Hood Canal blooms occur in part because of warm weather and the slow turnover of water in the southern end of the canal, causing the build-up of nutrients from fertilizers and leaky septic systems. Organic matter, brought in by ocean water and certain trees, could additionally be contributing to the high nitrogen levels in the basin. Excess nutrients and organic matter causes a body of water to lose oxygen, through a process called eutrophication. In Hood Canal, eutrophication has led to unwanted algae blooms. Nitrogen combined with sunlight triggers algal growth. A lack of sufficient consumers has resulted in a mass overgrowth
Plant defense against herbivory change their defenses in response to changes in nutrients. For example, if plants are grown in low-nitrogen conditions, then these plants will implement a defensive strategy composed of constitutive carbon-based defenses. If nutrient levels subsequently increase, by for example the addition of fertilizers, these carbon-based defenses will decrease. The growth rate hypothesis, also known as the "resource availability hypothesis", states that defense strategies are determined by the inherent growth rate of the plant, which is in turn determined by the resources available to the plant. A major assumption is that available resources are the limiting factor in determining the maximum