No abstract

Cultivated mucklands (Histosols) in western New York State were investigated as a nonpoint source of P to Lake Ontario. The 70 500‐ha Oak Orchard Creek watershed, which contains 3250 ha of heavily fertilized muck cropland, was monitored at several sites for a year in order to construct a P budget for the system and determine the mucklands' relative contribution. Runoff during the late winter‐early spring period appears to be the most important hydrologic factor in governing annual phosphorus loading from the mucklands, greater than either total precipitation or total runoff for the year. Surplus P leached from muckland soils and delivered to the creek in subsurface runoff accounts for the large dissolved P load measured in the creek at the study site draining the muck cropland. At this stream monitoring location, the mucklands represented only 27% of the drainage area, but were estimated to contribute between 55 and 86% of the annual dissolved reactive P (DRP) load. The load from Oak Orchard Creek to Lake Ontario for the study period was 37 000 kg of total P (TP), 20 000 kg of which was DRP. Half of the P load was delivered to Lake Ontario in 3 months—March, April, and May—when rain and snowmelt produced significant runoff and high creek flows. A mass balance calculation suggests that as much as 72% of the DRP load and 39% of the TP load entering Lake Ontario from Oak Orchard Creek could be attributed to P losses from the cultivated mucklands located 65 km upstream.

No abstract

A 2-year investigation of fish and waterfowl populations was conducted on St. Lawrence River marshes that had been polluted with No. 6 industrial fuel on June 23, 1976. The heavy oil, which penetrated as much as 5 meters into the dense cattail stands, was removed along with the oiled vegetation. This was a zone of intense animal activity and mortality was great during the first few weeks. Marshes having different levels of oiling were selected for study along with a control area because prior baseline data were not available. The results suggested but could not prove that there was some long-range effects of the oil on these marsh communities. An example is the possible loss of eggs and larval fish for some species. However, the effects of the oil generally were masked by the effects of natural factors, and therefore difficult to identify or quantify. Variables such as water leve, time of year, water temperatures, type of oil, physical arrangement of the marshes, and the cleanup process each had an important role in the overall impact. The study demonstrated that the dynamic nature of marsh populations and communities make it imperative that the ecology of sensitive areas be studied in advance os that meaningful assessments can be made on a long-term basis. It also pointed out the danger of misinterpreting changes observed as being due to oil when in reality many interrelated natural factors are having their effects on populations and communities at the same time.