It was January and we’d spent the last few weeks following a group of Sperm Whales (Physeter macrocephalus), crisscrossing the upper half of the Sea of Cortez on the 40ft sloop Balaena, listening and recording their sounds as well as tracking their movements.
For six days now, we’d been struggling with strong northerly wind gusts. Spotting a protected cove, we seized the opportunity to escape the relentless winds on the open sea. Not much of an anchorage, but at least we were able to find some protection. We’d lose the whales, but the windy conditions made it impossible to achieve anything.
The following morning, we were woken by the deafening roar of sea lions bellowing from the shore. The winds had finally dropped and the dawn was breathtaking, we were excited to be back on open waters. The challenge now would be finding the whales again in the 800-mile long Sea of Cortez, like looking for a needle in a haystack.
As we cleared the western spit of Isla San Esteban where we had last seen the whales, we got into deeper water and let out 300 ft. of cable with the hydrophone.
Sperm Whales ‘echolocate’ i.e. make repetitive clicking sounds, to find their favorite food: squid. The hydrophone can pick up these clicking sounds up to five miles from the boat.The on-board computer and a brilliant program called ‘Rainbow Click’ process the hydrophone recordings, enabling us to track and record the whales. Despite the high-tech equipment, locating whales can sometimes take days. Generally one heads for where they feed or mate, but they could be anywhere by now. A couple of hours later while sailing west, we heard the first weak, but unmistakable sound of whale clicks. There was a great roar of excitement aboard. We’d found them!
Everyone jumped back to their tasks: manning the hydrophone, taking pictures for photo ID, collecting skin samples, taking notes or in our case, steering the boat and filming the whales. We all worked together, a well-oiled machine … extraordinary when you think that this team was only put together a few weeks before.
Now that we were back on track, we certainly weren’t going to lose them. The following week we worked hard, tracking them night and day, the hydrophone endlessly gathering useful data in our wake. Occasionally we would stop Balaena and float silently amongst these vast and impressive creatures as they fed. Surrounded by up to 50 animals, some up to 70ft long was an impressive sight indeed! At night, the stars were breathtaking. The silent calm of the deep dark waters only punctuated by the blowing of the whales, the chatter of dolphins and the gentle tinkering of Manolo, one of the Mexican scientists, on his Spanish guitar.
Early one morning, while Balaena was sailing silently at 3 knots, we were greeted by at least 10 to 12 Sperm Whales right behind the stern, their huge heads well out of the water effortlessly keeping up with us for at least an hour and a half. Did they think we were some kind of whale or were they just curious about the hydrophone being towed behind us? We would soon find out.
A few days later, a large pod of whales was happily relaxing and socializing, yes whales do socialize! Barely moving, they drift along on the surface ‘logging’ as it’s called. Balaena was drifting in the middle of this large group who seemed to be having a good old chinwag, communicating with ‘codas’. Some of them became quite intrigued by our presence and were producing plenty of interesting ‘codas’. Clicks are for echo locating food, and ‘codas’ which sound quite different, are used to communicate. We immediately switched to ‘record’ and listened carefully. One of the whales sent a strong beam of echo-locating clicks directly into the hydrophone. The pitch rapidly increased until it was so loud that Manolo had to snatch off his headphones. Suddenly everything went quiet and the computer screen went dark. We rushed on deck to investigate. We leaned over the side and realized that one of the whales had actually plucked the hydrophone off the end of the cable with its mouth!! 300 ft of cable was left dangling, only the frazzled remains of the wires connecting it to the hydrophone remained . . . unbelievable! Fortunately, we still had a directional hydrophone on the side of the boat.
We finished our last approach to the whales just as the daylight was starting to fade. With so little wind, we could hear the whales and dolphins all around us, one of the most surreal moments of our journey.
Finally we pointed Balaena to the south and with all sails up, we slipped quietly through the water at 3 to 4 knots, enjoying the evening skies. The Sea of Cortez is famous for its reddish tinge at sunset. That evening it was easy to see why we Mexicans call it “Mar Bermejo” (red-tinted sea). With a tinge of sadness we entered Santa Rosalia Harbour at daybreak, marking the end of a truly memorable journey in this magical place.
Sperm Whales are a deep-water species, found in all three oceans, from the Arctic to the Antarctic. After years of relentless hunting, their numbers are slowly recovering. Sperm Whales spend most of their life underwater, only coming to the surface for air, and occasionally to socialize. They are highly vocal animals, emitting loud, regular clicks almost continuously. Their sensitive hearing and well developed echo-location system enables them to find food and communicate. They are the world’s deepest divers. By slowing their heartbeat down to a mere 10 beats per minute, they can stay underwater for over 90 minutes, reaching depths of over 2000 meters.
The recordings from Balaena will now be compared to other recordings from the Galapagos and Chile. It is thought that Sperm Whales from different regions have similar ‘codas’ or language. By studying the different ‘codas’, we hope to understand if they move between the Pacific, Atlantic and Indian Ocean. Using DNA techniques, the skin samples will now be analyzed, enabling us to study the genetics of the individual animals and establish the various family groups. The photographs we took will help us to identify individual animals returning to specific locations in different parts of the world.
It always amazes me to see how the whales navigate in the vast expanse of the sea. It’s extraordinary how the male Sperm Whales manage to find their way back to a specific group of females. Female Sperm Whales live in temperate and tropical waters (between approx. 40 N and 40 S), whilst the male Sperm Whales reach sexual maturity and leave the maternal group at around 9 years of age to live alone, normally in the higher latitudes, returning to the tropics only to mate and socialize. Even in the 21st century, there is still so much to learn about Sperm Whales. For example, we know they eat squid but we’re still not sure how they catch them.
Small sailing boats such as Balaena are ideal for studying cetaceans, providing a perfect platform for gathering data and tracking the whales for long periods of time at relatively low cost. There are currently several sailing vessels solely dedicated to whale research around the world like R/V Odyssey. Odyssey completed a 5 year round the world expedition studying the health of the World’s Oceans, using the sperm whale as an indicator species (see www.pbs.org/odyssey). I was fortunate enough to participate in this trip as her Captain and Field Coordinator for half her journey round the world. Having taken blubber samples from several hundred whales in the Atlantic, the Pacific and the Indian Oceans, we were able to study the contents of non-biodegradable man-made pollutants that accumulate in the whales, the fish we eat and ultimately of course, in humans. The results from this landmark expedition has given us the first comprehensive picture of how polluted our beloved Oceans have become. We discovered alarmingly high levels of pollution even in the most remote areas such as Galapagos, Kiribati, and Papua New Guinea.