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.
Neonicotinoid insecticides are based on the natural toxin nicotine, and are of particular concern because they bind virtually irreversibly to the nicotinic-acetylcholine receptors in the insect’s nervous system. Many observations show that the longer the exposure time, the less amount of total chemical is needed to kill the insects; in other words, the lethal exposure concentration decreases with exposure time.
The black-faced spoonbill (Platalea minor) has the most restricted distribution of all spoonbills, and it is the only one regarded as endangered. There remain only about 3,300 spoonbills, and the species spends the mating season on small islands along the west coast of the Korean Peninsula and in China’s Liaoning province, the WWF says. “With such a small global population, the black-faced spoonbill is inherently vulnerable to extinction,” it says.
The population of blue-footed boobies (Sula nebouxii) - the seabirds with characteristically colorful feet - has been declining in the Galápagos islands. The birds' numbers have dropped more than 50 percent in less than 20 years, according to a study published Monday (April 21) in the journal Avian Conservation and Ecology. The researchers speculated that a lack of sardines, a source of food for the boobies, might be to blame for the decline.
In September, the U.S. Fish and Wildlife Service denied a petition to put the Bicknell’s thrush (Catharus bicknelli) on the federal list of endangered species. The Bicknell’s is a medium-size (6-7.5 inches) thrush—brown on the back with a white, spotted underside—that dwells in dense balsam-fir forests in high elevations in the Adirondacks. Following is a primer on other wildlife in trouble in the Adirondack Park.
Bees and butterflies are experiencing widespread population decline, creating public concern in recent years. Data collected in Germany suggest that it’s not just bees and butterflies at risk: insect populations overall have plummeted by more than 75 percent since 1989. Scientists have known about the population decline for several years. However, they didn’t know how many species were declining, and they didn’t expect it to be happening so fast.
Steelhead anglers may have to start looking for another fish to catch. Four groups have released a joint statement sounding the alarm about the decline of steelhead numbers returning to B.C. rivers. The focal point of that concern is the Thompson River, a major tributary of the Fraser River. Where it once supported a thriving recreational steelhead fishery of 4,000 spawners in the mid-1980s, today the Thompson River has about 250 spawners projected for 2018.