National Geographic : 1990 Feb
vehicles have opened the canyon to sustained exploration. "Mon terey Bay is a microcosm of the open ocean," says Bruce Robi son of the Monterey Bay Aquar ium Research Institute, one of five research facilities on the bay. "It's big enough to be an intellectual challenge but small enough to grasp, physically and mentally." Surface waters > 0 TO 100 METERS Anchors of the food chain, microscopic algae called diatoms bloom in these sunny waters, fed by an upwelling of nutrients from the canyon. They are eaten by zooplankton, such as krill, which in turn feed the world's largest animal, the blue whale. Many open-ocean creatures spend the day in deeper water and rise at night to eat. Seasonal anchovies and squid attract salmon and migrating birds such as the sooty shearwater. SARGENT FAULT SAN ANDREAS FAULT . r oratories (desrye n rthquake); graduate School oterey Bay Aquarium and Monterey Bay Aquarium Research Institute Hopkins Marine Station; Stanford University Dive sites Symbols for a scuba diver, a remotely operated vehicle, and the manned submersible Alvin show approximate locations of the underwater photographs appearingin this article. Intertidal zone to sandy bottom 0 TO 100 METERS Built to endure the assault of waves and to feed on food brought in by the tide, a multitude of invertebrates cling to the rocky shores. Hunting at sea, marine mammals such as harbor seals and birds such as cormorants sleep on land. Beyond kelp forests teeming with life, plumy sea pens and other bottom dwellers populate the sandy mud plains that lead to the canyon. a Canyon walls I and bottom 300 TO 3,600 METERS Relatives of rock dwellers common in the shallows, sea stars, sponges, corals, sea anemones, and tunicates populate canyon walls. Often destroyed by turbiditycurrents or rockfalls, these communities recolonize on new rock faces. Eggs and tiny larvae- like those of creatures near the shore and in mid-water- drift to surface waters, where food is abundant. Animals not drawn to scale. <Mid-water 100 TO 3,500 METERS Weak sunlight fades to blackness in this realm. Like the lantern fish and wide mouthed hatchetfish, 90 percent of the animals are bioluminescent. Many are transparentfor camouflage. Gelatinous siphonophores and larvaceans act as a floating substrate for smaller animals. Much of the bay's sinking organic matter is consumed here. NGSCARTOGRAPHIC DIVISION DESIGN:CHRISTOPHER A. KLEIN RESEARCH/COMPILATION: LISA R. RITTER/MARY C. LATHAM PRODUCTION: ARTHURJ. COX, CHARLESE. MARTIN MAPEDITOR:GUSPLATIS CONSULTANT: H. GARYGREENE, UNITEDSTATESGEOLOGICAL SURVEY SOURCEFORBATHYMETRY: NATIONALOCEANIC AND ATMOSPHERIC ADMINISTRATION HABITATPAINTINGSBY NATIONALGEOGRAPHIC ARTIST WILLIAMH. BOND PRIMARYCONSULTANTS: DICKBARBER ANDBRUCEROBISON,MONTEREY BAY AQUARIUMRESEARCHINSTITUTE; CHUCK BAXTER,HOPKINSMARINESTATION J' .. ZAYANTE VERGELES FAULT NJ% Soundings in meters Scale varies in this perspective.