Pacific Salmon Essay
There are 7 different species of salmon that can be found in the Pacific Ocean, each species has a unique appearance and has different habitats but they share many characteristics. Salmon are also a very unique species, they are anadromous, meaning that their eggs are laid and hatch in freshwater, and their youth spend some of their early lives there in freshwater before swimming to the ocean to grow and mature. Pacific salmon spawn only once and dies within days of digging their nest and mating. Their bodies will float down the stream and decompose, filling the water will nutrients for other species and plants as food. Both live and dead salmons plays an important food source for birds, such as eagles and gulls and mammals, such as bears. In one way or the other, salmon plays a big role in the ecosystem, which leads us to discover more about the threats to the pacific salmon stocks.
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Pacific salmons have experienced a dramatic declines in abundance starting from the last few decades due to human induced and natural factors.
There are many factors of human induced that greatly affect the quality and the quantity of salmon stocks. For example, water storage, withdrawal, conveyance, the diversions for agriculture, flood control, domestic and lastly hydropower purposes like dams, this examples have greatly affect and reduced or eliminated the habitat and resulted indirectly entrainment the mortality of pacific salmon stocks. The modification of natural flow regimes or system have resulted an increased in water temperature, changed the fish community structure, depleted flows for migration, rearing, spawning, gravel recruitment, flushing sediments from spawning gravels and the transportation of large woody debris, such as fallen dead trees and the remains of large branches. Hydropower purposes like dams, turbines and sluiceways have also resulted in an increased of mortality of both adults and youth of pacific
salmons.
Industrialism have also greatly impact the pacific salmons by using natural resources and extraction leading to habitat modification that can have significant direct and indirect affects to population of pacific salmons. Land use activities that are associated with mining, logging, road construction, agriculture, urban development and recreation have significantly altered pacific salmon’s habitat quality and the quantity. Due to all these activities, it resulted includes the alteration of stream banks and channel morphology, degradation of water quality, alteration of ambient stream water temperatures, reduction in available food supply, fragmentation of available habitats, elimination of spawning and rearing habitat, elimination of downstream recruitment of spawning gravels and large woody debris, pool habitat and suitable gravel substrate. Studies indicate that in most western states, like United States and Canada, about 80% to 90% of historic habitat has been eliminated or distinguished. In the last 200 years, the lower 48 United Stated have lost approximately 53% of all wetlands. Washington and Oregon’s wetlands have been estimated to have been diminished by one third and California has experienced a 91% loss of its wetland habitat. The glaciers retreated after the last ice age 11,000 years ago, salmon were confined to a few small refuge areas in the eastern Pacific.
Pacific salmons have experienced a dramatic declines in abundance starting from the last few decades due to human induced and natural factors.
There are many factors of human induced that greatly affect the quality and the quantity of salmon stocks. For example, water storage, withdrawal, conveyance, the diversions for agriculture, flood control, domestic and lastly hydropower purposes like dams, this examples have greatly affect and reduced or eliminated the habitat and resulted indirectly entrainment the mortality of pacific salmon stocks. The modification of natural flow regimes or system have resulted an increased in water temperature, changed the fish community structure, depleted flows for migration, rearing, spawning, gravel recruitment, flushing sediments from spawning gravels and the transportation of large woody debris, such as fallen dead trees and the remains of large branches. Hydropower purposes like dams, turbines and sluiceways have also resulted in an increased of mortality of both adults and youth of pacific
salmons.
Industrialism have also greatly impact the pacific salmons by using natural resources and extraction leading to habitat modification that can have significant direct and indirect affects to population of pacific salmons. Land use activities that are associated with mining, logging, road construction, agriculture, urban development and recreation have significantly altered pacific salmon’s habitat quality and the quantity. Due to all these activities, it resulted includes the alteration of stream banks and channel morphology, degradation of water quality, alteration of ambient stream water temperatures, reduction in available food supply, fragmentation of available habitats, elimination of spawning and rearing habitat, elimination of downstream recruitment of spawning gravels and large woody debris, pool habitat and suitable gravel substrate. Studies indicate that in most western states, like United States and Canada, about 80% to 90% of historic habitat has been eliminated or distinguished. In the last 200 years, the lower 48 United Stated have lost approximately 53% of all wetlands. Washington and Oregon’s wetlands have been estimated to have been diminished by one third and California has experienced a 91% loss of its wetland habitat. The glaciers retreated after the last ice age 11,000 years ago, salmon were confined to a few small refuge areas in the eastern Pacific.