Age, growth and mortality of redfish Centroberyx affinis

2001 ◽  
Vol 52 (4) ◽  
pp. 637 ◽  
Author(s):  
A. K. Morison ◽  
K. R. Rowling
Keyword(s):  
Growth Rate ◽  
Significant Variation ◽  
Fork Length ◽  
Age And Growth ◽  
Average Error ◽  
Natural Mortality ◽  
Commercial Catch ◽  
Thin Sections ◽  
The Mean ◽  
Age Estimates

Age and growth of 5678 redfish, collected during 1991–98 from Australia’s South East Fishery, were estimated from thin sections of otoliths. A maximum age of 44 years was recorded for a 30 cm (fork length) female, but 80%of females in the commercial catch were <10 years, and 80%of males were <13 years. The largest was a 34 cm female estimated to be 36 years old. Repeated age estimates of a subsample revealed an average error of 3.79%. There was significant variation in the mean length-at-age among years, and there were significant effects for age*year, age*sex, age*region, region*year, and sex*region*year interactions. Assessments of the fishery have assumed a single stock, because tagging results from the 1980s indicate movement of redfish along the coast. This study found consistent differences in sex ratio and growth rate between regions, which indicate some structuring within the population. However, the differences in growth rates are not consistent among years and could not be explained by differences in depths fished, suggesting a more dynamic situation than spatially segregated stocks. Estimates of natural mortality ranged from 0.07 to 0.11 year–1 and differed between regions.

Age and Growth of the Shortfin Mako, Isurus oxyrinchus, Using Four Methods

1983 ◽  
Vol 40 (11) ◽  
pp. 1944-1957 ◽  
Author(s):  
Harold L. Pratt Jr. ◽  
John G. Casey
Keyword(s):  
Growth Rate ◽  
Full Range ◽  
Fork Length ◽  
Growth Function ◽  
Temporal Analysis ◽  
Age And Growth ◽  
Length Frequency ◽  
Isurus Oxyrinchus ◽  
Shortfin Mako ◽  
Age Estimates

Age and growth rate of shortfin mako, Isurus oxyrinchus, captured by hook and line between 1961 and 1981 were determined using four methods: (1) temporal analysis of length–month information, (2) results of tagging data, (3) length–frequency analysis, and (4) ring counts on vertebrae. A temporal analysis of length–month information relating size to age for individuals less than 150 cm fork length (FL) was used to determine size (60–70 cm FL), time of birth (late spring), and early growth rate (50 cm/yr for ages 0–I, 32 cm/yr for ages I–II). This growth rate was used as a basis for interpreting the accuracy of other methods. Annual growth rates were calculated from 32 tag–recaptured mako sharks and resolved graphically into a growth curve. Length–frequency modes extended age estimates to intermediate-sized makos. Counts of growth rings on vertebral centra stained with silver nitrate were employed to back-calculate lengths at ages for the full range (69–328 cm). Our interpretation was based on the hypothesis that two rings are formed on the centrum each year; these age estimates agreed well with results from other methods. Males and females had a similar growth rate even though females grow much larger than males. The oldest female in the sample was 11.5 yr at 328 cm. The oldest male was 4.5 yr at 225 cm. The von Bertalanffy asymptotic growth function adequately described shortfin mako growth: male L∞ = 302 cm, K = 0.266, t0 = −1; female L∞ = 345 cm, K = 0.203, t0 = −1.

scholarly journals Starost, rast i morfometrija otolita palamide (Sarda sarda Block, 1793) iz istočnog Sredozemnog mora

2018 ◽  
Vol 59 (1) ◽  
pp. 97-110 ◽  
Author(s):  
Mado Kotsiri ◽  
Ioannis E. Batjakas
Keyword(s):  
Growth Parameters ◽  
Eastern Mediterranean ◽  
Fork Length ◽  
Cold Season ◽  
Age And Growth ◽  
Fish Length ◽  
Thin Sections ◽  
Significant Relationships ◽  
The One ◽  
Sarda Sarda

The otoliths of the Atlantic bonito, Sarda sarda (Bloch, 1793), were examined with the aim to estimate the age and growth of the species in the eastern Mediterranean Sea and to reveal possible relationships between otolith shape or size and age. All specimens used in this study, ranging from 7.2 to 70.4 cm in fork length and from 20 to 4889 g in total weight, were caught in the Aegean and Ionian Seas during the period 1997-2010. Otolith morphometry was studied using image analysis techniques for all intact sagittae ranging in weight from 0.6 to 11.3 mg and four shape indices were calculated. No statistical significant differences between left and right otolith morphometric variables were found. The age of fish was estimated by counting the pairs of opaque and translucent bands in transversal thin sections of otoliths. The estimated ages ranged from 0+ to 7 years and the von Bertalanffy growth parameters were determined \((L∞=79.9 cm, k=0.261 and to=-1.230 years)\). The examination of the type of growth bands at the outside margin of each otolith per month showed that one translucent band is formed annually during the cold season. The results revealed statistically significant relationships between otolith morphometric variables and fish length or age. Among the variables, otolith weight was the one that showed the highest correlation with age (R=0.77). Therefore, otolith weight could represent a valuable criterion for age estimation in Atlantic bonito that is objective, economic and easy to perform compared to annuli counting method in hard parts.

Age and growth of Murray Cod, Maccullochella peelii (Perciformes: Percichthyidae), in the Lower Murray-Darling Basin, Australia, from thin-sectioned Otoliths

1992 ◽  
Vol 43 (5) ◽  
pp. 983 ◽  
Author(s):  
JR Anderson ◽  
AK Morison ◽  
DJ Ray
Keyword(s):  
Growth Rates ◽  
Growth Parameters ◽  
Age And Growth ◽  
Average Error ◽  
Fish Length ◽  
Exponential Relationship ◽  
Thin Sections ◽  
False Rings ◽  
Murray Darling Basin ◽  
Murray Cod

Transverse thin sections (0.5 mm thick) of sagittal otoliths from 290 Murray cod up to 1400 mm in total length and 47.3 kg in weight were used to establish the age and growth of cod in the lower Murray-Darling Basin, including comparisons of recent (1986-91) and past (1949-51) growth rates and growth in different waters. The maximum estimated age was 48 years. Quantitative and qualitative analysis of the seasonal changes in otolith marginal increments showed that annuli in fish of all ages were laid down each spring, and 1 October was assigned as the birthday. The thin-sectioning method was validated by comparing age estimates for 55 Murray cod from Lake Charlegrark (age 0-21 years), which had been validated by using burnt and polished half-otoliths. The new method had an accuracy of 96.4% and it offers major advantages in ease of preparation, reading, and batch-handling of large numbers of otoliths. The precision of the method, estimated as an average error for four readers, was 5.4% (3.0% after ignoring discrepancies in relation to annuli on otolith edges). There was a linear relationship between otolith weight and fish age and an exponential relationship between otolith weight and fish length. Both otolith length and otolith width reached an asymptote at about 15 years, when fish length also approached its maximum. However, otolith thickness continued to increase throughout the life of the fish and, after about 15 years, contributed most to the increase in otolith weight. This confirmed that otoliths continued to grow in thickness and that annuli were laid down throughout life, and that cod could be aged reliably to the maximum age. The annulus pattern is very clear and distinct, and the reading techniques are fully described, including recognition of 'larval' and 'false' rings. Various differences were found in the growth rates, and the length-weight relationships for males and females, for cod caught in 1986-91 and those caught in 1949-51, and various subpopulations are discussed. The von Bertalanffy growth parameters (all individuals combined) were estimated at L∞ = 1202 mm, k=0.108 and t0= -0.832. The availability of a reliable ageing method provides the first opportunity to determine year of birth and thus to examine the age structure of populations and to effectively manage cod populations that have declined in abundance.

scholarly journals Queen triggerfish Balistes vetula: Validation of otolith-based age, growth, and longevity estimates via application of bomb radiocarbon

PLoS ONE ◽  
2022 ◽  
Vol 17 (1) ◽  
pp. e0262281
Author(s):  
Virginia R. Shervette ◽  
Jesús M. Rivera Hernández
Keyword(s):  
Age Estimation ◽  
Atlantic Coast ◽  
Fork Length ◽  
Growth Function ◽  
Age And Growth ◽  
Future Research ◽  
Fisheries Science ◽  
Fish Samples ◽  
Age Estimates

Ensuring the accuracy of age estimation in fisheries science through validation is an essential step in managing species for long-term sustainable harvest. The current study used Δ14 C in direct validation of age estimation for queen triggerfish Balistes vetula and conclusively documented that triggerfish sagittal otoliths provide more accurate and precise age estimates relative to dorsal spines. Caribbean fish samples (n = 2045) ranged in size from 67–473 mm fork length (FL); 23 fish from waters of the southeastern U.S. (SEUS) Atlantic coast ranged in size from 355–525 mm FL. Otolith-based age estimates from Caribbean fish range from 0–23 y, dorsal spine-based age estimates ranged from 1–14 y. Otolith-based age estimates for fish from the SEUS ranged from 8–40 y. Growth function estimates from otoliths in the current study (L∞ = 444, K = 0.13, t0 = -1.12) differed from spined-derived estimates in the literature. Our work indicates that previously reported maximum ages for Balistes species based on spine-derived age estimates may underestimate longevity of these species since queen triggerfish otolith-based ageing extended maximum known age for the species by nearly three-fold (14 y from spines versus 40 y from otoliths). Future research seeking to document age and growth population parameters of Balistes species should strongly consider incorporating otolith-based ageing in the research design.

Mercury content of edible flesh from snapper, Chrysophrys auratus (Bloch & Schneider), in the Victorian commercial catch

1981 ◽  
Vol 32 (1) ◽  
pp. 75 ◽  
Author(s):  
TI Walker
Keyword(s):  
Mercury Concentration ◽  
Fork Length ◽  
Mercury Content ◽  
Total Weight ◽  
Commercial Fishing ◽  
Management Options ◽  
Commercial Catch ◽  
Wet Weight ◽  
The Mean ◽  
Statutory Limit

The concentrations of total mercury (range 0.1-1.5 �g /g) in 40 individual snapper, C. auratus, caught in two commercial fishing areas in Victorian waters were adequately correlated with fork length by a power-law relationship. From further relationships established between length and total weight, and between filleted weight and total weight, the mean mercury concentration in the edible flesh of this species was estimated for each of the six years (1973-78) for which information on the length-frequency distribution was available for the Victorian commercial catch. The annual estimates ranged from 0.47 to 0.52 �g/g wet weight, and 45-52% of the edible flesh had values exceeding the Victorian statutory limit of 0.5 �g/g. Various management options available to health and fisheries agencies are discussed, and the methods of calculating the important parameters corresponding to these options are described. For example, graphs are presented from which can be read a legal maximum length of landed snapper, designed to reduce the mean mercury concentration of the catch to below a nominated level.

Validation of the use of thin-sectioned Otoliths for determining the age and growth of Golden Perch, Macquaria ambigua (Perciformes: Percichthyidae), in the Lower Murray-Darling Basin, Australia

1992 ◽  
Vol 43 (5) ◽  
pp. 1103 ◽  
Author(s):  
JR Anderson ◽  
AK Morison ◽  
DJ Ray
Keyword(s):  
Growth Rates ◽  
Total Weight ◽  
Birth Date ◽  
Fish Length ◽  
Thin Sections ◽  
Continuous Growth ◽  
Total Length ◽  
Murray Darling Basin ◽  
The Mean ◽  
Age Estimates

Golden perch, Macquaria ambigua, from the Murray-Darling Basin were aged by using transverse thin sections of their sagittal otoliths. Samples from 889 fish were obtained from riverine and lacustrine habitats and from wild and stocked populations. Error in the precision of age estimates (calculated as the mean percentage error of the independent age estimates of four readers) was 5.6% (3.9% after allowing for discrepancies in relation to the annual mark on the edge of the otolith). Validation was accomplished by using a combination of analysis of the progression of modes in length-frequency distributions, qualitative and quantitative marginal-increment analysis, and analysis of age estimates of fish from populations with a known stocking history. The technique was validated for fish up to 8 years of age (455-545 mm total length, 1695-3988 g total weight), and the greatest recorded age was 16 years (530-600 mm total length, 2607-4050 g total weight). Annual marks become visible in otolith sections in most fish of all ages in October, and 1 October was designated as the birth date. A description of our method of reading sections of golden perch otoliths, including recognition of false annual marks, is given. Otolith length, width and thickness increased linearly with fish length and with loglo(fish age), whereas otolith weight increased linearly with fish age and exponentially with fish length. The continuous growth of the otoliths and the consistency in the appearance of annual marks support the accuracy of estimates up to the maximum recorded age. The mean length-at-age and the parameters of the length-weight relationship were estimated. The von Bertalanffy growth parameters were also estimated (L∞ =507 mm, to=0.420 years, K=0.454). No significant differences were found in growth rates or length-weight relationships between males and females. However, growth (particularly in weight) was highly variable among sites and years, and slow-growing 5-year-olds may be shorter than fastgrowing 1-year-olds. Ages were estimated for a sample of 86 golden perch caught between 1949 and 1951 but a comparison of growth rates between these and more recent collections was inconclusive.

scholarly journals Bomb radiocarbon dating of three important reef-fish species using Indo-Pacific Δ14C chronologies

2011 ◽  
Vol 62 (11) ◽  
pp. 1259 ◽  
Author(s):  
Allen H. Andrews ◽  
John M. Kalish ◽  
Stephen J. Newman ◽  
Justine M. Johnston
Keyword(s):  
Fish Species ◽  
Age Estimation ◽  
Radiocarbon Dating ◽  
Reef Fishes ◽  
Growth Zone ◽  
Age And Growth ◽  
Thin Sections ◽  
Bomb Radiocarbon ◽  
Reef Fish Species ◽  
Age Estimates

Demersal reef fishes of the Indo-Pacific are under increasing pressure as a fisheries resource, yet many of the important life history characteristics required for suitable management are poorly known. The three fish species, eightbar grouper (Hyporthodus octofasciatus), ruby snapper (Etelis carbunculus) and the spangled emperor (Lethrinus nebulosus), are important components of fisheries and ecosystems throughout the Indo-Pacific. Despite their importance, age and growth information is incomplete. Age has been estimated for E. carbunculus and L. nebulosus, but validated age beyond the first few years is lacking and for H. octofasciatus no age estimates exist. Bomb radiocarbon dating can provide age estimates that are independent of growth-zone counting, but only if appropriate reference Δ14C chronologies exist. In this study, a series of Δ14C records from hermatypic corals was assembled to provide a basis for bomb radiocarbon dating in the western Indo-Pacific region. Results provided (1) valid age estimates for comparison to age estimates from two facilities investigating growth-zones in otolith thin sections; (2) support for age estimation protocols using otolith thin sections; and (3) the information necessary for further refinement of age estimation procedures. Estimates of longevity from bomb radiocarbon dating agree with some prior studies: H. octofasciatus, E. carbunculus and L. nebulosus all being long-lived species with life spans of at least 43, 35 and 28 years respectively.

scholarly journals Spatial patterns in the demography of a large estuarine teleost: king threadfin, Polydactylus macrochir

2011 ◽  
Vol 62 (8) ◽  
pp. 937 ◽  
Author(s):  
B. R. Moore ◽  
D. J. Welch ◽  
C. A. Simpfendorfer
Keyword(s):  
Spatial Patterns ◽  
Fisheries Management ◽  
Significant Variation ◽  
Fork Length ◽  
Total Mortality ◽  
Age And Growth ◽  
Eastern Coast ◽  
Estuarine Fish ◽  
Fitzroy River ◽  
River Fish

Understanding spatial patterns in demographic parameters of exploited fish species is of critical importance to effective fisheries management. In the present study, patterns in demography of a large, protandrous, estuarine teleost, king threadfin, Polydactylus macrochir, were compared among three estuaries on the eastern coast of Queensland, Australia. Significant variation in age and growth was observed between fish from the Fitzroy River and those from the Mary and Brisbane Rivers, with Fitzroy River fish living longer (22 years v. 10 and 14 years, respectively), reaching a greater asymptotic length (1222-mm fork length (FL) v. 975- and 1047-mm FL, respectively), and attaining greater length-at-ages of 6 years and beyond. No difference in growth was detected between Mary and Brisbane River fish, or in total mortality among any of the sites. Fitzroy River fish were generally found to mature and change sex at greater lengths and ages than those from the Mary and Brisbane Rivers. The observed variability suggests that spatially segregated populations of P. macrochir may respond differently to fishing pressure and highlights the importance of understanding the spatial patterns in demography of exploited estuarine fish populations.

On the Age and Growth Rate of Giant Cacti: Radiocarbon Dating of the Spines of Cardon (Pachycereus Pringlei)

Radiocarbon ◽  
2016 ◽  
Vol 58 (3) ◽  
pp. 479-490 ◽  
Author(s):  
Mariana Delgado-Fernández ◽  
Pedro P Garcillán ◽  
Exequiel Ezcurra
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Annual Growth ◽  
Age And Growth ◽  
Limiting Factor ◽  
Annual Growth Rate ◽  
Columnar Cacti ◽  
Rate Versus ◽  
The Mean ◽  
Pachycereus Pringlei

AbstractAge estimation has been a limiting factor in the study of giant columnar cacti. In order to test the feasibility of using radiocarbon methods to estimate the age of the giant cardon cacti (Pachycereus pringlei), we selected six sites spanning the latitudinal and precipitation range of the species in the Baja California peninsula. In each site, we selected four individuals of different heights and sampled a spine from the lowest areole in the stem. The age of the spine was estimated using 14C dating, and the mean annual growth rate of the plant was calculated dividing the height of the lead shoot by the plant’s age. Mean annual growth rate was 0.098 m/yr, with values varying between 0.03 and 0.23 m/yr. Within the range of plants sampled, mean annual growth rates were significantly correlated with the height of the plant (r2=0.82, P<0.0001), and no other site-specific variable such as precipitation or latitude was a significant predictor of mean annual growth rates. A model integrating mean growth rate versus height showed that relatively small differences in growth rates between plants accumulate during the plants’ lifetime, so that plants of similar size may have very different ages. We conclude that 14C dating provides a robust method to explore the growth and demography of columnar cacti.

Changes in Walleye (Stizostedion vitreum vitreum) Population in Rainy Lake and Factors in Abundance, 1924–75

1977 ◽  
Vol 34 (10) ◽  
pp. 1696-1702 ◽  
Author(s):  
J. R. Chevalier
Keyword(s):  
Growth Rate ◽  
Linear Regression Analysis ◽  
Multiple Linear Regression Analysis ◽  
Water Levels ◽  
Stizostedion Vitreum ◽  
Brood Stock ◽  
Commercial Catch ◽  
Compensatory Response ◽  
The Mean ◽  
Significant Factors

Annual commercial harvests of walleye (Stizostedion vitreum vitreum) from Rainy Lake steadily declined from 150,000 kg in the 1920s to 19,000 in the early 1970s; total (all species) harvests averaged 374,000 kg from 1924 to 1975, 45% greater than the MEI estimated allowable harvest. The walleye catch per unit of effort from commercial 102 mm gill nets declined from 43.63 kg/km in 1948 to 18.43 in 1969. Growth rate of walleye increased from 1959 to 1965, probably as a compensatory response to decreased abundance. The increased growth rate, in conjunction with heavy exploitation, caused the mean age of the walleye commercial catch to decline from 1957 to 1967. Both spring water levels and brood stock abundance were significant factors in walleye abundance 5 yr later. From multiple linear regression analysis, these two variables accounted for 65% of the variation in commercial walleye CUE. Key words: Percidae, Stizostedion, walleye, population dynamics, abundance, yield, exploitation, water level, Rainy Lake, Ontario–Minnesota

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