Science Metropolis – Boston

Michelle Ridgway prepares for her canyon expedition. (Credit: Michelle Ridgway’s Blog)

– by Jennifer Berglund

West of Alaska is buried one of Earth’s most glorious and unexplored frontiers – the Zhemchug Canyon. The giant cavity, over a mile and a half deep, could consume the Grand Canyon with room to spare. When currents flow into the canyon, they slam against its walls before being thrust upwards towards the ocean’s surface. Within these upwellings, hordes of nutrients amass, feeding some of the largest concentrations of phytoplankton on Earth, which in turn nourishes a thriving cornucopia of life.

Into these dark depths, Michelle Ridgway made her descent.  Ridgway is a marine ecologist from Juneau, Alaska, and one of the last true explorers to plunge into a great unknown. As part of a public lecture series at the New England Aquarium, she shared her experiences in this final frontier earlier this week. Her story begins when she first sat in a tiny, eight-foot long research submarine resembling a backward forklift with pontoons. 

One year ago, Ridgway was on a mission to explore the deepest depths of the Zhemchug canyon and to document all traces of life that she could find. Out of a 200-person crew on the Greenpeace ship Esperanza, she was one of only five pilots allowed to operate the tiny sub. This status gave her the privilege to personally explore the canyon’s depths. 

As Ridgway descended, she took her first glimpse of the canyon wall.  Spots of bright oranges, blues and purples filled her view. Although the water was just a few degrees above freezing, it was indeed coral, a staple of tropical reefs. With her sub’s robotic arm, she reached out and grabbed the end of a 9-foot-tall piece. Much of the coral Ridgway found in the canyon had yet to be described.

Nearby, the mouthparts of tubeworms lined the rock walls, resembling the mountainsides of tropical rainforests speckled with ferns.  Between the coral and tubeworms hid an orange speck – a tiny prickly crab.  It was the younger version of a giant King Crab, one of the most sought after crab species in the world. Only a few millimeters long as a youth, it can grow to be nearly five feet in diameter as an adult. 

Ridgway’s sub was soon a fifth of the way down Zhemchug canyon and suddenly incapable of handling the enormous water pressure. She began her retreat, stopping for a moment at the top of the canyon.  The seafloor below resembled a desert, sandy debris gathered in waves and what appeared to be the coral reef’s rejects moved sporadically on the floor around her.  A large greenish-brown flatfish stared with two eyes that seem to have bumped into each other on one side of its head.

As Ridgway ended her dive, she quickly gathered a few more samples. She found a giant brown ball resembling a rock, which, when later examined, turned out to be compacted dirt. It was determined to contain traces of various species of ice algae, many of which scientists thought to have been extinct for 15,000 years. 

Ridgway returned to her research vessel full of stories, specimens, and enthusiasm for her next big dive. It was only 1of 25 in this particular mission – the first of many fruitful expeditions to come.  

– Upcoming Aquarium events include: “Whales: Candles, Cheeses and Pigs in Disguise” on Oct. 5, “Tuna: A Love Story” on Oct. 14, and “Journey with a National Geographic Photographer” on Nov. 10.