Salmon migrate yearly from the open Pacific Ocean to the coastal areas of the Pacific Northwest in order to spend about 5-6 weeks reproducing. During this time bears also migrate to these coastal areas to feed on the salmon which is a large part of their diet. This natural interaction has been an important factor of the ecosystem in the Pacific Northwest for many years and now that humans have imposed on this process by overfishing we are seeing changes in the ecosystem itself. While knowledge of this issue has been around for about 30 years, scientists only began researching it beginning in the early 90’s. According to this research the ongoing problem of overfishing is already beginning to show its effects on the ecosystem, what may happen to the forests and animals of the Pacific Northwest if this issue is not resolved?
Through the research of Dr. Tom Reimchen and other scientists, an interaction between salmon and the forests of the Pacific Northwest has been discovered. Each year black and grizzly bears travel from far away to the streams and rivers in the Pacific Northwest to feed on the salmon that migrate there during their six week spawning period. This causes a local interaction, when the bears catch a fish they take it into the forest so they can eat it and not be disturbed. Usually the bears only eat about half of each fish they catch and leave the rest on the forest floor, which is then consumed by birds, other small animals and insects. Through the decomposition of the salmon as well as the bodily wastes of the bears and other animals, the soil in the forest absorbs nutrients as well as nitrogen from the salmon. “The use of stable nitrogen isotopes allows us to identify the relative contribution of salmon to the ecosystem” (Reimchen 2001: 14), this research showed that nitrogen 15, an isotope of nitrogen is present in a large number of the plants in the Pacific Northwest forests. Nitrogen 15 is mostly found in marine algae and salmon are...
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