17 research outputs found
Tag retention, wound healing, and subsequent reproductive history of southern right whales following satellite-tagging
This paper presents data from 48 resightings of 16 southern right whales that
were satellite-tagged on the South African coast in September 2001, up to and
including 2012. Tag performance in terms of number of days with locations received
was significantly higher in males than females, and lowest in cows with calves, and
attributed to behavioral differences leading to variable degrees of antenna damage.
Resightings occurred from 4 to 4,054 d after tagging: tags were retained in all
whales seen within 27 mo, but were apparently shed in all but one individual seen
within 36 mo of tagging. The exception was a whale that still had the tag present
11 yr after tagging. Healing at the tag site occurred gradually and within 5 yr of
tagging (and 2 yr after tag shedding). No significant difference in the subsequent
frequency of calving was detected between 12 tagged and 382 untagged females
photographed contemporaneously, and although statistical power was low, a 21% or
greater reduction in calving rate in tagged females would seem incompatible with
the observations. The death of one female 3 yr after tagging was more likely attributable
to a ship strike on an animal debilitated by a prolapsed uterus.U.S. National Marine Fisheries Service, Office of Naval Research and gifts from donors to the Oregon State University Marine Mammal Program.http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1748-76922016-04-30hb201
Coastal, offshore, and migratory movements of South African right whales revealed by satellite telemetry
In September 2001, 21 satellite-monitored radio tags were deployed on southern right
whales in South African waters, 15 of which transmitted for 25-161 d. Most coastwise
movement on the south coast occurred in a westerly direction with cow-calf pairs
moving slowest. Three whales tagged on the west coast and one tagged on the south
coast moved north into St Helena Bay, a probable feeding ground, where residence
times were 36-100 d. Five animals tracked after leaving the coast maintained a
bearing of 201-220o before branching out over the southeast Atlantic from 37-60o S
and between 13o W and 16o E, travelling 3800-8200 km over the ensuing 53-110 d
before transmissions ceased. Their locations were categorized as migrating or nonmigrating
based on the relative orientation of the track and net speed. An average of
42% of non-migrating locations were between 37-45o S and 53% south of 52o S,
possibly associated with the Sub Tropical Convergence and Antarctic Polar Front
respectively. Whaling data suggest right whales fed largely on copepods at the former
and euphausiids at the latter. If the non-migrating locations represented feeding at
these frontal zones, switching between them would seem to have obvious cost-benefit
implications.P. B. B. acknowledges the support of the
National Research Foundation of South Africa (GUN number 2047517). B. R. M. acknowledges
the support of the National Oceanic and Atmospheric Administration through the
Northeast Consortium, based at the University of New Hampshire (Grant #NA16FL1324),
the U.S. Office of Naval Research, and donors to the Oregon State University Endowed Marine
Mammal Program.http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1748-7692ab201
Global age-sex-specific mortality, life expectancy, and population estimates in 204 countries and territories and 811 subnational locations, 1950–2021, and the impact of the COVID-19 pandemic: a comprehensive demographic analysis for the Global Burden of Disease Study 2021
Background: Estimates of demographic metrics are crucial to assess levels and trends of population health outcomes. The profound impact of the COVID-19 pandemic on populations worldwide has underscored the need for timely estimates to understand this unprecedented event within the context of long-term population health trends. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021 provides new demographic estimates for 204 countries and territories and 811 additional subnational locations from 1950 to 2021, with a particular emphasis on changes in mortality and life expectancy that occurred during the 2020–21 COVID-19 pandemic period.
Methods: 22 223 data sources from vital registration, sample registration, surveys, censuses, and other sources were used to estimate mortality, with a subset of these sources used exclusively to estimate excess mortality due to the COVID-19 pandemic. 2026 data sources were used for population estimation. Additional sources were used to estimate migration; the effects of the HIV epidemic; and demographic discontinuities due to conflicts, famines, natural disasters, and pandemics, which are used as inputs for estimating mortality and population. Spatiotemporal Gaussian process regression (ST-GPR) was used to generate under-5 mortality rates, which synthesised 30 763 location-years of vital registration and sample registration data, 1365 surveys and censuses, and 80 other sources. ST-GPR was also used to estimate adult mortality (between ages 15 and 59 years) based on information from 31 642 location-years of vital registration and sample registration data, 355 surveys and censuses, and 24 other sources. Estimates of child and adult mortality rates were then used to generate life tables with a relational model life table system. For countries with large HIV epidemics, life tables were adjusted using independent estimates of HIV-specific mortality generated via an epidemiological analysis of HIV prevalence surveys, antenatal clinic serosurveillance, and other data sources. Excess mortality due to the COVID-19 pandemic in 2020 and 2021 was determined by subtracting observed all-cause mortality (adjusted for late registration and mortality anomalies) from the mortality expected in the absence of the pandemic. Expected mortality was calculated based on historical trends using an ensemble of models. In location-years where all-cause mortality data were unavailable, we estimated excess mortality rates using a regression model with covariates pertaining to the pandemic. Population size was computed using a Bayesian hierarchical cohort component model. Life expectancy was calculated using age-specific mortality rates and standard demographic methods. Uncertainty intervals (UIs) were calculated for every metric using the 25th and 975th ordered values from a 1000-draw posterior distribution.
Findings: Global all-cause mortality followed two distinct patterns over the study period: age-standardised mortality rates declined between 1950 and 2019 (a 62·8% [95% UI 60·5–65·1] decline), and increased during the COVID-19 pandemic period (2020–21; 5·1% [0·9–9·6] increase). In contrast with the overall reverse in mortality trends during the pandemic period, child mortality continued to decline, with 4·66 million (3·98–5·50) global deaths in children younger than 5 years in 2021 compared with 5·21 million (4·50–6·01) in 2019. An estimated 131 million (126–137) people died globally from all causes in 2020 and 2021 combined, of which 15·9 million (14·7–17·2) were due to the COVID-19 pandemic (measured by excess mortality, which includes deaths directly due to SARS-CoV-2 infection and those indirectly due to other social, economic, or behavioural changes associated with the pandemic). Excess mortality rates exceeded 150 deaths per 100 000 population during at least one year of the pandemic in 80 countries and territories, whereas 20 nations had a negative excess mortality rate in 2020 or 2021, indicating that all-cause mortality in these countries was lower during the pandemic than expected based on historical trends. Between 1950 and 2021, global life expectancy at birth increased by 22·7 years (20·8–24·8), from 49·0 years (46·7–51·3) to 71·7 years (70·9–72·5). Global life expectancy at birth declined by 1·6 years (1·0–2·2) between 2019 and 2021, reversing historical trends. An increase in life expectancy was only observed in 32 (15·7%) of 204 countries and territories between 2019 and 2021. The global population reached 7·89 billion (7·67–8·13) people in 2021, by which time 56 of 204 countries and territories had peaked and subsequently populations have declined. The largest proportion of population growth between 2020 and 2021 was in sub-Saharan Africa (39·5% [28·4–52·7]) and south Asia (26·3% [9·0–44·7]). From 2000 to 2021, the ratio of the population aged 65 years and older to the population aged younger than 15 years increased in 188 (92·2%) of 204 nations.
Interpretation: Global adult mortality rates markedly increased during the COVID-19 pandemic in 2020 and 2021, reversing past decreasing trends, while child mortality rates continued to decline, albeit more slowly than in earlier years. Although COVID-19 had a substantial impact on many demographic indicators during the first 2 years of the pandemic, overall global health progress over the 72 years evaluated has been profound, with considerable improvements in mortality and life expectancy. Additionally, we observed a deceleration of global population growth since 2017, despite steady or increasing growth in lower-income countries, combined with a continued global shift of population age structures towards older ages. These demographic changes will likely present future challenges to health systems, economies, and societies. The comprehensive demographic estimates reported here will enable researchers, policy makers, health practitioners, and other key stakeholders to better understand and address the profound changes that have occurred in the global health landscape following the first 2 years of the COVID-19 pandemic, and longer-term trends beyond the pandemic.
Funding: Bill & Melinda Gates Foundation
Interactions between South American sea lions Otaria flavescens (Shaw) and salmon farms in southern Chile
Summer and fall habitat of North Atlantic right whales (Eubalaena glacialis) inferred from satellite telemetry
Author Posting. © National Research Council Canada, 2005. This article is posted here by permission of National Research Council Canada for personal use, not for redistribution. The definitive version was published in Canadian Journal of Fisheries and Aquatic Sciences 62 (2005): 527-543, doi:10.1139/F04-238.Satellite-monitored radio tags were attached to North Atlantic right whales (Eubalaena glacialis) in Grand Manan Basin of the lower Bay of Fundy during the summer and early fall seasons of 1989–1991 and 2000. Monte Carlo tests were used to examine the distribution of the tagged whales in space and time and with respect to a variety of environmental variables to characterize right whale habitat on their northern feeding grounds. These environmental variables included depth, depth gradient, climatological surface and bottom hydrographic properties, and remotely sensed surface temperature, chlorophyll concentration, and their respective horizontal gradients. Site fidelity in the Bay of Fundy was very low during 1989–1991 and high during 2000. When the tagged animals left the Bay, they did not frequently visit the deep basins of the Gulf of Maine and Scotian Shelf, where abundances of their primary copepod prey, Calanus finmarchicus, are thought to be high. Instead, right whales visited areas characterized by low bottom water temperatures, high surface salinity, and high surface stratification. No evidence was found that the tagged right whales associated with oceanic fronts or regions with high standing stocks of phytoplankton.This study was supported by the
Office of Naval Research, National Marine Fisheries Service,
Oregon State University Marine Mammal Endowment,
and the Space Grant and Earth System Science fellowship
programs of the National Aeronautics and Space Administration
