Thanks so much for your very informative reply Dave.  I really appreciated the input of scientists who are working in this field of research.  I will email tassygirl directly to ensure that she sees your comment.

There is definitely increasing evidence of climate-change induced range shifts for Aussie fishes, especially in SE Australia where we have the dual effects of increasing sea temperature and East Australian (EAC) current flow. We have been studying the influx of coral reef fish larvae into the Sydney and southwards. (summary can be heard at http://www.aqob.com.au/details.php?p_id=717&search=booth&searchid=1&seo=No_small_change Basically, the numbers vary greatly year to year, partly depending on EAC patterns. However, we also showed a strong link between winter water temperature and overwinter survival of these fishes (tropical butterflyfishes and damselfishes)- we saw survival over about 18C, which occurred in 2001 and 2006, 2 of the warmest winters in 150 years! A lot more needs to be researched and the jury is still out on whether we might seem major biogeographic shifts in fish species. I’d also suggest talking a look at the recent Marine Climate change Report Card for Australia at http://www.oceanclimatechange.org.au/content/index.php/site/welcome/ Our “temperate fishes” paper in that, plus those on tropical and pelagic fishes are relevant.

Hi tassygirl.  Thank you for your comment.  Climage change is an issue that I believe we should all be taking very seriously.  I'm not 100% sure which species you are refering to as a 'gummy dogshark'.  There is a Gummy Shark, Mustelus antarcticus and also quite a number of dogsharks that are in a different family, the Squalidae.  Having said that, however, I don't think it detracts one bit from your concern about changing distribution patterns as a result of ocean warming (don't get me taking about ocean 'acidification'!).  The Whitley Award winning add link redmap website is trying to document changes in species distributions in Tasmania.  Dr Peter Last from CSIRO Hobart, who was one of the interviewees in the ABC story is a close colleague of us fish-folk here at the Australian Museum.  One of the comments he made in the interview is particularly scary, "If things keep changing in this way we're not sure what would happen to those elements or those fishes that occur right at the southern tip of Tasmania. These have got nowhere else to go."

Just heard on ABC TV news that with increasing temperatures in our seas, some northern species are crossing Bass Strait - in early March I travelled with family to the North Coast of Tasmania where I saw on incoming tides in a rocky shore area the largest fish I have seen onshore literally 1 metre from the beach - and also a school of about 40 toadfish in the same area - the larger fish moved like a shark and I believe it was a gummy dogshark with dark and sandy mottled markings - I would think just over a metre long. Is this perhaps a species not seen here before?