During the latter half of the 20th century, it was noticed that global amphibian populations had entered a state of unusually rapid decline. Hundreds of species have since become categorized as “missing” or “lost,” a growing number of which are now believed extinct. Amphibians are often regarded as environmental indicator species because of their highly permeable skin and biphasic life cycles, during which most species inhabit aquatic zones as larvae and as adults become semi or wholly terrestrial. This means their overall health is closely tied to that of the landscape.
Imidacloprid (IMI) is the largest selling insecticide internationally. Little is known about the toxicokinetics of IMI in fish, however. In vivo time-course studies were conducted to study the distribution and elimination of IMI in rainbow trout. Animals confined to respirometer-metabolism chambers were injected with a low (47.6 ìg/kg), medium (117.5 ìg/kg) or high (232.7 ìg/kg) dose directly into the bloodstream and allowed to depurate.
Federal scientists have determined that a family of widely used pesticides poses a threat to dozens of endangered and threatened species, including Pacific salmon, Atlantic sturgeon and Puget Sound orcas. The National Marine Fisheries Service issued its new biological opinion on three organophosphate pesticides - chlorpyrifos, diazinon and malathion - after a yearslong court fight by environmental groups.
A 2015 study co-authored by Paul Ehrlich, professor emeritus of biology, and colleagues showed that Earth has entered an era of mass extinction unparalleled since the dinosaurs died out 66 million years ago. The specter of extinction hangs over about 41 percent of all amphibian species and 26 percent of all mammals, according to the International Union for Conservation of Nature (IUCN), which maintains a list of threatened and extinct species.
Mit rund 25'800 bedrohten Tier- und Pflanzenarten sei im zu Ende gehenden Jahr ein neuer dramatischer Höchststand erreicht worden. Ein Jahr zuvor waren es noch 24'000 bedrohte Arten. "Wir Menschen verursachen das grösste Artensterben seit Ende der Dinosaurier", resümierte Eberhard Brandes, Vorstand des WWF Deutschland. Auch in der Schweiz gingen die Bestände einiger Arten merklich zurück. Mehr als 40 Prozent der Insektenarten in der Schweiz gälten als bedroht, darunter Bienen und Schmetterlinge, sagte WWF-Sprecherin Perrette Rey in Lausanne auf Anfrage.
Rivers in England are contaminated with powerful insecticides, new testing has revealed, increasing concerns over the impact of the toxic chemicals on fish and birds. Eight rivers in England are heavily contaminated with neonicotinoid pesticides. Two of the rivers, the Waveney on the border between Norfolk and Suffolk, and the Tame in the West Midlands, had an “acute level” of pollution, according to tests conducted by the Environment Agency last year.
Ooit zwommen er zalmen in alle grote Europese rivieren, van de Seine tot de Maas en Rijn, maar tegenwoordig leven alleen in Ierland, Schotland, IJsland en Noorwegen nog gezonde populaties. Sinds 1990 zit er weer zalm in de Rijn, al is het vergeleken met vroeger nog mondjesmaat. Tot begin 2003 zijn er aanwijsbaar meer dan 1900 volwassen zalmen teruggekeerd in de Rijn en zijn zijrivieren. Omdat niet alle zalmen bij hun terugkeer geteld kunnen worden, zal het werkelijke aantal teruggekeerde zalmen duidelijk hoger liggen.
Salmon is a unique kind anadromous fish that are born in the fresh waters of rivers and streams. They swim to the ocean as they grow older and return to their home stream to lay eggs when the time comes for spawning. Every year, millions of salmon return to their home stream and produce their next generation of fish. Some species of salmon make several trips in their lifetime, while others make just one round trip before they die. Salmon are native to tributaries of the North Atlantic and Pacific Ocean.
A “CATASTROPHIC” failure of the salmon run in Argyll’s largest and most closely monitored river has prompted demands for the closure of some fish farms and a review of the expansion of the industry. This year’s run of salmon in the River Awe is by far the lowest since records began in 1964, according to figures released today. The annual salmon count for 2017 has been confirmed as 480, which compares with 807 in 2016 and a five-year average of 1400. The previous lowest total was 781 in 1998.
A recent assessment of higher tier studies on the toxicity and risks of neonics in honeybees by Solomon and Stephenson reported a colony-level NOAEC of 25 μg/kg (ppb) for imidacloprid and clothianidin. The toxicity of these insecticides to honeybees is however known to be reinforced with chronic exposure, and extrapolation of time-to lethal-effect toxicity plots compiled from published studies indicate that an imidacloprid level of 0.25 ppb, i.e. one-hundredth of the reported colony NOAEC, would kill a large proportion of bees nearing the end of their life.