Study examined the effects of pesticides on fish near two Canadian golf courses
A new study indicates that some pesticides applied to golf courses in the Precambrian Shield of central Ontario may have an impact on aquatic organisms in adjacent watersheds. The study is published in the latest issue of Environmental Toxicology and Chemistry.
Golf courses affect the environment by altering the habitat through the release of nutrients and pesticides. The Precambrian Shield region of central Ontario, a major recreational area, is especially susceptible to the impacts of golf courses as a result of the geology and hydrology of the region. The Shield area is characterized by many lakes, rivers and streams. Golf courses in this area typically place turf on top of a sand base, which allows chemicals used on the courses to migrate into surrounding bodies of water.
The study set out to determine whether organic substances that are toxic to early life stages of fish are transported from golf courses in the Precambrian Shield and whether toxic compounds occur in watersheds of golf courses at times that coincide with the application of pesticides to golf courses and other conditions conducive to surface runoff.
To do so, two golf courses in the Muskoka region of central Ontario were monitored from May to November of 2002. Passive samplers (i.e., semipermeable membrane devices [SPMDs]) were deployed within the golf course watersheds at monthly intervals. After the SPMDs were retrieved, they were tested for toxicity using the Japanese medaka fish species.
A range of herbicides, insecticides and fungicides accumulated in the SPMDs, the researchers noted. Elevated toxicity occurred in the SPMDs that were deployed during periods of maximum fungicide application. Overall, no single compound or class of compounds in the SPMD extracts was wholly responsible for the observed toxicity to the early life stages of medaka.
The present study indicated that the compounds accumulated in the passive sampling devices were toxic to early life stages of the fish species. It cannot be stated definitively, however, that the contaminants discharged from the golf courses were a toxic hazard to other fish and aquatic organisms. Aquatic organisms’ sensitivity to toxins, stream flow and other factors affect the degree of hazard.
Several beneficial management practices can be employed to decrease the potential that pesticides can leach from golf courses into the surrounding aquatic environment—restraint in the use of pesticides being the key to reducing the impacts. Golf courses often require intensive applications of chemicals for turf maintenance, both because high-quality turf conditions are expected by the users and because the turf must withstand low mowing and heavy traffic. The researchers suggested that educating golfers to lower their cosmetic standards may be the best management strategy.