How many trophic level are these in the following food chain phytoplankton-shrimp-perch-pike-osprey?

The food chain you provided contains four trophic levels. Phytoplankton represents the first trophic level as primary producers. Shrimp, which feeds on phytoplankton, is the second trophic level (primary consumers). Perch, feeding on shrimp, is the third trophic level (secondary consumers), and pike, preying on perch, is the fourth trophic level (tertiary consumers), with the osprey as a top predator potentially representing an additional level.