44 research outputs found
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): 847â855, 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 300âm 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 50âm (Râ=â0.54), but this correlation decreases with depth (Râ=â0.22 at 200âm), and becomes insignificant below 250âm. 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
Google haul out : Earth observation imagery and digital aerial surveys in coastal wildlife management and abundance estimation
© The Author(s), 2017. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Bioscience 67 (2017): 760â768, doi:10.1093/biosci/bix059.As the sampling frequency and resolution of Earth observation imagery increase, there are growing opportunities for novel applications in population monitoring. New methods are required to apply established analytical approaches to data collected from new observation platforms (e.g., satellites and unmanned aerial vehicles). Here, we present a method that estimates regional seasonal abundances for an understudied and growing population of gray seals (Halichoerus grypus) in southeastern Massachusetts, using opportunistic observations in Google Earth imagery. Abundance estimates are derived from digital aerial survey counts by adapting established correction-based analyses with telemetry behavioral observation to quantify survey biases. The result is a first regional understanding of gray seal abundance in the northeast US through opportunistic Earth observation imagery and repurposed animal telemetry data. As species observation data from Earth observation imagery become more ubiquitous, such methods provide a robust, adaptable, and cost-effective solution to monitoring animal colonies and understanding species abundances.We would like to thank generous support from International Fund for Animal Welfare, the Bureau of Ocean Energy, and the Oak Foundation for funding support for the telemetry devices
Rapid circulation of warm subtropical waters in a major glacial fjord in East Greenland
Author Posting. © The Authors, 2009. This is the author's version of the work. It is posted here by permission of Nature Publishing Group for personal use, not for redistribution. The definitive version was published in Nature Geoscience 3 (2010): 182-186, doi:10.1038/ngeo764.The recent rapid increase in mass loss from the Greenland Ice Sheet is primarily
attributed to an acceleration of outlet glaciers. One possible cause is increased
melting at the ice/ocean interface driven by the synchronous warming of
subtropical waters offshore of Greenland. This hypothesis is largely untested,
however, because of the lack of observations from Greenlandâs glacial fjords and
our limited understanding of their dynamics. Here, we present new ship-based and
moored oceanographic data, collected in Sermilik Fjord, a large glacial fjord in East
Greenland, showing that subtropical waters are present throughout the fjord and
are continuously replenished via a wind-driven exchange with the shelf, where they
occur year-round. The temperature and rapid renewal of these waters suggest that,
at present, they drive enhanced submarine melting at the terminus. Key controls on
the melting rate are the volume and properties of subtropical waters on the shelf
and the patterns of the along-shore winds, suggesting the glaciersâ acceleration
was triggered by a combination of atmospheric and oceanic changes. These
measurements provide evidence of rapid advective pathway for the transmission of
oceanic variability to the ice-sheet margins and highlight an important process that
is missing from prognostic ice-sheet models.F.S. acknowledges support from WHOIâs Ocean and
Climate Change Instituteâs Arctic Research Initiative and from NSF OCE 0751896, and G.S.H and L.A.S
from NASAâs Cryospheric Sciences Program. Funding for the hooded seal deployments was obtained from
the International Governance and Atlantic Seal Research Program, Fisheries and Oceans, Canada, to G. B.
S. and to the Greenland Institute of Natural Resources to A. R. A
Convergence of marine megafauna movement patterns in coastal and open oceans
Author Posting. © The Author(s), 2017. This is the author's version of the work. It is posted here for personal use, not for redistribution. The definitive version was published in Proceedings of the National Academy of Sciences of the United States of America 115 (2018): 3072-3077, doi:10.1073/pnas.1716137115.The extent of increasing anthropogenic impacts on large marine
vertebrates partly depends on the animalsâ movement patterns.
Effective conservation requires identification of the key drivers of
movement including intrinsic properties and extrinsic constraints
associated with the dynamic nature of the environments the animals
inhabit. However, the relative importance of intrinsic versus
extrinsic factors remains elusive. We analyse a global dataset of
2.8 million locations from > 2,600 tracked individuals across 50
marine vertebrates evolutionarily separated by millions of years
and using different locomotion modes (fly, swim, walk/paddle).
Strikingly, movement patterns show a remarkable convergence,
being strongly conserved across species and independent of body
length and mass, despite these traits ranging over 10 orders of
magnitude among the species studied. This represents a fundamental
difference between marine and terrestrial vertebrates not
previously identified, likely linked to the reduced costs of locomotion
in water. Movement patterns were primarily explained by the
interaction between species-specific traits and the habitat(s) they
move through, resulting in complex movement patterns when
moving close to coasts compared to more predictable patterns
when moving in open oceans. This distinct difference may be
associated with greater complexity within coastal micro-habitats,
highlighting a critical role of preferred habitat in shaping marine
vertebrate global movements. Efforts to develop understanding
of the characteristics of vertebrate movement should consider the
habitat(s) through which they move to identify how movement
patterns will alter with forecasted severe ocean changes, such as
reduced Arctic sea ice cover, sea level rise and declining oxygen
content.Workshops funding granted by the UWA Oceans Institute, AIMS, and
KAUST. AMMS was supported by an ARC Grant DE170100841 and an IOMRC
(UWA, AIMS, CSIRO) fellowship; JPR by MEDC (FPU program, Spain); DWS by
UK NERC and Save Our Seas Foundation; NQ by FCT (Portugal); MMCM by
a CAPES fellowship (Ministry of Education)
Marine mammals exploring the oceans pole to pole
Polar oceans are poorly monitored despite the important role they play in
regulating Earthâs climate system. Marine mammals equipped with biologging devices
are now being used to fill the data gaps in these logistically difficult to sample regions.
Since 2002, instrumented animals have been generating exceptionally large data sets
of oceanographic CTD casts (>500,000 profiles), which are now freely available to
the scientific community through the MEOP data portal (http://meop.net). MEOP
(Marine Mammals Exploring the Oceans Pole to Pole) is a consortium of international
researchers dedicated to sharing animal-derived data and knowledge about the polar
oceans. Collectively, MEOP demonstrates the power and cost-effectiveness of using
marine mammals as data-collection platforms that can dramatically improve the ocean
observing system for biological and physical oceanographers. Here, we review the
MEOP program and database to bring it to the attention of the international community.http://www.tos.org/oceanographyam2017Mammal Research InstituteZoology and Entomolog
Distribution and Cconnection to other Plant-Communities of Genista radiata (L.) Scop in the South Tyrol (Italy)
Es werden die Genista radiata-BestĂ€nde an der Mendel in SĂŒdtirol (Italien) beschrieben und ihr GesellschaftsanschluĂ diskutiert. Das Genisto-Festucetum alpestris Peer 83 besidelt steile sĂŒdexponierte KalkhĂ€nge der hochmontanen und subalpinen Stufe und ersetzt z.T. den ZwergstrauchgĂŒrtel mit Pinus mugo. Ăhnlich zusammengesetzt ist das Genisto-Festucetum alpestris pinetosum Peer 83, das in den ÂĄlockeren Erika-KiefernwĂ€ldern auftritt und bis in die tiefmontane Stufe hinunterreicht. Keinerlei syntaxonomische Bedeutung besitzt Genista radiata in den thermophilen Buschwaldgesellschaften, in denen die Pflanze lediglich eine Variante zum Orno-Ostryetum seslerietosum Peer 81 darstellt und speziell in der Saumzone anzutreffen ist. Auch in den LĂ€rchenwiesen der Kammlagen kommt Genista radiata nur sporadisch vor. Sie ist hier mit dem Festucetum nigrescentis laricetosum subass. prov. verzahnt.IstraĆŸene su vegetacijske sastojine vrste Genista radiata u juĆŸnom Tirolu i razmatrana njihova fitocenoloĆĄka pripadnost. Asocijacija Genisto-Festucetum alpestris Peer 83 nastava strme, juĆŸne vapnenaÄke obronke visokobrdskog i subalpskog pojasa. Subasocijacija Genisto-Festucetum alpestris pinetosum Peer 83 dolazi u rijetkim borovim ĆĄumama s crnjuĆĄom i spuĆĄta se do u niĆŸi brdski pojas. Termofilne niske ĆĄume, u kojima Genista radiata nema posebno sintaksonomsko znaÄenje, oznaÄene su samo kao varijanta zajednice Orno-Ostryetum seslerietosum Peer 81. Genista radiata dolazi takoÄer na travnjacima s ariĆĄem, ali samo sporadiÄno i to u mjeĆĄavini sa zajednicom Festucetum nigrescentis laricetosnm subass. prov.The Genista radiata-communities of the Mendel in the South Tyrol (Italy) are described and their connection to other plant-communities is discussed. Genisto-Festucetum alpestris Peer 83 settles on steep, south- exposed colcareous slopes of high-mountain and subalpine altitudes and replaces particularly the dwarf-shrub-belt with Firms mugo. Similar contents aire found in Genisto-F estucetum alpestris pinetasum Peer 83, which occurs in undensed Erico-Pinetum-communities and reaches down to the low-mountain-altitude. In the thermophilic bush-communities, in which Genista radiata is found only as a variant of Orneto-Ostryetum seslerie- tosum (Peer 81), the plant has no syntaxonomic importance. Genista radiata especially is found in the edge-zone. In the grassland of the larch- communities of the ridges Genista radiata appears only sporadically. Here the plant appeals in Festucetum nigrescentis laricetosum subass. prov
Animal-borne telemetry: An integral component of the ocean observing toolkit
Animal telemetry is a powerful tool for observing marine animals and the physical environments that they inhabit, from coastal and continental shelf ecosystems to polar seas and open oceans. Satellite-linked biologgers and networks of acoustic receivers allow animals to be reliably monitored over scales of tens of meters to thousands of kilometers, giving insight into their habitat use, home range size, the phenology of migratory patterns and the biotic and abiotic factors that drive their distributions. Furthermore, physical environmental variables can be collected using animals as autonomous sampling platforms, increasing spatial and temporal coverage of global oceanographic observation systems. The use of animal telemetry, therefore, has the capacity to provide measures from a suite of essential ocean variables (EOVs) for improved monitoring of Earth's oceans. Here we outline the design features of animal telemetry systems, describe current applications and their benefits and challenges, and discuss future directions. We describe new analytical techniques that improve our ability to not only quantify animal movements but to also provide a powerful framework for comparative studies across taxa. We discuss the application of animal telemetry and its capacity to collect biotic and abiotic data, how the data collected can be incorporated into ocean observing systems, and the role these data can play in improved ocean management
Habitat selection by hooded seals (Cystophora cristata) in the Northwest Atlantic Ocean
We examined annual habitat use for 65 hooded seals (32 adult females, 17 adult males, and 16 juveniles) equipped with satellite relay data loggers (SRDLs) in spring or summer during five field seasons (2004â2008). A combined approach using first passage time (FPT) analysis and a generalized additive model (GAM) was applied to test for habitat selection, with a focus on environmental parameters of depth, slope, ice, sea surface temperature (SST), and chlorophyll. The models were run on adult males, adult females, and juveniles separately, and the results identified SST, depth, and chlorophyll as the most important factors influencing habitat selection across all categories. Furthermore, males and females preferred similar habitat conditions, but were separated geographically, and by depth, at various times of the year. Males appeared to be more localized in their habitat use patterns, focusing their search effort in areas of complex seabed relief such as Baffin Bay, Davis Strait, and the Flemish cap, while females concentrated their search effort along shelf areas (e.g. the Labrador shelf). These findings support our hypothesis that hooded seals prefer areas where topography and oceanographic processes create favourable foraging conditions
Inuit Knowledge of Beluga Whale (Delphinapterus leucas) Foraging Ecology in Nunavik (Arctic Quebec), Canada
The beluga whale (Delphinapterus leucas (Pallas, 1776)) is expected to be influenced by changes in the environment. In Nunavik, the Arctic region of Quebec, Nunavimmiut (Inuit of Nunavik) have depended on beluga for centuries developing an extensive understanding of the species and its ecology.
Forty semi-directive interviews were conducted with Inuit hunters and Elders from four Nunavik communities, who had a range of 28 to 47 years of beluga hunting experience. Interviews followed an ethnocartographic format and were analyzed using a mixed methods approach. Hunters most commonly reported prey species from the sculpin, cod, salmon, and crustacean families; regional variations in prey as well as foraging habitat were found. Hunters identified significant changes in body condition (i.e. blubber thickness), which were associated with observations about the seasonality of feeding. The timing of fat accumulation in the late fall and winter coupled with the understanding that Hudson Bay is not known as a productive area suggest alternate hypotheses to feeding for the seasonal movements exhibited by these whales. Inuit Knowledge of beluga foraging ecology presented here provides information on diet composition and seasonality of energy intake of the beluga and can be an important component of monitoring diet composition for this species into the future.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author