"The Census of Marine Life was conducted globally between 2000 and 2010 by more than 2000 researchers, and this book takes readers with the scientists from the shallows to the ocean depths in their quest to identify species. Picture-book size and packed with exhilarating photographs of astonishing underwater creatures, the narrative describes the work of the scuba divers, often using the second-person voice for immediacy. These census takers used such tools as light boxes to count and capture nighttime reef creatures and an ROV (remotely operated underwater vehicle) where necessary. They also extracted DNA from various creatures in order to construct a library of ocean life and made contour maps of the ocean floor using sound waves. Text boxes explain technical concepts such as chemosynthesis, marine snow, moving plates, DNA, and water pressure. Pungent quotes from marine scientists are sprinkled throughout. Sometimes there's so much information on each spread that it's almost distracting, but the photos are excellent in quality and plentiful. This engaging volume is fun for browsing, useful for assignments, and inspiring for budding marine scientists." (School Library Journal)

"This heavily illustrated title contains a wealth of information about the fascinating science of ocean life. Readers will start off browsing the close-up color photographs and text boxes on every double-page spread, including sidebars that explain DNA, water pressure, chemosynthesis, and much more. But the focus of this photo-essay is the Census of Marine Life, a 10-year study, conducted from 2000 to 2010, in which international teams of scientists have explored the ocean from surface to seafloor, from deep-sea mountains to deep dark depths, and from pole to pole. Their amazing discoveries cover big-picture overviews as well as tiny creatures, and throughout the book, the chatty, informative text invites the reader along with scientists at work: 'scrunched inside a submersible that has just passed 1,478 feet, you're descending through a dark world few people have seen.' Along with the 250,000 species that are presently known, there is also the lure of the estimated 10 or even 50 million more species waiting to be discovered, and students will find the remaining mysteries as compelling as the facts." (Booklist)

"Drawing on findings from the decade-long Census of Marine Life, Johnson travels down into the ocean's depths, explaining living conditions in various zones and regions as well as the sophisticated technologies of data collection. Excellent color photographs showcase fascinating marine organisms and the scientists who found them." (The Horn Book Guide)