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.

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.

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 TRUKTUR UKURAN DAN BEBERAPA PARAMETER POPULASI IKAN CAKALANG (Katsuwonus pelamis Linnaeus, 1758) DI SAMUDERA PASIFIK UTARA PAPUA

2017 ◽  
Vol 9 (2) ◽  
pp. 113
Author(s):  
Thomas Hidayat ◽  
Tegoeh Noegroho ◽  
Karsono Wagiyo
Keyword(s):  
Growth Rate ◽  
Mortality Rate ◽  
Size Structure ◽  
Fork Length ◽  
Total Mortality ◽  
Status Quo ◽  
Skipjack Tuna ◽  
Population Parameters ◽  
Katsuwonus Pelamis ◽  
Exploitation Rate

Ikan cakalang (Katsuwonus pelamis Linnaeus, 1758) merupakan salah satu sumberdaya ikan pelagis besar yang mempunyai nilai ekonomis penting. Informasi mengenai struktur ukuran dan beberapa parameter populasinya masih sangat terbatas khususnya di perairan Indonesia timur. Penelitian ini dilakukan di Morotai, Biak dan Jayapura dari Januari sampai Desember 2013. Tujuan penelitian ini adalah untuk menganalisis ukuran ikan yang tertangkap dan menganalisis parameter populasi meliputi laju pertumbuhan, mortalitas dan tingkat eksploitasi. Estimasi parameter pertumbuhan, mortalitas dan laju eksploitasi dihitung menggunakan program FiSAT (FAO-ICLARM Stock Assessement Tools). Ukuran ikan cakalang hasil tangkapan pancing tonda dan pancing ulur berkisar antara 15 – 94 cmFL (Fork Length), dengan modus antara 40-45 cmFL. Ukuran pertama kali tertangkap sebesar 40,1 cmFL dan kebanyakan adalah ukuran ikan yang sedang memijah. Hasil analisis menggunakan FiSAT II diperoleh laju pertumbuhan (K) sebesar 0,41/tahun, panjang asimptotik (L) 101,85 cmFL. Laju kematian alami (M) 0,6 / tahun, laju kematian karena penangkapan (F) 0,62 /tahun dan laju mortalitas total (Z) 1,22 /tahun. Tingkat eksploitasi ikan cakalang hampir fully exploited (E= 0,46). Disarankan tidak perlu ada penambahan upaya penangkapan atau status quo untuk menjaga agar sumberdaya ikan cakalang tetap terjaga kelestariannya. Skipjack tuna (Katsuwonus pelamis Linnaeus, 1758) is one of the large pelagic fish resources which have high economic value. Information on the size structure and population parameters is still limited especially in the waters of eastern Indonesia. The Research was conducted from January to December 2013 at Morotai, Biak and Jayapura. The aim of this study was to analyze the size of the fish caught and some of population parameters such as the growth rate, mortality rates, and exploitation rate. Estimated of growth parameters, mortality and exploitation rate using the program FiSAT (FAO-ICLARM Stock Assessement Tools). The size of skipjack tuna caught by troll line and handline in between 15-94 cmFL, with a mode of 40-45 cmFL. The Length at first capture was 40.1 cmFL, most of them had condition of spawning. By using program FiSAT II analysis resulted that growth rate (K) of skipjack tuna was 0.41/year, with length asimptotik (L) reaches 101.85 cmFL. The natural mortality rate (M) was 0.6 / year. The fishing mortality rate (F) was 0.62 / year and total mortality rate (Z) was 1.22 / year. The exploitation rate of skipjack tuna was nearly fully exploited (E = 0.46). It was recommended the exploitation rate of this fish should be no additional effort (status quo) to keep sustainability of the skipjack tuna resource.

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.

scholarly journals Population Parameters of Two Commercially Important Species belonging to the Family Sciaenidae Encountered in the Coast of Ghana

2020 ◽  
pp. 21-29
Author(s):  
Samuel K. K. Amponsah ◽  
Selasi Yao Avornyo ◽  
Kofi Ferni Anyan
Keyword(s):  
Mortality Rate ◽  
Fish Species ◽  
Coastal Waters ◽  
Total Mortality ◽  
Population Parameters ◽  
Recruitment Pattern ◽  
Important Species ◽  
The Family ◽  
Exploitation Rate ◽  
Commercially Important

Population parameters for two commercially important fishes of Sciaenidae from the coastal waters of Ghana were assessed using length-frequency data obtained from August 2017 to June 2019. Samples of the assessed fish species were obtained through experimental fish trawl along the coast of Greater Accra, Ghana. Trawling was performed every quarter for an average of one hour at an average speed of 3.0 km/hr. In all, a total of 399 samples were measured and the obtained data were analyzed with FiSAT II. The assessed fish species included Pteroscion peli (165 samples) and Pseudotolithus senegalensis (234 samples). The asymptotic length (L∞) was 19.4 cm and 41.5 cm forPteroscion peli and Pseudotolithus senegalensis. Pteroscion peli and Pseudotolithus senegalensis recorded growth rate (K) of 0.48 and 0.50 per year respectively. Both assessed fish species exhibited continuous recruitment pattern with minor and major recruitment peaks. The total mortality rate (Z) was 1.86 and 1.63 per year for Pteroscion peli and Pseudotolithus senegalensis. The fishing mortality rate (F) was estimated at 0.66 and 0.63 per year for Pteroscion peli and Pseudotolithus senegalensis. The natural mortality rate (M) estimated for Pteroscion peli and Pseudotolithus senegalensis was 1.20 and 1.00 per year respectively. The exploitation rate (E) of Pseudotolithus senegalensis (0.39) and Pteroscion peli (0.36) respectively was far below the maximum exploitation rate (Emax), indicating under-exploitation of its fishery in the coastal waters of Ghana, hence the need to enhance the exploitation of these species.

Tagging Experiments on British Columbia Pilchards

1943 ◽  
Vol 6b (2) ◽  
pp. 164-182 ◽  
Author(s):  
John Lawson Hart
Keyword(s):  
United States ◽  
British Columbia ◽  
Mortality Rate ◽  
Total Mortality ◽  
The United States ◽  
First Year ◽  
Central California ◽  
San Pedro ◽  
General Movements ◽  
Minimum Estimate

Internal iron tags recovered by magnets demonstrate general movements of pilchards (Sardinops caerulea (Girard)) from Canadian to California fishing grounds. Consideration of recoveries in respect to tonnages of fish landed, size of fish landed, and efficiency of recovery show that in the first year after tagging, tagged fish are more concentrated on northern fishing grounds than on those of California. After the first year the reverse is true. Canadian tags during their first year are more concentrated on the fishing grounds off San Pedro than off central California. Later this condition is not observed. Fish of the 1939 year-class present in California waters in 1940 were taken by the Canadian fishery in 1941. The dates of recovery of first year tags on the United States coast indicate a rather orderly migration. Minimum estimate of the fastest rate of migration indicated gave 14.3 km. per day. In contrast to the inferred condition on major migrations, pilchard movements on northern fishing grounds are very confused. Definite movements from the Washington coast to the Canadian coast are demonstrated. Fish taken in the inlets of Vancouver island during the winter months are part of the general pilchard population. The total mortality rate of the large pilchards tagged in connection with Canadian fishing operations is about 71% per annum.

scholarly journals PARAMETER POPULASI DAN POLA REKRUITMEN IKAN TONGKOL LISONG (Auxis rochei Risso, 1810) DI PERAIRAN BARAT SUMATERA

2015 ◽  
Vol 7 (3) ◽  
pp. 129
Author(s):  
Tegoeh Noegroho ◽  
Umi Chodrijah
Keyword(s):  
Mortality Rate ◽  
Frequency Analysis ◽  
Growth Parameters ◽  
Fork Length ◽  
Total Mortality ◽  
Von Bertalanffy ◽  
Population Parameters ◽  
Length Frequency ◽  
Exploitation Rate ◽  
Length Frequency Analysis

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.

scholarly journals Growth Pattern, Mortality and Exploitation Rate of the Giant African Threadfin, Polydactylus quadrifilis (Cuvier, 1829) from Ebrié Lagoon (Potou Sector, Côte d’Ivoire)

2020 ◽  
pp. 33-42
Author(s):  
Théophile Aké Bédia ◽  
Bakari Coulibaly ◽  
Yao Aristide Konan ◽  
Essetchi Paul Kouamelan ◽  
Valentin N’douba
Keyword(s):  
Growth Rate ◽  
Mortality Rate ◽  
Growth Pattern ◽  
Total Mortality ◽  
Fishing Effort ◽  
Natural Mortality ◽  
Fishing Mortality ◽  
Population Parameters ◽  
Exploitation Rate ◽  
First Maturity

The study evaluated some population parameters of Polydactylus quadrifilis within Ebrié lagoon (Potou sector). Samples were obtained using artisanal gillnet fishery from April 2004 to March 2006. A total of 741 individuals of P. quadrifilis ranged from 11 to 70 cm were examined. Population parameters were estimated where asymptotic length (L∞) was found 60 cm, growth rate (K) 0.33 per year, the longevity (T max) 9.09 years, and growth performance index (Φ′) 3.06. The length at first capture (Lc50 = 10.60 cm) was lower than the length at first maturity (Lm50 = 40 cm). Total mortality rate (Z) was calculated as 1.10 per year including natural mortality and fishing mortality. The exploitation rate (E=0.36) was found to be less than the maximum exploitation rate (E max = 0.44) and indicated that P. quadrifilis is not overexploited. The current exploitation rate should be maintained by sustainable fisheries measures including monitoring of fishing effort.

scholarly journals ALCAPA: The Al Capone of coronary artery anomalies

2012 ◽  
Vol 16 (3) ◽  
pp. 100-101 ◽  
Author(s):  
Farzanah Ismail
Keyword(s):  
Coronary Artery ◽  
Mortality Rate ◽  
Left Coronary Artery ◽  
First Year ◽  
Coronary Artery Anomalies ◽  
Perfusion System ◽  
Anomalous Left Coronary Artery ◽  
First Year Of Life ◽  
Anomalous Left Coronary ◽  
Artery Perfusion

Anomalous left coronary artery originating from the pulmonary artery (ALCAPA) is a rare coronary artery anomaly that presents with myocardial ischaemia or infarction and/or cardiac failure in infants. It is associated with a mortality rate of 90% within the first year of life. Surgical correction to re-establish a two-coronary artery perfusion system is the treatment of choice, once patients are medically stable.

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