The dark frontier

The deep sea "may well be the largest, most diverse, most consequential habitat on Earth," writes marine microbiologist Marlow in his moving debut exploration. Still largely unexplored, the deep sea--the vast, cold zone below the ocean's surface where no sunlight reaches--is at a "precarious inflection point," he contends, as human activity threatens its biodiversity and other key features. Attempting to understand this immense habitat before it's forever changed, Marlow takes numerous research trips into the Atlantic and Pacific oceans, including an expedition in the "world's most scientifically advanced submersible," Alvin, which brings him thousands of meters below the surface of the Caribbean Sea. He traces the history of deep-sea exploration, from the discovery in the mid-1800s that the ocean's depths were filled with life to more recent revelations, like hydrothermal vents (fissures in the seafloor that spew heated, mineral-rich water). Elsewhere, he explains how the deep sea impacts terrestrial life by absorbing carbon from the atmosphere, and the threats posed by such exploitative activities as seabed mining and overfishing. Marlow's fascination with underwater environments is palpable throughout, as he studies microbes that can exist by metabolizing methane, and discovers hidden ecosystems of strange fish, crustaceans, and worms ("It was amazing to think how these bizarre bodies came to be, molded by the gradual yet uncompromising scalpel of evolution"). This is science writing at its finest. (Apr.)

An eloquent scientist's rare view into deep-ocean expeditions. Few people have plumbed the mysteries of the deep sea like Marlow, a Boston University biologist. A gifted writer whose prose leaps off the page, he takes the reader along on varied expeditions to research, mine, and map biodiversity throughout his career. Until the last century, many believed the ocean didn't even have a floor. But some curious creatures were found clinging to a copper cable that stretched from North America to Europe, launching a new era in our understanding of the planet. Marlow played a role in many scientific journeys to illuminate more of this dark frontier. He rides on deep-ocean submersibles, spends his first internship studying microbes, consults on mining operations, and offers cinematic descriptions of the forming--and suctioning up--of polymetallic nodules scattered on the seafloor. The goopy, smelly rot of a submerged whale carcass is somehow entrancing. In his telling, even the most staid, diplomatic meetings are riveting. His tales lend context and continuity to a fragmented picture of the unseeable seas. Marlow has learned that the deep sea lives on a vastly different timescale from us, far slower, while humans' view of exploiting it is more akin to a "quarterly earnings report." The resources we seek to collect for profit are "unlikely to regenerate for hundreds, thousands, or millions of years," he writes. Marlow's tales of seafloor mountain ranges and the characters he encounters are delightful and emotive, whether they are humans or the hagfish that set about devouring a whale carcass left to sink to the seafloor. His science is injected with feeling and perspective. Unafraid to anthropomorphize, the author imagines everything from "bewildered tectonic plates" to a "regretful" tuna reeled in by fisherman off the Maldives. In the end, his is a cautionary tale. "The sad truth," he writes, "is that our reach has exceeded our grasp; we've irrevocably changed the deep sea before even getting to know it." A romantic, illuminating dive into the deep sea and the controversies of exploiting it. Copyright (c) Kirkus Reviews, used with permission.