Whales swimming in the ocean are never really alone. Even if one swims by itself with no other whales for miles around, it still has company—the tiny microbes that live on its skin. For a long time, these microbes went unnoticed or ignored. What scientists knew about skin microbes on whales was limited to studies on stranded or deceased animals, and virtually nothing was known about the microbes residing on healthy, free-ranging whales. But as links are now emerging between the microbiology of human skin and health , immunity and skin disorders, I realized that it could also be possible to...
The pre-industrial American landscape was once rightly described as a place where “the deer and the antelope roam.” On land, we take it for granted that the plant-eating deer and antelope far outnumber the wolves and other predators that eat them. Over the years, when scientists saw many plant-eaters and small fish on coral reefs but relatively few large predators like sharks and snappers, they assumed that the underwater landscape mirrored this familiar pattern. But as we explore reefs far from human settlements, we're finding that this assumption may be wrong: coral reefs and other coastal...
Sea ice is typically viewed as the domain of physical and natural scientists, the oceanographers, marine biologists, climate modelers, and navigators of the world. It is easy to forget another perspective—that of cultural anthropologists like myself. I have often written about how dramatic changes in the polar climate have impacted people’s cultures during centuries past, and now I am watching these changes with my own eyes. In the areas where polar people regularly venture out onto the ice, they view it as a part of their home environment and a familiar space. They use it as platform for...
Often it's the tiniest organisms that do the most harm. One example is microscopic algae, which can grow rapidly to form harmful algal blooms . Such blooms (some are called "red tides") create unhealthy water conditions or produce toxins that kill other organisms in the water. In 2013, hundreds of Florida manatees died from eating toxic red algae, which also killed off their usual seagrass food. That same year, more than 200 dead sea turtles washed ashore in El Salvador, also killed by eating toxic algae. In 2012, it was jumbo squid on the California coast , and the year before that it was...
Over the past several decades, Florida’s coastal wetlands have been changing. Along the eastern shore, researchers have seen small mangrove trees appearing in areas further north than they usually occur, in places that historically have been salt marsh. So why are these mangrove trees popping up in unexpected places? In order to figure out why this is happening, we first have to figure out exactly where it is happening. This is easier said than done. Florida has hundreds of thousands of acres of coastal wetlands, and it would take an enormous amount of time to survey all of those wetlands on...
Picture this: clear, warm water bathing spectacular coral reefs , clouds of fish, circling sharks, and 17 scientists intent on studying the pristine tropical marine ecosystems of the Southern Line Islands . What could go wrong? That these ecosystems are, at best, nearly two days' transit from modern medical facilities—they sit roughly between Hawaii and Tahiti—may not weigh heavily on the minds of our scientists. But as the Diving Safety Officer for the Scripps Institution of Oceanography , I am always aware that even a relatively minor mishap can lead to major problems. Our team is composed...
Not all slugs (snails without shells) are slimy brown pests found in your backyard garden. In the ocean they come in a huge variety of colors — some match the background and are hard to spot, but others are very conspicuous. Nudibranchs in particular are especially popular with divers and underwater photographers because of their often vibrant and beautiful color patterns . The coloration is useful for more than just a pretty photo, however. Bright colors warn predators that these nudibranchs would make a bad meal because they are armed with toxins and other defenses. Where do these defenses...
Stare at a tide pool and you will often see a crust of pink coating the bottom. No, this is not bubblegum from some careless teenager’s shoe: it’s a stony kind of seaweed that, like other seaweeds, harnesses energy from the sun through photosynthesis. It may not look like the kelps and other leafy seaweeds that we usually think of—but seaweeds, which are a type of algae, come in a wide variety of colors, sizes, shapes and textures. These pink stony crusts are found in sunlit parts of the seafloor from the poles to the tropics, and collectively are called crustose coralline algae. Crustose...
Diving can be a wild ride that evokes more than a little trepidation, especially in the Pacific Ocean's famously big, cold waves. Waves that are otherwise fun for my weekend surfing can turn a scientific dive into a serious challenge. But then, diving to support the mission of the Environmental Protection Agency (EPA) can be full of surprises. At a seafloor survey site at the mouth of the Chetco River off the Oregon coast, waves transmit so much energy that divers can feel the swells nearly 80 feet down on the seafloor. As divers swim along the bottom, these swells often push them several...
In recent years, I have taken to watching flying fish along the Maine coast. Not the usual flying fish that skim over tropical seas, but fish dangling from the beaks of flying puffins. Puffins are famous for loading their colorful beaks with a dozen or more fish and winging home to feed their solitary, ravenous chick. In the late 19th century, spotting such overladen beaks was rare, as hunting for food and feathers had depleted most puffin colonies along the Maine coast. Their recovery took 40 years of dedicated conservation work —but the work isn't over. We still need to keep a close eye on...