If you have access to a sophisticated real-time heat map of the world's oceans you'll know there is a great big blob near the Chatham Islands archipelago. It's an isolated pocket of warm water - four times the size of New Zealand - and nobody knows exactly why it's there.
Professor James Renwick from Victoria University's school of geography environment and earth sciences is trying to figure it out.
Pacific Ocean warm water 'blob' Photo: Screenshot /coralreefwatch.noaa.gov