The nutritional activity of these replenish nutrients that are essential ingredients for primary production. This contains an enormous amount of energy and nutrients. Saprophytes decompose detritus completing the cycle. The numerical relationship is called the pyramid of numbers. The energy pyramid is the energy distribution at each trophic level as it passes from producers through the consumers.
Most scavengers consume detritus rather than flesh and deep sea animals can feed on both.
If mortality is greater, then the population decreases. These favorable conditions depend on high concentration of nutrient rich water, rapid cycling of materials by decomposers, high numbers or rapid turnover of producer organisms Light nutrients including nitrate, phosphate, silicon, potassium, magnesium, copper, iron. Silicon dioxide needed for outer glass covering of diatoms and forms internal structural parts of sponges, K and NO4 and PO4 needed in plant proteins, lipids and carbohydrates during photosynthesis. Plankton comprise the large and small organisms that drift or float while tides and currents move them through the water. Most plankton do have a limited ability to move and can migrate vertically through the water from day to night.