scholarly journals Melting barriers to faunal exchange across ocean basins

Author(s):  
C. Seabird McKeon ◽  
Michele X. Weber ◽  
S. Elizabeth Alter ◽  
Nathaniel E. Seavy ◽  
Eric D. Crandall ◽  
...  

Accelerated loss of sea ice in the Arctic is opening routes connecting the Atlantic and Pacific oceans for longer periods each year. These changes will increase the ease and frequency with which marine birds and mammals are able to move between the Pacific and Atlantic ocean basins. Indeed, recent observations of birds and mammals suggest these movements are already occurring. Reconnection of the Pacific and Atlantic Ocean basins will present both challenges to marine ecosystem conservation and an unprecedented opportunity to examine the ecological and evolutionary consequences of faunal exchange in real time. To understand these changes and implement effective conservation of marine ecosystems, we need to further develop modeling efforts to predict the rate of dispersal and consequences of faunal exchange. These predictions can be tested by closely monitoring wildlife dispersal through the Arctic Ocean and using modern methods to explore the ecological and evolutionary consequences of these movements.

Author(s):  
C. Seabird McKeon ◽  
Michele X. Weber ◽  
S. Elizabeth Alter ◽  
Nathaniel E. Seavy ◽  
Eric D. Crandall ◽  
...  

Accelerated loss of sea ice in the Arctic is opening routes connecting the Atlantic and Pacific oceans for longer periods each year. These changes will increase the ease and frequency with which marine birds and mammals are able to move between the Pacific and Atlantic ocean basins. Indeed, recent observations of birds and mammals suggest these movements are already occurring. Reconnection of the Pacific and Atlantic Ocean basins will present both challenges to marine ecosystem conservation and an unprecedented opportunity to examine the ecological and evolutionary consequences of faunal exchange in real time. To understand these changes and implement effective conservation of marine ecosystems, we need to further develop modeling efforts to predict the rate of dispersal and consequences of faunal exchange. These predictions can be tested by closely monitoring wildlife dispersal through the Arctic Ocean and using modern methods to explore the ecological and evolutionary consequences of these movements.


2019 ◽  
Vol 59 (4) ◽  
pp. 544-552
Author(s):  
A. A. Vetrov ◽  
E. A. Romankevich

Particulate organic carbon (POC) is one of main component of carbon cycle in the Ocean. In this study an attempt to construct a picture of the distribution and fluxes of POC in the Arctic Ocean adjusting for interchange with the Pacific and Atlantic Oceans has been made. The specificity of this construction is associated with an irregular distribution of POC measurements and complicated structure and hydrodynamics of the waters masses. To overcome these difficulties, Multiple Linear Regression technic (MLR) was performed to test the significant relation between POC, temperature, salinity, as well depth, horizon, latitude and offshore distance. The mapping of POC distribution and its fluxes was carrying out at 38 horizons from 5 to 4150 m (resolution 1°×1°). Data on temperature, salinity, meridional and zonal components of current velocities were obtained from ORA S4 database (Integrated Climate Data Center, http://icdc.cen.uni-hamburg.de/las). The import-export of POC between the Arctic, Atlantic and Pacific Oceans as well as between Arctic Seas was precomputed by summer fluxes. The import of POC in the Arctic Ocean is estimated to be 38±8Tg Cyr-1, and the export is -9.5±4.4Tg Cyr-1.


2009 ◽  
Vol 6 (4) ◽  
pp. 7853-7896 ◽  
Author(s):  
M. Roy-Barman

Abstract. The "boundary scavenging" box model is a cornerstone of our understanding of the particle-reactive radionuclide fluxes between the open ocean and the ocean margins. However, it does not describe the radionuclide profiles in the water column. Here, I present the transport-reaction equations for radionuclides transported vertically by reversible scavenging on settling particles and laterally by horizontal currents between the margin and the open ocean. Analytical solutions of these equations are compared with existing data. In the Pacific Ocean, the model produces "almost" linear 230Th profiles (as observed in the data) despite lateral transport. However, omitting lateral transport biased the 230Th based particle flux estimates by as much as 50%. 231Pa profiles are well reproduced in the whole water column of the Pacific Margin and from the surface down to 3000 m in the Pacific subtropical gyre. Enhanced bottom scavenging or inflow of 231Pa-poor equatorial water may account for the model-data discrepancy below 3000 m. The lithogenic 232Th is modelled using the same transport parameters as 230Th but a different source function. The main source of 232Th scavenged in the open Pacific is advection from the ocean margin, whereas a net flux of 230Th produced in the open Pacific is advected and scavenged at the margin, illustrating boundary exchange. In the Arctic Ocean, the model reproduces 230Th measured profiles that the uni-dimensional scavenging model or the scavenging-ventilation model failed to explain. Moreover, if lateral transport is ignored, the 230Th based particle settling speed may by underestimated by a factor 4 at the Arctic Ocean margin. The very low scavenging rate in the open Arctic Ocean combined with the enhanced scavenging at the margin accounts for the lack of high 231Pa/230Th ratio in arctic sediments.


ZooKeys ◽  
2018 ◽  
Vol 771 ◽  
pp. 15-40 ◽  
Author(s):  
Hiroshi Yamasaki ◽  
Katarzyna Grzelak ◽  
Martin V. Sørensen ◽  
Birger Neuhaus ◽  
Kai Horst George

Kinorhynchs rarely show a wide distribution pattern, due to their putatively low dispersal capabilities and/or limited sampling efforts. In this study, a new kinorhynch species is described,Echinoderespterussp. n., which shows a geographically and bathymetrically wide distribution, occurring on the Karasik Seamount and off the Svalbard Islands (Arctic Ocean), on the Sedlo Seamount (northeast Atlantic Ocean), and on the deep-sea floor off Crete and on the Anaximenes Seamount (Mediterranean Sea), at a depth range of 675–4,403 m. The new species is characterized by a combination of middorsal acicular spines on segments 4–8, laterodorsal tubes on segment 10, lateroventral tubes on segment 5, lateroventral acicular spines on segments 6–9, tufts of long hairs rising from slits in a laterodorsal position on segment 9, truncated tergal extensions on segment 11, and the absence of any type-2 gland cell outlet. The specimens belonging to the populations from the Arctic Ocean, the Sedlo Seamount, and the Mediterranean Sea show morphological variation in the thickness and length of the spines as well as in the presence/absence of ventromedial sensory spots on segment 7. The different populations are regarded as belonging to a single species because of their overlapping variable characters.


1973 ◽  
Vol 12 (65) ◽  
pp. 173-185 ◽  
Author(s):  
R. M. Koerner

AbstractFrom data taken on the British Trans-Arctic Expedition it is calculated that 9% of the Arctic Ocean surface between the North Pole and Spitsbergen was hummocked or ridged ice, 17% was unridged ice less than a year old, 73% was unridged old ice and 0.6% was ice-free. The mode of 250 thickness measurements taken through level areas of old floes along the entire traverse lies between 2.25 and 2.75 m. The mean end-of-winter thickness of the ice is calculated to be 4.6 m in the Pacific Gyral and 3.9 m in the Trans-Polar Drift Stream. From measurements of the percentage coverage and thickness of the various ice forms, it is calculated that the total annual ice accumulation in the Arctic Ocean is equivalent to a continuous layer of ice 1.1 m thick. 47% of this accumulation occurs in ice-free areas and under ice less than 1 year old. 20% of the total ice production is either directly or indirectly related to ridging or hummocking. An ice-ablation rate of 500 kg m−2 measured on a level area of a multi-year floe is compared with the rate on deformed and ponded ice. Greatest melting occurs on new hummocks and least on old smooth hummocks. The annual balance of ice older than 1 year but younger than multi-year ice is calculated from a knowledge of ice-drift patterns and the percentage coverage of first-year ice. The same calculations give a mean-maximum drift period of 5 years for ice in the Trans-Polar Drift Stream and 16 years in the Pacific Gyral. It is calculated that for the period February 1968 to May 1969 the annual ice export was 5 580 km3.


PMLA ◽  
2010 ◽  
Vol 125 (3) ◽  
pp. 693-702 ◽  
Author(s):  
Adriana Craciun

We'll get crushed by the ocean but it will not get us wet.—Isaac Brock, “Invisible” (2007)“There is no Sea With Which Our Age is So Imperfectly Acquainted as the Frozen Ocean,” Wrote the Eighteenth-Century Russian hydrographer Gavriil Sarychev, “and no empire which has more powerful motives and resources for extending its information, in this quarter, than Russia” (iii). Russia's Great Northern Expedition of the 1730s and later expeditions, like Sarychev's in 1785, mapped the shores of the Arctic Ocean across continental Asia, an impressive feat by any century's standards. Meanwhile, the American shores of the Arctic Ocean remained entirely unknown to the European empires (England, France, Spain) most interested in passing to and from the Pacific and Atlantic oceans via the Northwest and Northeast passages. Alexander MacKenzie, Samuel Hearne, and John Franklin, each traveling with native people, walked thousands of miles to reach the Frozen Ocean, leaving in their wake the occasional human disaster and an unimpeachable record of publishing successes, like MacKenzie's Voyages from Montreal to the Frozen Ocean (1801) and Franklin's Narrative of a Journey to the Shores of the Polar Sea (1824).


2019 ◽  
Vol 2 (1) ◽  
Author(s):  
Julian David Hunt ◽  
Andreas Nascimento ◽  
Fabio A. Diuana ◽  
Natália de Assis Brasil Weber ◽  
Gabriel Malta Castro ◽  
...  

AbstractThe world is going through intensive changes due to global warming. It is well known that the reduction in ice cover in the Arctic Ocean further contributes to increasing the atmospheric Arctic temperature due to the reduction of the albedo effect and increase in heat absorbed by the ocean’s surface. The Arctic ice cover also works like an insulation sheet, keeping the heat in the ocean from dissipating into the cold Arctic atmosphere. Increasing the salinity of the Arctic Ocean surface would allow the warmer and less salty North Atlantic Ocean current to flow on the surface of the Arctic Ocean considerably increasing the temperature of the Arctic atmosphere and release the ocean heat trapped under the ice. This paper argues that if the North Atlantic Ocean current could maintain the Arctic Ocean ice-free during the winter, the longwave radiation heat loss into space would be larger than the increase in heat absorption due to the albedo effect. This paper presents details of the fundamentals of the Arctic Ocean circulation and presents three possible approaches for increasing the salinity of the surface water of the Arctic Ocean. It then discusses that increasing the salinity of the Arctic Ocean would warm the atmosphere of the Arctic region, but cool down the oceans and possibly the Earth. However, it might take thousands of years for the effects of cooling the oceans to cool the global average atmospheric temperature.


2018 ◽  
Vol 28 (4) ◽  
pp. 163-168
Author(s):  
I. O. Nekhaev

Only four species of the family Cancellariidae had been reported from the Arctic. However, known distribution of three of them had been limited to the extreme north of the eastern Atlantic so far. The present paper describes findings of Admete contabulata Friele, 1879 from the Barents and the Kara seas and Iphinopsis inflata (Friele, 1879) from the Pacific part of the Arctic Ocean. Lectotype for Admete contabulata is here designated.


2012 ◽  
Vol 9 (4) ◽  
pp. 2749-2792
Author(s):  
B. Rabe ◽  
P. Dodd ◽  
E. Hansen ◽  
E. Falck ◽  
U. Schauer ◽  
...  

Abstract. The East Greenland Current in the Western Fram Strait is an important pathway for liquid freshwater export from the Arctic Ocean to the Nordic Seas and the North Atlantic subpolar gyre. We analysed five hydrographic surveys and data from moored current meters around 79° N in the Western Fram Strait between 1998 and 2010. To estimate the composition of southward liquid freshwater transports, inventories of liquid freshwater and components from Dodd et al. (2012) were combined with transport estimates from an inverse model between 10.6° W and 4° E. The southward liquid freshwater transports through the section averaged to 92 mSv (2900 km3 yr−1), relative to a salinity of 34.9. The transports consisted of 123 mSv water from rivers and precipitation (meteoric water), 28 mSv freshwater from the Pacific and 60 mSv freshwater deficit due to brine from ice formation. Variability in liquid freshwater and component transports appear to have been partly due to advection of these water masses to the Fram Strait and partly due to variations in the local volume transport; an exception are Pacific Water transports, which showed little co-variability with volume transports. An increase in Pacific Water transports from 2005 to 2010 suggests a release of Pacific Water from the Beaufort Gyre, in line with an observed expansion of Pacific Water towards the Eurasian Basin. The co-variability of meteoric water and brine from ice formation suggests joint processes in the main sea ice formation regions on the Arctic Ocean shelves. In addition, enhanced levels of sea ice melt observed in 2009 likely led to reduced transports of brine from ice formation. At least part of this additional ice melt appears to have been advected from the Beaufort Gyre and from north of the Bering Strait towards the Fram Strait. The observed changes in liquid freshwater component transports are much larger than known trends in the Arctic liquid freshwater inflow from rivers and the Pacific. Instead, recent observations of an increased storage of liquid freshwater in the Arctic Ocean suggest a decreased export of liquid freshwater. This raises the question how fast the accumulated liquid freshwater will be exported from the Arctic Ocean to the deep water formation regions in the North Atlantic and if an increased export will occur through the Fram Strait.


2020 ◽  
Vol 125 (10) ◽  
Author(s):  
Maria V. Luneva ◽  
Vladimir V. Ivanov ◽  
Fedor Tuzov ◽  
Yevgeny Aksenov ◽  
James D. Harle ◽  
...  

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