Four representative ponds in the park are measured for ecological integrity, and assessed for abundance and diversity. As of 2015, the status of this measure is fair and the trend is stable.

Fish species found in PEI National Park:

  • Atlantic Tomcod (Microgadus tomcod)
  • Atlantic Cod (Gadus morhua)
  • American Sand Lance (Ammodytes americanus)
  • Blueback Herring (Alosa aestivalis)
  • Alewife (Alosa pseudoharengus)
  • Fourspine Stickleback (Apeltes quadracus)
  • Brook Trout (Salvelinus fontinalis)
  • Ninespine Stickleback (Pungitius pungitius)
  • Rainbow Smelt (Osmerus mordax)
  • Striped Bass (Morone saxatilis)
  • White Perch (Morone americana)
  • American Eel (Anguilla rostrata)
  • Threespine Stickleback (Gasterosteus aculeatus) 
  • Banded Killifish (Fundulus diaphanus)
  • Mummichog (Fundulus heteroclitus)

Sticklebacks, mummuchogs and killifish can often be observed at water’s edge. They are a favourite food of the blue herons.

Although not a fish, you will often see jellyfish along the coastal waters of PEI National Park. These are a favourite food of the large ocean sea turtles.