Determination of Natural and Fishing Mortalities of Cod and Haddock from Analysis of Tag Records off Western Nova Scotia

1958 ◽  
Vol 15 (6) ◽  
pp. 1371-1381 ◽  
Author(s):  
J. E. Paloheimo
Keyword(s):  
Nova Scotia ◽  
Mortality Rate ◽  
Total Mortality ◽  
Marine Species ◽  
First Year ◽  
Natural Mortality ◽  
Independent Estimate

With marine species the population of tagged fish is unlikely to be a closed one, and previously described methods of determining natural and fishing mortalities are then hardly applicable. It is shown that when no data on effort or catch, related to tag returns, are available, a relationship between fishing and natural mortalities can be calculated, subject to some restrictive assumptions. An independent estimate of total mortality is then necessary to arrive at values of natural and fishing mortality.The method is applied to taggings of cod and haddock off Nova Scotia (McCracken, 1956). For cod the calculations show wide variations in effort. We obtain a rather low value of the natural mortality in the first year of recoveries. In subsequent years the numbers of returns are so low that heavy losses of tags are suspected. For haddock the calculations show that the effort may be constant and that already developed methods (Leslie and Davies, Ketchen, DeLury, Beverton and Holt) may be applied. Results leave several alternative explanations possible, giving a range from 0 to.36 for the instantaneous natural mortality rate, depending on the unknown initial loss of tags.

scholarly journals POPULATION DYNAMICS OF MALAYAN LEAF FISH (Pristolepisgrooti Blkr.) IN RANAU LAKE, SOUTH SUMATRA

2018 ◽  
Vol 24 (2) ◽  
pp. 125
Author(s):  
Sevi Sawetri ◽  
Subagdja Subagdja ◽  
Dina Muthmainnah
Keyword(s):  
Mortality Rate ◽  
Growth Parameters ◽  
Total Mortality ◽  
Natural Mortality ◽  
Fishing Mortality ◽  
Frequency Data ◽  
Length Frequency ◽  
Lake Ecosystems ◽  
Exploitation Rate ◽  
Length Frequency Data

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.  

scholarly journals ANÁLISIS DEL CRECIMIENTO Y LA MORTALIDAD DE ANISOTREMUS INTERRUPTUS (GILL) (PERCIFORMES: HAEMULIDAE) EN LA COSTA DE COLIMA, MÉXICO

2016 ◽  
Vol 33 ◽  
Author(s):  
Elaine Espino Barr ◽  
Manuel Gallardo Cabello ◽  
Fernando González Orozco ◽  
Arturo Garcia Boa
Keyword(s):  
Mortality Rate ◽  
Growth Parameters ◽  
Total Mortality ◽  
Condition Index ◽  
First Year ◽  
The Third ◽  
Second Year ◽  
First Year Of Life ◽  
Mortality Analysis

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.

Age, growth and the potential for growth overfishing of spot (Leiostomus xanthurus) from the Chesapeake Bay, eastern USA

2004 ◽  
Vol 55 (6) ◽  
pp. 553 ◽  
Author(s):  
Kevin R. Piner ◽  
Cynthia M. Jones
Keyword(s):  
Mortality Rate ◽  
Chesapeake Bay ◽  
Total Mortality ◽  
First Year ◽  
Leiostomus Xanthurus ◽  
Vital Rates ◽  
Population Parameters ◽  
Lack Of Information ◽  
Eastern Usa ◽  
Management Advice

Spot (Leiostomus xanthurus) are a popular commercial and sport fish in the Chesapeake Bay region (USA), but have not been managed with age-based models because of a lack of information on vital rates. This study determined that transversely sectioned otoliths were the most appropriate structure to age spot, and subsequently used those ages to estimate biological parameters and evaluate the potential for growth overfishing. Because spot are short-lived, this study explored estimating population parameters using both whole annulus counts and fractional ages. Although fractional ages may be more realistic, parameters estimated using fractions of a year should be interpreted with caution. Growth of spot was rapid (84% of length attained in the first year), the natural mortality rate was high (59% year−1), and the total mortality rate (natural + fishing) was very high (80–94% year−1). Spot maximised cohort biomass early in life (≈1 year) and were relatively impervious to growth overfishing. This study illustrates the difficulty in providing management advice for species that maximise cohort biomass about the same time as their first potential spawning event. This study also documents that high exploitation rates and size selective fishing gear probably affect estimates of population parameters.

Estimation of Recruitment and Natural Mortality Rate from Age-Composition and Catch Data in British Columbia Herring Populations

1955 ◽  
Vol 12 (5) ◽  
pp. 649-681 ◽  
Author(s):  
Albert L. Tester
Keyword(s):  
Mortality Rate ◽  
Age Groups ◽  
Total Mortality ◽  
Vancouver Island ◽  
Island Population ◽  
Natural Mortality ◽  
Age Composition ◽  
Catch Data ◽  
Population Average ◽  
Stable Conditions

If absolute recruitment (R) and natural mortality rate (q) are both presumed constant in each of two or more periods of stabilized fishing, it is shown that i = q + (1/R)iC, where i is instantaneous total mortality rate and C is catch in numbers. The relationship yields approximate estimates of R and q under semi-stable conditions if "average referable C" is related to apparent i, the former derived from catch data and the latter from age-composition data for post-recruited age-groups. In the herring population, in which recruitment takes place mostly at age III but is spread from ages I to IV, the average of the catch of years x and x + 1 is referable to apparent i at ages IV to V in year x + 2, at ages V to VI in year x + 3, etc. When q increases with advancing age, it is shown that R is most accurately estimated from data for ages IV to V; q is slightly overestimated at ages IV to V and underestimated at ages VI to VII and VII to VIII. From data for periods of approximate stability in the lower east coast of Vancouver Island population, average R is estimated at about 500 million fish per year; average q appears to increase with age, ranging from about 0.4 at ages IV to V to about 0.85 at ages VII to VIII. For a recent period of stabilized intensive fishing, a rough estimate of the average initial size of the fishable stock, based on age-composition and catch data, agrees well with that estimated by another method. For populations along the west coast of Vancouver Island, q also appears to increase with advancing age; R is estimated at about 400 million fish. In an appendix it is shown that a method of estimating q from age-composition and effort data gives unsatisfactory results because effort expended in herring fishing is not proportional to rate of fishing of the stock.

scholarly journals DINAMIKA POPULASI IKAN GABUS (Channa striata) DI RAWA DANAU PANGGANG, KALIMANTAN SELATAN

2018 ◽  
Vol 14 (1) ◽  
pp. 16
Author(s):  
Dini Sofarini ◽  
Mohammad Mahmudi ◽  
Asus Maizar S. Hertika ◽  
Endang Yuli Herawati
Keyword(s):  
Growth Rate ◽  
Mortality Rate ◽  
Population Dynamic ◽  
Growth Pattern ◽  
Total Mortality ◽  
Natural Mortality ◽  
Von Bertalanffy ◽  
Fishery Resource ◽  
Exploitation Rate ◽  
Channa Striata

The province of South Kalimantan has the largest peat swamp that is named Danau Panggang Swamp with an area of 5,390.7 Ha. This swamp has ecological, economic and potential functions of a large fishery resource. The purposes of this study are to evaluate the exploitation rate of Snake Head Fish (Channa striata) in Danau Panggang Swamp, by population dynamic analysis using FISAT program of Von Bertalanffy method.  The results showed that the growth pattern of Snake Head Fish (Channa striata) has the tendency to grow negative allometric with 63.4 cm of long infifer (L¥), growth rate (k) 0.15 per year, theoretical age at the time of the fish is equal to 0 (t0) is -1.48257 years. While the natural mortality rate (M) was 0.43, the mortality rate due to catch (F) of 0.69/year and the total mortality rate  (Z) of 1.12/year, and the rate of exploitation value E = 0.62.  These results indicated that the exploitation rate of Head Snake Fish (Channa striata) in Danau Panggang swamp has a tendency to overfishing.

scholarly journals Analisis dinamika populasi ikan selar kuning (Selaroides leptolepis) dalam upaya pengelolaan sumberdaya ikan pelagis kecil di perairan Bintan, Provinsi Kepulauan Riau

DEPIK ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 428-434
Author(s):  
Septiyawati Septiyawati ◽  
Muhammad Fauzi ◽  
Deni Efizon
Keyword(s):  
Mortality Rate ◽  
Total Mortality ◽  
Natural Mortality ◽  
Salted Fish ◽  
Fisheries Resources ◽  
Exploitation Rate ◽  
Raw Fish ◽  
Pelagic Fisheries

This raw fish is used as fisheries products such as salted fish, grilled fish, fishmeal and surimi. This study aims to analyze mortality and recruitment of yellowstipe scad (Selaroides leptolepis) and the information about management of small pelagic fisheries resources in Bintan Waters. This research was carried out in February-June 2019 at the Barek Motor Fish Landing Area (TPI) with fishing areas in Bintan waters. The number of fish studied was 2.550 with a length of 102-215 mm and a weight of 15-102 gr. The highest recruitment peak occurred in Mei of 18.11% and June of 19.48%. The highest and lowest condition factors are 0.83 and 1.09. The total mortality rate (Z) of yellow strait fish is 4.61 per year with a natural mortality rate (M) of 1.66 per year and the capture mortality rate of 2.95 per year so that the exploitation rate is 0.63. The death of yellowstipe scade in the Bintan Sea most of the caused by fishing activities (F) of 2.95 per year.Keywords:Yellowstipe scad Bintan WatersRecrutmentCondition factorsMortalityABSTRAKIkan selar kuning merupakan salah satu jenis ikan ekonomis penting. Ikan ini banyak dimanfaatkan sebagai bahan baku produk olahan perikanan seperti ikan asin, ikan bakar, pindang, tepung ikan dan surimi. Penelitian ini bertujuan untuk menganalisis, mortalitas dan rekrutmen ikan selar kuning (Selaroides leptolepis) dan informasi tentang pengelolaan sumberdaya ikan pelagis kecil di Perairan Bintan. Penelitian ini telah dilaksanakan bulan Februari-Juni 2019 di Tempat Pendaratan Ikan (TPI) Barek Motor dengan wilayah penangkapan di perairan Bintan. Jumlah ikan yang diteliti 2.550 ekor dengan panjang 102-215 mm dan berat 15-102 gr. Puncak rekrutmen tertinggi terjadi bulan Mei sebesar 18,11% dan Juni sebesar 19,48%,. Nilai tertinggi dan terendah faktor kondisi yaitu 0,82 dan 1,09. Laju mortalitas total (Z) ikan selar kuning 4,61 per tahun dengan laju mortalitas alami (M) 1,66 per tahun dan laju mortalitas penangkapan 2,95 per tahun sehingga diperoleh laju eksploitasi 0,63. Kematian ikan selar kuning di laut Bintan sebagian besar diakibatkan oleh aktivitas penangkapan (F) sebesar 2,95 per tahun.Kata kunci:Ikan selar kuning Perairan Bintan Rekrutmen Faktor kondisi Mortalitas

scholarly journals Growth, maturation, and longevity of maturation cohorts of Norwegian spring-spawning herring

2004 ◽  
Vol 61 (2) ◽  
pp. 165-175 ◽  
Author(s):  
Raymond J.H. Beverton ◽  
Arvid Hylen ◽  
Ole-Johan Østvedt ◽  
John Alvsvaag ◽  
Terence C. Iles
Keyword(s):  
Mortality Rate ◽  
Small Proportion ◽  
Stock Assessment ◽  
Adult Life ◽  
Total Mortality ◽  
Mortality Rates ◽  
Natural Mortality ◽  
Marine Research ◽  
First Time ◽  
Age At Maturation

Abstract In 1907, the Bergen Institute of Marine Research started regular sampling of scales and lengths from landings of mature Norwegian spring-spawning herring. The actual age of each fish when caught was recorded, and from the early 1920s also the age at which it spawned for the first time. The present analyses concern biological samples secured during the fishing seasons 1940–1964. Herring in this stock do not all reach maturity at the same age. A small proportion of any one year class matures at 3 years. The majority matures from the age of 4–7 years, and a small proportion of some year classes at 8 and even 9 years of age. Subsequent age composition and growth of each maturation cohort were followed throughout mature life after spawning for the first time. The maximum age was found to increase with age at maturation, rising to an asymptote of about 22 years. The von Bertalanffy parameter L∞ shows an increasing trend with age at maturation, while K decreases. There is no strict length threshold at maturation and the curve joining the length at which each maturation cohort reaches maturity is less steep than the growth curve itself over the range of maturation ages. The data suggest that fish in this stock spawn, on average, eight times during a period of their life history in which the mortality rate is independent of age. After these eight spawnings, at an age referred to in this paper as the hinge age, the mortality rate increases sharply. Thus, the adult life is divided into two phases, called here pre-senescent and senescent. The total mortality rates in the pre-senescent phase are relatively stable for all maturation cohorts 3–9, but there is some evidence of a trend towards higher mortality rates during the senescent phase for the youngest maturing fish. This trend is caused mainly by a reduced natural mortality in the fish that mature when older. These findings have interesting demographic implications. Additional mortality due to fishing will change the relative contribution of young and old maturation cohorts in the senescent phase, thus making it appear that natural mortality is dependent on the intensity of fishing. Consequently, for stock assessment, analysis on a cohort basis seems advisable.

Yield-per-recruit and egg-per-recruit analyses of the Omani abalone, Haliotis mariae

1995 ◽  
Vol 46 (3) ◽  
pp. 663 ◽  
Author(s):  
SA Shepherd ◽  
JL Baker ◽  
DW Johnson
Keyword(s):  
Mortality Rate ◽  
Sexual Maturity ◽  
Egg Production ◽  
Arabian Sea ◽  
Total Mortality ◽  
Natural Mortality ◽  
Fishing Mortality ◽  
Northern Arabian Sea ◽  
Size At Sexual Maturity ◽  
Yield Per Recruit

The fecundity, size at sexual maturity, sex ratios and total mortality of Haliotis mariae on the Dhofar coast of the northern Arabian Sea were measured. These data, and estimates of the growth rate, were used for yield-per-recruit and egg-per-recruit analyses. Maximum yields occur at 3+ to 4+ years of age, depending on the natural mortality rate chosen. At the present age at first capture egg production levels are 2-29% of the unfished stock, depending on estimates of the fishing mortality rate and the natural mortality rate, and are considered to be far too low to maintain recruitment. At 40% egg production, of the maximum possible the age at first capture is 4 to 4.5 years, i.e. 105-115 mm shell length, depending on site.

scholarly journals PARAMETER POPULASI LOBSTER BAMBU (Panulirus versicolor) DI PERAIRAN SIMEULUE

2018 ◽  
Vol 9 (3) ◽  
pp. 185
Author(s):  
Helman Nur Yusuf ◽  
Ali Suman ◽  
Thomas Hidayat ◽  
Anthony Sisco Panggabean
Keyword(s):  
Mortality Rate ◽  
Random Sampling ◽  
Sustainable Management ◽  
Government Regulation ◽  
Carapace Length ◽  
Total Mortality ◽  
Landing Site ◽  
Natural Mortality ◽  
Population Parameters ◽  
Site Analysis

Lobster bambu (Panulirus versicolor) merupakan komoditas perikanan penting yang telah diekspolitasi di perairan Simeulue. Peningkatan permintaan dan pengusahaan lobster menyebabkan tekanan penangkapan terhadap populasi lobster semakin intensif dan tidak terkendali. Untuk itu  diperlukan informasi tentang biologi reproduksi dan parameter populasi lobster dalam rangka pengelolaan sumberdaya lobster yang berkelanjutan. Penelitian dilaksanakan pada Mei sampai dengan Desember 2015 diperairan Simeulue dengan tujuan untuk mengestimasi parameter populasi lobster bambu. Pengamatan dan pengukuran lobster dilakukan di tempat pengumpul lobster dengan sistem sampling acak (random sampling). Analisis data parameter populasi menggunakan software FiSAT (Stock Assessement Tools). Dari hasil penelitian diperoleh bahwa kondisi lobster bambu jantan dan betina tidak seimbang (1 : 1,5),  pola pertumbuhan bersifat alometrik negatif dengan nilai b sebesar 2,924 dan rata-rata pertama kali tertangkap (Lc) = 86 mmCL. Laju pertumbuhan (K) = 0,320 per tahun dan panjang karapas asimtotik (CL) 149,1 mm. Laju mortalitas alami (M) = 0,99 per tahun, laju kematian akibat penangkapan (F) sebesar 0,84 per tahun dan laju kematian total (Z) sebesar 1,83 per tahun. Tingkat eksploitasi (E) sebesar 0,46 atau pemanfaatan sumberdaya lobster bambu belum optimum. Penambahan baru dalam populasi berlangsung sepanjang tahun dan mencapai puncaknya pada Juni dan Juli bersamaan dengan musim timur. Untuk itu perlu adanya regulasi pemerintah dalam pengelolaan perikanan lobster yang berkelanjutan dengan menerapkan close season lobster pada puncak musim pemijahan.The painted green/bamboo lobster (Panulirus versicolor) is an important fish commodities that have been exploited in the waters of Simeulue. Increased utilization and uncontrolled exploitation of lobster causing pressure on the lobster population. For this reason, there is a need for information about the parameters of the lobster population in the management for the sustainability of lobster resource. The experiment was conducted in May to December 2015 Simeulue waters for the purpose of estimating the population parameters lobster green. Sampel collected randomly in the lobster landing site. Analysis of the data using FiSAT II software (FAO-ICLARM Stock Assessement Tools). The results obtained unbalanced condition of green lobster (1:1.5), the growth pattern is allometrically negative with value b of 2,924, length at fish first caught (Lc) = 86 mm CL. The lobster growth rate (K) = 0,320 per year and asymptotic carapace length (CL) 149.10 mm. The rate of natural mortality (M) = 0.99 per year, the mortality rate due to the arrest of (F) of 0.84 per year and total mortality rate (Z) of 1.83 per year. The rate of exploitation (E) 0,46 or green lobster resource was not optimum. Recruitment occur throughout the year with peak recruitment in June and July of the southeast monsoon. A government regulation is needed for the sustainable management of lobster resources by applying a close season during the peak spawning peri.

scholarly journals BEBERAPA PARAMETER POPULASI UDANG PUTIH (Penaeus merguiensis de Mann) DI PERAIRAN TARAKAN, KALIMANTAN UTARA

2017 ◽  
Vol 9 (2) ◽  
pp. 85
Author(s):  
Umi Chodrijah ◽  
Ali Suman
Keyword(s):  
Mortality Rate ◽  
Total Mortality ◽  
Fishing Effort ◽  
Natural Mortality ◽  
Fishing Mortality ◽  
Population Parameters ◽  
Spawning Period ◽  
Exploitation Rate ◽  
First Maturity ◽  
Penaeus Merguiensis

Tingkat eksploitasi udang putih (Penaeus merguiensis) sangat intensif. Hal ini terindikasi dengan hasil tangkapan udang di WPP-NRI 716 selama 9 tahun terakhir meningkat. Tujuan penelitian ini untuk mengkaji beberapa parameter populasi dan aspek biologi udang putih di perairan Tarakan. Data panjang karapas dan tingkat kematangan gonad udang putih dikumpulkan dari tempat pendaratan udang di Selumit Pantai, Tarakan, Kalimantan Utara pada Januari sampai dengan November 2016. Pendugaan parameter populasi dengan aplikasi model analisis menggunakan program ELEFAN 1. Hasil penelitian menunjukkan rata-rata ukuran udang putih pertama kali tertangkap (Lc) pada panjang karapas 32,51 mm dan rata-rata ukuran pertama kali matang gonad 33,58 mm. Puncak musim pemijahan terjadi pada Maret dan Agustus. Laju pertumbuhan (K) sebesar 1,33 per tahun (betina) dan 1,55 per tahun (jantan). Laju kematian total (Z) sebesar 7,5 per tahun (betina) dan 8,85 per tahun (jantan), laju kematian alamiah (M) sebesar 1,82 per tahun (betina) dan 2,16 per tahun (jantan) serta laju kematian akibat penangkapan (F) sebesar 5,68 per tahun (betina) dan 6,69 per tahun (jantan). Laju pengusahaan (E) udang putih di perairan Tarakan adalah sebesar 0,76 per tahun. Hal ini menunjukkan tingkat pemanfaatan udang putih telah mengalami lebih tangkap (overfishing). Kondisi ini menggambarkan perlunya dilakukan pengurangan upaya sekitar 52 %.  The banana prawn (Penaeus merguiensis) have been exploited intensively. For instance, within nine years the number of shrimp production in FMA 716 increased dramatically. This research aims to identify the some population parameters of banana prawn in the Tarakan waters. This research was carried out from January to November 2016. Data were analyzed using the analytical model application with ELEFAN I. The result showed that the length at first capture (Lc) of banana prawn was 32,51 mmCL and the length at first maturity (Lm) was 33,58 mm CL. The peak season of spawning period was indicated on March and August. The growth rate (K) was 1,33 /year (female) and 1.55/year (male). Total mortality rate (Z) was 7.5/year (female) and 8,85/year (male), natural mortality rate (M) rate was 1.82/year (female) and 2.16/year (male) and fishing mortality rate ( F) were 5.68/ year (female) and 6.69/year (male). The exploitation rate (E) of banana prawn in the Tarakan waters was 0.76 per year. Therefore, level of existing fishing effort of the banana prawn should reduced about 52 % in the next year.

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