Which consumer level from question #1 would you predict to have the highest concentration of toxin? why?

Im assuming this is the question:

You have been studying a large lake ecosystem. You learn that toxins have been dumped into the water. You predict that the population with the highest concentration of the toxin would be the

ducks

zooplankton

algae

predatory birds

small fish

The answer to that question is predatory fish.  In contaminated areas, bottom-dwelling fish are especially likely to have high levels of these chemicals because these substances settle to the bottom where the fish feed.

Here's an article to help in case:

https://www.doh.wa.gov/CommunityandEnvironment/Food/Fish/ContaminantsinFish

not sure if this what   you'r looking for would be percent composition