Ocean warming is driving marine species polewards with potential for impacts on the economy, health and ecosystems.

Over 100 marine species have been documented as shifting their geographic distribution pole-wards along the south-east coast of Australia.

"Several dozen marine species have already reached Tasmania due to warming in the Tasman Sea – with temperature increases up to four times the global average," said Jorge Ramos Castillejos, a PhD candidate at the Institute for Marine and Antarctic Studies (IMAS).

In a review released today by the Ecological Society of Australia, Mr Ramos Castillejos, and Associate Professor Gretta Pecl highlighted that major changes are well under way in our oceans.

Impacts of concern include range-shifting sea urchins that can destroy kelp beds, stinging jellyfish on southern Australian beaches, and shifts in the distribution or frequency of occurrence of toxic microalgae.

"The toxic microalgae can affect human health and could have economic impacts on tourism, fisheries, and aquaculture," explained Associate Professor Pecl.

"Local marine communities are experiencing changes as new comers interact with local species. For example, the common Sydney ‘gloomy’ octopus, has recently starting breeding in new areas of Tasmania, and a study in progress suggests these new octopus populations could be eating commercial scallops" said Mr Ramos Castillejos.

The natural environment is also suffering a major hit. Grazing by the range-extending long spined sea urchin has created ‘urchin barrens’ contributing to the destruction of the once abundant Tasmanian kelp beds. Kelp beds are nursery grounds and habitat for several marine species of ecological and commercial importance.

"However, it's not all bad news.  Newly arriving marine species may be a favourable catch for commercial and recreational fishers or an exciting sighting for divers" said Associate Professor Pecl.

Several collaborative efforts by scientists, managers and policy makers are now underway to better understand the capacity of marine species to undergo changes in distribution, establish how we can more promptly detect range-shifting species, and how we can determine the extent of their impacts, mitigating threats and maximizing opportunities.


Jorge E. Ramos Castillejos, PhD.

Institute for Marine and Antarctic Studies

University of Tasmania, Australia

E-mail: jeramos@utas.edu.au

Associate Professor Gretta Pecl

Institute for Marine and Antarctic Studies

University of Tasmania, Australia

E-mail: Gretta.Pecl@utas.edu.au