Differences in the Age of Pacific Hake (Merluccius productus) Using Whole Otoliths and Sections of Otoliths

1979 ◽  
Vol 36 (2) ◽  
pp. 141-151 ◽  
Author(s):  
R. J. Beamish
Keyword(s):  
Key Words ◽  
Age Determination ◽  
Otolith Growth ◽  
Strait Of Georgia ◽  
Merluccius Productus ◽  
Key Words Age ◽  
Two Populations

Ages determined for older Pacific hake from sections through the nucleus of otoliths were older than the ages determined from the otolith surface for the two populations studied. Growth of all parts of the otolith was not identical throughout the life of the fish. The change in the pattern of otolith growth occurred about the age at which the growth in length of the fish was reduced. Despite the disproportionate growth in length and height of the otolith, the thickness of the otolith, especially in the ventral interior portion, continued to increase with age. Section ages appear to be more reliable for older fish because of this allometric change in otolith growth with increasing fish age. It is suggested that the examination of sections of otoliths should become a routine approach in any attempt to age fish using otoliths. Key words: age determination, otolith, otolith section, otolith growth, aging errors, Pacific hake, Strait of Georgia

New Information on the Longevity of Pacific Ocean Perch (Sebastes alutus)

1979 ◽  
Vol 36 (11) ◽  
pp. 1395-1400 ◽  
Author(s):  
Richard J. Beamish
Keyword(s):  
Pacific Ocean ◽  
Key Words ◽  
West Coast ◽  
Growth Pattern ◽  
Age Determination ◽  
The West ◽  
Thin Sections ◽  
New Information ◽  
Key Words Age

A comparison of ages determined from surfaces of otoliths and from sections of otoliths showed that ages were similar up to a section age of 22–24 yr. The growth pattern observed on thin sections of otoliths and from broken and burned otoliths from the region of the nucleus was interpreted to indicate that Pacific ocean perch probably live much longer than previously thought. Because the criteria used to identify annuli from otoliths sections appeared valid for younger fish, there was no justification to reject the application of these criteria for estimating ages of older fish and thus no reason to reject the possibility that Pacific ocean perch might live to be older than 70 yr. Ages determined from sections of otoliths from other rockfish species found off the west coast of Canada such as Sebastes fiavidus and Sebastes brevispinis have ranged from 30 to 60 yr indicating that many species of rockfish may live longer than previously thought. Key words: age determination, otolith, maximum age, age determination errors, Pacific ocean perch, otolith sections

Age Determination of Lingcod (Ophiodon elongatus) Using Dorsal Fin Rays and Scales

1977 ◽  
Vol 34 (9) ◽  
pp. 1305-1313 ◽  
Author(s):  
Richard J. Beamish ◽  
D. Chilton
Keyword(s):  
Key Words ◽  
Cross Sections ◽  
Age Determination ◽  
Fish Length ◽  
Dorsal Fin ◽  
Ophiodon Elongatus ◽  
Fin Ray ◽  
Fin Rays ◽  
Key Words Age

Cross sections of the 4th–8th fin rays from the second dorsal fin provided reliable ages of lingcod (Ophiodon elongatus), although there was some difficulty interpreting the ages of 1- and 2-yr-old fish. Length was an acceptable indicator of age 1- and 2-yr-old fish. After a scale age of 5 or 6 yr, the scale annulus became difficult to identify. After age 7 or about 75–85 cm, fin-ray ages were older than scale ages. Some of the oldest fish averaged 8 yr older by the fin-ray method.Mature females attained much larger mean sizes than males of similar age, and there was considerable variation in size of similar-aged older fish. Key words: Age determination, fin rays, scales, Ophiodon elongatus, ageing errors.

Age determination and growth of orange roughy (Hoplostethus atlanticus): a comparison of annulus counts with radiometric ageing

1995 ◽  
Vol 52 (2) ◽  
pp. 391-401 ◽  
Author(s):  
David C. Smith ◽  
Simon G. Robertson ◽  
Gwen E. Fenton ◽  
Stephen A. Short
Keyword(s):  
Age Determination ◽  
Percentage Reduction ◽  
Age At Maturity ◽  
Otolith Growth ◽  
Two Stage ◽  
Orange Roughy ◽  
Mass Growth ◽  
Hoplostethus Atlanticus ◽  
Age Estimates ◽  
Radiometric Data

Ages of orange roughy (Hoplostethus atlanticus) determined by two methods (counting annuli on the surface of whole and in longitudinally sectioned otoliths) were similar up to maturity. Beyond maturity, age estimates from sectioned otoliths exceeded those from whole otoliths. Maximum recorded age was 125 years for an individual 41 cm standard length (SL), and age at maturity was estimated to be 25 years (30–32 cm SL). These are consistent with ages estimated previously by radiometric methods. Results demonstrated a two-stage linear relationship between otolith weight and age that confirmed the two-stage otolith mass growth model previously used in radiometric ageing. However, in the radiometric analyses the reduction in otolith growth was arbitrarily estimated at 45% of the immature rate whereas annuli data demonstrated a reduction after maturity to 62% of the immature rate. The new estimates of otolith mass growth rate were incorporated into the radiometric data and ages recalculated, which reduced age estimates for 38–40 cm SL fish from 77–149 to 59–101 years. The radiometric data were also recalculated using only the percentage reduction in otolith growth after maturity, giving the radiometric age of 125 ± 9 years for the oldest fish.

Construction of the Iona Outfall submarine section

1990 ◽  
Vol 17 (1) ◽  
pp. 113-118 ◽  
Author(s):  
T. W. Lively ◽  
C. D. Gowe ◽  
H. R. Woodhead
Keyword(s):  
Key Words ◽  
Joint Venture ◽  
Sewage Treatment ◽  
Bolted Joints ◽  
Fraser River ◽  
Strait Of Georgia ◽  
Alternative Method

In February 1987, the Greater Vancouver Sewerage and Drainage District awarded an $8.5 million contract for the construction of the Iona Outfall submarine section. The contract awarded to the Dillingham–Manson joint venture involved the installation of approximately 3200 m of twin 2.3 m diameter steel outfall, of which 500 m was twin 2.1, 1.8, and 1.4 m diameter steel diffuser sections. The outfall extended from the end of the Iona Jetty into the Strait of Georgia near the mouth of the Fraser River and was 107 m deep at the end of the diffuser. The tender documents suggested a method of installation such that the entire twin outfall pipe was fabricated on an existing jetty complete with flotation pipe and pulled into the water. The contractor submitted an alternative method with the tender and was the successful low bidder. The proposed installation method was to assemble the pipe into nominal 300 m lengths in Dillingham's North Vancouver yard, launch them, tow them to the site, and sink and bolt them together underwater. This paper discusses the more interesting aspects of the project. Key words: construction, pipelines, robotics, sewage treatment, bolted joints.

Biology of the Bathylagid Fish, Leuroglossus schmidti, in the Strait of Georgia, British Columbia, Canada

1985 ◽  
Vol 42 (6) ◽  
pp. 1144-1153 ◽  
Author(s):  
J. C. Mason ◽  
A. C. Phillips
Keyword(s):  
British Columbia ◽  
Slow Growth ◽  
Calanoid Copepods ◽  
Strait Of Georgia ◽  
Merluccius Productus ◽  
Short Life Span ◽  
Adult Sex Ratio ◽  
Juvenile Stages ◽  
Eggs And Larvae ◽  
Temporal Overlap

The northern smoothtongue (Leuroglossus schmidti), a deep-sea smelt, coexists with Pacific hake (Merluccius productus) and walleye pollock (Theragra chalcogramma) in the Strait of Georgia, British Columbia. Their eggs and larvae rank third in abundance, and these three pelagic stocks show marked spatial and temporal overlap in deeper waters, especially during reproduction. Development to hatching occurs in the spring at depths > 150 m. Smelt larvae metamorphose at 22 mm standard length (SL), some 90 d from hatching, and juveniles join the adults at depths > 200 m by autumn. Larger juveniles mature as 2-yr-olds > 50 mm SL. Males seldom live beyond 3 yr or exceed 60 mm SL but females may live[Formula: see text] and attain 100 mm SL. Adult sex ratio is 2:3 in favor of females. Larger females are multibatch spawners, 2 batches/yr, with a mean fecundity of 100 eggs∙g−1∙batch−1. Larval diet includes eggs and early stages of crustaceans dominated by Copepoda. juveniles and adults fed mainly of polychaetes, amphipods, euphausiids, and calanoid copepods found at depths > 100 m. Except for the postlarval and early juvenile stages lasting some 3 mo, the life cycle is pursued at depths > 150 m. Their bathypelagic existence in the Strait emphasizes predator avoidance coupled with low fecundity, slow growth, and short life span.

A new method for robust feature extraction of otolith growth marks using fingerprint recognition methods

2005 ◽  
Vol 56 (5) ◽  
pp. 791 ◽  
Author(s):  
M. Palmer ◽  
A. Álvarez ◽  
J. Tomás ◽  
B. Morales-Nin
Keyword(s):  
Image Analysis ◽  
Feature Extraction ◽  
Age Determination ◽  
Fingerprint Recognition ◽  
New Method ◽  
Otolith Growth ◽  
Contour Analysis ◽  
Recent Developments ◽  
Robust Feature Extraction ◽  
Essential Knowledge

Individual and population age structures constitute essential knowledge for proper management of commercial fisheries. Despite the important advances made in age determination using otolith growth structures, there is still a need to improve both precision and accuracy. The problem of increasing precision in age estimations has been addressed via increasing automation in the identification of growth marks. However, approaches based on otolith size, weight, perimeter, and related measurements (including contour analysis) have moderate success in age prediction. Likewise, early attempts of image analysis have reported poor results, both in cases of 1D (grey-intensity profiles) or 2D images. Recent developments in image analysis have broken this trend, and fully automatic techniques could be an alternative for routine ageing in the near future. Here, we propose a new method for 2D feature extraction that provides robust numerical descriptors of the growth structures of otoliths.

scholarly journals Skeletochronological Age Determination and Comparative Demographic Analysis of Two Populations of the Gold-spotted Pond Frog (Rana chosenica)

2007 ◽  
Vol 30 (1) ◽  
pp. 57-62 ◽  
Author(s):  
Seok-Wan Cheong ◽  
Dae-Sik Park ◽  
Ha-Cheol Sung ◽  
Jung-Hyun Lee ◽  
Shi-Ryong Park
Keyword(s):  
Age Determination ◽  
Demographic Analysis ◽  
Two Populations

Perspectives on the relationship between otolith growth and the conversion of isotope activity ratios to fish ages

1995 ◽  
Vol 52 (10) ◽  
pp. 2296-2303 ◽  
Author(s):  
Daniel K. Kimura ◽  
Craig R. Kastelle
Keyword(s):  
Growth Model ◽  
Linear Growth ◽  
Age Determination ◽  
Growth Curves ◽  
Otolith Growth ◽  
Daunting Task ◽  
Activity Ratios ◽  
Linear Growth Model ◽  
Isotope Activity Ratios ◽  
The Relationship

Ageing of fish otoliths using radiometric methods is now becoming widely accepted. Using this methodology, one has the choice of extracting otolith cores or modeling otolith mass growth. Modeling otolith growth forgoes the difficult work of extracting cores, but one is left with the nearly equally daunting task of selecting and validating an otolith growth model and deriving the corresponding decay equations. We note that the mathematical aspects of this problem appear to have been satisfactorily resolved. However, problems of interpretation remain, and it is not clear whether practitioners fully appreciate the sensitivity of their results to growth model selection and interpretation. We note that the two-stage linear growth model appears to be generally misapplied in the literature. Also, we present evidence that the process of using otolith growth curves estimated from annular ring counts to validate the method of counting annular rings can constitute circular reasoning. Although tedious work, extracting otolith cores seems the most valid way to avoid some serious problems in radiometric age determination work.

Androgen deficiency in patients with prostatic diseases

2020 ◽  
Vol 8 (1) ◽  
pp. 60-64
Author(s):  
A.A. Kamalov ◽  
◽  
R.P. Vasilevskiy ◽  
D.A. Okhobotov ◽  
E.A. Neplokhov ◽  
...  
Keyword(s):  
Replacement Therapy ◽  
Key Words ◽  
Diagnostic Algorithm ◽  
Androgen Deficiency ◽  
Negative Effects ◽  
Testosterone Levels ◽  
Age Related ◽  
Key Words Age ◽  
Somatic Disorders ◽  
Prostatic Diseases

Negative effects of androgen deficiency in males can be avoided by regular androgen screening in patients over 50 years of age. We measured testosterone levels in 521 men aged between 18 and 93 years (mean age 60.94 years). A total of 235 patients (45.2%) were found to have age-related hypogonadism. We have developed a diagnostic algorithm for androgen deficiency at outpatient facilities. We also assessed the prevalence of prostatic diseases and a number of somatic disorders in patients with age-related hypogonadism. We have proposed a variant of medical correction of androgen deficiency. Key words: age-related hypogonadism, testosterone, prostate, screening, androgen replacement therapy

History and present status of fisheries for marine fishes and invertebrates in the Strait of Georgia, British Columbia

1983 ◽  
Vol 40 (7) ◽  
pp. 1095-1119 ◽  
Author(s):  
K. S. Ketchen ◽  
N. Bourne ◽  
T. H. Butler
Keyword(s):  
Clupea Harengus ◽  
Pacific Cod ◽  
Cancer Magister ◽  
Strait Of Georgia ◽  
Merluccius Productus ◽  
Management Measures ◽  
Clupea Harengus Pallasi ◽  
Protothaca Staminea ◽  
Dungeness Crabs ◽  
Parophrys Vetulus

An historical account is given of the development of Strait of Georgia commercial fisheries (other than salmon) from their beginnings in the middle to late 19th century to the 1980s. Where possible, attempts were made to explain past fluctuation in abundance, especially to distinguish natural effects from those of fishing or socioeconomic origin. The review deals with commercial exploitation of herring (Clupea harengus pallasi), dogfish (Squalus acanthias), lingcod (Ophiodon elongatus), Pacific cod (Gadus macrocephalus), English sole (Parophrys vetulus), pollock (Theragra chalcogramma), hake (Merluccius productus), Dungeness crab (Cancer magister), shrimps (Pandalopsis dispar, Pandalus platyceros, P. jordani, P. hypsinotus and P. danae), oyster (Crassostrea gigas), butter clams (Saxidomus giganteus), little neck clams (Protothaca staminea), Manila clams (Tapes phillipinarum), geoduck clams (Panope generosa), and other invertebrates. Lingcod and the various shellfish species are also the object of recreational fisheries. Commercial landings in 1980 totalled 25 575 t with a landed value of over 20 million dollars. Over 57% of the weight landed and 70% of its landed value consisted of herring. Oysters, geoduck clams, Pacific cod, and Dungeness crabs were next in importance. We conclude that the future of the fishery will depend on policy regarding the coexistence of commercial and recreational components, the effectiveness of management measures, and probably on the success of controlling domestic and industrial pollution.

Sign in / Sign up

Export Citation Format

Share Document