Ecological Monitoring for Assessing the State of the Nearshore and Open Waters of the Great Lakes

The Great Lakes Water Quality Agreement stipulates that the Governments of Canada and the United States are responsible for restoring and maintaining the chemical, physical and biological integrity of the waters of the Great Lakes Basin Ecosystem. Due to varying mandates and areas of expertise, monitoring to assess progress towards this objective is conducted by a multitude of Canadian and U.S. federal and provincial/state agencies, in cooperation with academia and regional authorities. This paper highlights selected long-term monitoring programs and discusses a number of documented ecological changes that indicate the present state of the open and nearshore waters of the Great Lakes.     

Bestimmung von Tier- und Pflanzenarten auf einer Sonderabfalldeponie

Pr?ambel Ziel und Absicht  Zur Entwicklung eines Bewusstseins für die Artenvielfalt in unserer Umwelt hat die Zeitschrift GEO 1999 den ‚Tag der Artenvielfalt’ ausgerufen. Seitdem finden jedes Jahr europaweit Feldforschungsaktionen statt. Für Bayer Industry Services ist die Artenbestimmung auf der Sonderabfalldeponie in Bürrig eine Gelegenheit zu zeigen, dass sich Umweltschutz und fachgerechte Deponierung von Sonderabf?llen nicht widersprechen. Methoden  Die Teilnehmer am ‚Tag der Artenvielfalt’ bestimmen selbst, welches Gel:ande sie untersuchen wollen. Innerhalb eines Tages im Juli werden die dort vorkommenden Tier- und Pflanzenarten bestimmt und an GEO gemeldet. Ergebnisse und Schlussfolgerungen  Innerhalb eines Nachmittages wurden 47 Pflanzen-, 25 Vogel- und 7 weitere Tierarten bestimmt. Das Interesse der Teilnehmer an der Naturbeobachtung wurde durch die Aktion gef?rdert. Weitere Termine zur Bestimmung der Artenvielfalt wurden vereinbart. Empfehlung und Ausblick  Zur genauen Beobachtung eines definierten Naturraumes ist die Begehung zu unterschiedlichen Jahreszeiten sinnvoll. Bei Schulklassen müssen die Exkursionen mit dem Lehrplan abgestimmt werden.     

SOLIDS DISTRIBUTION IN LAKE CHAPALA,MEXICO1

ABSTRACT: Lake Chapala is the largest natural water body in Mexico and also one of the most important shallow lakes in Latin America. For the past several years it has suffered various environmental problems such as the upstream overuse of water, contamination, and sedimentation. For the past 10 years the lake has had less than 50 percent of its historical water level over the past century. No criteria are reported in the literature that establish a water storage volume that will guarantee water quality conditions necessary for the survival of the lake. After determining the behavior of total solids concentrations in relation to the variations in the lake's depth, we proposed a minimum water column height of 5.0 m, representing a storage volume of about 5,000 Mm³. This volume would result in the recommended water quality standards for total dissolved solids. Calculated distribution maps show that the total solids concentration in the lake has increased since the end of the 1970s. The solids are primarily concentrated in the eastern part of the lake, as a consequence of the high solids discharged from the Lerma River, its main tributary.     

Phylogeography of Australia’s king brown snake (Pseudechis australis) reveals Pliocene divergence and Pleistocene dispersal of a top predator

King brown snakes or mulga snakes (Pseudechis australis) are the largest and among the most dangerous and wide-ranging venomous snakes in Australia and New Guinea. They occur in diverse habitats, are important predators, and exhibit considerable morphological variation. We infer the relationships and historical biogeography of P. australis based on phylogenetic analysis of 1,249 base pairs from the mitochondrial cytochrome b, NADH dehydrogenase subunit 4 and three adjacent tRNA genes using Bayesian, maximum-likelihood, and maximum-parsimony methods. All methods reveal deep phylogenetic structure with four strongly supported clades comprising snakes from New Guinea (I), localities all over Australia (II), the Kimberleys of Western Australia (III), and north-central Australia (IV), suggesting a much more ancient radiation than previously believed. This conclusion is robust to different molecular clock estimations indicating divergence in Pliocene or Late Miocene, after landbridge dispersal to New Guinea had occurred. While members of clades I, III and IV are medium-sized, slender snakes, those of clade II attain large sizes and a robust build, rendering them top predators in their ecosystems. Genetic differentiation within clade II is low and haplotype distribution largely incongruent with geography or colour morphs, suggesting Pleistocene dispersal and recent ecomorph evolution. Significant haplotype diversity exists in clades III and IV, implying that clade IV comprises two species. Members of clade II are broadly sympatric with members of both northern Australian clades. Thus, our data support the recognition of at least five species from within P. australis (auct.) under various criteria. We discuss biogeographical, ecological and medical implications of our findings.Electronic Supplementary Material  Supplementary material is available in the online version of this article at     

Musterbildung bei Drosophila

Drosophila proved an excellent system to study molecular processes in establishing the body pattern of an embryo. Genes which are active during oogenesis provide localized cues which regulate a cascade of zygotic genes that determines the developmental fate of the blastoderm cells along the longitudinal axis of the embryo.     

Tracing the diet of the monitor lizard Varanus mabitang by stable isotope analyses (delta(15)N,delta(13)C)

In this study, we used analyses of stable isotopes of nitrogen ('¹⁵N) and carbon ('¹³C) to determine the trophic ecology of the monitor lizard Varanus mabitang. Stable isotopes from claws, gut contents, and soft tissues were measured from the type specimen. Samples from Varanus olivaceus, Varanus prasinus, Varanus salvator, the herbivorous agamid lizard Hydrosaurus pustulatus, and some plant matter were included for comparison. Our data show a rapid decrease in '¹³C (about10‰) from food plants towards gut contents and soft tissues of herbivorous species. For the varanids, we found a significant linear correlation of decreasing '¹³C and increasing '¹⁵N from herbivorous towards carnivorous species. In terms of trophic isotope ecology, the type specimen of V. mabitang is a strict herbivore. Thus it differs significantly in its isotopic composition from the morphologically next closest related species V. olivaceus. The most highly carnivorous species is V. salvator, while '¹⁵N values for V. prasinus and V. olivaceus are intermediate. Claws provide very valuable samples for such measurements, because they can be sampled from living animals without harm. Additionally, their range of variability is relatively small in comparison with measurements from soft tissues.