The Global Fool

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Quality Water, Quality Life: Aquatic Health and Contaminants in the Midcoast Oregon Salmon Watersheds

Quality Water, Quality Life: Aquatic Health and Contaminants in the Midcoast Oregon Salmon Watersheds

A guest post by Ray Kinney From ridge tops to reefs, environmental degradation has caused many salmon populations to decline to one to ten percent of former numbers. Young salmon survival in freshwater is only 2 to 5% from egg to smolt phase just before entering the ocean phase of their life cycle. Many causative effects for this decline are known, but many remain to be clarified. Politics often prevents adequate investigation of contaminant effects for water quality. Chronic low dose accumulative effects of toxic contaminants take a toll that is generally unrecognized by fisheries managers. Our benevolent rainfall flows down out of the Coast Range to become, once again, part of the sea and the productivity of the salmon cycle of the near-shore ocean. Nutrients from the ocean, in the form of salmon and lamprey spawner carcasses, had fertilized our forests, streams, and rivers like an incoming tide for thousands of years. Our forest garden grew rich because of this tide of nutrients. Reduced numbers means reduced nutrients, which reduces development, growth, and survival abilities of the fish. The land also nourishes the sea. Freshwater flows down out of the mountains, past our farms and towns, through the jetties, and out over the continental shelf. These nutrient tides over land and sea have been shaping salmon for thousands of years, providing diversity, fitness, and resilience to the young fish and other stream organisms that support the salmon cycle complexity. For many hundreds of years humans have increasingly affected the quality of this complexity in ways that have stressed the fish. In the last two hundred years we have greatly increased pollution. Fish harvest levels increased unsustainably, while beaver and timber harvests altered the landscape stressing the salmon cycle. Increasing pollutants have contaminated the flow to the sea. Copious leaching rainfall and snowmelt dissolve and transport nutrients and contaminants down the river out of the Coast Range. Calcium and iron ride the waters downstream and out over the shelf during the winter, enriching the sea floor mud. As upwelling conditions increase in the summer, much of this iron distributes northward with the currents and combines with nitrates to fertilize plankton blooms that feed the food chain for the salmon. Iron and nitrate are in shorter supply over much of the ocean and limit productivity in many parts of the ocean. Here, off of the Oregon coast, the iron leached from our soils provides an important key to salmon ocean productivity. Large quantities of nitrate ride downstream through the freshwater, from red alder tree vegetation cover concentrations in our timberland. The red alder ‘fix’ nitrogen out of the air providing fertilizer...

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