The Mystery of Migration

Humpback whale and her calf

A mother humpback whale and calf on the Silver Bank

Each winter, up to 7,000 of the 10,000 or so humpbacks in the western North Atlantic spend time in and around the warm, shallow waters of the Silver Bank, where we are lucky to rendezvous with them. Swimming half an ocean basin is a long haul by any standards but is a twice-yearly undertaking for the humpback whale. Reflecting on their journey raises more questions for me than it answers.

We understand why; they travel north to feed, south to breed. But I can’t help but wonder what it’s like. What triggers the decision to leave? Do they discuss it? How tiring is it after not feeding for months in the Caribbean? Are the calves whining at their moms (as my child would be!)? How do groups stay in contact? How do they navigate so precisely? When do they sleep? Continue reading

Humpback Whales of Tonga

The tiny Kingdom of Tonga, 176 islands and 100,000 people, in the clear blue, coral seas of the south Pacific is one of only two locations in the world where swimming with humpback whales is officially permitted. Whales in the southern hemisphere feed in the rich waters around Antarctica and travel north as days get shorter to mate and breed in tropical seas. Humpbacks arrive in July and congregate in the sanctuary of islands around the Vava’u group. A whaling nation until 1979, these annual visits are so important to Tonga that whales are now mentioned in 80% of tourism promotions. Studies estimate that a single humpback returning every year could generate US $1 million in whale-watching revenue over the course of its lifetime.

Humpback whale in Tonga

Humpback whale in Vavau, Tonga

In contrast to the Sanctuary for Marine Mammals of the Silver Bank of the Dominican Republic, (location of the other legally sanctioned and managed swim with whales program) Tongan whales are much closer to shore and can be experienced on a day trip. Twelve licensed Tongan operators run programs and while this is more than in the Dominican Republic where only three permits are in effect, a smaller number of people (just 4) can enter the water with whales at any time. Rules regarding approach distances and being sensitive to signs of distress are similar and cautious. Given the much smaller number of animals this is important, around 500 whales are thought to winter in the Vava’u island group compared to mid-range estimates of 5,000 on the Silver Bank. Continue reading

A Crude Awakening

Infamous as Moby Dick and also known as the cachalot (who was, ironically, caught a lot), is the sperm whale, Physeter macrocephalis. They are the largest of the world’s toothed whales, have the biggest brain in the animal kingdom and can dive to nearly two miles. In short, they are really cool! Life is not so cool right now though for a resident population, numbering around 140, just off the mouth of the Mississippi, where crude oil has been gushing into the Gulf of Mexico from a pipe ruptured when the Deepwater Horizon rig exploded on April 26th, 2010. As Gulf States prepare for clean up activities on-shore and commence the census of shorebirds, turtles, fish, dolphins, invertebrates and plant communities lost; we consider the sperm whale. Continue reading