Falls in whale sightings, rare seabirds appearing – is something unusual happening in the Southern Ocean?

In late June, whale watchers in southwest Western Australia sounded the alarm. They had seen far fewer humpback whales at a time when they normally migrate up from the Southern Ocean to calve and feed. Numbers were 60% below normal. A week later, birdwatchers spotted a “once in a lifetime event” as large numbers of rarely seen albatrosses and petrels appeared off Australia’s east coast, thousands of kilometres from their usual foraging grounds deep in the Southern Ocean. Many birds were in…