This interactive demonstrates bioaccumulation of marine toxins. It shows how toxins move through a marine food web.

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Rights: 2012. University of Waikato. All Rights Reserved. Published 4 September 2012, Updated 28 June 2016

Marine toxins, produced by phytoplankton, can accumulate in organisms in the food web. This process is called bioaccumulation. This interactive demonstrates one way toxins can accumulate. Ultimately, they can be passed on to people who can become very ill and even die from different types of seafood toxins.

You will need the Adobe Flash Player to view it.


Instructions: Begin with the phytoplankton that are producing toxins. The red dots are toxins. Drag the phytoplankton to its consumer. Then drag that primary consumer to a secondary consumer and then the secondary consumer to a tertiary consumer. Watch to see how the toxins accumulate as you follow a food chain. Try another food chain, beginning with the toxin-producing phytoplankton.


Producer: Phytoplankton produce food through photosynthesis. Some phytoplankton produce toxins.
Image acknowledgement: Public domain


Primary consumer: These are plant eaters (herbivores). Zooplankton eat phytoplankton. Some will ingest toxins from the phytoplankton.
Image acknowledgement: Malcolm Francis

Small fish (yellow –eyed mullet)

Secondary consumer: These are consumers that eat primary consumers. Some will ingest the toxins from the primary consumers.
Image acknowledgement: Dive Kaikoura

Larger fish (Kahawai)

Tertiary consumer: These consumers eat other consumers. Some may ingest the increasing amounts of toxins.
Image acknowledgement: Kahawai, Kermadec Islands, by Tom Hitchon, 2008


Tertiary consumer: These consumers eat other consumers. Sharks, in particular, are known to bioaccumulate high levels of toxins.
Image acknowledgement: Crown Copyright: Department of Conservation Te Papa Atawhai (9 September 2009)


People are at the top of the food web. They can get very sick eating fish or seafood that contains high levels of toxins through bioaccumulation. Try another consumer pathway (food chain) in the food web.
Image acknowledgement:


Tertiary consumer: An octopus is a carnivore eating mostly bivalves such as mussels. They will also eat crabs, shrimp, snails and small fish. Toxins can be ingested.
Image acknowledgement:


Scavenger: Seastars eat both plants and animals, dead or alive. Mostly they eat mussels and other molluscs. They can ingest toxins.
Image acknowledgement: Starfish, Kermadec Islands, by Tom Hitchon, 2008.


Primary consumer: Mussels are generally considered primary consumers. They feed on microscopic plants. Toxins can be ingested.
Image acknowledgement: Ian McLeod Creative Commons Attribution 3.0 Unported