The European shore crab (Carcinus maenas) was first recorded in Port Phillip Bay in 1900, introduced there accidentally as a hitch-hiker on ships from the UK or Europe. The European shore crab is an invasive species which competes with, and predates upon native species. The species has become prolific throughout the Gippsland Lakes.
In June 2007 prior to dredging by the Pelican, Australian Marine Ecology were retained by Gippsland Ports to carry out a study around the entrance titled Lakes Entrance Existing Conditions: Marine Habitats and Communities. Unfortunately the study fell short as it did not identify the presence of the European shore crab which soon after the 2008 dredge of the entrance rapidly spread through the lakes.
Around this time sting-rays and squid were also entering the lakes as well as a range of sharks and marine fish species. To date the invasion of European shore crab and the die-back of sandworm and freshwater bi-valves has not been investigated.