Time recruitment occurred throughout the year, with two peak seasons, i.e., in April-June and September-November. Moreover, the length of the carapace during recruitment was 15-20 mm. While the carapace length of the first caught (CL∞50) was 18.3 mm for male and 17.6 mm for female indicating that the P. indicus caught was still in the small size, as well as below the first mature gonad (CLm50 = 22-39 mm). This is because the mesh size of cod-end is 0.75 inches or about 2 cm.

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Population dynamics and the management of the Indo-Pacific king mackerel Scomberomorus guttatus from the upper Bay of Bengal off Bangladesh coast

Bangladesh Veterinarian ◽

10.3329/bvet.v27i2.7558 ◽

1970 ◽

Vol 27 (2) ◽

pp. 82-90 ◽

Cited By ~ 2

Author(s):

H Rashid ◽

MG Mustafa ◽

S Dewan

Keyword(s):

Bay Of Bengal ◽

Sustainable Management ◽

Growth Parameters ◽

Fishing Mortality ◽

Length Frequency ◽

Growth Constant ◽

Recruitment Pattern ◽

Exploitation Rate ◽

King Mackerel ◽

Bangladesh Coast

Growth and mortality parameters, exploitation rates, annual recruitment patterns and length-weight relationships were estimated using FiSAT program from monthly length-frequency and weight samples of Indo-Pacific king mackerel, Scomberomorus guttatus, captured mainly by drift gill nets from the upper Bay of Bengal off Bangladesh coast. The aim was to estimate growth parameters, mortality rates, exploitation rate and recruitment pattern of S. guttatus for sustainable management. The von Bertalanffy growth parameters asymptotic length L∞ (cm) and growth constant K (per year) were 73.5 and 0.6, respectively. The L∞ and Z/K estimates provided by Wetherall plot were 73.3 and 2.3 cm. The annual rate of fishing mortality (F = 0.806) was low compared to the relatively high natural mortality (M = 0.994). The exploitation rate (E = 0.45) shows that the species was not over-exploited in the region. About 77.1% of S. guttatus were recruited during May-July and 23.0% during September-October. The growth performance index (φ′) was 3.5. The total length and body weight relationship was W = 0.0101 L 2.8622 suggesting that the growth rate was negative allometric (b<3). The growth parameters derived in the current study are comparable with previous estimates available for the same species. DOI: 10.3329/bvet.v27i2.7558 Bangl. vet. 2010. Vol. 27, No. 2, 82-90

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Population dynamics of Sardinella aurita (Val., 1847) within Ghana’s coastal waters

Research in Agriculture Livestock and Fisheries ◽

10.3329/ralf.v4i3.35103 ◽

2017 ◽

Vol 4 (3) ◽

pp. 237-248

Author(s):

Samuel KK Amponsah ◽

Patrick K Ofori Danson ◽

Francis KE Nunoo ◽

Godfred A Ameyaw

Keyword(s):

Mortality Rate ◽

Coastal Waters ◽

Total Mortality ◽

Mesh Size ◽

Reference Points ◽

Recruitment Pattern ◽

Commercial Fish ◽

Management Interventions ◽

Exploitation Rate ◽

Sardinella Aurita

Following the declining stocks of Sardinella aurita within the coastal waters of Ghana, this study aimed at examining some population parameters of Sardinella aurita as a guide for managing this important stock sustainably. Length-frequency data of 717 samples were obtained from June, 2014 to January 2015 and measured for total length with the resultant data analyzed using FiSAT II. The asymptotic length (L∞) and growth rate (K) were 21.53 cm SL and 0.25yr-1 respectively. The theoretical age at birth (t0), longevity (tmax) and growth performance index (ϕ) were -0.74yr-1, 12 years and 1.849 respectively. Total mortality rate (Z), natural mortality rate (M) and fishing mortality rate (F) were 3.17, 0.76 and 2.41yr-1 respectively. The ages at first recruitment and first capture signaled future collapse of the stock, in the absence of proper management interventions. VPA outcome showed that mid- lengths of 11 cm and 12 cm SL experienced the highest harvesting rate with MSY estimated at 7733 tons. The recruitment pattern was continuous with two major recruitment pulses. Exploitation rate (Ecurr=0.76) was higher than the maximum exploitation rate (Emax=0.56), indicating unsustainable exploitation. Further, the fishing regime fell within the overfished stage based on the Quadrant Rule. For sustainable exploitation of this commercial fish species, implementation of relevant biological reference points through reduction in fishing efforts, creation of marine protected areas and mesh size regulation are urgently advocated.Res. Agric. Livest. Fish.4(3): 237-248, December 2017

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