Algemeen

The Boreal Chorus Frog (Pseudacris maculata) was once common in the eastern Ottawa area. To assess its current status, we conducted auditory surveys at 184 wetlands in 2011 and 2012. Boreal Chorus Frogs were heard at only five (2.7%) of the surveyed sites. These five sites were spatially aggregated, with only 0.5–7.5 km between any two sites. Sites occupied by Boreal Chorus Frogs in eastern Ottawa were surrounded by significantly greater agricultural cover (at 1.0-, 1.5-, and 2.0-km radii), less forest cover (1.0- and 2.0-km radii), and less wetland cover (1.5- and 2.0-km radii) than occupied sites in western Ottawa. Sites in eastern Ottawa that were apparently unoccupied were surrounded by significantly greater agricultural cover (only at the 2.0-km radius), similar forest cover (all radii), and less wetland cover (all radii) compared with occupied sites in western Ottawa. Boreal Chorus Frog populations are commonly subject to extirpation resulting from stochastic events. The reduced wetland cover in eastern Ottawa may be accompanied by reduced wetland connectivity, making recolonization of wetlands difficult or impossible. Our data do not show whether wetland connectivity has been reduced, but future research should address this important topic.

Frogs and other amphibians are under pressure. Nearly one-third of the world’s amphibians are threatened or extinct, according to a report from the International Union for the Conservation of Nature (IUCN). The spread of a fungus called chytrid (Batrachochytrium dendrobatidis) has taken a toll, leading to the catastrophic decline or extinction of at least 200 species. The amphibian specialists at the IUCN put together a list of five frogs that face the greatest risk of extinction.

Concerns over the role of pesticides affecting vertebrate wildlife populations have recently focussed on systemic products which exert broad-spectrum toxicity. Given that the neonicotinoids have become the fastest-growing class of insecticides globally, we review here 150 studies of their direct (toxic) and indirect (e.g. food chain) effects on vertebrate wildlife—mammals, birds, fish, amphibians and reptiles. We focus on two neonicotinoids, imidacloprid and clothianidin, and a third insecticide, fipronil, which also acts in the same systemic manner. Imidacloprid and fipronil were found to be toxic to many birds and most fish, respectively. All three insecticides exert sub-lethal effects, ranging from genotoxic and cytotoxic effects, and impaired immune function, to reduced growth and reproductive success, often at concentrations well below those associated with mortality. Use of imidacloprid and clothianidin as seed treatments on some crops poses risks to small birds, and ingestion of even a few treated seeds could cause mortality or reproductive impairment to sensitive bird species. In contrast, environmental concentrations of imidacloprid and clothianidin appear to be at levels below those which will cause mortality to freshwater vertebrates, although sub-lethal effects may occur. Some recorded environmental concentrations of fipronil, however, may be sufficiently high to harm fish. Indirect effects are rarely considered in risk assessment processes and there is a paucity of data, despite the potential to exert population-level effects. Our research revealed two field case studies of indirect effects. In one, reductions in invertebrate prey from both
imidacloprid and fipronil uses led to impaired growth in a fish species, and in another, reductions in populations in two lizard species were linked to effects of fipronil on termite prey. Evidence presented here suggests that the systemic insecticides, neonicotinoids and fipronil, are capable of exerting direct and indirect effects on terrestrial and aquatic vertebrate wildlife, thus warranting further review of their environmental safety.

Given its fragile and unusually rich ecology, the Hawaiian island of Kauai seems ill-suited as a site for agricultural experiments that use heavy amounts of toxic chemicals. But four transnational corporations — BASF Plant Science, Dow AgroSciences, DuPont Pioneer, and Syngenta — have been doing just those kinds of experiments here for about two decades, extensively spraying pesticides on their GMO test fields. As a result, the landscape on the southwest corner of the island, around the town of Waimea, has become one of the most toxic chemical environments in all of American agriculture. This poses serious risks for the people of Kauai, as I’ve documented, but even less noticed are the hazards posed to the unique flora and fauna of the island and the coral reefs just off its shores. Each of the seven highly toxic pesticides most commonly used by the GMO giants on Kauai (alachlor, atrazine, chlorpyrifos, methomyl, metolachlor, paraquat, and permethrin) is known to be toxic to wildlife, plants, or both. The isolated geography of Kauai has fostered the evolution of a great diversity of birds, bugs, and plants. Kauai has more unique species — species that live only on the island — than anywhere else in the world, said Carl Berg, an ecologist and long-time advocate for clean water with the Kauai chapter of the Surfrider Foundation. Berg and others fear that these endemic species are being put at great risk of extinction by exposure to the chemicals, though he says he has no idea the extent of the damage. The U.S. Fish and Wildlife Service added 48 species that live only on Kauai to the endangered species list in 2010, including two different species of the Hawaiian honeycreeper, a small bird, and the large Hawaiian picture-wing fly. Also, several protected marine species rest or breed on the island’s beaches, including the highly endangered Hawaiian monk seal and the threatened green sea turtle. Occasionally, an endangered leatherback and hawksbill sea turtle will wander close in. A total of 17 different kinds of dolphins and whales frolic in the island’s harbors and bays.

Butterfly Conservation warns that Britain’s biodiversity is under threat following analysis of data from the National Moth Recording Scheme (NMRS), which has collated more than 16 million moth sightings dating back to 1769. The study by Butterfly Conservation, the Centre for Ecology and Hydrology and University of York, published in the Journal of Applied Ecology, is the first to examine long-term trends for all of Britain’s resident larger moth species; common and scarce, nocturnal and day-flying. Trends for 673 species were calculated, 60% of which showed a significant change over the 40-year period. Two thirds more species declined than increased. Moths are a key part of the food chain and act as pollinators for plants. The substantial declines revealed by this study provide further evidence of a wider utterfly Conservation warns that Britain’s biodiversity is under threat following analysis of data from the National Moth Recording Scheme (NMRS), which has collated more than 16 million moth sightings dating back to 1769.