Harp Seals: Monitors of Change in Differing Ecosystems

Harp seals are the most abundant marine mammal in the north Atlantic. As an ice obligatory predator, they reflect changes in their environment, particularly during a period of climatic change. As the focus of a commercial hunt, a large historic data set exists that can be used to quantify changes. There are three populations of harp seals: White Sea/Barents Sea, Greenland Sea and Northwest Atlantic. The objective of this paper is to review their current status and to identify the factors that are influencing population dynamics in different areas. Although important historically, recent catches have been low and do not appear to be influencing trends in either of the two northeast Atlantic populations. Massive mortalities of White Sea/Barents Sea seals occurred during the mid 1980s due to collapses in their main prey species. Between 2004 and 2006, pup production in this population declined by 2/3 and has remained low. Body condition declined during the same period, suggesting that ecosystem changes may have resulted in reduced reproductive rates, possibly due to reduced prey availability and/or competition with Atlantic cod. The most recent estimate of pup production in the Greenland Sea also suggests a possible decline during a period of reduced hunting although the trend in this population is unclear. Pupping concentrations are closer to the Greenland coast due to the reduction in ice in the traditional area and increased drift may result in young being displaced from their traditional feeding grounds leading to increased mortality. Reduced ice extent and thickness has resulted in major mortality of young in the Northwest Atlantic population in some years. After a period of increase, the population remained relatively stable between 1996 and 2013 due to increased hunting, multiple years with increased ice-related mortality of young seals, and lower reproductive rates. With a reduction in harvest and improved survival of young, the population appears to be increasing although extremely large interannual variations in body condition and fecundity have been observed which were found to be influenced by variations in capelin biomass and ice conditions. Each of these populations has been impacted differently by changes in their ecosystems and hunting practices. By identifying the factors influencing these three populations, we can gain a better understanding of how species may respond to changes that are occurring in their ecosystems.publishedVersio

Post-Foucauldian governmentality: what does it offer critical social policy analysis?

This article considers the theoretical perspective of post-Foucauldian governmentality, especially the insights and challenges it poses for applied researchers within the critical social policy tradition. The article firstly examines the analytical strengths of this approach to understanding power and rule in contemporary society, before moving on to consider its limitations for social policy. It concludes by arguing that these insights can be retained, and some of the weaknesses overcome, by adopting a ‘realist governmentality’ approach (Stenson 2005, 2008). This advocates combining traditional discursive analysis with more ethnographic methods in order to render visible the concrete activity of governing, and unravel the messiness, complexity and unintended consequences involved in the struggles around subjectivity

The Scalar Meson f0(980) in Heavy-Meson Decays

A phenomenological analysis of the scalar meson f0(980) is performed that relies on the quasi-two body decays D and Ds -> f0(980)P, with P=pi, K. The two-body branching ratios are deduced from experimental data on D or Ds -> pi pi pi, K Kbar pi and from the f0(980) -> pi+ pi- and f0(980) -> K+ K- branching fractions. Within a covariant quark model, the scalar form factors F0(q2) for the transitions D and Ds -> f0(980) are computed. The weak D decay amplitudes, in which these form factors enter, are obtained in the naive factorization approach assuming a quark-antiquark state for the scalar and pseudoscalar mesons. They allow to extract information on the f0(980) wave function in terms of u-ubar, d-dbar and s-sbar pairs as well as on the mixing angle between the strange and non-strange components. The weak transition form factors are modeled by the one-loop triangular diagram using two different relativistic approaches: covariant light-front dynamics and dispersion relations. We use the information found on the f0(980) structure to evaluate the scalar and vector form factors in the transitions D and Ds -> f0(980), as well as to make predictions for B and Bs -> f0(980), for the entire kinematically allowed momentum range of q2.Comment: 45 pages, 9 figures and 9 tables. The use of dispersion relations to calculate the weak transition form factors is better justified. A more extensive discussion on the strange and non-strange flavor content mixing is introduced. Results unchanged. Version to appear in Phys. Rev.

Atlantic water variability on the SE Greenland continental shelf and its relationship to SST and bathymetry

Author Posting. © American Geophysical Union, 2013. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 118 (2013): 847–855, doi:10.1029/2012JC008354.Interaction of warm, Atlantic-origin water (AW) and colder, polar origin water (PW) advecting southward in the East Greenland Current (EGC) influences the heat content of water entering Greenland's outlet glacial fjords. Here we use depth and temperature data derived from deep-diving seals to map out water mass variability across the continental shelf and to augment existing bathymetric products. We compare depths derived from the seal dives with the IBCAO Version 3 bathymetric database over the shelf and find differences up to 300 m near several large submarine canyons. In the vertical temperature structure, we find two dominant modes: a cold mode, with the typical AW/PW layering observed in the EGC, and a warm mode, where AW is present throughout the water column. The prevalence of these modes varies seasonally and spatially across the continental shelf, implying distinct AW pathways. In addition, we find that satellite sea surface temperatures (SST) correlate significantly with temperatures in the upper 50 m (R = 0.54), but this correlation decreases with depth (R = 0.22 at 200 m), and becomes insignificant below 250 m. Thus, care must be taken in using SST as a proxy for heat content, as AW mainly resides in these deeper layers.Funding for this work came from National Science Foundation OPP grant 0909373 and OCE grant 1130008, plus the WHOI Arctic Research Initiative. The Greenland Institute of Natural Resources and the Department of Fisheries and Oceans, Canada, supported the seal tagging logistics.2013-08-2

Seasonal variability of the warm Atlantic Water layer in the vicinity of the Greenland shelf break

The warmest water reaching the east and west coast of Greenland is found between 200?m and 600?m. Whilst important for melting Greenland's outlet glaciers, limited winter observations of this layer prohibit determination of its seasonality. To address this, temperature data from Argo profiling floats, a range of sources within the World Ocean Database and unprecedented coverage from marine-mammal borne sensors have been analysed for the period 2002-2011. A significant seasonal range in temperature (~1-2?°C) is found in the warm layer, in contrast to most of the surrounding ocean. The phase of the seasonal cycle exhibits considerable spatial variability, with the warmest water found near the eastern and southwestern shelf-break towards the end of the calendar year. High-resolution ocean model trajectory analysis suggest the timing of the arrival of the year's warmest water is a function of advection time from the subduction site in the Irminger Basin

Bottom-Up Regulation of Capelin, a Keystone Forage Species

The Northwest Atlantic marine ecosystem off Newfoundland and Labrador, Canada, has been commercially exploited for centuries. Although periodic declines in various important commercial fish stocks have been observed in this ecosystem, the most drastic changes took place in the early 1990s when the ecosystem structure changed abruptly and has not returned to its previous configuration. In the Northwest Atlantic, food web dynamics are determined largely by capelin (Mallotus villosus), the focal forage species which links primary and secondary producers with the higher trophic levels. Notwithstanding the importance of capelin, the factors that influence its population dynamics have remained elusive. We found that a regime shift and ocean climate, acting via food availability, have discernible impacts on the regulation of this population. Capelin biomass and timing of spawning were well explained by a regime shift and seasonal sea ice dynamics, a key determinant of the pelagic spring bloom. Our findings are important for the development of ecosystem approaches to fisheries management and raise questions on the potential impacts of climate change on the structure and productivity of this marine ecosystem

Neonatal research:the parental perspective

Objectives: To investigate the recollections of parents consenting for their infants to be research subjects and determine their views about the need for consent. Subjects: Parents of 154 sick newborn infants enrolled in a randomised trial in the early neonatal period. All parents had given written consent and received printed information. Methods: A questionnaire and accompanying letter was sent to the parental home 18 months later. Non-responders were sent a further questionnaire and letter. Results: Response rate was 64% (99/154). Some respondents (12%) did not remember being asked to consent to their baby joining a study, and a further 6% were unsure. Most of the respondents (79%) were happy, 13% neutral, and 8% unhappy with their decision to give consent. None felt heavy pressure to agree. Entering the trial caused 24% of respondents to feel more anxious, 56% neutral, and 20% less anxious about their baby. Most of the respondents (83%) would be unhappy to forgo the consent process for trials passed by the institutional ethics committee. Conclusions: A significant proportion of parents who give written consent for a trial in the early neonatal period do not later remember having done so. Parents who have had experience of neonatal research would be unhappy for their baby to be enrolled in a study that had ethics committee approval without their consent being obtained

The Effects of COVID-19 Restrictions on College Students Physical Activity and Mental Health

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