This summer, many of you have likely enjoyed feasting on crabs, be they blue, stone, or Dungeness, and a special treat will have been the big, easy morsels of claw meat. The size of this muscle is testament to its role in applying a forceful pinch to prey, predator, or competitor. But many crabs also use their lovely long claws to attract females—a function that does not depend on the power of the pinch. So which of these two uses was more important in driving the claw's evolution: its beauty or its strength? Female fiddler crabs have two small claws that they use to pick up bits of sediment...
Oceanic birds are a rare treat to see because these birds are not casual visitors to our coastline—to see them you normally have to get on a boat. So late last spring I was amazed to find hundreds of shearwaters stranded on the beach along the Atlantic coast of Florida. Shearwaters are oceanic birds related to albatrosses that spend most of their lives at sea, normally coming to land only to breed. In talking with locals, I learned that the strandings happen when strong winds blow out of the East. Weak from their long migrations, these birds had the bad luck to encounter strong winds as they...
Tags: Migration
Any floating object in the ocean tends to attract life; fishermen know this and deploy floating buoys to concentrate fish for harvesting. Plastic marine debris is no different and, at microscopic scales, microbes such as bacteria, algae and other single-celled organisms gather around and colonize plastic and other objects floating in water. Even small pieces of plastic marine debris the size of your pinky nail can act as microbe aggregating devices. We call this community of microbes growing as a thin layer of life (a biofilm) on the outside of plastic the “plastisphere,” analogous to the...
For more than two centuries, Boston Harbor has been a dumping ground. In 1773, colonists famously dumped shiploads of tea to protest taxes. But in recent decades, the harbor has received less tea and more sewage. In the 1970s, 43 communities sent their wastewater to Boston where it was barely treated before its release into the harbor. The harbor's pollution was so severe that local newspapers dubbed it “The Harbor of Shame” in the 1980s! But nowadays, after almost 25 years of intensive work by government and local organizations, sewage is no longer discharged into Boston Harbor and, as a...
Even on an early winter morning, it was sunny and warm in southern Florida. This was great because, regardless of the weather, Dr. Jon Norenburg and I were going to walk chest-deep into the water to scrape off animals encrusting some pier pilings near Miami Beach. Composed mostly of barnacles, sponges and sea squirts, this crust also harbors our quarry: intertidal ribbon worms , or nemerteans. We were looking for them to study their ability to regenerate missing ends after amputation. We have all probably heard about regeneration: if an earthworm is cut in two, each piece can sometimes grow...
When snorkeling in the Kahekili Herbivore Fisheries Management Area (KHFMA) in West Maui, I keep an eye out for certain kinds of fish. Not the brightest or the biggest, but those herbivores such as uhu (parrotfish), lau'ipala (yellow tang), or na'ena'e (orangeband surgeonfish) that mow algae. These fish can tell me whether a unique experiment in coral reef management that has the potential to restore ecological resilience —the ability for an ecosystem to rebound after a disturbance—is working. Inside the KHFMA, fishing for herbivorous fishes and urchins is banned, so the species I’m hoping to...
Those of us who can't see the ocean from our window might feel disconnected from the life there. It might seem that, because the ocean feels far away, its problems will only harm those people that fish or make their living directly from the sea. But this isn’t true: the sea is far more important than that. It's easy to forget the critical role the ocean plays in human life. The salty water of the ocean covers more than 70 percent of the Earth's surface. Ocean plants produce some 50% of the planet's oxygen. Seawater absorbs a quarter of the carbon dioxide we pump into the atmosphere. And...
Most people have never heard of the Hawaiian petrel , an endangered, crow-sized seabird that spends the majority of its life searching for food over the North Pacific Ocean. Nevertheless, this bird is no stranger to human influence, and it has a stern lesson to teach us about the history of the open ocean. When it comes to what marine predators can find to eat, humans are changing things, and fast. My colleagues and I have spent a number of years studying the history of this amazing seafarer. We’ve come to view it as a sort of indicator of food web history in the oceanic zone of the North...
Tags: Food web
As a research diver for the US Environmental Protection Agency (EPA), one of my jobs is to make sure that people and companies working in the fish industry don’t dump too much waste in the ocean. On my first dive at an underwater waste site, my old salt of a dive partner hinted, “you might see a shark… or three” with a wink. “Okay,” I thought, “I can deal with a couple of sharks.” Descending to the dump site, I soon saw circling dogfish and salmon sharks extending all the way from 80 feet to the surface—maybe 50 sharks, perhaps more. All those dogfish were drawn to a pile of Alaskan salmon...
Tags: Salmon
Even if you aren't a hardcore birder, chances are you have some hidden love for penguins. These flightless birds have captured our hearts through countless movies, beautiful images and their adorable fluffy young. Panoramic scenes of their large breeding colonies make penguin populations seem limitless, but the IUCN Red List of Threatened Species lists 11 of the 18 species as Vulnerable or Endangered. Penguins have certain characteristics that make them especially vulnerable to large-scale changes to our oceans and climate: their reproductive lifestyle of laying only one or two eggs,...