(Beyond Pesticides, July 11, 2012) Hundreds of dead fish have been found in Prince Edward Island, Canada, the second in two years, prompting concerns about the use of pesticides in the province’s agriculture industry, and the effectiveness of mitigation measures to reduce pesticide runoff. It is believed that pesticide runoff from nearby agricultural fields after heavy rains are to blame for the massive fish kill.
More than 2,000 fish have been scooped from the near two-mile stretch of Barclay Brook in Coleman since last Thursday following heavy rainfall, more than triple the amount of fish that washed up on the same shores of the brook last year, although the current discovery is concentrated in a smaller area. It is believed the actual number of dead fish is much higher, as predators and river currents would have quickly taken away the remains of other fish. Barclay Brook is part of the Trout River watershed, the scene of a devastating fish kill last July that mainly wiped out large fish. An investigation is underway to determine the exact cause of the fish kill, given that water temperature and oxygen levels were within acceptable ranges and the fish looked healthy and well-fed. As a result, officials believe that an acute toxic event was responsible for the kill. The provincial government is collecting fish, water and soil samples from the latest kill. They are also inspecting fields and conducting an aerial survey to try to pinpoint a possible source.
Local environmental leaders say legislation that requires a 15-meter buffer zone between waterways and farm fields is not working. They believe pesticides should be eliminated from the province’s agriculture industry altogether, as pesticide runoff has historically been a major cause of fish kills.
“There’s a lot of support in Prince Edward Island for a 100 per cent organic province,” said Provincial Green party Leader Sharon Labchuk. “There’s a very strong sense in Prince Edward Island that the root cause of all this is industrial agriculture and that there are no ways that these kind of effects can be mitigated through ”¦ (a piece) of new legislation.”
In July 2007, investigators suggested that pesticides from farmers’ fields had killed thousands of fish that were found floating in the Dunk and Tryon Rivers in western Prince Edward Island. Two farmers in that area were charged with violating buffer zone regulations. That fish kill prompted the provincial government to draft changes to regulations that she hopes will be introduced in the legislature this fall.
Agricultural runoff into streams and other aquatic habitat is not a rare occurrence. Runoff can impact aquatic life, especially sensitive and endangered species. Sizeable fish kills have resulted from pesticide use, and have often made sensational news headlines, including the 1991 death of over one million fish in Louisiana after aerial spraying of the insecticide azinphos-methyl (Guthion) on sugarcane fields. In 1995, toxic concentrations of endosulfan and methyl parathion along a 16-mile stretch of the Tennessee River in Alabama resulted in 240,000 fish killed. In 2005, an estimated 100,000 to 300,000 black crappie fish died suddenly in Clear Lake in Waseca County, Minnesota. Water samples show the presence of permethrin, the pesticide that had been used two days prior for mosquito control. The pesticide apparently contaminated the lake as runoff from a subsequent rainstorm.
Pesticide regulation in the U.S. under the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA) does not go far enough to protect aquatic environments from pesticide contamination, as a result of the prevalence of data gaps in the scientific knowledge of many of the registered pesticides, and a general lack of compliance with pesticide labels. The National Marine Fisheries Service (NMFS) has notified the U.S. Environmental Protection Agency (EPA) that current use patterns for certain pesticides are “likely to jeopardize the continued existence” of endangered salmon and steelhead populations on the West Coast protected by the Endangered Species Act. NMFS calls for use restrictions in several draft Biological Opinions that would prohibit aerial applications of the pesticides within 300 feet of salmon waters; mandate a 10-foot vegetated strip or a 20-foot no spray zone between salmon waters and places where these herbicides are applied; and establish mandatory reporting of fish kills near where these chemicals are applied.
NMFS’ findings contradict significant conclusions of EPA’s work and highlight weaknesses in the agency’s current ecological risk assessment process that underestimate risk and fail to meet modern standards of analysis. For example, NMFS cites EPA’s failures to provide any analysis of the pesticides’ breakdown products or of the other ingredients -whether active or inert, which are added to commercial product formulations. Additionally, NMFS states that EPA’s modeling procedures would likely underestimate exposure to the pesticides and the resulting risk and that the EPA-approved pesticide labels lack sufficient information to prevent excessive and unnecessary applications.
In November 2011, a federal judge dismissed a lawsuit brought by Dow AgroSciences that challenged EPA’s authority to implement new use restrictions based on the NMFS Biological Opinions. Due to the delay resulting from that lawsuit, none of the use restrictions designed to protect threatened and endangered species from the pesticides deemed to pose the greatest risk, including chlorpyrifos, diazinon and malathion, have been implemented.
The recently implemented National Pollutant Discharge Elimination System (NPDES) permit program for pesticide discharges, while it does not prevent pesticides from being discharged into waterways, would help authorities know what is sprayed and when it is sprayed, so that the public may know what chemicals are used in their waterways which can then be monitored for any downstream adverse effects, including fish kills and the contamination of drinking waters. For more information on the pesticide NPDES permit, read, “Clearing up the Confusion Surrounding the New NPDES General Permit.” Currently, pesticide labels typically provide the user with direction to avoid runoff to nearby aquatic streams, however these measures have been proven to be ineffective.
Source: The Chronicle Herald Canada
Photo Courtesy CBC News
All unattributed positions and opinions in this piece are those of Beyond Pesticides.