By Susan Hand Shetterly
In April and May, whales swim into the Gulf of Maine, not far from our islands and shore. A few females have at their sides their precious calves. I am thinking about the whales’ journey, not only from the South Atlantic and Caribbean, for right whales and humpbacks, but through time, beginning when the first creatures to crawl out of the sea transformed into land animals. A few species turned again to water, trading their legs for fins and flukes. The newest research suggests that small deer-like animals that were waders and grazers may have become the whales we know today. I am stuck on the fact that the nose traveled. It went from the front of the face onto the top of the head, where the splashguard protects the blowhole from water as the whale surfaces and breathes. Biologists find tiny bones of former femurs tucked within whale bodies, vestigial chunks that speak to the thousands of years that got them here.
Oil for lamps and machinery, soap to keep us clean, margarine to spread on toast, baleen for whips and corsets, and ambergris, from the guts of sperm whales, to set the scents of expensive perfumes: as late as the 1900s, most people in the developed world couldn’t get through the day without touching something made from the body of a whale. In the 20th century, approximately 270,000 whales were killed in the Northwest Atlantic alone, and this after centuries of intense commercial whaling. But whaling drew to a close in the Gulf of Maine in the 1890s, and every returning whale today reinvigorates a part of this huge but diminished body of water.
Now, tour boats in our summer bays list from one side to the other as crowds rush from starboard to port to catch sight of the leviathans. I’ve seen people’s joy at seeing whales, and I share it.
Ecstatic as these sightings are, the most precious gifts that whales offer today are not glimpses of their private lives, but, in fact, their fecal plumes, astonishing defecations that leave long, floating ribbons of buoyant fertilizer.
I’ve seen people’s joy at seeing whales, and I share it.
On the water’s surface float plankton — both phytoplankton, minute algae, and zooplankton, species of tiny animals that move up and down in the top layer of the water column. The phytoplankton use the rich offerings of nitrogen, phosphorus, and iron in the whales’ fecal plumes to photosynthesize and grow. The zooplankton, such as krill and copepods, eat the phytoplankton. Schools of fish feed on the zooplankton, and then the right whale comes along and eats the copepods, and the humpback eats the krill and fish, and they rise to defecate at the water’s surface as the cycle replenishes itself and begins again. Scientists call the up-and-down movements in the water column of feeding whales “the whale pump” because it creates a whisking effect, stirring even more nutrients from the depths to the surface.
The blooms of phytoplankton found around the plumes and the pumps jolt our atmosphere with enormous infusions of oxygen, another gift. And here’s a final one: a dead whale sinks to the bottom, carrying approximately 30 tons of sequestered CO2 within it. Lying in the cold dark, it becomes food for the creatures that live in that peculiar habitat. They strip it clean.
What value would we assign to the oxygen that phytoplankton produce, supplemented by a single whale over its long lifetime? Or to the carbon that a whale takes with it when it dies? Or to a child in Bar Harbor seeing a humpback rise out of the water on her first whale-watching tour?