scholarly journals Image-enhanced burnt otoliths, bomb radiocarbon and the growth dynamics of redfish (Sebastes mentella and S. fasciatus) off the eastern coast of Canada

2016 ◽  
Vol 67 (7) ◽  
pp. 925 ◽  
Author(s):  
Steven E. Campana ◽  
Alexandra E. Valentin ◽  
Shayne E. MacLellan ◽  
Joanne B. Groot
Keyword(s):  
Deep Water ◽  
Fork Length ◽  
Somatic Growth ◽  
Eastern Coast ◽  
Age Validation ◽  
Species Identity ◽  
North West ◽  
Bomb Radiocarbon ◽  
Sebastes Mentella ◽  
Age Determinations

Many past attempts to age deep-water redfish (Sebastes mentella) and Acadian redfish (S. fasciatus) in the north-west Atlantic have been stymied by inappropriate ageing methods, the absence of age validation and the failure to differentiate among species. Herein we report substantial improvements in methods for ageing Sebastes spp. by linking the established ‘crack and burn’ method to modern sectioning and image-enhancement protocols. Bomb radiocarbon assays of the otolith core and monitoring of year-class progression confirmed the accuracy of the resulting age determinations to an age of 46 years. The use of microsatellite DNA to confirm species identity eliminated past confusion caused by species mixtures. Age determinations of 1252 redfish from the eastern coast of Canada demonstrated the presence of significant differences in growth rate and longevity both between the two redfish species and among populations and stocks, with a maximum observed longevity of 70 years. Even within species and stocks, an individual fish with a fork length of 38cm could be anywhere between 15 and 50 years of age, highlighting a near cessation of somatic growth after sexual maturation. In keeping with other deep-water species, sustainable management will require more attention to the low productivity expected of redfish stocks, rather than the high initial biomass that can support short-term but high catch rates.

scholarly journals Bomb dating, age validation and quality control of age determinations of monodontids and other marine mammals

2014 ◽  
Vol 8 ◽  
Author(s):  
Steven E Campana ◽  
Robert EA Stewart
Keyword(s):  
Quality Control ◽  
Marine Mammals ◽  
Age Determination ◽  
Age Validation ◽  
Age Bias ◽  
Bomb Radiocarbon ◽  
Control Protocols ◽  
The 1960S ◽  
Age Determinations

Methods for confirming the accuracy of age determination methods are reasonably well established in fishes, but the millions of routine age determinations which take place every year require their own quality control protocols. In contrast, methods for ensuring accuracy in age determination of monodontids and other marine mammals are still being developed. Here we review the basis and application of bomb radiocarbon to marine mammal age validation, highlighting its value for providing unambiguous estimates of age for belugas and other long-lived animals which form growth bands. Bomb radiocarbon is particularly useful for marine mammals, given that the age of an individual animal can be determined to within ±1-3 years, as long as it was alive during the 1960s. However, ongoing age determinations require careful monitoring to ensure that age interpretations remain consistent across ages and through time. Quality control protocols using reference collections of ageing material, in conjunction with age bias plots and measures of precision, are capable of detecting virtually all of the systematic ageing errors that often occur once age determinations of an animal become routine.

Blue marlin (Makaira nigricans) longevity estimates confirmed with bomb radiocarbon dating

2018 ◽  
Vol 75 (1) ◽  
pp. 17-25 ◽  
Author(s):  
Allen H. Andrews ◽  
Robert L. Humphreys ◽  
Jeffery D. Sampaga
Keyword(s):  
Fork Length ◽  
Age Validation ◽  
Blue Marlin ◽  
Makaira Nigricans ◽  
Lower Jaw ◽  
Chemical Signatures ◽  
Bomb Radiocarbon ◽  
Dating Method ◽  
The Tropical Pacific ◽  
Age Reading

The longevity of blue marlin (Makaira nigricans) remains unresolved. The use of fin spines and sagittal otoliths for age reading has led to unconfirmed longevity estimates near 20–30 years. Age validation has been elusive because large individuals are uncommonly caught, and a technique that can be applied to structures that provide estimates of age was absent. The use of otolith chemical signatures has been limited by sagittal otoliths that are very small — whole otolith mass of adult blue marlin rarely exceeds 10 mg for the largest fish. Recent advances in the detection limits of radiocarbon (14C) with accelerator mass spectrometry — coupled with recently acquired knowledge of marine bomb 14C signals spanning the tropical Pacific Ocean — have led to an opportunity to age blue marlin from small amounts of otolith material. In this study, otoliths from a recently collected 1245 lb (565 kg) female blue marlin at a measured 146-inch (371 cm) lower jaw fork length were analyzed for 14C. Estimated longevity was either 12–21 or 32–44 years on the basis of bomb 14C dating. Using multiple lines of evidence, it was determined that the young age scenario was most likely, with evidence for an age close to 20 years using a series of deductions in the bomb 14C dating method.

Turbidite depositional architecture across three interconnected deep-water basins on the north-west African margin

Sedimentology ◽  
2002 ◽  
Vol 49 (4) ◽  
pp. 669-695 ◽  
Author(s):  
Russell B. Wynn ◽  
Philip P. E. Weaver ◽  
Douglas G. Masson ◽  
Dorrik A. V. Stow
Keyword(s):  
Deep Water ◽  
West African ◽  
North West ◽  
The North ◽  
Depositional Architecture

Quantitative analysis of a deep-water bryozoan collection from the Hebridean continental slope

2001 ◽  
Vol 81 (6) ◽  
pp. 987-993 ◽  
Author(s):  
David J. Hughes
Keyword(s):  
Quantitative Analysis ◽  
Continental Slope ◽  
Deep Water ◽  
The Other ◽  
Depth Range ◽  
Species Accumulation Curve ◽  
North West ◽  
Colony Density ◽  
Accumulation Curve ◽  
Total Fauna

Bryozoans were collected from nine stations between 569 and 1278 m depth on the Hebridean continental slope north-west of Lewis. The 21 species recorded from 1544 colonies included three species new to the British fauna. The bryozoan fauna, growing on pebbles, cobbles and small boulders, was dominated by species with encrusting, spot or ribbon-like colony morphologies. The few erect species were rare. Colony density on available rock substrata declined from 569 to 855 m, but was high at 1278 m, where the nodular species Turbicellepora boreale occurred on pebbles as small as 1 cm diameter. Cyclostomates made up >90% of the colonies in the shallowest sample and were present in lower numbers to 855 m. None were recorded at 1278 m. In the 569–855 m depth range, diversity and evenness were lowest at 569 m but relatively constant at the other stations. A species accumulation curve suggests that the 20 species recorded is a good estimate of the total fauna in this depth range.

scholarly journals Chlorophyll increases off the coasts of Japan after the 2011 tsunami using NASA/MODIS data

2014 ◽  
Vol 14 (8) ◽  
pp. 1999-2008 ◽  
Author(s):  
E. Sava ◽  
B. Edwards ◽  
G. Cervone
Keyword(s):  
Deep Water ◽  
Tsunami Wave ◽  
Temporal Patterns ◽  
Temporal Analysis ◽  
Maximum Force ◽  
Eastern Coast ◽  
Aqua Satellite ◽  
Spatio Temporal ◽  
Epicentral Region ◽  
Chlorophyll Concentrations

Abstract. Large chlorophyll anomalies are observed after the 2011 Japanese tsunami using the NASA MODIS instrument onboard the TERRA and AQUA satellites. These anomalies are observed both along the eastern coast of Japan, where the tsunami wave hit with maximum force, and in the deep water surrounding the epicentral region. Although both satellites show agreeing spatio-temporal patterns, larger anomalies are detected using the AQUA satellite. A temporal analysis shows increased chlorophyll concentrations immediately after the tsunami, and higher values are observed for nearly one month before reversing to pre-tsunami levels.

Great longevity of speckled hind (Epinephelus drummondhayi), a deep-water grouper, with novel use of postbomb radiocarbon dating in the Gulf of Mexico

2013 ◽  
Vol 70 (8) ◽  
pp. 1131-1140 ◽  
Author(s):  
Allen H. Andrews ◽  
Beverly K. Barnett ◽  
Robert J. Allman ◽  
Ryan P. Moyer ◽  
Hannah D. Trowbridge
Keyword(s):  
Gulf Of Mexico ◽  
Deep Water ◽  
Radiocarbon Dating ◽  
Early Growth ◽  
Economic Importance ◽  
Growth Characteristics ◽  
Adult Age ◽  
Bomb Radiocarbon ◽  
Growth Zones ◽  
Age Estimates

Growth characteristics are poorly understood for speckled hind (Epinephelus drummondhayi), a tropical deep-water grouper of economic importance that is considered overfished. Age has been validated for early growth, but the validity of adult age estimates is unknown. A few studies of growth zones in otoliths have revealed maximum age estimates of 15–35 years, which have been uncritically assumed as longevity. To answer questions about adult age, bomb radiocarbon dating was used to provide validated age estimates. A novel aspect of this study was use of the postbomb radiocarbon decline period (ca. 1980–2004) to age younger fish, an approach that was validated with known-age otoliths. Bomb radiocarbon dating provided valid length-at-age estimates ranging from ∼5 years to more than 45 years. Age was unexpectedly greater than previous estimates for more than half the fish used in this study, and longevity may approach 60–80 years. This study extends the utility of bomb radiocarbon dating by more than 20 years and adds to the growing perspective that deep-water tropical fishes can be long-lived.

Deep Water Deposits Of The North-West Caucasus. Excursion Guidebook

2019 ◽  
Author(s):  
E.Yu. Baraboshkin
Keyword(s):  
Deep Water ◽  
North West ◽  
The North

scholarly journals Comparative growth, age at maturity and sex change, and longevity of Hawaiian parrotfishes, with bomb radiocarbon validation

2018 ◽  
Vol 75 (4) ◽  
pp. 580-589 ◽  
Author(s):  
Edward E. DeMartini ◽  
Allen H. Andrews ◽  
Kathrine G. Howard ◽  
Brett M. Taylor ◽  
Dong-Chun Lou ◽  
...  
Keyword(s):  
Fork Length ◽  
Logistic Models ◽  
Growth Curves ◽  
Sex Change ◽  
Terminal Phase ◽  
Large Species ◽  
Small Species ◽  
Bomb Radiocarbon ◽  
Current Minimum ◽  
Fishery Species

Growth rates and longevities were estimated for five major fishery species of parrotfishes (“uhu”) at Oahu, Hawai’i. All species grew rapidly with von Bertalanffy growth formula k values ≥0.4·year−1. Longevities were found to range broadly among the three small species, 4 years in Calotomus carolinus and 6 and 11 years in Scarus psittacus and Chlorurus spilurus, and to 15–20 years in Scarus rubroviolaceus and Chlorurus perspicillatus for the two large species. Age reading and growth curves for the latter two large species were validated using bomb radiocarbon dating. Median ages at sexual maturity as females (AM50) and at sex change (from female to terminal phase male, AΔ50) were estimated using logistic models. Sexual maturation occurred at 1–2 years for the small species and at 3–3.5 years in the large species. AΔ50 estimates ranged from 2 to 4 years in the small species and were about 5 and 7 years in S. rubroviolaceus and C. perspicillatus, respectively. Estimated milestones poorly corresponded to the current minimum legal size for uhu in Hawai’i (12 in. or 30.5 cm fork length). Pooling these parrotfishes for management seems generally inappropriate, especially for the two large species. Age-based metrics are more informative than size-based metrics for these fishes.

scholarly journals Evidence of underestimation of European hake growth in the Bay of Biscay, and its relationship with bias in the agreed method of age estimation

2006 ◽  
Vol 63 (9) ◽  
pp. 1674-1681 ◽  
Author(s):  
Hélène de Pontual ◽  
Anne Laure Groison ◽  
Carmen Piñeiro ◽  
Michel Bertignac
Keyword(s):  
Age Estimation ◽  
Good Condition ◽  
Estimation Method ◽  
Somatic Growth ◽  
Biological Knowledge ◽  
Data Sets ◽  
Bay Of Biscay ◽  
Age Validation ◽  
Management Advice ◽  
European Hake

Abstract In 2002, a pilot experiment on hake tagging was carried out using methodology specifically developed to catch and handle fish in good condition. By the end of 2005, 36 hake and five tags had been returned to the laboratory (a 3.1% return rate) with a maximum time at liberty of 1066 days. The somatic growth of the recoveries proved to be twofold higher than that expected from published von Bertalanffy growth functions for the species in the Bay of Biscay. The growth underestimation was related to age overestimation, as demonstrated by two independent analyses. The first was based on a blind interpretation of marked otoliths conducted independently by two European experts involved in the routine age estimation of hake. The result shows that the age estimates were neither accurate (inconsistent with oxytetracycline mark positions) nor precise. The second approach compared the predicted otolith growth with the observed growth, and the discrepancy between the two data sets was large. Both types of analyses invalidate the internationally agreed age estimation method and demonstrate a need for further research. Although based on limited data, the study highlights the need to improve biological knowledge of the species in order to improve assessment and management advice. It also strengthens the argument for age validation.

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