Lake Opeongo: Effects of Exploitation and Introductions on the Salmonid Community

1972 ◽  
Vol 29 (6) ◽  
pp. 795-805 ◽  
Author(s):  
N. V. Martin ◽  
F. E. J. Fry
Keyword(s):  
Growth Rate ◽  
Mortality Rate ◽  
Lake Trout ◽  
Total Mortality ◽  
Smallmouth Bass ◽  
Fishing Pressure ◽  
Sport Fishery ◽  
Trout Population ◽  
Lake Waters

Lake Opeongo, a 58.6 km2 lake in the highlands of Algonquin Park, Ontario, has been under study since 1936. Due to little human development of the area, environmental conditions have been stable but because of its geological setting and location the lake waters are relatively unproductive.The smallmouth bass introduced in 1928 has had no apparent major impact on the salmonid community but has served to buffer fishing pressure on the lake trout. The cisco introduction in 1948 resulted in faster growing, better conditioned, and more fecund lake trout but has also contributed to their later maturity. Weight production of trout increased and in recent years stronger classes have apparently resulted from the improvement in fecundity. Declines in the perch and benthic insects and a decrease in growth rate of certain fishes since the mid-1950s are apparently related to the cisco introduction.Harvest of lake trout by the sport fishery has varied from 630 to 2700 fish/year representing a long term yield of 0.33 kilos/ha. Mean total mortality rate is 50%/year and exploitation has served to double the mortality rate after the trout have entered the fishery. Year-class production is correlated with spawning escapement and exploitation has limited recruitment to the trout population.

Population Biology of Lake Trout (Salvelinus namaycush) of Lake Superior before 1950

1971 ◽  
Vol 28 (1) ◽  
pp. 65-71 ◽  
Author(s):  
Gary T. Sakagawa ◽  
Richard L. Pycha
Keyword(s):  
Mortality Rate ◽  
Population Biology ◽  
Lake Trout ◽  
Lake Superior ◽  
Indirect Evidence ◽  
Total Mortality ◽  
Growth Yield ◽  
Salvelinus Namaycush ◽  
Natural Mortality ◽  
Trout Population

Scale samples collected in 1948 were used to estimate the instantaneous total mortality rate (0.70) and growth for lake trout (Salvelinus namaycush) in Lake Superior before the population had been significantly reduced by the sea lamprey (Petromyzon marinus). Indirect evidence indicates that the instantaneous natural mortality rate was probably 0.10–0.25. The Ricker model was used to calculate yield per recruitment, which varied with natural mortality and growth. Natural mortality was more critical than growth; yield per recruitment increased 183.3% with a 60% decrease in instantaneous natural mortality (from 0.25 to 0.10). For the prelamprey lake trout population the yield per recruitment was about 12–34 lb; the recruitment of about 3.6–10.1 million lake trout of age 1.5 resulted in an annual commercial production of 4 million lb.

An Evaluation of RNA–DNA Ratio as a Measure of Long-Term Growth in Fish Populations

1973 ◽  
Vol 30 (2) ◽  
pp. 195-199 ◽  
Author(s):  
Terry A. Haines
Keyword(s):  
Growth Rate ◽  
Population Growth ◽  
Growth Rates ◽  
Population Growth Rate ◽  
Environmental Changes ◽  
Age Distribution ◽  
Smallmouth Bass ◽  
Fish Populations ◽  
Population Growth Rates

The value of RNA–DNA ratio as a measure of long-term growth of fish populations under semi-natural conditions and when subjected to environmental manipulations was determined. Populations of carp and smallmouth bass of known age distribution were established in artificial ponds maintained at two fertility levels. After 15 months, population growth rates (as percent increase in weight) and RNA–DNA ratios of muscle tissue from selected fish were measured. Each species exhibited a range of population growth rates. The relation between population growth rate and individual fish RNA–DNA ratio for each species was significant. When reproduction occurred, the relation was not significant unless young-of-the-year fish were excluded from population growth rate calculations. Age of fish was also found to have an important effect on RNA–DNA ratio, with the ratio being higher in younger fish.RNA–DNA ratio can be a reliable indicator of long-term population growth in fish when population age structure is known and recruitment is controlled. The method has potential for use in detecting response to environmental changes before growth rate changes become severe.

Optimal Use of Creel Survey Data in Assessing Population Behaviour: Lake Opeongo Lake Trout (Salvelinus namaycush) and Smallmouth Bass (Micropterus dolomieui), 1936–83

1987 ◽  
Vol 44 (S2) ◽  
pp. s229-s238 ◽  
Author(s):  
B. J. Shuter ◽  
J. E. Matuszek ◽  
H. A. Regier
Keyword(s):  
Lake Trout ◽  
Total Mortality ◽  
Salvelinus Namaycush ◽  
Fish Population ◽  
Smallmouth Bass ◽  
Fishing Mortality ◽  
Assessment Data ◽  
Creel Survey ◽  
Micropterus Dolomieui ◽  
Independent Assessment

Creel survey and independent assessment data on the lake trout (Salvelinus namaycush) and smallmouth bass (Micropterus dolomieui) populations of Lake Opeongo were evaluated. Annual estimates of total mortality, fishing mortality, and abundance were generated for each population over the period 1936–83. Large variations in survey efficiency, angler efficiency, fishing mortality, and abundance were identified over this period. We argue that a creel survey, which is expected to provide reliable information on fish population dynamics, requires an overall study design which includes collection of data on the number and relative efficiency of different kinds of anglers and periodic assessment studies aimed at providing independent checks on both survey effectiveness and population behaviour.

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 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 Trends in mortality and heart failure after acute myocardial infarction in Italy from 2007 to 2017

2020 ◽  
Vol 30 (Supplement_5) ◽  
Author(s):  
S Rosato ◽  
P D'Errigo ◽  
V Manno ◽  
A Maraschini ◽  
F Cerza ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Heart Failure ◽  
Acute Myocardial Infarction ◽  
Mortality Rate ◽  
Cox Model ◽  
Total Mortality ◽  
Index Admission ◽  
Hospital Treatment ◽  
Risk Of Death

Abstract Background Uncertainties on long-term outcomes after acute myocardial infarction (AMI) still exist, despite the ongoing progresses in the management of patients with AMI. This study aims to appraise early and 1-year outcome of patients hospitalized due to AMI and to describe the role of heart failure (HF) as complication affecting prognoses. Methods Retrospective nationwide cohort study based on administrative data on patients with AMI admitted in all Italian hospitals from 2007 to 2017. Index admission mortality rate (I-MR), 30-day and 1-year post-discharge mortality rate (PD-MR), and 30-day and 1-year total mortality rate (T-MR) were analysed; mortality average annual changes (AC) and their 95% CI were calculated; the Cox model, adjusting for age, sex, comorbidities and length of stay, was used to analyse 1-year PD-MR Results 1,148,820 patients were considered. From 2007 to 2017, both I-MR and T-MR up to 1 year decreased significantly (from 10.9 to 8.4%; AC: -0.28%; CI: -0.31 to -0.25 and from 20.2% to 17.1%: AC: -0.33%; CI: -0.39 to -0.28, respectively). From 2010, also the rate of PD-MR decreased significantly from 11.7% to 10.4%, with such favourable trend confirmed at multivariable analyses. The HF diagnosis at the index admission is always associated with a significant increase in the risk of death (1-year T-MR average: 43% and 12% in patients with or without HF, respectively; both patients with and without HF show a constant improvement in I-MR, T-MR and PD-MR over time. Conclusions In the last decade, the remarkable improvements in the in-hospital treatment of patients with AMI and in the overall prognosis up to 1 year are confirmed by a constant decrease in both early and long-term mortality. Since complication from HF remains a dangerous condition that significantly worsens the prognosis of the AMI patient, appropriate management strategies must be identified and implemented to guarantee best results from both clinic and public health perspective. Key messages Remarkable improvements achieved in overall prognosis after AMI over the past 10 years. HF confirms to be a condition able to worsen AMI patients’ prognosis.

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 DINAMIKA POPULASI DAN LAJU PEMANFAATAN IKAN BANDENG (Chanos chanos) DI WADUK SEMPOR, JAWA TENGAH

2018 ◽  
Vol 10 (1) ◽  
pp. 29
Author(s):  
Aisyah Aisyah Aisyah ◽  
Chairulwan Umar ◽  
Setiya Triharyuni ◽  
Husnah Husnah
Keyword(s):  
Growth Rate ◽  
Mortality Rate ◽  
Logistic Model ◽  
Condition Factor ◽  
Growth Parameters ◽  
Total Mortality ◽  
Von Bertalanffy ◽  
Chanos Chanos ◽  
Weight Relationship ◽  
Exploitation Rate

Ikan bandeng (Chanos chanos) di Waduk Sempor diintroduksi pada tahun 2014 melalui penerapan teknologi perikanan tangkap berbasis budidaya (Culture Based Fisheries, CBF). Penelitian ini bertujuan untuk mengevaluasi pertumbuhan bandeng melalui pengamatan parameter pertumbuhan dan biologi populasinya di Waduk Sempor, Jawa Tengah. Data yang dianalisis diperoleh dari hasil pencatatan enumerator periode September 2014 sampai– Desember 2015. Kajian dinamika populasi ikan bandeng yang meliputi laju pertumbuhan, laju kematian dan tingkat pemanfaatan mengacu pada persamaan Von Bertalanffy dan turunannya. Aspek biologi meliputi hubungan panjang berat mengacu pada model logistik, serta faktor kondisi, keseluruhan analisis dilakukan secara manual dengan program excel 2007. Hasil penelitian menunjukan bahwa parameter pertumbuhan panjang-asimtotik L∞ = 55,97 cm TL dan K= 0,38 per tahun. Laju kematian total (Z) = 1,17 per tahun, kematian alami (M) = 0,56 per tahun, kematian akibat penangkapan (F) = 0,61 per tahun serta laju eksploitasi (E) = 0,5. Pertumbuhan populasi dan laju pemanfaatan menunjukkan bahwa bandeng sudah dimanfaatkan secara optimal oleh masyarakat di sekitar Waduk Sempor.  Milkfish (Chanos chanos) was introduced at 2014 in Sempor Reservoir through culture based fisheries (CBF) technology. This study aims to evaluate population growth of the milkfish in Sempor Reservoir. Data were collected from September 2015 to December 2016, and were analyzed using excel 2007 programe manually. Analysis of length-weight relationship is refers to logistic model, population dynamic like growth rate, mortality and mortality rate are refers to Von Bertalanffy and differentiate of it. Biology of population like length-weight relationship are refers to logistic model, and condition factor. The results showed that growth parameters were L∞ = 55.97 cm TL and K = 0.38 year-1. Total mortality (Z) = 1.17 year-1; M = 0.56 year-1; F = 0.61 year-1; and E=0.5. The growth rate and exploitation rate of Milkfish (Chanos chanos) in Sempor Reservoir has been utilized optimally.

Estimate of Lamprey-Induced Mortality in a Lake Trout (Salvelinus namaycush) Population

1980 ◽  
Vol 37 (11) ◽  
pp. 2151-2158 ◽  
Author(s):  
William D. Youngs
Keyword(s):  
Lake Trout ◽  
Risk Model ◽  
Age Groups ◽  
Total Mortality ◽  
Salvelinus Namaycush ◽  
Likelihood Method ◽  
Fishing Mortality ◽  
Regression Methods ◽  
Trout Population ◽  
Cayuga Lake

A competing risk model was applied to mortality occurring in a lake trout population subjected to fishing and lamprey parasitism. Two indices are proposed as a measure of lamprey-induced mortality in the lake trout (Salvelinus namaycush) population: the average number of wounds per fish (W/F) and the average number of scars per fish (S/F) accumulated by a cohort over a period of 1 yr. These indices were used as a measure of the force of lamprey-induced mortality. Fishing mortality was estimated from angler returns of tags on lake trout. Tag returns were also used in a maximum likelihood method to estimate survival of lake trout. Fishing and lamprey-induced mortality components of the model were analyzed by linear regression methods with the force of total mortality (i) as the independent variable. The component for lamprey-induced mortality (either W/F or S/F) did not contribute significantly to the reduction in variation of the force of total mortality, but the component for fishing mortality was significant. A negative coefficient for some analyses associated with the component for lamprey-induced mortality suggested a possible conditioning influence by other factors. Growth of lake trout was examined as a possible conditioning factor but analyses suggested that growth did not influence survival. Lamprey did not apparently cause any appreciable mortality in the lake trout population, age 4 and older, in Cayuga Lake during the years studied. It was not possible to consider younger age-groups of lake trout. Keywords: lake trout, lamprey, mortality

The Mortality Rate of COVID-19 in Iraq Compare with Iran and Turkey, its Association with the Bacillus Calmette-Guerin (BCG) vaccine and the Iraqi Preparedness Plan Prior to Pandemics. (Preprint)

2020 ◽  
Author(s):  
Rawand Essa
Keyword(s):  
Middle East ◽  
Mortality Rate ◽  
Daily Basis ◽  
Bcg Vaccine ◽  
Critical Position ◽  
Preparedness Plan ◽  
Contagious Diseases ◽  
History Of ◽  
The Government

BACKGROUND In the span of COVID-19, the mortality rate has been different from one country to another. As a country in the Middle East Iraq has a critical position, lies between Iran and Turkey while both countries coronavirus cases increase on daily basis, while Iranian mortality rate record is high similar to Turkey. After Wuhan city of China, Lombard of Italy, Qum city in Iran has the highest number of COVID-19 as a first country in the Middle East. OBJECTIVE aim of this study is to show the effect of BCG vaccine during pandemic diseases, especially nowadays at the time of COVID-19. One of the crucial observations is the government preparedness and strategic planning prior pandemics, in which the BCG vaccine is an attenuated live vaccine for control of tuberculosis (TB). BCG vaccine has a non-specific immune effect that is used against pathogens like bacteria and viruses, through the promotion of pro-inflammatory cytokines' secretion. METHODS An epidemiological study has been performed, and it shows that some countries are more prone to contagious diseases like COVID-19, regardless of the main cultural, religious, societal similarities among the three mentioned countries. The information data has been collected from WHO reports and worldometer in 18 February 2020 to 10 May 2020. Regarding the efficacy of the BCG vaccine, relevant data has been retrieved from Google scholar, Pub-med and BCG world-atlas. RESULTS COVID-19 mortality rates are at peak in Iran and Turkey while the mortality rate is very low in Iraq, while the patients that died in Iraq all had history of other long-term diseases as heart disease, blood pressure, cancer etc. CONCLUSIONS From the experiences of the three countries in the life span of COVID-19, the historical plan of BCG vaccine in Iraq in cooperation with WHO since the last decades it shows that COVID-19 mortality rate is lower than other countries due to the early vaccination of the Iraqis, otherwise Iraq is more fragile than Iran and Turkey due to the poor conditions of Iraq in terms of economics, politics, war and other aspects.

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