The fisheries management implications of maternal-age-dependent larval survival

2006 ◽  
Vol 63 (10) ◽  
pp. 2249-2258 ◽  
Author(s):  
Michael R O'Farrell ◽  
Louis W Botsford
Keyword(s):  
Mortality Rate ◽  
Fisheries Management ◽  
Maternal Age ◽  
Egg Production ◽  
Larval Mortality ◽  
Reproductive Potential ◽  
Larval Survival ◽  
Age Effects ◽  
Fishing Mortality ◽  
Black Rockfish

A common goal of conventional fisheries management is to maintain fishing mortality at a rate that ensures an adequate level of lifetime egg production (LEP) for population sustainability. However, larvae from young spawners can experience higher mortality rates than larvae of older spawners, reducing the effect of egg production by young females (hereafter, maternal age effects). This reduction leads to an error in LEP that can be accounted for by reducing the fishing mortality rate, but raises the question of the magnitude of these errors if they are present but not accounted for. Calculations using parameters from a typical long-lived fish demonstrated that maternal age effects resulted in large errors in estimates of lifetime reproduction when there was a large contrast in the larval mortality rate extending over the reproductive life span. Errors were small when maternal age effects reduced the reproductive potential of only the very youngest spawners, at ages when a small fraction of females are mature. A specific example using the empirically derived maternal age effect for black rockfish (Sebastes melanops) indicated that errors in traditional management would be small for this species.

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.

Muskellunge Management: Fifty Years of Cooperation Among Anglers, Scientists, and Fisheries Biologists

2017 ◽  
Keyword(s):  
Mortality Rate ◽  
Reproductive Potential ◽  
Older Age ◽  
Cooperative Interaction ◽  
Reproductive Capacity ◽  
Fishing Mortality ◽  
Catch And Release ◽  
The Past ◽  
Size Limits ◽  
Annual Mortality

<em>Abstract</em>.—Sustainability of trophy Muskellunge <em>Esox masquinongy </em>populations and fisheries was examined from Muskies, Inc. catch data (335,954) from 43 years (1971–2013), along with more than 35 years (late 1970s–2013) of trophy Muskellunge data and cleithra (2,633) submitted to the Cleithrum Project. Catch has increased substantially over the past five decades, but harvest has been greatly reduced because of increased size limits (e.g., in Ontario, set by using growth potential) and voluntary catch and release of legal-sized fish promoted by organized Muskellunge anglers. The Cleithrum Project exemplifies cooperative interaction; although fewer samples have been submitted in recent years, length, weight, and age have increased significantly. Pivotal change occurred in the mid-1990s (means for late 1970s–1994, total length 108.7 cm, total weight 9.7 kg, age 11.6 years; 1995–2013, 121.0 cm, 13.4 kg, 15.1 years). A predictive mortality rate–longevity relationship was used on the Cleithrum Project age data to estimate mortality rate of trophy Muskellunge. Annual mortality rate (<EM>A</EM>) of trophy Muskellunge usually ranged from 16% to 26% and corresponded to maximum ages of 24 to 14 years. Estimated annual mortality of the oldest Muskellunge increased slightly over the past 35 years—13.0% to 14.3%, with a decrease in maximum age from 30 to 27 years. Mortality was high to the mid-1990s but has decreased subsequently, even though angling pressure has increased. Size and mean age of trophy Muskellunge have increased substantially (10.2 to 15.8 years) with associated decreases in annual mortality (<EM>A</EM>, 31.0% to 21.9%), indicating an increase in the mature population and reproductive potential. To ensure sustainable trophy Muskellunge populations, fish younger than 15 years should not be exposed to fishing mortality and older fish should not have a fishing mortality rate that exceeds the rate of natural mortality (<EM>F ≯</EM> <EM>M</EM>). Management for large size (older age) by using excessive size limits, in combination with catch and release, can have unexpected outcomes because older fish are increasingly sensitive to stress (e.g., viral hemorrhagic septicemia [VHS] mortalities). If Muskellunge populations are managed for high reproductive capacity (protecting fish to larger size and older age), they will be more reproductively resilient, producing larger year-classes, better sustaining trophy populations and fisheries.

scholarly journals Growth, reproductive cycle, and movement of berried European lobsters (Homarus gammarus) in a local stock off southwestern Norway

2006 ◽  
Vol 64 (2) ◽  
pp. 288-297 ◽  
Author(s):  
Ann-Lisbeth Agnalt ◽  
Tore S. Kristiansen ◽  
Knut E. Jørstad
Keyword(s):  
Reproductive Cycle ◽  
Egg Production ◽  
Reproductive Potential ◽  
Fishing Ground ◽  
Fishing Mortality ◽  
Homarus Gammarus ◽  
Spawning Stock ◽  
Release Area ◽  
Local Stock ◽  
Spawning Biomass

Abstract Agnatt, A-L., Kristiansen T. S., and Jorstad K. E. 2007. Growth, reproductive cycle, and movement of berried kuropean lobsters (Homarus gammarus) in a local stock off southwestern Norway. – ICES Journal of Marine Science, 64: 288–297. The Norwegian fishery for the European lobster (Homarus gammarus) collapsed between 1960 and 1980, to <10% of its pre-1960 level, and since then the spawning stock seems to be too low to generate good recruitment. In 1998, a project to evaluate the feasibility and effect of protecting berried female lobsters as a management restriction was initiated. The study area selected was previously an important fishing ground in Kvitsøy off southwestern Norway, and 125 000 hatchery-reared juveniles were released between 1990 and 1994. From spring 1998 to spring 2000, a total of 942 wild and 480 cultured berried females was purchased from fishers, individually tagged with a streamer-tag, and released. The proportion of berried females in the landings varied annually from 19 to 58% for wild females, and from 22 to 44% for cultured females. By spring 2000, 23% of the tagged females had been recaptured at least once, and 3% twice or more. Average moult increment was 7 mm carapace length (CL), independent of pre-moult size in both wild and cultured females. Reproduction (spawning) and growth (moulting) alternated in a 2 y cycle for >90% of the females. A small number moulted and spawned a few weeks after hatching. More than 95% of the recaptures were taken within a radius of 1 km of the release area. Egg production varied considerably between seasons. Reproductive potential (RP) of landed berried females underestimated egg production compared with what was actually produced (AE). For the entire period, RP was estimated to be about 15.0 million eggs, and AE to be 17.2 million eggs. Cultured females contributed 27% of AE. To reduce the fishing mortality in a heavily fished and depleted population is vital. A ban on landing berried females would be a valuable first step in attempting to increase the spawning biomass.

scholarly journals Biparental age effects in the burying beetle Nicrophorus vespilloides

2021 ◽  
Author(s):  
Hilary Cope ◽  
Edward Ivimey-Cook ◽  
Jacob Moorad
Keyword(s):  
Maternal Age ◽  
Larval Survival ◽  
Age Effects ◽  
Paternal Age ◽  
Offspring Size ◽  
Laboratory Population ◽  
Parental Age ◽  
Burying Beetle ◽  
Negative Results ◽  
Nicrophorus Vespilloides

AbstractParental age at reproduction influences offspring size and survival by affecting prenatal and postnatal conditions in a wide variety of species, including humans. However, most investigations into this manifestation of ageing focus upon maternal age effects; the effects of paternal age and interactions between maternal and paternal age are often neglected. Furthermore, even when maternal age effects are studied, pre- and postnatal effects are confounded. Using a cross-fostered experimental design, we investigated the joint effects of paternal and pre- and postnatal maternal ages on numerous offspring outcomes in a laboratory population of a species of burying beetle, Nicrophorus vespilloides. When we correct our tests for significance for multiple comparisons, we found no clear evidence for any parental effect senescence acting on egg size, larval weight, or larval survival. Nor did we find a statistical effect of paternal or egg producer age on the outcomes of foster mothers as measured by weight change experienced during caregiving. These findings are consistent with recent negative results reported in a similar study of N. vespilloides maternal age effects while also expanding these to other offspring traits and to paternal age effects. We discuss how the peculiar life history of this species may promote selection to resist the evolution of parental age effects, and how this might have influenced our ability to detect senescence.

Parental breeding age effects on descendants’ longevity interact over two generations in matrilines and patrilines

2019 ◽  
Author(s):  
Zac Wylde ◽  
Foteini Spagopoulou ◽  
Amy K Hooper ◽  
Alexei A Maklakov ◽  
Russell Bonduriansky
Keyword(s):  
Maternal Age ◽  
First Generation ◽  
Age Effects ◽  
Population Variation ◽  
Paternal Age ◽  
Interactive Effects ◽  
Competitive Environment ◽  
Larval Diet ◽  
Negative Effects ◽  
Two Generations

Individuals within populations vary enormously in mortality risk and longevity, but the causes of this variation remain poorly understood. A potentially important and phylogenetically widespread source of such variation is maternal age at breeding, which typically has negative effects on offspring longevity. Here, we show that paternal age can affect offspring longevity as strongly as maternal age does, and that breeding age effects can interact over two generations in both matrilines and patrilines. We manipulated maternal and paternal ages at breeding over two generations in the neriid fly Telostylinus angusticollis. To determine whether breeding age effects can be modulated by the environment, we also manipulated larval diet and male competitive environment in the first generation. We found separate and interactive effects of parental and grandparental ages at breeding on descendants’ mortality rate and lifespan in both matrilines and patrilines. These breeding age effects were not modulated by grandparental larval diet quality or competitive environment. Our findings suggest that variation in maternal and paternal ages at breeding could contribute substantially to intra-population variation in mortality and longevity.

FAKTOR-FAKTOR YANG BERHUBUNGAN DENGAN KEJADIAN BBLR DI RUMAH SAKIT UMUM DAERAH PALEMBANG BARI TAHUN 2013

2019 ◽  
Vol 4 (2) ◽  
Author(s):  
Juliana Widyastuti Wahyuningsih Juliana Widyastuti Wahyuningsih
Keyword(s):  
Birth Weight ◽  
Mortality Rate ◽  
Low Birth Weight ◽  
Random Sampling ◽  
Maternal Age ◽  
Univariate Analysis ◽  
Infant Mortality Rate ◽  
Survey Method ◽  
P Value ◽  
Chi Square

ABSTRACT   Low birth weight (LBW) infants with birth weight is less than 2500 grams, regardless of gestational age. Statistically showed 90 % incidence of LBW obtained in developing countries with a mortality rate 35 times higher tinggi.Di South Sumatra Province Infant Mortality Rate ( IMR ) is 29 per 1,000 live births. In Palembang BARI hospitals incidence of LBW in 2013 amounted to 317 cases . The purpose of this study is to determine is there a relationship between the factors of age, education, and parity with the incidence of Low Birth Weight in Palembang BARI hospitals in 2013. This study used survey method crosss sectional analytic approach. The study population was all women who gave birth and was admitted to hospital obstetrics Palembang BARI installations in 2013 amounted to 901. This research was conducted in February 2014. Samples were taken with a random sampling method sistematic. Analyze data using statistical test Chi - Square. Results of univariate analysis of this study showed that 193 (69.4 %) of the respondents had low birth weight, and 85 (30.6 %) respondents had BBLN. 63 (22.7 %) of respondents with a high risk of maternal age and 215 (77.3 %) of respondents with a low risk of maternal age. 157 (56.5 %) respondents with low education mothers and 121 (43.5 %) of respondents with higher education mothers. 48 (17.3 %) respondents with high parity mothers and 230 (82.7 %) respondents with low parity mothers. So the bivariate analysis showed no significant association between maternal age with the incidence of LBW with P value = 0.035, no significant association between education and the incidence of LBW with P value = 0.006, and no significant relationship between the incidence of low birth weight with parity P value = 0.041. It is recommended for health care workers (midwives) hospital in order to be used as material information regarding the occurrence of LBW and as an input as well as the evaluation of success in good health or when needed to do counseling and care of LBW, especially to mothers who give birth to low birth weight baby.   ABSTRAK Berat badan lahir rendah (BBLR) adalah bayi dengan berat lahir kurang dari 2500 gram tanpa memandang masa gestasi. Secara statistik menunjukkan 90% kejadian BBLR didapatkan di negara berkembang dengan angka kematiannya 35 kali lebih tinggi.Di Propinsi Sumatera Selatan Angka Kematian Bayi (AKB) sebesar 29 per 1.000 kelahiran hidup. Di RSUD Palembang BARI Tahun 2013 angka kejadian BBLR berjumlah 317 kasus. Tujuan Penelitian ini adalah untuk mengetahui adakah hubungan antara faktor umur, pendidikan, dan paritas dengan kejadian Berat Badan Lahir Rendah di RSUD Palembang BARI Tahun 2013. Penelitian ini menggunakan metode survey analitik dengan pendekatan crosss sectional. Populasi penelitian ini adalah semua ibu yang melahirkan dan dirawat inap di instalasi kebidanan RSUD Palembang BARI Tahun 2013 berjumlah 901. Penelitian ini dilakukan pada bulan Februari 2014. Sampel penelitian diambil dengan metode sistematic random sampling. Analisa data menggunakan uji statistik Chi – Square. Hasil penelitian analisis univariat ini menunjukkan bahwa 193 (69,4%) responden mengalami BBLR, dan 85 (30,6%) responden mengalami BBLN. 63 (22,7%) responden dengan umur ibu resiko tinggi dan 215 (77,3%) responden dengan umur ibu resiko rendah. 157 (56,5%) responden dengan ibu pendidikan rendah dan 121 (43,5%) responden dengan ibu pendidikan tinggi. 48 (17,3%) reponden dengan ibu paritas tinggi dan 230 (82,7%) responden dengan ibu paritas rendah. Sehingga analisa bivariat menunjukkan ada hubungan yang bermakna antara umur ibu dengan kejadian BBLR dengan P value = 0,035, ada hubungan yang bermakna antara pendidikan dengan kejadian BBLR dengan P value = 0,006 dan ada hubungan yang bermakna antara paritas dengan kejadian BBLR dengan P value = 0,041. Disarankan bagi petugas kesehatan (bidan) rumah sakit agar dapat dijadikan sebagai bahan informasi mengenai terjadinya BBLR dan sebagai bahan masukan serta evaluasi keberhasilan dalam pelayanan kesehatan yang baik atau bila perlu dilakukannya penyuluhan serta asuhan  tentang BBLR khususnya kepada ibu yang melahirkan Bayi dengan BBLR.  

Reproductive Status Modulates Mortality Rate, Lifespan and Egg Production, but Do Not the Physiological Aging in the Field Cricket Gryllus assimilis (Fabricius, 1775) (Orthoptera: Gryllidae)

2021 ◽  
Vol 50 (2) ◽  
pp. 237-246
Author(s):  
Guilherme Martins Limberger ◽  
Luiz Eduardo Maia Nery ◽  
Duane Barros da Fonseca
Keyword(s):  
Mortality Rate ◽  
Egg Production ◽  
Reproductive Status ◽  
Field Cricket ◽  
Physiological Aging

scholarly journals Depleted marine fish stocks and ecosystem-based management: on the road to recovery, we need to be precautionary

2010 ◽  
Vol 68 (1) ◽  
pp. 212-220 ◽  
Author(s):  
Anna Gårdmark ◽  
Anders Nielsen ◽  
Jens Floeter ◽  
Christian Möllmann
Keyword(s):  
Fisheries Management ◽  
Marine Fish ◽  
Assessment Model ◽  
Fishing Mortality ◽  
Fish Stocks ◽  
The Road ◽  
Stock Status ◽  
Ecosystem Based Management ◽  
Management Plans ◽  
On The Road

Abstract Gårdmark, A., Nielsen, A., Floeter, J., and Möllmann, C. 2011. Depleted marine fish stocks and ecosystem-based management: on the road to recovery, we need to be precautionary. – ICES Journal of Marine Science, 68: 212–220. Precautionary management for fish stocks in need of recovery requires that likely stock increases can be distinguished from model artefacts and that the uncertainty of stock status can be handled. Yet, ICES stock assessments are predominantly deterministic and many EC management plans are designed for deterministic advice. Using the eastern Baltic cod (Gadus morhua) stock as an example, we show how deterministic scientific advice can lead to illusive certainty of a rapid stock recovery and management decisions taken in unawareness of large uncertainties in stock status. By (i) performing sensitivity analyses of key assessment model assumptions, (ii) quantifying the uncertainty of the estimates due to data uncertainty, and (iii) developing alternative stock and ecosystem indicators, we demonstrate that estimates of recent fishing mortality and recruitment of this stock were highly uncertain and show that these uncertainties are crucial when combined with management plans based on fixed reference points of fishing mortality. We therefore call for fisheries management that does not neglect uncertainty. To this end, we outline a four-step approach to handle uncertainty of stock status in advice and management. We argue that it is time to use these four steps towards an ecosystem-based approach to fisheries management.

scholarly journals Can stock–recruitment points determine which spawning potential ratio is the best proxy for maximum sustainable yield reference points?

2013 ◽  
Vol 70 (6) ◽  
pp. 1075-1080 ◽  
Author(s):  
Christopher M. Legault ◽  
Elizabeth N. Brooks
Keyword(s):  
Life History ◽  
Mortality Rate ◽  
Maximum Sustainable Yield ◽  
Reference Points ◽  
Sustainable Yield ◽  
Marine Science ◽  
Fishing Mortality ◽  
Scatter Plots ◽  
Stock Recruitment ◽  
Spawning Potential Ratio

Abstract Legault, C. M., and Brooks, E. N. 2013. Can stock–recruitment points determine which spawning potential ratio is the best proxy for maximum sustainable yield reference points? – ICES Journal of Marine Science, 70: 1075–1080. The approach of examining scatter plots of stock–recruitment (S–R) estimates to determine appropriate spawning potential ratio (SPR)-based proxies for FMSY was investigated through simulation. As originally proposed, the approach assumed that points above a replacement line indicate year classes that produced a surplus of spawners, while points below that line failed to achieve replacement. In practice, this has been implemented by determining Fmed, the fishing mortality rate that produces a replacement line with 50% of the points above and 50% below the line. A new variation on this approach suggests FMSY proxies can be determined by examining the distribution of S–R points that are above or below replacement lines associated with specific SPRs. Through both analytical calculations and stochastic results, we demonstrate that this approach is fundamentally flawed and that in some cases the inference is diametrically opposed to the method's intended purpose. We reject this approach as a tool for determining FMSY proxies. We recommend that the current proxy of F40% be maintained as appropriate for a typical groundfish life history.

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