Google's Head of Search Spam Matt Cutts has forewarned of a "very significant" Panda update to Google's search algorithm at the Search Marketing Expo, coming Friday (March 15th) or Monday (March 18th).

The announcement is the latest in a busy few months for the search giant, with Google's punishment of floral retailer Interflora for suspicious link-building activity following the earlier Panda update in January affecting 1.2% of all English searches.

This latest change to the search algorithm is typically shrouded in mystery, with marketers and SEO analysts already fearing the worst for their search traffic. The original Panda release was designed to push high-quality content above duplicated, cheaper content, resulting in unique content from social networks and news outlets dominating sites populated with adverts.

This 25th incarnation of the algorithm has started a mini-frenzy as webmasters look to protect their search ranking.

Google have previously advised users to "expect some flux" over their updates.

Cutts also announced that Google was “working on the next generation of Penguin,” Google's anti-black-hat software which last year affected a whopping 3% of searches - and even fired a warning to e-commerce specialists.

“We have a potential launch later this year, maybe a little bit sooner, looking at the quality of merchants and whether we can do a better job on that, because we don’t want low quality experience merchants to be ranking in the search results.” he said.