Health agencies in the US and Canada recommend that people (particularly children and pregnant women) should not eat tuna on a regular basis (le more than once a week) because of mercury (a heavy metal that can be poisonous) contamination Other fish like salmon are safe to eat regularly

Draw a simple food chain consisting of at least four trophic levels, including the organisms mentioned above. Label the trophic levels

Draw a food chain and illustrate why tuna may have more mercury contamination than salmon or trout