Don't start cheering

yet over that decision in the International Court of Justice. The whales may be "safe" for now but this is only a battle in a war.
Japan has called a "halt" to whaling - not a stop. There is a difference.
Japan also plans to continue to be a member of the International Whaling Commission - for now.
Japan has also "lost face". It has been humiliated at the highest possible level.
The Japanese will not readily accept that. What country would? There will be consequences.
At the IWC they will attempt to get more of the smaller nations on side. If necessary they will bribe them with financial assistance. They will, once again, put a case for whaling on cultural and scientific grounds.
The IWC is not a very stable body. It may crack under an onslaught of such activities. Japan may yet get the IWC to agree that they, the Japanese, have the right to hunt and catch whales.
Then there is the "research" issue. Japan will almost certainly endeavour to redesign the "research" in a way which will make it impossible to deny them the right to kill whales.
There will also be economic consequences for Australia. Some tourists may decide to go elsewhere as an obvious first but there will also be less favourable terms of trade and other economic ties. Whatever our Prime Minister may say about our "strong relationship" with Japan the "free trade agreement" just got a lot harder to negotiate and the terms for Australia will not be as favourable. 
Australia can also expect a polite but cool reception at regional meetings - not just from Japan but from other Asian countries who see one of their own as being slighted and humiliated.
On the "up" side this was a first in that it is the first environmental issue to have successfully brought before an international court. It was an issue with bipartisan support here in Australia. It was an issue that had the support of New Zealand and other non-whaling countries. It paves the way for other environmental issues to be brought before the ICJ - though the bar for even partial success is still very high.
Australia likes to think of itself as "part of the Asian region". It is not of course anything of the sort and the decision is going to put that goal even further out of reach. I doubt it will ever be realised.
The decision to take Japan to the ICJ had majority support. Any negative consequences will be entirely the fault of the present government. The whales won't even be aware of these things - but I am still pleased to think they are safe, for now.