Why are saprotrophs so important to a marine food web? they break down dead organisms and recycle nutrients. they directly to maintain the population sizes of different predators. they primarily eliminate toxins from the water that can harm phytoplankton. they produce significant amounts of energy that is used by top consumers.

They break down dead organisms and recycle nutrients.  

Explanation:

Saprophytes are the living organisms which feed upon dead organisms such as plants, animals and their decaying products. They contribute to the food web because they help in clearing up the biological waste from the environment and makes the resources after degradation available to the plants as soil nutrients. Therefore, helps in the nutrient recycling in an ecosystem.

can you give me more to work here with plzs and you

"do a testcross with a homozygous recessive plant."