scholarly journals Recovery of acidified Sudbury, Ontario, Canada, lakes: a multi-decade synthesis and update

2019 ◽  
Vol 27 (1) ◽  
pp. 1-16 ◽  
Author(s):  
W. (Bill) Keller ◽  
Jocelyne Heneberry ◽  
Brie A. Edwards
Keyword(s):  
Aquatic Ecosystems ◽  
Large Scale ◽  
Dispersal Ability ◽  
Chemical Recovery ◽  
Biological Recovery ◽  
Lake Recovery ◽  
Multiple Stressor ◽  
Complicated Process ◽  
Limited Dispersal ◽  
Brighter Future

The Sudbury region of northeastern Ontario, Canada, provides one of the world’s best examples of the resilience of aquatic ecosystems after reductions in atmospheric contaminant deposition. Thousands of lakes around the Sudbury metal smelters were badly damaged by acid deposition. Lakes closest to the smelters were also contaminated by metal particulates. However, large reductions in atmospheric SO2 and metal emissions starting in the early 1970s have led to widespread chemical improvements in these lakes, and recovery has been observed for various aquatic biota. Studies of Sudbury-area lakes are advancing our understanding of chemical and biological lake recovery; however, recovery is a complicated process and much remains to be learned. Biological recovery has often been slow to follow chemical recovery, and it has become apparent that the recovery of lakes from acidification is closely linked to interactions with other large-scale environmental stressors like climate change and Ca declines. Thus, in our multiple-stressor world, recovery may not bring individual lakes back to their exact former state. However, with time, substantial natural biological recovery toward typical lake communities can be reasonably expected for most but not necessarily all biota. For organisms with limited dispersal ability, particularly fish, human assistance may be necessary to re-establish typical communities. In lakes where food webs have been severely altered, re-establishment of typical diverse fish communities may in fact be an important element aiding the recovery of other important components of aquatic ecosystems including zooplankton and benthic macroinvertebrates. In the lakes closest to the smelters, where historically watersheds as well as lakes were severely damaged, the recovery of aquatic systems will be closely linked to ongoing terrestrial recovery and rehabilitation, particularly through the benefits of increased inputs of terrestrially derived organic matter. The dramatic lake recovery observed in the Sudbury area points to a brighter future for these lakes. However, continued monitoring will be needed to determine future changes and help guide the management and protection of Sudbury-area lakes in this multiple-stressor age.

Limnology in northeastern Ontario: from acidification to multiple stressorsThis Perspective is based on the author’s F.H. Rigler Lecture delivered at the annual meeting of the Society of Canadian Limnologists in Halifax, Nova Scotia, January 2008.

2009 ◽  
Vol 66 (7) ◽  
pp. 1189-1198 ◽  
Author(s):  
W. (Bill) Keller
Keyword(s):  
Climate Change ◽  
Acid Deposition ◽  
Large Scale ◽  
Environmental Science ◽  
Environmental Stressors ◽  
Lake Recovery ◽  
Recovery Processes ◽  
Multiple Stressor ◽  
Future Outcomes ◽  
Sulphur Emission

Thousands of lakes around Sudbury, in northeastern Ontario, Canada, were badly damaged by acid deposition and many were also metal-contaminated. Large reductions in atmospheric sulphur and metal emissions have led to widespread chemical improvements in these lakes, and recovery has been documented for various biota. These findings were very important in establishing the necessity and value of sulphur emission controls during the international debates about the effects of acid deposition and the need for cleaner air. Studies of northeastern Ontario lakes are continuing to advance our understanding of chemical and biological recovery processes; however, that knowledge is still incomplete. It has become apparent that the recovery of lakes from acidification is closely linked with the responses to, and interactions with, other large-scale environmental stressors like climate change and calcium declines. Developing a better understanding of lake recovery processes and their future outcomes within such a multiple stressor context will be difficult. It will demand the merging of various approaches, including monitoring, experimentation, paleolimnology, and modelling, and will require effective collaboration among different research and monitoring sites and various agencies and institutions engaged in environmental science.

Crustacean zooplankton communities in lakes recovering from acidification

2002 ◽  
Vol 59 (4) ◽  
pp. 726-735 ◽  
Author(s):  
W Keller ◽  
N D Yan ◽  
K M Somers ◽  
J H Heneberry
Keyword(s):  
Large Scale ◽  
Zooplankton Community ◽  
Crustacean Zooplankton ◽  
Chemical Recovery ◽  
Species Dispersal ◽  
Aquatic Communities ◽  
Biological Recovery ◽  
Community Recovery ◽  
Zooplankton Communities ◽  
Reference Lakes

Large reductions in sulphur emissions at the Sudbury, Ont., Canada, smelters in recent decades have resulted in decreased lake acidity, and biological improvements have followed. Lakes in the Sudbury area offer a very unique opportunity to develop our understanding of the processes regulating biological restructuring in aquatic ecosystems recovering from acidification. Here, we examine changes in crustacean zooplankton communities that have accompanied the chemical recovery of Whitepine and Sans Chambre lakes, near Sudbury, over the last two decades. In both these formerly acidic lakes, pH has increased to ~6.0, and some zooplankton community recovery has occurred. However, zooplankton communities have not completely recovered based on multivariate comparisons with the community composition of reference lakes. Although a number of acid-sensitive species have appeared, many did not persist, or did not achieve abundances typical of the reference lakes. This indicates that zooplankton community recovery will most likely depend on biotic and abiotic interactions within these lakes and not on factors affecting species dispersal. Both chemical and biological factors have large influences on biological recovery processes. Assessing biological recovery is very important since the restoration of healthy aquatic communities is a major objective of large-scale sulphur emission control programs.

scholarly journals Relicts from Glacial Times: The Ground Beetle Pterostichus adstrictus Eschscholtz, 1823 (Coleoptera: Carabidae) in the Austrian Alps

Insects ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 84
Author(s):  
Wolfgang Paill ◽  
Stephan Koblmüller ◽  
Thomas Friess ◽  
Barbara-Amina Gereben-Krenn ◽  
Christian Mairhuber ◽  
...  
Keyword(s):  
Ground Beetle ◽  
Distribution Patterns ◽  
Morphological Characters ◽  
Molecular Data ◽  
Ice Age ◽  
Dispersal Ability ◽  
Austrian Alps ◽  
Alpine Regions ◽  
Extant Species ◽  
Limited Dispersal

The last ice age considerably influenced distribution patterns of extant species of plants and animals, with some of them now inhabiting disjunct areas in the subarctic/arctic and alpine regions. This arctic-alpine distribution is characteristic for many cold-adapted species with a limited dispersal ability and can be found in many invertebrate taxa, including ground beetles. The ground beetle Pterostichus adstrictus Eschscholtz, 1823 of the subgenus Bothriopterus was previously known to have a holarctic-circumpolar distribution, in Europe reaching its southern borders in Wales and southern Scandinavia. Here, we report the first findings of this species from the Austrian Ötztal Alps, representing also the southernmost edge of its currently known distribution, confirmed by the comparison of morphological characters to other Bothriopterus species and DNA barcoding data. Molecular data revealed a separation of the Austrian and Finish specimens with limited to no gene flow at all. Furthermore, we present the first data on habitat preference and seasonality of P. adstrictus in the Austrian Alps.

Colonization of depopulated crinoids by symbionts: who comes from the bottom and who from the water column?

2015 ◽  
Vol 95 (8) ◽  
pp. 1607-1612 ◽  
Author(s):  
E.S. Mekhova ◽  
P.Y. Dgebuadze ◽  
V.N. Mikheev ◽  
T.A. Britayev
Keyword(s):  
Water Column ◽  
Field Experiments ◽  
Dispersal Ability ◽  
Long Distance ◽  
Sandy Substrate ◽  
Limited Dispersal ◽  
Set Up ◽  
Almost All ◽  
High Degree

Previous experiments with the comatulid Himerometra robustipinna (Carpenter, 1881) demonstrated intensive host-to-host migration processes for almost all symbiotic species both within host aggregations and among hosts separated by several metres. The aim of this study was to check the ability of symbionts to complete long-distance migrations, by means of two in situ experiments which depopulated the crinoid host. Two different sets of field experiments were set up: exposure of depopulated crinoids (set 1) on stony ‘islands’ isolated from native crinoid assemblages by sandy substrate, and (set 2) in cages suspended in the water column. Hosts from set 1 were exposed for 1, 2, 3 and 4 weeks to assess whether substrate has an influence on the symbionts' long-distance migrations. In set 2 cages were exposed for 10–11 days, aiming to check whether symbionts were able to disperse through the water column with currents. These experiments allow the conclusion that post-settled symbionts can actively migrate among their hosts. Symbionts are able to reach their hosts by employing two different ‘transport corridors’, by drifting or swimming in water column, and by moving on the bottom. Comparison of experimental results allows the division of symbionts into two conventional groups according to the dispersal ability of their post-settled stages: (1) species able to complete long-distance migrations, (2) species unable to migrate or having limited dispersal ability. The finding of the free-living shrimp Periclimenes diversipes Kemp, 1922 in set 2 raises the question about the factors that affect such a high degree of specialization of crinoid assemblages.

scholarly journals Northern Apennines as centre of speciation: a new Verdanus species group (Hemiptera, Cicadomorpha, Cicadellidae) from Italy and its phylogenetic relationships with V. bensoni and the V. limbatellus group

Zootaxa ◽  
2009 ◽  
Vol 2264 (1) ◽  
pp. 1-22 ◽  
Author(s):  
ADALGISA GUGLIELMINO ◽  
CHRISTOPH BÜCKLE
Keyword(s):  
New Taxa ◽  
Phylogenetic Relationships ◽  
Cladistic Analysis ◽  
Morphological Characters ◽  
Species Group ◽  
Northern Apennines ◽  
Dispersal Ability ◽  
Group V ◽  
Central Eurasia ◽  
Limited Dispersal

A small sector of Northern Apennines the Tuscan-Emilian Apennines constitutes an interesting diversity centre of a new Verdanus species group closely related to V. bensoni and the V. limbatellus group. It consists of three species: V. tyrannus sp. nov., V. saurosus sp. nov. and V. rosaurus sp. nov., the latter with two subspecies, V. rosaurus rosaurus ssp. nov. and V. rosaurus rex ssp. nov., which doubtless form a monophyletic group (V. rosaurus group). Data on their distribution, ecology and life cycle are added to their original descriptions. The new taxa live allopatrically in a very restricted area and thus occupy a distribution gap of another species group of Verdanus, the V. abdominalis group, present in Italy in the mountain regions of the Alps and Central and Southern Apennines. A hypothesis of the origin of the new taxa is presented based on the ecological conditions in the Tuscan-Emilian Apennines during the last Postglacial period and on the limited dispersal ability of these normally brachypterous insects. Possible synapomorphic characters and phylogenetic relationships of the new taxa with each other and with V. bensoni (China) and the V. limbatellus group (V. limbatellus (Zetterstedt), V. kyrilli (Emeljanov), V. sichotanus (Anufriev), V. kaszabi (Dlabola)) are discussed and a cladistic analysis is conducted. Comparing V. bensoni and the V. limbatellus group on the one hand and the V. rosaurus group on the other, some morphological characters appear to change often in parallel on the same paths, independently from the phylogenetic hypothesis. Remarkably, within the same morphological characters the range of variation among species inhabiting the comparatively minute area of the Tuscan-Emilian Apennines is similar to that found among other taxa distributed across vast areas of northern and central Eurasia.

scholarly journals An evaluation of the accuracy and speed of metagenome analysis tools

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Stinus Lindgreen ◽  
Karen L. Adair ◽  
Paul P. Gardner
Keyword(s):  
Aquatic Ecosystems ◽  
Large Scale ◽  
High Throughput Sequencing ◽  
Data Sets ◽  
Metagenome Analysis ◽  
Analysis Tools ◽  
Sequencing Platforms ◽  
Capacity Data ◽  
High Degree ◽  
Realistic Data

Abstract Metagenome studies are becoming increasingly widespread, yielding important insights into microbial communities covering diverse environments from terrestrial and aquatic ecosystems to human skin and gut. With the advent of high-throughput sequencing platforms, the use of large scale shotgun sequencing approaches is now commonplace. However, a thorough independent benchmark comparing state-of-the-art metagenome analysis tools is lacking. Here, we present a benchmark where the most widely used tools are tested on complex, realistic data sets. Our results clearly show that the most widely used tools are not necessarily the most accurate, that the most accurate tool is not necessarily the most time consuming and that there is a high degree of variability between available tools. These findings are important as the conclusions of any metagenomics study are affected by errors in the predicted community composition and functional capacity. Data sets and results are freely available from http://www.ucbioinformatics.org/metabenchmark.html

scholarly journals The dilemma of controlling cultural eutrophication of lakes

2012 ◽  
Vol 279 (1746) ◽  
pp. 4322-4333 ◽  
Author(s):  
David W. Schindler
Keyword(s):  
Large Scale ◽  
Ecosystem Processes ◽  
Nutrient Fluxes ◽  
Nutrient Cycles ◽  
Case Histories ◽  
Short Term ◽  
Ecosystem Responses ◽  
Lake Recovery ◽  
Recent Claim

The management of eutrophication has been impeded by reliance on short-term experimental additions of nutrients to bottles and mesocosms. These measures of proximate nutrient limitation fail to account for the gradual changes in biogeochemical nutrient cycles and nutrient fluxes from sediments, and succession of communities that are important components of whole-ecosystem responses. Erroneous assumptions about ecosystem processes and lack of accounting for hysteresis during lake recovery have further confused management of eutrophication. I conclude that long-term, whole-ecosystem experiments and case histories of lake recovery provide the only reliable evidence for policies to reduce eutrophication. The only method that has had proven success in reducing the eutrophication of lakes is reducing input of phosphorus. There are no case histories or long-term ecosystem-scale experiments to support recent claims that to reduce eutrophication of lakes, nitrogen must be controlled instead of or in addition to phosphorus. Before expensive policies to reduce nitrogen input are implemented, they require ecosystem-scale verification. The recent claim that the ‘phosphorus paradigm’ for recovering lakes from eutrophication has been ‘eroded’ has no basis. Instead, the case for phosphorus control has been strengthened by numerous case histories and large-scale experiments spanning several decades.

scholarly journals Shell development, growth and sexual dimorphism in the Recent thecideide brachiopod Thecidellina meyeri sp. nov. from the Lesser Antilles, Caribbean

2009 ◽  
Vol 89 (3) ◽  
pp. 469-479 ◽  
Author(s):  
Jana Hoffmann ◽  
Carsten Lüter
Keyword(s):  
Morphological Characters ◽  
Lesser Antilles ◽  
Caribbean Region ◽  
Dispersal Ability ◽  
High Species Diversity ◽  
Limited Dispersal ◽  
Complete Series ◽  
The Caribbean ◽  
Insight Into ◽  
Material Study

A new thecideide brachiopod species, Thecidellina meyeri, is described from the southern Lesser Antilles (Aruba, Bonaire, Curaçao), Caribbean Sea, with unique morphological characters which clearly separate it from all other described species of Thecidellina in the region. A virtually complete series of ontogenetic stages is recorded, providing insight into the plasticity of shell development during growth in thecideide brachiopods and offering a well-defined standard for comparison with fossil material. Study of the soft tissue suggests that T. meyeri is dioecious, which contradicts the idea of Thecidellina to be hermaphroditic. The limited distribution and the unexpectedly high species diversity within the genus Thecidellina in the Caribbean region support the idea of allopatric speciation due to limited dispersal ability.

scholarly journals Validation of Quantitative and Digital Polymerase Chain Reaction Assays Targeting the Mating Types of Phyllosticta citricarpa, the Causal Agent of Citrus Black Spot

2021 ◽  
Author(s):  
Hector Urbina ◽  
Taylor Smith ◽  
Callie Jones ◽  
Xiaoan Sun ◽  
John McVay ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Mating Type ◽  
Citrus Fruit ◽  
Black Spot ◽  
Dispersal Ability ◽  
Mating Types ◽  
Chain Reaction ◽  
Citrus Black Spot ◽  
Limited Dispersal ◽  
Polymerase Chain

Citrus black spot (CBS) is a disease caused by the ascomycetous fungus Phyllosticta (formerly Guignardia) citricarpa (Botryosphaeriales, Pezizomycotina) currently present in citrus groves in five counties in southwest Florida. Within Florida, P. citricarpa shows limited reproduction via asexual sporulation due to the presence of only one (MAT1-2-1) of the two required mating types for sexual reproduction. Here we present two novel polymerase chain reaction (PCR) assays standardized in quantitative (qPCR) and digital (dPCR) platforms to distinguish both mating types (MAT1-1-1 and MAT1-2-1) of P. citricarpa, to monitor for the potential introduction of the MAT1-1-1 mating type into Florida and a novel protocol for DNA extraction from asymptomatic leaves. During citrus harvesting season 2018−2019, fruit lesions, as well as asymptomatic leaves adjacent to symptomatic fruit and asymptomatic trees in CBS-infected groves were surveyed for P. citricarpa presence and mating types. Results support the presence of only MAT1‑2-1 mating type in Florida, after surveying more than 1,145 citrus fruit lesions. We also confirmed the limited dispersal ability of the asexual state of P. citricarpa in Florida in ten groves using the enhanced capabilities of the dPCR platform in the detection of P. citricarpa directly from asymptomatic leaves with low pathogen inoculum.

scholarly journals Genetic diversity in the Alpine flatworm <i>Crenobia alpina</i>

Web Ecology ◽  
2017 ◽  
Vol 17 (2) ◽  
pp. 29-35 ◽  
Author(s):  
Martin Brändle ◽  
Jan Sauer ◽  
Lars Opgenoorth ◽  
Roland Brandl
Keyword(s):  
18S Rrna ◽  
Phylogenetic Analyses ◽  
Rrna Genes ◽  
Dispersal Ability ◽  
European Alps ◽  
Habitat Specificity ◽  
Limited Dispersal ◽  
The Alps ◽  
18S Rrna Genes ◽  
Species Speciation

Abstract. The freshwater flatworm Crenobia alpina (Platyhelminthes, Tricladida, Planariidae) lives almost exclusively in cold springs and crenal streams and possesses only limited dispersal ability. In this study fragments of the COI and 18S rRNA genes were used to estimate genetic divergences among 37 C. alpina populations from the European Alps. Phylogenetic analyses revealed five geographically and genetically distinct groups and at least 10 distinct lineages of C. alpina across the European Alps. Our study suggests that C. alpina represents a complex of numerous cryptic species. Speciation (allopatric and/or sympatric) may have been facilitated by the orogenetic activity of the Alps and the high habitat specificity.

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