Bomb radiocarbon dating of the endangered white abalone (Haliotis sorenseni): investigations of age, growth and lifespan

2013 ◽  
Vol 64 (11) ◽  
pp. 1029 ◽  
Author(s):  
Allen H. Andrews ◽  
Robert T. Leaf ◽  
Laura Rogers-Bennett ◽  
Melissa Neuman ◽  
Heather Hawk ◽  
...  
Keyword(s):  
Endangered Species ◽  
Radiocarbon Dating ◽  
Marine Invertebrate ◽  
Extinction Risk ◽  
Predictive Modelling ◽  
Age And Growth ◽  
Large White ◽  
Adult Lifespan ◽  
Bomb Radiocarbon ◽  
The Status

Understanding basic life-history characteristics of white abalone (Haliotis sorenseni), such as estimated lifespan, is critical to making informed decisions regarding the recovery of this endangered species. All predictive modelling tools used to forecast the status and health of populations following restoration activities depend on a validated estimate of adult lifespan. Of the seven Haliotis species in California, white abalone is considered to have the highest extinction risk and was the first marine invertebrate listed as an endangered species under the Federal Endangered Species Act (ESA). Lifespan was previously estimated from observations of early growth; however, no study has generated ages for the largest white abalone. To address questions of age and growth, bomb radiocarbon (Δ14C) dating was used on shells from large white abalone. Measured bomb Δ14C levels were compared to regional Δ14C reference records to provide estimates of age, growth and lifespan. Bomb radiocarbon dating indicated that growth was variable among individuals, with a maximum estimated age of 27 years. The findings presented here provide support for previous age and growth estimates and an estimated lifespan near 30 years. These age data support the perception of a critical need for restoring the remnant aging and potentially senescent population.

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.

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.

Using evidence of decline and extinction risk to identify priority regions, habitats and threats for plant conservation in Australia

2018 ◽  
Vol 66 (7) ◽  
pp. 541 ◽  
Author(s):  
J. L. Silcock ◽  
R. J. Fensham
Keyword(s):  
At Risk ◽  
Threatened Species ◽  
Extinction Risk ◽  
Plant Conservation ◽  
State Legislation ◽  
Risk Of Extinction ◽  
The Status ◽  
Species Lists ◽  
Key Issues ◽  
Efficient Recovery

Threatened species lists are used at global, national and regional scales to identify species at risk of extinction. Many species are listed due to restricted population size or geographic distribution, and decline is often inferred rather than quantified. Vascular plants comprise over 70% of nationally listed threatened species, but there is an incomplete picture of which species are most at risk of extinction, where these occur and the factors behind their declines. We compiled published information and the best available field knowledge including 125 expert interviews to identify declining and at risk species. The candidate list comprised 1135 taxa, which were mostly listed as Critically Endangered or Endangered under Federal and/or State legislation, but included 80 that are currently unlisted but considered to be highly threatened. In total, 418 taxa were assessed as having a documented, suspected or projected continuing decline. These were ranked based on extinction risk and magnitude of continuing decline, which suggest that 296 are at risk of extinction under current management regimes, including 55 at high risk of extinction. Declining and imperilled taxa are concentrated in a relatively small number of regions and habitats, and six threatening processes are driving the majority of declines. Field surveys and robust, repeatable monitoring are required to better inform population trends and extinction risk, as well as inform the status of almost 200 taxa that are potentially imperilled but poorly known. Identification of declining taxa can identify key issues for flora conservation across a continent, and allow for targeted and efficient recovery efforts.

Testing Decision Rules for Categorizing Species’ Extinction Risk to Help Develop Quantitative Listing Criteria for the U.S. Endangered Species Act

2013 ◽  
Vol 27 (4) ◽  
pp. 821-831 ◽  
Author(s):  
TRACEY J. REGAN ◽  
BARBARA L. TAYLOR ◽  
GRANT G. THOMPSON ◽  
JEAN FITTS COCHRANE ◽  
KATHERINE RALLS ◽  
...  
Keyword(s):  
Endangered Species ◽  
Extinction Risk ◽  
Decision Rules ◽  
Endangered Species Act ◽  
Species Extinction ◽  
The U.S

Age and growth of the white shark, Carcharodon carcharias, in the western North Atlantic Ocean

2015 ◽  
Vol 66 (5) ◽  
pp. 387 ◽  
Author(s):  
Lisa J. Natanson ◽  
Gregory B. Skomal
Keyword(s):  
Atlantic Ocean ◽  
North Atlantic ◽  
North Atlantic Ocean ◽  
White Shark ◽  
Age And Growth ◽  
Carcharodon Carcharias ◽  
Vertebral Centra ◽  
Bomb Radiocarbon ◽  
History Information ◽  
Age Estimates

Age and growth estimates for the white shark (Carcharodon carcharias) in the western North Atlantic Ocean (WNA) were derived from band pair counts on the vertebral centra of 81 specimens collected between 1963 and 2010. We used two previously published criteria to interpret band pairs and assessed the validity of each method using Δ14C levels from a recent bomb radiocarbon validation study and existing Δ14C reference chronologies in the WNA. Although both criteria produced age estimates consistent, to varying degrees, with different reference chronologies, only one was considered valid when life history information was used to select the appropriate reference chronology and minimum/maximum ages based on bomb carbon values were taken into consideration. These age estimates, validated up to 44 years, were used to develop a growth curve for the species, which was best described using the Schnute general model (sexes combined). These results indicate that white sharks grow more slowly and live longer than previously thought.

scholarly journals Foreword: A perspective on the role of emerging technologies for the propagation of companion animals, non-domestic and endangered species

2007 ◽  
Vol 19 (6) ◽  
pp. iii ◽  
Author(s):  
Monique C. J. Paris ◽  
Gabriela F. Mastromonaco ◽  
Damien B. B. P. Paris ◽  
Rebecca L. Krisher
Keyword(s):  
Endangered Species ◽  
Emerging Technologies ◽  
Assisted Reproductive Technologies ◽  
Companion Animals ◽  
Reproductive Technologies ◽  
Reproductive Physiology ◽  
In Vitro Fertilisation ◽  
Genetic Management ◽  
The Status

Assisted reproductive technologies (ART) have been used successfully in humans, domestic and laboratory species for many years. In contrast, our limited knowledge of basic reproductive physiology has restricted the application of ART in companion animal, non-domestic and endangered species (CANDES). Although there are numerous benefits, and in some cases a necessity, for applying ART for the reproductive and genetic management of CANDES, the challenges encountered with even the most basic procedures have limited the rate of progress. In this foreword we discuss the status of conventional ART, such as artificial insemination and in vitro fertilisation, as well as their benefits and inherent difficulties when applied to CANDES. It is upon these techniques, and ultimately our knowledge of basic reproductive physiology, that the success of emerging technologies, such as those described in this special issue, are dependent for success.

Using bomb radiocarbon analyses to validate age and growth estimates for the tiger shark, Galeocerdo cuvier, in the western North Atlantic

2008 ◽  
Vol 154 (3) ◽  
pp. 423-434 ◽  
Author(s):  
Jeff Kneebone ◽  
Lisa J. Natanson ◽  
Allen H. Andrews ◽  
W. Hunt Howell
Keyword(s):  
North Atlantic ◽  
Age And Growth ◽  
Tiger Shark ◽  
Galeocerdo Cuvier ◽  
Bomb Radiocarbon

scholarly journals The changing fates of the world's mammals

2011 ◽  
Vol 366 (1578) ◽  
pp. 2598-2610 ◽  
Author(s):  
Michael Hoffmann ◽  
Jerrold L. Belant ◽  
Janice S. Chanson ◽  
Neil A. Cox ◽  
John Lamoreux ◽  
...  
Keyword(s):  
Captive Breeding ◽  
Extinction Risk ◽  
Conservation Status ◽  
Iucn Red List ◽  
Red List ◽  
Mammal Species ◽  
International Union ◽  
The Status ◽  
Conservation Actions ◽  
In The Wild

A recent complete assessment of the conservation status of 5487 mammal species demonstrated that at least one-fifth are at risk of extinction in the wild. We retrospectively identified genuine changes in extinction risk for mammals between 1996 and 2008 to calculate changes in the International Union for Conservation of Nature (IUCN) Red List Index (RLI). Species-level trends in the conservation status of mammalian diversity reveal that extinction risk in large-bodied species is increasing, and that the rate of deterioration has been most accelerated in the Indomalayan and Australasian realms. Expanding agriculture and hunting have been the main drivers of increased extinction risk in mammals. Site-based protection and management, legislation, and captive-breeding and reintroduction programmes have led to improvements in 24 species. We contextualize these changes, and explain why both deteriorations and improvements may be under-reported. Although this study highlights where conservation actions are leading to improvements, it fails to account for instances where conservation has prevented further deteriorations in the status of the world's mammals. The continued utility of the RLI is dependent on sustained investment to ensure repeated assessments of mammals over time and to facilitate future calculations of the RLI and measurement against global targets.

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