General

EFSA external report on toxicity of pesticides to aquatic and terrestrial life stages of amphibians

The aim of this study was to provide EFSA with information relating to assessment of the risk to amphibians posed by pesticide exposure. In the first part of the study the European amphibian species associated with agricultural habitats were identified with the aim of collating information for representative species such as body size and life-cycle. Also collated were the results of studies of amphibians in European agricultural habitats to provide information on activity in areas where they may be at risk of exposure to pesticides.

Atrazine acts as an immune disruptor at the same effective doses that it disrupts the endocrine system

Atrazine, the most widely used herbicide in the United States, has been shown in several studies to be an endocrine disruptor in adult frogs. Results from this study indicate that atrazine also functions as an immune disruptor in frogs. Exposure to atrazine (21 ppb for 8 d) affects the innate immune response of adult Rana pipiens in similar ways to acid exposure (pH 5.5), as we have previously shown. Atrazine exposure suppressed the thioglycollate-stimulated recruitment of white blood cells to the peritoneal cavity to background (Ringer exposed) levels and also decreased the phagocytic activity of these cells. Unlike acid exposure, atrazine exposure did not cause mortality. Our results, from a dose–response study, indicate that atrazine acts as an immune disruptor at the same effective doses that it disrupts the endocrine system.

Exposure to pesticides can cause suppressive immune changes in adult frogs and is doing so in wild populations

An injection study and a field study were used to investigate the hypothesis that environmental xenobiotics have the potential to alter the immune function of northern leopard frogs (Rana pipiens). Three assays, IgM-specific antibody response to keyhole limpet hemocyanin linked to dinitrophenyl (KLH-DNP), zymozan induced chemiluminescence (CL) of whole blood and the delayed-type hypersensitivity (DTH), were used to assay humoral, innate and cell-mediated immune endpoints. Sublethal doses of DDT (923 ng/g wet wt), malathion (990 ng/g wet wt), and dieldrin (50 ng/g wet wt) were used in the injection study. In all pesticide-injected groups, antibody response was dramatically suppressed, DTH reactions were enhanced, and respiratory burst was lower. When the order of administration of pesticides and antigens was reversed, no differences in immune function between the control and dosed groups were apparent, indicating that frogs exposed to pathogens prior to pesticide exposure can still respond. A field study found significant differences in immune function between frog populations in pesticide-exposed and pesticide-free locations. The antibody response and CL were suppressed and the DTH enhanced in frogs from Essex County (ON, Canada).
Overall, the results suggest that exposure to these pesticides can cause both stimulatory and suppressive immune changes in adult frogs and is doing so in wild populations.

Immune functions of toads from pesticide-contaminated sites of Bermuda are significantly altered, which may contribute to the decline in their population

Recently, a decrease in the populations of marine toads (Bufo marinus) and whistling frogs (Eleutherodactylus johnstonei and E. gossei) has been noted on the island of Bermuda. In the current study, we investigated whether this decline was related to altered immune functions. During August 1998, a significant proportion (25%) of the toads exhibited deformities. Analysis of soil samples revealed presence of chlorinated pesticides and polychlorinated biphenyls (PCBs). Spleen cells from toads collected from more polluted areas of Bermuda exhibited a decrease in B-cell proliferative response to lipopolysaccharide when compared to the responsiveness of B cells from toads collected from less polluted areas. In contrast, the T-cell responsiveness to mitogens in these two groups was not significantly altered. Histological examination of major parenchymatous organs in marine toads and whistling frogs showed alterations in hepatic and splenic morphology, indicative of exposure to toxicants. Together, the current study suggests that the immune functions of toads from contaminated sites of Bermuda are significantly altered, which may contribute to the decline in their population.

Het uitsterven van amfibieën is de meest ernstige uitstervingsgolf die momenteel plaatsvindt

Amfibieën verdwijnen nog sneller en worden nog meer bedreigd dan zowel vogels en zoogdieren. De IUCN Rode Lijst van Bedreigde Soorten laat zien dat tenminste 1900 van de 6638 tot 6686 bekende soorten amfibieën op deze planeet met uitsterven worden bedreigd. In 2008 stonden 120 soorten amfibieën als 'Ernstig Bedreigd (Mogelijk Uitgestorven)' op de IUCN Rode Lijst en de meeste van de vermiste soorten zijn waarschijnlijk verdwenen sinds 1980. De voornaamste oorzaak van deze snelle achteruitgang is zeer waarschijnlijk chytridiomycose, een besmettelijke schimmelziekte bij amfibieën, veroorzaakt door de schimmel Batrachochytrium dendrobatidis. Steeds meer wetenschappers verdenken bestrijdingsmiddelen er van de eigenlijke veroorzaker van deze epidemieën te zijn. Vermoed wordt dat blootstelling aan lage concentraties van bestrijdingsmiddelen een aantasting van het immuunsysteem veroorzaakt waardoor de gevoeligheid voor ziekteverwekkers toeneemt.

Vuursalamander met uitsterven bedreigd

Het gaat niet goed met de vuursalamander (Salamandra salamandra), één van de grootste Europese amfibieën met een onmiskenbaar kleurpatroon; een zwarte kleur met gele vlekken en strepen. Hij wordt zelfs met uitsterven bedreigd. Dat is ernstig, want het is een van de in totaal maar zestien soorten amfibieën in Nederland. De vuursalamander komt voor in Zuid-Limburg. Een paar jaar terug werden er nog honderden gespot, nu zijn het er nog maar een paar. De vuursalamander laat op basis van de monitoringsdata in de periode 1997-2011 een sterke afname zien. De jaarlijkse achteruitgang is gemiddeld 9%. Over de hele periode is er sprake van een achteruitgang van 75%. Hoewel er over de hele periode sprake is van variatie in het waargenomen aantal dieren, is het aantal vuursalamanders in 2011 opvallend laag. Een bekende oorzaak voor de achteruitgang en het uitsterven van amfibieën wereldwijd is chytridiomycose.

Immune suppression by neonicotinoid insecticides at the root of global wildlife declines

Outbreaks of infectious diseases in honey bees, fish, amphibians, bats and birds in the past two decades have coincided with the increasing use of systemic insecticides, notably the neonicotinoids and fipronil. A link between insecticides and such diseases is hypothesised. Firstly, the disease outbreaks started in countries and regions where systemic insecticides were used for the first time, and later they spread to other countries. Secondly, recent evidence of immune suppression in bees and fish caused by neonicotinoids has provided an important clue to understand the sub-lethal impact of these insecticides not only on these organisms, but probably on other wildlife affected by emerging infectious diseases. While this is occurring, environmental authorities in developed countries ignore the calls of apiarists (who are most affected) and do not target neonicotinoids in their regular monitoring schedules. Equally, scientists looking for answers to the problem are unaware of the new threat that systemic insecticides have introduced in terrestrial and aquatic ecosystems.

Staggering Biodiversity Loss in the Garden of England During the 20th Century

Kent is one the UK’s most wildlife-rich counties, a result of its varied geology, long coastline, landscape history, southerly location and proximity to mainland Europe. Its important wildlife habitats include estuaries, chalk cliffs, woodlands, and chalk downland, and encompass some of the South East’s most iconic landscapes, such as the shingle headland of Dungeness and the White Cliffs of Dover. Kent lost eight species of butterfly during the last 100 years, and at least three further species now only survive as very localised populations. Kent’s moth fauna has undergone substantial change, with species being lost and gained, but the number of species lost far outweighs the number gained. During the 20th century, Kent lost one of its five reptile species, and one of its six amphibians. Thirty-seven regularly occurring bird species have decreased or been lost entirely to Kent. The Greater and Lesser Horseshoe bats became extinct in Kent during the 20th Century. Between 1900 and 2010, more than 30 wild plants were lost from Kent.

Unerwarteter Weltuntergang - Ohne Insekten würde die Welt ins Chaos stürzen

Und wenn es plötzlich keine Insekten mehr gäbe? Die Entomologen stellen sich die Frage immer wieder, und wenn auch die Prognosen variieren, so herrscht in einem Punkt Einigkeit: Das menschliche Leben, wie wir es kennen, würde wahrscheinlich enden. Der namhafte Entomologe Edward O. Wilson, ausgezeichnet mit zwei Pulitzerpreisen und der National Medal of Science, gibt den Menschen nach dem hypothetischen Aussterben aller Wirbellosen (von denen Insekten die Mehrzahl stellen) noch zehn Jahre. Der Science-fiction-Autor Charles Pellegrino dagegen, der in seinem Roman «Dust» die katastrophalen Folgen eines globalen, programmierten Aussterbens aller Insekten beschreibt, lässt es weniger als sechs Monate dauern, bis die Menschheit auf eine Hand voll bedauernswerte, in alle Welt zerstreute Überlebende geschrumpft ist.

Onrustwekkende achteruitgang van flora en fauna in Europa

Het natuurlijke erfgoed van Europa laat, volgens nieuw onderzoek, een zorgwekkende daling zien. Met de Europese rode lijst, onderdeel van de rode lijst van bedreigde diersoorten™ van de internationale natuurbeschermingsunie IUCN, wordt de toestand van een aanzienlijk deel van de inheemse flora en fauna van de EU beoordeeld. Uit de beoordeling van ongeveer 6000 soorten blijkt dat 44% van alle zoetwaterweekdieren, 37% van de zoetwatervissen, 23% van de amfibieën, 20% van bepaalde groepen van landweekdieren, 19% van de reptielen, 15% van de zoogdieren en libellen, 13% van de vogels, 11% van bepaalde groepen van houtkevers, 9% van de vlinders en 467 soorten vaatplanten nu worden bedreigd.