Beneath the Surface
New discoveries in the Aleutians
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"Oh, my God, the beauty"
Shawn Harper, a UAF graduate student, photographer and amateur underwater videographer, grasps the rope attached to the rubber skiff and flips backwards, splashing into the water. It's a graceful movement, slow and controlled, but nevertheless requires a total commitment from the diver as he tumbles into the 45-degree water. With one hand still holding the rope, Harper checks that his regulator and tank are working, and then he slips beneath the surface. He sinks slowly towards the bottom, about 40 feet beneath the skiff, bubbles trailing quietly behind him.
As he adjusts the buoyancy in his dive suit to hover a couple of feet above the seafloor, Harper's camera captures a bouquet of dramatic colors -- reds, oranges, yellows and pinks. Most of the seafloor in the region is composed primarily of boulders and rocks.
These rocky areas are completely covered with assemblages of brightly colored creatures and plants -- sea stars, urchins, sea cucumbers, sponges, anemones, chitons and algae. Among this throng, a small fish or shrimp might suddenly appear, although it is often hidden within the brilliant colors. In many areas, it appears that the bottom has been painted pink because of a layer of coralline algae that grows as a hard crust on the rocky substrate. This organism, officially a plant, contains enough calcium carbonate to make it rigid and rock-like. Sea urchins, mollusks, chitons and other animals all feed on it, and entire mini-ecosystems are built upon this unique algae species.
Harper's dive buddy, Max Hoberg, a marine taxonomist with UAF, says that when he first sank to the bottom on a dive in the Aleutian Islands, he was stunned by what he saw.
"I'd never seen anything like this before, other than in the tropics. It was just amazing. The sponges were bright reds, oranges, yellows. In some ways it is indescribable. You're sitting there and your mind is going,'Oh, my God, the beauty,'" said Hoberg.
It wasn't just the colors that made diving along the Aleutian coast unique. The divers would not have been able to see the vibrant hues if it weren't for the outstanding underwater visibility. The seawater, in many places, was practically clear -- as clear as seawater can get. According to dive leader Jewett, the visibility was what made the underwater scenes so exceptional.
"Diving in the nearshore zone of the Aleutians is the best diving I've ever experienced in North America, especially from the standpoint of it being a cold-water dive. Visibility was just incredible. There were times when visibility approached 100 feet," said Jewett.
Jewett adds that this kind of visibility is unusual, especially during summer in Alaska, where large glacier-fed rivers bring tons of sediment into the nearshore waters. The particles remain suspended in the water column, making it appear murky nd preventing light from penetrating. Typical good visibility underwater in Alaska is about 30 feet, so 100 feet is just amazing, Jewett said.
Even though the seawater is clear, it is packed with nutrients -- and organic material that help provide sustenance for all marine creatures. Along the southern shore of the Aleutian Islands, the cooler, nutrient-rich waters from the deep ocean continuously replace the warmer, nutrient-depleted surface water. Jewett says the upwelling on the south side of the islands is part of the reason the area is so biologically productive.
"The diversity out there is unbelievable," added Jewett. "The mixture of invertebrates, fishes and kelps in that nearshore zone was head-and-shoulders above anywhere else I've dived in my 35 years of diving in Alaska."