Unfortunatley most of the otters have moved to the pygmy hippo exhibit and there were only two in here on my last visit. Binturongs have been tried in here but they kept escaping.
i don't know why they even tried with the binturongs. its an otter exhibit (a rather good one). it has a deep pool and a stream running through it. bah!
I was reading the otter CMP (published in July, 2010) a few days ago and discovered that Melbourne Zoo plan to build a new complex for their otters consisting of two exhibits which after it's completion, would see them importing a breeding pair in 2011.