PLENARY

 

Population units of cubozoans –ecology, gaps in our understanding and how do we best respond to threats?

 

Michael J  Kingsford, Christopher Mooney and Jodie Schlaefer

James Cook University, Australia

 

Cubozoans are found from tropical to temperate seas of the world, they are biologically interesting and are a threat to humans, but our knowledge of their taxonomy, ecology and population structure is weak.  Here I review what is known on the ecology of the Cubozoa and particularly the spatial extent of population units from metapopulations to local populations.   Of the 45 known species, most have been found at only one or two locations.  Despite problems with taxonomy, three species have widespread distributions at multiple countries and sites.  Where data are available on temporal and spatial patterns of abundance, there is great variance at small spatial scales.  From distribution studies and research using elemental chemistry, a picture is emerging of strong local populations where there is great self-recruitment and perhaps rarer founder effects that start other local populations which in turn contribute to stocks (=mesopopulations).   A bipartite life history (ie polypoid and medusoid phases) and the behavior of medusa probably contribute to strong local population structures.  Cubozoans are strong swimmers and can see – limited movements and an ability to respond to currents would facilitate the resilience of local populations.  The probability of envenomation to humans, therefore, is probably variable on a scale of hundreds of metres to kilometers.  Risks may be better managed with stakeholders taking control at local levels using technology such as ‘jellycams’, physical water measurements and predictive models.