Plankton Salmon

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Introduction

Salmon are a very important fish species that contribute to the economy and play a very critical part in the food chain as they are the primary source of food for many animals and a food source for humans. Their annual migration is a miracle of nature that provides an insight into the yearly population and the abundance of their species OLWQS (2014). However, over the past few decades the salmon population has seen a steady decrease due to environmental issues such as suboptimal diets having caused a decrease in salmon health leading to death. Predators are turning to a higher salmon diet to fulfill their needs as other prey are becoming less abundant. Increases human activity disturbs the habitat of salmon, causing the salmon …show more content…

And these “ marine ecosystems can be far more sensitive to even the most modest temperature changes” (National Geographic’s 2016). As ocean temperature rise it has been recorded that less nutritious plankton has been flooding into salmon populated area McSheffrey (2016). This can be a disaster for the salmon as the prey they consume also feed on this plankton. As the salmon prey cannot survive on such unhealthy plankton they start to die off and the salmon are left with no choice but to substitute their regular diets to higher plankton filled diet. Figure 1 shows the overall change in the salmon diet from 1966 to 2002 Fisheries and Oceans Canada (2010). In the short term this can sustain the fish but in the long term, this plankton filled diets leads to lower energy level and a less nutritious diet making the fish weaker and more likely to die. These suboptimal diets cause mass salmon die off and eventually a population …show more content…

Predators that prey on salmon have to change their diets as their other prey have been steadily decreasing so they must resort to eating a higher percentage of salmon in their diets. For decades the salmon and prey population has coexisted, “but salmon populations have come under stress from many sides, reducing salmon numbers and causing an unnatural predator-prey balance” PBS. Some of the salmon’s main predators include gulls, sharks, pollack, cod, seals, pike otters and killer whales. Atlantic Salmon Trust (2016). The result of these predators consuming a higher number of salmon causes an overall decrease in the number of salmon. Figure 2 shows the relationship ship between the Salmon Abundance and Killer Whales Wieland (2011) . These predators are also very selective of the fish they feed upon prey mostly on the young and the sexually mature fish, which are, curtail to the survival of the salmon population in the future. This predator to prey ratio has a very drastic role in the depreciation of salmon and due to this, the salmon population is

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