Susceptibility of small boreal lakes to environmental changes as inferred from organic sediments of Lake Talvilampi (Finland)

During the Holocene, multiple thermal changes commonly occurred in the northern hemisphere. They are well-recorded in lakes with minimum human impact from the Arctic Circle area. The development of these lakes reflects ecological and climatic changes occurring from the formation of the lakes until present-day times. All environmental fluctuations affect biodiversity and are reflected in the number and composition of species. The goals of this study were to detect the ecological changes in a small Finnish lake using pollen, Cladocera and geochemical analyses. The research area is located within the northern zone of boreal coniferous forest and is the most sparsely populated region of Finland. The lake is located in Kuusamo uplands, E Finland, near the polar circle and over 20 km from the Russian border. Indicators of cold water were found only during the initial stage, after the 8.2 ka event and then the temperature was higher. Trophy was high at the beginning of the lake development and then a significant increase in trophy was found after 2600 BP. The impact of human activity is hardly traceable in Arctic Circle Finland throughout the Holocene Thermal Maximum. During the late-Holocene (after 4200 yr cal. BP), this impact is still weak and, even as late as the 20th century, only a few traces of human activity are recorded. General conclusion is that long-term climatic shift has been the most important factor driving changes in the limnology of Lake Talvilampi.

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Environmental evolution and anthropogenic forcing in the Garigliano coastal plain (Italy) during the Holocene

The Holocene ◽

10.1177/09596836211003242 ◽

2021 ◽

pp. 095968362110032

Author(s):

Halinka Di Lorenzo ◽

Pietro Aucelli ◽

Giuseppe Corrado ◽

Mario De Iorio ◽

Marcello Schiattarella ◽

...

Keyword(s):

Human Activity ◽

Coastal Plain ◽

Forest Cover ◽

Environmental Changes ◽

Pollen Data ◽

Human Environment ◽

The Holocene ◽

Natural Processes ◽

History Of ◽

The Rich

The Garigliano alluvial-coastal plain, at the Latium-Campania border (Italy), witnessed a long-lasting history of human-environment interactions, as demonstrated by the rich archaeological knowledge. With the aim of reconstructing the evolution of the landscape and its interaction with human activity during the last millennia, new pollen results from the coastal sector of the Garigliano Plain were compared with the available pollen data from other nearby sites. The use of pollen data from both the coastal and marine environment allowed integrating the local vegetation dynamics within a wider regional context spanning the last 8000 years. The new pollen data presented in this study derive from the analysis of a core, drilled in the coastal sector, which intercepted the lagoon-marshy environments that occurred in the plain as a response to the Holocene transgression and subsequent coastal progradation. Three radiocarbon ages indicate that the chronology of the analyzed core interval ranges from c. 7200 to c. 2000 cal yr BP. The whole data indicate that a dense forest cover characterized the landscape all along the Prehistoric period, when a few signs of human activity are recorded in the spectra, such as cereal crops, pasture activity and fires. The main environmental changes, forced by natural processes (coastal progradation) but probably enhanced by reclamation works, started from the Graeco-Roman period and led to the reduction of swampy areas that favoured the colonisation of the outer plain.

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The impact of Sahara desertification on Arctic cooling during the Holocene

Climate of the Past ◽

10.5194/cp-11-571-2015 ◽

2015 ◽

Vol 11 (3) ◽

pp. 571-586 ◽

Cited By ~ 9

Author(s):

F. J. Davies ◽

H. Renssen ◽

M. Blaschek ◽

F. Muschitiello

Keyword(s):

Vegetation Type ◽

The Arctic ◽

Direct Result ◽

Strong Increase ◽

Earth Model ◽

Climate Modelling ◽

Trade Winds ◽

The Holocene ◽

The Impact ◽

Humid Period

Abstract. Since the start of the Holocene, temperatures in the Arctic have steadily declined. This has been accredited to the orbitally forced decrease in summer insolation reconstructed over the same period. However, here we present climate modelling results from an Earth model of intermediate complexity (EMIC) that indicate that 17–40% of the cooling in the Arctic, over the period 9–0 ka, was a direct result of the desertification that occurred in the Sahara after the termination of the African Humid Period. We have performed a suite of sensitivity experiments to analyse the impact of different combinations of forcings, including various vegetation covers in the Sahara. Our simulations suggest that over the course of the Holocene, a strong increase in surface albedo in the Sahara as a result of desertification led to a regional increase in surface pressure, a weakening of the trade winds, the westerlies and the polar easterlies, which in turn reduced the meridional heat transported by the atmosphere to the Arctic. We conclude that during interglacials, the climate of the Northern Hemisphere is sensitive to changes in Sahara vegetation type.

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How relevant is the deposition of mercury onto snowpacks? – Part 2: A modeling study

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-12-2647-2012 ◽

2012 ◽

Vol 12 (1) ◽

pp. 2647-2706 ◽

Cited By ~ 10

Author(s):

D. Durnford ◽

A. Dastoor ◽

A. Ryzhkov ◽

L. Poissant ◽

M. Pilote ◽

...

Keyword(s):

Sea Ice ◽

Arctic Ocean ◽

Atmospheric Mercury ◽

The Arctic ◽

Hudson Bay ◽

Arctic Circle ◽

Surface Level ◽

The Arctic Ocean ◽

Simulated Concentration ◽

The Impact

Abstract. An unknown fraction of mercury that is deposited onto snowpacks is revolatilized to the atmosphere. Determining the revolatilized fraction is important since mercury that enters the snowpack meltwater may be converted to highly toxic bioaccumulating methylmercury. In this study, we present a new dynamic physically-based snowpack/meltwater model for mercury that is suitable for large-scale atmospheric models for mercury. It represents the primary physical and chemical processes that determine the fate of mercury deposited onto snowpacks. The snowpack/meltwater model was implemented in Environment Canada's atmospheric mercury model GRAHM. For the first time, observed snowpack-related mercury concentrations are used to evaluate and constrain an atmospheric mercury model. We find that simulated concentrations of mercury in both snowpacks and the atmosphere's surface layer agree closely with observations. The simulated concentration of mercury in both in the top 30 cm and the top 150 cm of the snowpack, averaged over 2005–2009, is predominantly below 6 ng l−1 over land south of 66.5° N but exceeds 18 ng l−1 over sea ice in extensive areas of the Arctic Ocean and Hudson Bay. The average simulated concentration of mercury in snowpack meltwater runoff tends to be higher on the Russian/European side (>20 ng l−1) of the Arctic Ocean than on the Canadian side (<10 ng l−1). The correlation coefficient between observed and simulated monthly mean atmospheric surface-level GEM concentrations increased significantly with the inclusion of the new snowpack/meltwater model at two of the three stations (midlatitude, subarctic) studied and remained constant at the third (arctic). Oceanic emissions are postulated to produce the observed summertime maximum in concentrations of surface-level atmospheric GEM at Alert in the Canadian Arctic and to generate the summertime volatility observed in these concentrations at both Alert and Kuujjuarapik on subarctic Hudson Bay, Canada. We find that the fraction of deposited mercury that is revolatilized from snowpacks increases with latitude from 28% between 30 and 45° N, to 51% from 45 to 66.5° N, to 70% polewards of 66.5° N on an annual basis. Combining this latitudinal gradient with the latitudinally increasing coverage of snowpacks causes yearly net deposition as a fraction of gross deposition to decrease from 98% between 30 and 45° N to 85% between 45 and 66.5° N to 44% within the Arctic Circle. The yearly net deposition and net accumulation of mercury at the surface within the Arctic Circle north of 66.5° N are estimated at 153 and 117 Mg, respectively. We calculate that 63 and 45 Mg of mercury are deposited annually to the Arctic Ocean directly and indirectly via melting snowpacks, respectively. For terrestrial surfaces within the Arctic Circle, we find that 24 and 21 Mg of mercury are deposited annually directly and indirectly via melting snowpacks, respectively. Within the Arctic Circle, multi-season snowpacks gained an estimated average of 136 kg of mercury annually on land but lost an average of 133 kg annually over sea ice, possibly as a result of increased melting caused by rising temperatures. The developed snowpack/meltwater model can be used for investigating the impact of climate change on the snowpack/atmosphere exchange of mercury.

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Factors of Human Activities Impact on the Nature in the Arctic Regions

Journal of Environmental Management and Tourism ◽

10.14505//jemt.11.3(43).15 ◽

2020 ◽

Vol 11 (3) ◽

pp. 613

Author(s):

Natalia V. KARMANOVSKAYA ◽

Mikhail A. ELESIN ◽

Tatyana P. BAZELYANSKAYA

Keyword(s):

Human Activity ◽

Molecular Genetic ◽

Integrated Approach ◽

Field Work ◽

Qualitative Assessment ◽

Practical Significance ◽

The Arctic ◽

Impact Factors ◽

General Nature ◽

The Impact

Ecological monitoring of the environment constitutes the basis for the study of natural objects and an integrated approach to the organization of both production and human activity at large. The purpose of the paper is to investigate the factors that influence human activity on the nature of the Arctic. The leading research methods for this problem are the method of analysing several factors of human activity on the dynamics of changes in nature, including the method of qualitative assessment, during which the general nature of the impact was identified. As a result, continuous observations were made of the state of the atmosphere. The data on the concentration of fine dust obtained from the Norilsk stationary post allow to identify the level of pollution. The assessment of impact factors was carried out, which allowed to determine the extent of impact on nature. The authors also conducted field work and tested 50 biological samples of wild reindeer in West Taimyr using the molecular genetic marker system. The novelty of the study is that organizational and methodological recommendations were developed for conducting production activities. The practical significance of the study is determined by the necessity of implementing the necessary scientific and administrative apparatus for the preparation and implementation of practical measures, since many theoretical aspects for further proposal of measures have not been sufficiently developed.

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The History of Pastoral Activities in S Italy Inferred from Palynology: A Long-Term Perspective to Support Biodiversity Awareness

Sustainability ◽

10.3390/su11020404 ◽

2019 ◽

Vol 11 (2) ◽

pp. 404 ◽

Cited By ~ 9

Author(s):

Assunta Florenzano

Keyword(s):

Environmental Sustainability ◽

Southern Italy ◽

Environmental Changes ◽

Coprophilous Fungi ◽

Human Environment ◽

The Holocene ◽

Mediterranean Habitats ◽

15Th Century ◽

The Impact

The present-day Mediterranean landscape is a result of the long-term human–environment–climate interactions that have driven the ecological dynamics throughout the Holocene. Pastoralism had (and still has) an important role in shaping this landscape, and contributes to maintaining the mosaic patterns of the Mediterranean habitats. Palaeoecological records provide significant multi-proxy data on environmental changes during the Holocene that are linked to human activities. In such research, the palynological approach is especially useful for detailing the complexity of anthropogenically-driven landscape transformations by discriminating past land uses and pastoral/breeding activities. This paper focuses on the palynological evidence for the impact of centuries of grazing on the vegetation of Basilicata, a region of southern Italy where animal breeding and pastoralism have a long tradition. A set of 121 pollen samples from eight archaeological sites (dated from the 6th century BC to the 15th century AD) and five modern surface soil samples were analyzed. The joint record of pollen pasture indicators and spores of coprophilous fungi suggests that continuous and intense pastoral activities have been practiced in the territory and have highly influenced its landscape. The palaeoecological results of this study provide us with better knowledge of the diachronical transformations of the habitats that were exposed to continuous grazing, with a shift toward more open vegetation and increase of sclerophyllous shrubs. The palynological approach gives insights into the vocation and environmental sustainability of this southern Italy region on a long-term basis.

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How relevant is the deposition of mercury onto snowpacks? – Part 2: A modeling study

Atmospheric Chemistry and Physics ◽

10.5194/acp-12-9251-2012 ◽

2012 ◽

Vol 12 (19) ◽

pp. 9251-9274 ◽

Cited By ~ 30

Author(s):

D. Durnford ◽

A. Dastoor ◽

A. Ryzhkov ◽

L. Poissant ◽

M. Pilote ◽

...

Keyword(s):

Sea Ice ◽

Arctic Ocean ◽

Atmospheric Mercury ◽

The Arctic ◽

Hudson Bay ◽

Arctic Circle ◽

Surface Level ◽

The Arctic Ocean ◽

Simulated Concentration ◽

The Impact

Abstract. An unknown fraction of mercury that is deposited onto snowpacks is revolatilized to the atmosphere. Determining the revolatilized fraction is important since mercury that enters the snowpack meltwater may be converted to highly toxic bioaccumulating methylmercury. In this study, we present a new dynamic physically-based snowpack/meltwater model for mercury that is suitable for large-scale atmospheric models for mercury. It represents the primary physical and chemical processes that determine the fate of mercury deposited onto snowpacks. The snowpack/meltwater model was implemented in Environment Canada's atmospheric mercury model GRAHM. For the first time, observed snowpack-related mercury concentrations are used to evaluate and constrain an atmospheric mercury model. We find that simulated concentrations of mercury in both snowpacks and the atmosphere's surface layer agree closely with observations. The simulated concentration of mercury in both in the top 30 cm and the top 150 cm of the snowpack, averaged over 2005–2009, is predominantly below 6 ng L−1 over land south of 66.5° N but exceeds 18 ng L−1 over sea ice in extensive areas of the Arctic Ocean and Hudson Bay. The average simulated concentration of mercury in snowpack meltwater runoff tends to be higher on the Russian/European side (>20 ng L−1) of the Arctic Ocean than on the Canadian side (<10 ng L−1). The correlation coefficient between observed and simulated monthly mean atmospheric surface-level gaseous elemental mercury (GEM) concentrations increased significantly with the inclusion of the new snowpack/meltwater model at two of the three stations (midlatitude, subarctic) studied and remained constant at the third (arctic). Oceanic emissions are postulated to produce the observed summertime maximum in concentrations of surface-level atmospheric GEM at Alert in the Canadian Arctic and to generate the summertime volatility observed in these concentrations at both Alert and Kuujjuarapik on subarctic Hudson Bay, Canada. We find that the fraction of deposited mercury that is revolatilized from snowpacks increases with latitude from 39% between 30 and 45° N, to 57% from 45 to 60° N, 67% from 60 to 66.5° N, and 75% polewards of 66.5° N on an annual basis. Combining this latitudinal gradient with the latitudinally increasing coverage of snowpacks causes yearly net deposition as a fraction of gross deposition to decrease from 98% between 30 and 45° N to 89% between 45 and 60° N, 73% between 60 and 66.5° N, and 44% within the Arctic Circle. The yearly net deposition and net accumulation of mercury at the surface within the Arctic Circle north of 66.5° N are estimated at 153 and 117 Mg, respectively. We calculate that 58 and 50 Mg of mercury are deposited annually to the Arctic Ocean directly and indirectly via melting snowpacks, respectively. For terrestrial surfaces within the Arctic Circle, we find that 29 and 16 Mg of mercury are deposited annually directly and indirectly via melting snowpacks, respectively. Within the Arctic Circle, multi-season snowpacks on land and over sea ice gained, on average, an estimated 0.1 and 0.4 Mg yr−1 mercury, respectively, from 2000–2005. The developed snowpack/meltwater model can be used for investigating the impact of climate change on the snowpack/atmosphere exchange of mercury.

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Contribution of Northern European Universities to the Implementation of Research Policy in the Arctic

Arctic and North ◽

10.37482/issn2221-2698.2021.42.200 ◽

2021 ◽

pp. 200-222

Author(s):

Konstantin S. Zaikov ◽

◽

Nikolay A. Kondratov ◽

Keyword(s):

Natural Resources ◽

Environmental Changes ◽

Research Policy ◽

Scientific Research ◽

World Politics ◽

The Arctic ◽

Arctic Zone ◽

Research Activities ◽

Northern European ◽

The Impact

The Arctic region has long been at the center of world politics and economy. One of the reasons for the transformation of the global fringe into a center of attraction for the economic, geo-ecological and geopolitical interests of foreign countries is the Arctic is undergoing dynamic transformations. In the socio-political and scientific research agenda of the Arctic States, there are acute issues of accumulation and exchange of knowledge about changes taking place in the natural and socio-economic environment of a non-standard region from the point of view of management. The Arctic strategies of the Northern European States seek to fill the vacuum about the trends of environmental changes in the Arctic, the impact of natural transformations on the environment, socio-economic development, population security, and the use of natural resources by indigenous peoples. This task is planned to be solved through the development of research activities of universities located in the Far North and in the Arctic zone of Denmark, Norway, Finland and Sweden, as well as Iceland. The article describes the scientific interests of the Northern European States in the Arctic. Using analytical and comparative methods, the goal is achieved — to characterize universities as one of the parts of their scientific and educational space in the Nordic countries. An attempt is made to answer the question: how does educational and research activities contribute to the implementation of state program documents for the development of natural resources in the Arctic and the use of its spaces? The further direction of scientific research may be to compare the educational and research activities of universities in Northern Europe and universities in the Arctic zone of the Russian Federation.

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Holocene environmental changes and human activity at the Jijitan site in the Nihewan Basin, China

The Holocene ◽

10.1177/0959683618761544 ◽

2018 ◽

Vol 28 (7) ◽

pp. 1151-1159

Author(s):

Jingyao Lu ◽

Qinghai Xu ◽

Yao Liu ◽

Ya’nan Hu ◽

Manyue Li ◽

...

Keyword(s):

Human Activity ◽

Forest Cover ◽

Environmental Changes ◽

Asian Summer Monsoon ◽

Regional Climate ◽

Peak Level ◽

Northern China ◽

High Northern Latitude ◽

The Holocene ◽

Nihewan Basin

Knowledge of the relationship between human activities and environmental changes during the Holocene is important for understanding the survival and development of prehistoric humans. Using AMS 14C dating and pollen and charcoal analysis, we reconstructed the history of environmental changes and human activity during the Holocene at the Jijitan site in the Nihewan Basin. During 13,000–7500 cal. yr BP, the East Asian Summer Monsoon (EASM) gradually intensified and precipitation increased, the vegetation changed from temperate grassland to wooded grassland and human activity remained at a low intensity. During 7500–5500 cal. yr BP, the EASM reached peak level, and the climate was warm and humid interval, and human activity intensified substantially. Within this interval, from 6600 to 6000 cal. yr BP, the forests were burned to increase the area of farmland. After 5500 cal. yr BP, the forest cover continued to gradually decrease due to the combined influences of the weakening EASM and increasing human activity. Comparison with regional climate records shows that the optimum period of forest development in northern China was approximately 8000–5000 cal. yr BP, indicating that the EASM reached a peak level in the mid-Holocene, which we suggest may have been due to the reduced influence of the high northern-latitude ice sheets and rising global sea level, rather than in the early Holocene.

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The impact of Arctic warming on the timing of Indian monsoon and ice season in the Sea of Okhotsk

10.5194/egusphere-egu21-13582 ◽

2021 ◽

Author(s):

Elena Surovyatkina

Keyword(s):

Pacific Ocean ◽

Sea Ice ◽

Early Onset ◽

Sea Of Okhotsk ◽

Indian Monsoon ◽

The Arctic ◽

Arctic Warming ◽

Arctic Circle ◽

The Sea Of Okhotsk ◽

The Impact

In 2020, the Arctic Circle warming in Siberia was extraordinary. Strong anticyclones have been dominant over a large area in Northern Siberia through spring. It resulted in an all-time high-temperature record in the Arctic Circle - more than 6&#176;C above the average (1981&#8211;2010). Thus, it accelerated the melting of snow, ice, permafrost and has gotten the wildfire in Siberia off to an unusually early and severe start. The Arctic warming has repercussions not only for Siberia but for the entire Eurasia and the Northern Hemisphere. Specifically, the Arctic conditions affect atmospheric circulation in the Pacific Ocean and the strength and direction of trade winds in the tropical zone.Here, I show that Arctic Circle warming has impacted the timing of monsoon and sea ice seasons. First, I found the observational evidence of Arctic warming causing colder than average temperatures over the east of Eurasia, Central Europe, and Central Asia. Notably, North Pakistan and Northern India saw temperatures distinctly below the long-term average (1981&#8211;2010): 4&#176;C below from March to December. Second, I took this evidence into account while developing a new method for forecasting the sea-ice timing and the recent long-range forecasting method of monsoon season [1]. Third, based on the forecast results for 2020, I found that utilizing only recent trends is an inadequate strategy for predictions. However, considering the current Arctic warming outcomes in specific regions overcomes this problem and results in successful forecasts for both sea-ice and monsoon seasons.The results imply that when North Pakistan's temperature is cooler than usual: (i) it slows down an advance of monsoon, (ii) it accelerates the cooling of the entire Indian subcontinent during withdrawal from northern Pakistan to the east coast of central India. Hence, North Pakistan's cooling in 2020 caused a protracted offensive and early end of the Indian summer monsoon, thus, shortening its duration. As a result, it led to the early onset of the seasonal wind reversal in the eastern Pacific Ocean in the middle of October and, therefore, to the surprisingly early onset of the winter monsoon in South Asia and India [2]. The consequences of this change in monsoon timing strongly affected 70% of the Indian population directly related to farming.In the Sea of Okhotsk in 2020, the sea ice retreated early due to heatwaves in Siberia. In December, the onset date of ice season was around average, but ice grew faster than average, creating a hazard to navigation safety.Hence, the proposed forecasting methodology applied to India and the Sea of Okhotsk opens new possibilities to forecasting monsoon and sea ice seasons around the globe.The author acknowledges financial support from RFBR, project number 20-07-01071 .&#160;[1] Stolbova, V., E. Surovyatkina, B. Bookhagen, and J. Kurths (2016): Tipping elements of the Indian monsoon: Prediction of onset and withdrawal. GRL 43, 1&#8211;9 [doi:10.1002/2016GL068392][2] https://www.pik-potsdam.de/en/output/infodesk/forecasting-indian-monsoon

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Foraminifera and the Holocene History of the Gulf of St. Lawrence

Canadian Journal of Earth Sciences ◽

10.1139/e72-104 ◽

1972 ◽

Vol 9 (9) ◽

pp. 1204-1215 ◽

Cited By ~ 10

Author(s):

Grant A. Bartlett ◽

Linda Molinsky

Keyword(s):

Shallow Water ◽

Prince Edward Island ◽

Cold Water ◽

Sediment Cores ◽

Water Environment ◽

The Arctic ◽

Globigerinoides Ruber ◽

The Holocene ◽

Foraminiferal Species ◽

History Of

Foraminifera have been utilized to interpret the response of waters in the Gulf of St. Lawrence to climatic changes during the Holocene. Sediment cores (up to 1000 cm long) from the Gulf of St. Lawrence and environs, are characterized throughout by meager foraminiferal faunas. The microfaunas are characteristic of marginal marine environments and are typified by low foraminiferal numbers (less than 300 and generally less than 100 per unit sample), few genera and species, and hyposaline, shallow-water assemblages. The microfaunal information indicates that marine waters were more brackish and much shallower during the latter stages, and immediately following the Wisconsin glaciation. Shallow-water foraminiferal species such as Elphidium incertum clavatum, Islandiella islandica, and I. teretis are commonly the first to inhabit cool temperate to northern environments after glacial retreat. Consequently, because of the absence of deep water marine microfaunas it is believed that many areas in the Gulf of St. Lawrence were at least 100 to 200 m shallower than at present.The Holocene history of the area is one of transition from a rapidly fluctuating brackish water environment, to one which is more consistent with the present environment. The presence of Globigerinoides ruber (pink), a species commonly associated with subtropical waters, intermixed with the eurybathic benthonic fauna, indicates distinctive lateral and vertical water-mass zonation in a restricted geographic area. Warm water incursions into the Gulf of St. Lawrence from the Gulf Stream, which contained the subtropical foraminiferal species Globigerinoides ruber and Globorotalia menardii, were intermittent, whereas a persistent cold-water marine influence from the Arctic via the Labrador Current is indicated by the presence of Globigerina pachyderma. The adjoining Scotian Shelf faunas, alternating from sparse, to prolific and diverse, during the Holocene, suggest that conditions there were not significantly different from those in the Gulf of St. Lawrence.Extremely brackish and/or shallower waters were present in most of the western Laurentian Channel and shelf waters of the Gulf of St. Lawrence until recently (< 6400 ± 130 yr B.P.). The baymouth bars, persistent features restricting circulation with most bays, estuaries, and lagoons adjoining Prince Edward Island and New Brunswick were established between 4540 ± 180 and 2235 ± 155 yr B.P. Sediments containing subtropic and arctic planktonic species, alternating with eurythermal benthonic species, are indicative of environmental extremes throughout the Holocene. It is believed that many of these marine fluctuations were neither recorded nor preserved in adjoining continental sediments of equivalent age.

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