Relationship of DDE/ΣDDT in Marine Mammals to the Chronology of DDT Input into the Ecosystem

1984 ◽  
Vol 41 (6) ◽  
pp. 840-844 ◽  
Author(s):  
Alex Aguilar
Keyword(s):  
North Atlantic ◽  
Strong Correlation ◽  
Marine Mammals ◽  
Marine Biota ◽  
The North ◽  
A Value ◽  
The North Atlantic ◽  
Relationship Of

The DDE/ΣDDT (ΣDDT = DDT + DDE + DDD) ratios in the blubber of North Atlantic pinnipeds and odontocete cetaceans, as determined by several scientists and surveys, are compiled to obtain a biannual mean series. Conversion of DDT to DDE is interpreted as being due not only to the marine mammals but also to the overall detoxifying activity of the North Atlantic marine biota. The change of these ratios during the period 1964–81 is examined and a strong correlation between these ratios and time is found in both groups, which demonstrates that such an index can be tentatively used when one assesses the chronology of pollutant input into the ecosystem. An equilibrium value may be reached at the beginning of the next century when the ratio reaches a value of approximately 0.60, provided that no new inputs of contaminant into North Atlantic waters exist.

scholarly journals First monk seal from the Southern Hemisphere rewrites the evolutionary history of true seals

2020 ◽  
Vol 287 (1938) ◽  
pp. 20202318
Author(s):  
James P. Rule ◽  
Justin W. Adams ◽  
Felix G. Marx ◽  
Alistair R. Evans ◽  
Alan J. D. Tennyson ◽  
...  
Keyword(s):  
Southern Hemisphere ◽  
North Atlantic ◽  
Marine Mammals ◽  
Evolutionary History ◽  
Major Change ◽  
The North ◽  
History Of ◽  
Entire History ◽  
The North Atlantic ◽  
Monk Seals

Living true seals (phocids) are the most widely dispersed semi-aquatic marine mammals, and comprise geographically separate northern (phocine) and southern (monachine) groups. Both are thought to have evolved in the North Atlantic, with only two monachine lineages—elephant seals and lobodontins—subsequently crossing the equator. The third and most basal monachine tribe, the monk seals, have hitherto been interpreted as exclusively northern and (sub)tropical throughout their entire history. Here, we describe a new species of extinct monk seal from the Pliocene of New Zealand, the first of its kind from the Southern Hemisphere, based on one of the best-preserved and richest samples of seal fossils worldwide. This unanticipated discovery reveals that all three monachine tribes once coexisted south of the equator, and forces a profound revision of their evolutionary history: rather than primarily diversifying in the North Atlantic, monachines largely evolved in the Southern Hemisphere, and from this southern cradle later reinvaded the north. Our results suggest that true seals crossed the equator over eight times in their history. Overall, they more than double the age of the north–south dichotomy characterizing living true seals and confirms a surprisingly recent major change in southern phocid diversity.

Integrating cultural and biological perspectives on long-term human-walrus (Odobenus rosmarus rosmarus) interactions across the North Atlantic

2019 ◽  
pp. 1-21
Author(s):  
Xénia Keighley ◽  
Morten Tange Olsen ◽  
Peter Jordan
Keyword(s):  
North Atlantic ◽  
Marine Mammals ◽  
Historical Ecology ◽  
Faunal Remains ◽  
Population Modelling ◽  
The North ◽  
Odobenus Rosmarus ◽  
Biological Studies ◽  
The North Atlantic ◽  
Odobenus Rosmarus Rosmarus

AbstractThe hunting of marine mammals as a source of subsistence, trade, and commercial revenue has formed an important part of human cultures across the North Atlantic. One important prey species has been the Atlantic walrus (Odobenus rosmarus rosmarus), sought after for meat, skin, blubber, ivory, and bone. Unfortunately, biological studies of current walrus populations and studies across the humanities and social sciences into past use and hunting of walruses, have been poorly integrated. Disciplinary boundaries have left a gap in understanding the reciprocal effects of human-walrus interactions. Emerging interdisciplinary methods offer new opportunities to write the historical ecology of Atlantic walruses. The integration of methods such as ancient DNA, isotopes, past population modelling, zooarchaeological assemblages, and ethnographic interviews can now be used to answer previously intractable questions. For example, how has walrus hunting shaped and been influenced by changes in human settlement and trade, what have been the cumulative impacts on walrus populations, the extent of anthropogenic selective pressures or the effect of changing hunting regimes on particular populations of walruses? New, collaborative research approaches applied to the wealth of Arctic archaeological faunal remains already housed in museum collections offer a unique chance to explore the past dynamics of human-animal interactions.

Evidence of Brucella infection in marine mammals in the North Atlantic Ocean

1999 ◽  
Vol 144 (21) ◽  
pp. 588-592 ◽  
Author(s):  
M. Tryland ◽  
L. Kleivane ◽  
A. Alfredsson ◽  
M. Kjeld ◽  
A. Arnason ◽  
...  
Keyword(s):  
Atlantic Ocean ◽  
North Atlantic ◽  
Marine Mammals ◽  
North Atlantic Ocean ◽  
The North ◽  
Brucella Infection ◽  
The North Atlantic

scholarly journals Spatial Signature of Solar Forcing over the North Atlantic Summer Climate in the Past Millennium

2019 ◽  
Author(s):  
Maria Pyrina ◽  
Eduardo Moreno-Chamarro ◽  
Sebastian Wagner ◽  
Eduardo Zorita
Keyword(s):  
North Atlantic ◽  
Internal Variability ◽  
Total Solar Irradiance ◽  
Solar Forcing ◽  
Summer Climate ◽  
The North ◽  
The North Atlantic ◽  
Composite Maps ◽  
Relationship Of ◽  
Model Variability

Abstract. We investigate the effects of solar forcing during summer on the North Atlantic climate in comprehensive simulations of the preindustrial last millennium. We use two Earth System Models forced only by variations in Total Solar Irradiance (TSI). Specifically, we examine how different statistical techniques commonly used in current literature, namely linear methods and composite techniques can condition our understanding of the effects of solar forcing on climate. We demonstrate that the results obtained are strongly shaped by internal model variability. Linear methods like regression and correlation are not suitable to separate solar impacts on summer climate from internal variability. Composite maps show a response of SSTs off the European coasts and atmospheric blocking-like pressure anomalies over the subpolar North Atlantic, with some model-dependent variations of its spatial patterns and extent. In the models analyzed, the relationship of TSI to the tropospheric and surface circulation is linked through a baroclinic response to diabatic heating at the ocean surface. A tendency toward blocking-like patterns over the middle and high latitudes might be subsequently created during summer and in high TSI periods.

scholarly journals Polychlorinated biphenyl (PCB) concentrations and profiles in marine mammals from the North Atlantic Ocean

Chemosphere ◽  
2021 ◽  
pp. 132639
Author(s):  
David Megson ◽  
Thomas Brown ◽  
Gareth Rhys Jones ◽  
Mathew Robson ◽  
Glenn Johnson ◽  
...  
Keyword(s):  
Atlantic Ocean ◽  
North Atlantic ◽  
Marine Mammals ◽  
Polychlorinated Biphenyl ◽  
North Atlantic Ocean ◽  
The North ◽  
The North Atlantic

scholarly journals International legal protection of seals

Fisheries ◽  
2021 ◽  
Vol 2021 (6) ◽  
pp. 58-62
Author(s):  
Kamil Bekyashev
Keyword(s):  
North Atlantic ◽  
Coastal Waters ◽  
Marine Mammals ◽  
Legal Protection ◽  
The North ◽  
Antarctic Seals ◽  
The Russian Federation ◽  
The North Atlantic ◽  
The Government ◽  
The City

The article gives a brief description of the various species of seals. In the city of Arkhangelsk there is a monument to a seal. Two species of seals live in the coastal waters of Russia: the Steinger seal and the European seal. They are listed in the Red Book. The article analyzes the conventions and agreements on the protection of seals: Convention for the Conservation of Antarctic Seals 1972, the Agreement on the cooperation in research, conservation and management of marine mammals in the North Atlantic 1992, the Agreement between the Government of the USSR and the Government of Norway on Measures to regulate fishing, sealing and protection of seal stocks in the Northeast Atlantic 1957. The decisions of the 51st session of the Joint Norwegian–Russian Fisheries Commission are analyzed. The article ends with an outline of the contribution of the Russian Federation to the rational seal fishery.

scholarly journals On the 14C to Tritium Relationship in the North Atlantic Ocean

Radiocarbon ◽  
1980 ◽  
Vol 22 (3) ◽  
pp. 636-646 ◽  
Author(s):  
Wolfgang Roether ◽  
Karl-Otto Münnich ◽  
Hildegard Schoch
Keyword(s):  
Surface Water ◽  
North Atlantic ◽  
North Atlantic Ocean ◽  
Vertical Mixing ◽  
Tritium Concentration ◽  
Time Curve ◽  
The North ◽  
Northern Latitudes ◽  
The North Atlantic ◽  
Relationship Of

Nuclear-weapon produced 14C (or bomb 14C) in the ocean can be traced by simultaneous tritium observations. Data are presented on the general relationship of bomb 14C and tritium in the North Atlantic. For the period 1965 to 1973, the excess 14C to tritium ratios in the surface water vary, systematically, over a factor of 10: the ratios monotonically increase with time, and decrease with latitude, particularly so for the later observations. The sub-surface water ratios show that the mid- and low-latitude water below about the 15° C isothermal horizon (~500m depth) originates from higher northern latitudes, rather than being renewed by local vertical mixing. It is further shown that in the North Atlantic, bomb 14C did not penetrate beyond the horizon where the presently observed 14C concentration is Δ14C = —75‰. Observed concentrations up to about —40‰ can be corrected for a bomb contribution if the tritium concentration is known because the bomb 14C to tritium concentration ratio is rather uniform in this range. A surface water 14C concentration versus time curve is presented for the period since 1957. This curve is based on a North Atlantic mixing model and is fitted to the 14C observations. Making use of a previously published tritium versus time curve obtained by the same model, a time curve for the average excess 14C to tritium ratio in North Atlantic surface water is given. This curve reproduces the observations well. The presented data and theoretical curves show the usefulness of simultaneous 14C and tritium observations for mixing studies and to provide corrections for bomb 14C in sub-surface 14C data in the North Atlantic.

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