Chlorate Discharges from Pulp Mills: An Examination of Effects on River Algal Communities

1992 ◽  
Vol 27 (3) ◽  
pp. 473-486 ◽  
Author(s):  
C. J. Perrin ◽  
M. L. Bothwell

Abstract To avoid the formation of organochlorine compounds in pulp products and effluents discharged into the environment, there is a trend in the North American pulping industry to change from molecular chlorine to chlorine dioxide bleaching. However, chlorate (ClO3−) formed during chlorine dioxide bleaching is known to have toxic effects in some marine algae and has been implicated in environmental problems in the Baltic Sea. This study examined the potential effects of chlorate on natural freshwater, riverine diatom communities characteristic of many rivers in western Canada. Under low ambient river nitrate concentrations (ca. 10 µg•L−1 NO3−N), chlorate additions of up to 500 µg•L1 ClO3 did not reduce the specific growth rates (µ) or change the taxonomic composition of the attached riverine diatom community. The lack of chlorate toxicity to freshwater diatoms suggests that the nitrate uptake and/or reduction mechanism(s) of freshwater diatoms have much higher affinities for NO3 than ClO3 compared to many marine macroalgae. These results indicate that chlorate discharged from new or upgraded pulpmills into freshwater river environments will not cause environmental changes to the dominant algal producers such as diatoms.

2020 ◽  
Author(s):  
Luke Strotz ◽  
Bruce Lieberman

<p>A key topic in paleoecology and macroevolution is whether assemblages of species show patterns of persistence over millions of years; a phenomenon that has been variously referred to as ‘Turnover Pulse’ or ‘Coordinated Stasis’. It has generally been presumed that any abrupt environmental changes discernible in the geological record will often lead to community turnover and the establishing of a new community that is discrete from the previous iteration, even if environmental conditions return to those that existed prior to the disruptive event. A related topic is, if patterns of stability can and do prevail despite disruption, what are the processes that allow for this. Potential options include the degree of change in the physical environment, which may not be great enough to exceed the threshold required for community collapse, or due to ‘Ecological Locking’, where directional selection is constrained by ecological processes.</p><p>Our touchstone to consider these topics is the detailed fossil record of Carboniferous brachiopod communities from the Mid-continent of North America. These were highly diverse communities that persisted in a very dynamic environmental setting. In particular, these communities were subjected to frequent and geologically rapid phases of marine transgression and regression associated with climate change over approximately a 20-million-year period. These changes likely resulted in repeated community destruction and renewal as suitable habitat was lost and then subsequently re-established.</p><p>Using a suite of statistical techniques, we characterized the nature and scope of changes in these fossil communities over time. We found that, at one scale, fossil communities were not stable throughout this interval, both in terms of taxonomic composition and the associated abundance of those taxa. Thus, there is no evidence of obdurate ecological stasis, as new discrete communities, statistically dissimilar from previous and subsequent iterations, form following each environmental disruption. However, at a higher scale, stability is manifest, as diversity patterns are stable across time and despite episodes of environmental change. In particular, we identify a form of qualified ecological stasis for both the different environments present during this interval and for the larger region as a whole. Ultimately, whilst the individual taxa that comprise each community differ, there is a consistent number of species that can exist in any given community, such that communities remain functionally similar. This indicates that whilst the individual taxa that come to form communities arrive via the exigencies of recruitment, the overall diversity of the communities is set by some higher-level ecological rules. Specifically, the rules for taxon packing are seemingly constant in distinct environments, likely due to energetic controls that limit how many taxa can be maintained in an environmental setting and/or perhaps because the amount of space needed for any individual to develop into an adult is invariant across different taxa within the same clade. Further, these ecological rules lead to stability even in the face of constant disequilibrium, which matches patterns identified in the recovery of marine invertebrate communities from disruptive events in modern systems.</p>


Antiquity ◽  
2019 ◽  
Vol 93 (367) ◽  
pp. 260-263
Author(s):  
Harry K. Robson

This three-volume publication presents an up-to-date overview on the human colonisation of Northern Europe across the Pleistocene–Holocene transition in Scandinavia, the Eastern Baltic and Great Britain. Volume 1, Ecology of early settlement in Northern Europe, is a collection of 17 articles focusing on subsistence strategies and technologies, ecology and resource availability and demography in relation to different ecological niches. It is structured according to three geographic regions, the Skagerrak-Kattegat, the Baltic Region and the North Sea/Norwegian Sea, while its temporal focus is Late Glacial and Postglacial archaeology, c. 11000–5000 cal BC. These regions are particularly interesting given the long research history, which goes back as far as the nineteenth century (see Gron & Rowley-Conwy 2018), and the numerous environmental changes that have taken place throughout the Holocene: the presence of ice until c. 7500 cal BC, isostatic rebound alongside sea-level rise and the formation of the Baltic Sea, all of which have contributed to the preservation of outstanding archaeology.


1976 ◽  
Vol 3 (1) ◽  
pp. 43-46 ◽  
Author(s):  
Arne Jernelöv ◽  
Rutger Rosenberg

It is conventionally argued that a stable ecosystem, namely one with high species-diversity and high constancy in physical parameters, is less sensitive to additional stress than a system with varying physical parameters and low species-diversity. By this logic, the Baltic would be more susceptible to additional stress, such as that of pollution, than the North Sea.Examples of irreparable damage to some of the most stable ecosystems in the world, such as coral reefs and tropical rain-forests, suggest, on the contrary, that these systems are more vulnerable than low-diversity ecosystems, such as a brackish-water zone in the mouth of a river or a coniferous forest in a temperate region.Studies of stress tolerance in estuaries showed that the species already living under stress, such as that of reduced and changing salinities, were more tolerant to pollution than species in a less fluctuating environment. This adaptability to environmental changes seems to be characteristic of ecosystems with a low degree of individual specialization and high genetic diversity (i.e. a large number of alleles). Following this conclusion, we question the underlying assumptions in the statement that for example the Baltic Sea, which can be regarded as a large estuary, is an area particularly susceptible to stress; purely marine ecosystems are probably more sensitive.Ecosystem stress-tolerance should be made a top priority in ecological research; this is a necessity inter alia for future localization of industries, in order to minimize their effects on the environment.


2003 ◽  
pp. 136-146
Author(s):  
K. Liuhto

Statistical data on reserves, production and exports of Russian oil are provided in the article. The author pays special attention to the expansion of opportunities of sea oil transportation by construction of new oil terminals in the North-West of the country and first of all the largest terminal in Murmansk. In his opinion, one of the main problems in this sphere is prevention of ecological accidents in the process of oil transportation through the Baltic sea ports.


Author(s):  
Angelina E. Shatalova ◽  
Uriy A. Kublitsky ◽  
Dmitry A. Subetto ◽  
Anna V. Ludikova ◽  
Alar Rosentau ◽  
...  

The study of paleogeography of lakes is an actual and important direction in modern science. As part of the study of lakes in the North-West of the Karelian Isthmus, this analysis will establish the dynamics of salinity of objects, which will allow to reconstruct changes in the level of the Baltic Sea in the Holocene.


Author(s):  
Vera Rostovtseva ◽  
Vera Rostovtseva ◽  
Igor Goncharenko ◽  
Igor Goncharenko ◽  
Dmitrii Khlebnikov ◽  
...  

Sea radiance coefficient, defined as the ratio of the sunlight reflected by the water bulk to the sunlight illuminating the water surface, is one of the most informative optical characteristics of the seawater that can be obtained by passive remote sensing. We got the sea radiance coefficient spectra by processing the data obtained in measurements from board a moving ship. Using sea radiance coefficient optical spectra it is possible to estimate water constituents concentration and their distribution over the aquatory of interest. However, thus obtained sea radiance coefficient spectra are strongly affected by weather and measurement conditions and needs some calibration. It was shown that practically all the spectra of sea radiance coefficient have some generic peculiarities regardless of the type of sea waters. These peculiarities can be explained by the spectrum of pure sea water absorption. Taking this into account a new calibration method was developed. The measurements were carried out with the portative spectroradiometers from board a ship in the five different seas: at the north-east coast of the Black Sea, in the Gdansk Bay of the Baltic Sea, in the west part of the Aral Sea, in the Kara Sea with the Ob’ Bay and in the Philippine Sea at the coast of Taiwan. The new method of calibration was applied to the obtained spectra of the sea radiance coefficient that enabled us to get the corresponding absorption spectra and estimate the water constituents concentration in every region. The obtained concentration estimates were compared to the values obtained in water samples taken during the same measurement cycle and available data from other investigations. The revealed peculiarities of the sea radiance coefficient spectra in the aquatories under exploration were compared to the corresponding water content and some characteristic features were discussed.


1988 ◽  
Vol 23 (1) ◽  
pp. 55-68 ◽  
Author(s):  
J. H. Carey ◽  
J. H. Hart

Abstract The identity and concentrations of chlorophenolic compounds in the Fraser River estuary were determined under conditions of high and low river flow at three sites: a site upstream from the trifurcation and at downstream sites for each main river arm. Major chlorophenolics present under both flow regimes were 2,4,6-trichlorophenol (2,4,6-TCP), 2,3,4,6-tetrachlorophenol (2,3,4,6-TeCP), pentachlorophenol (PCP), tetrachloroguaiacol (TeCG) and a compound tentatively identified as 3,4,5-trichloroguaiacol (3,4,5-TCG). Under high flow conditions, concentrations of the guaiacols were higher than any of the Chlorophenols and concentrations of all five chlorophenolics appeared to correlate. Under low flow conditions, concentrations of chloroguaiacols were higher than Chlorophenols at the upstream site and at the downstream site on the Main Arm, whereas at the downstream site on the North Arm, concentrations of 2,3,4,6-TeCP and PCP were higher than the chloroguaiacols in some samples. Overall, the results indicate that pulp mills upstream from the estuary are important sources of chlorophenolics to the estuary under all flow conditions. Additional episodic inputs of 2,3,4,6-TeCP and PCP from lumber mills occur along the North Arm. When these inputs occur, they can cause the concentrations of Chlorophenols in the North Arm to exceed provisional objectives. If chloroguaiacols are included as part of the objective, concentrations of total chlorophenolics in water entering the estuary can approach and exceed these objectives, especially under low flow conditions.


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