Tag Archives: zooplankton

Scientists Use Marine Robots to Detect Endangered Whales

Two robots equipped with instruments designed to “listen” for the calls of baleen whales detected nine endangered North Atlantic right whales in the Gulf of Maine last month. The robots reported the detections to shore-based researchers within hours of hearing the whales (i.e., in real time), demonstrating a new and powerful tool for managing interactions between whales and human activities.

The team of researchers, led by Woods Hole Oceanographic Institution (WHOI) scientists Mark Baumgartner and Dave Fratantoni, reported their sightings to NOAA, the federal agency responsible for enforcing the Marine Mammal Protection Act. NOAA Fisheries Service, in turn, put in place on Dec. 5 a “dynamic management area,” asking mariners to voluntarily slow their vessel speed to avoid striking the animals. (more…)

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Scientists Discover New Trigger for Immense North Atlantic Ocean Spring Plankton Bloom

Ocean eddies help jump-start plankton blooms that spread across hundreds of square miles

On this July 4th week, U.S. beachgoers are thronging their way to seaside resorts and parks to celebrate with holiday fireworks. But across the horizon and miles out to sea toward the north, the Atlantic Ocean’s own spring and summer ritual unfolds. It entails the blooming of countless microscopic plants, or phytoplankton.

In what’s known as the North Atlantic Bloom, an immense number of phytoplankton burst into existence, first “greening,” then “whitening” the sea as one or more species take the place of others.

What turns on this huge bloom, what starts these ocean fireworks? Is it the Sun’s warmth? (more…)

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Not a One-Way Street: Evolution Shapes Environment of Connecticut Lakes

Environmental change is the selective force that preserves adaptive traits in organisms and is a primary driver of evolution. However, it is less well known that evolutionary change in organisms also trigger fundamental changes in the environment.

Yale University researchers found a prime example of this evolutionary feedback loop in a few lakes in Connecticut, where dams built 300 years ago in Colonial times trapped a fish called the alewife.

In a study published May 23 in the journal Proceedings of the Royal Academy B, the Yale team describes how this event fundamentally changed the structure of the alewife and, with it, the water flea that the alewife feeds upon and the food chain that supports them both. (more…)

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First Satellite Tag Study for Manta Rays Reveals Habits And Hidden Journeys of Ocean Giants

Using the latest satellite tracking technology, conservationists from the Wildlife Conservation Society, the University of Exeter and the Government of Mexico have completed a ground-breaking study on a mysterious ocean giant: the manta ray.

The research team has produced the first published study on the use of satellite telemetry to track the open-ocean journeys of the world’s largest ray, which can grow up to 25 feet in width.

Researchers say the manta ray—listed as ‘Vulnerable’ by the International Union for the Conservation of Nature (IUCN)—has become increasingly threatened by fishing and accidental capture and now needs more protection. (more…)

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Study Amplifies Understanding of Hearing in Baleen Whales

For decades, scientists have known that dolphins and other toothed whales have specialized fats associated with their jaws, which efficiently convey sound waves from the ocean to their ears. But until now, the hearing systems of their toothless grazing cousins, baleen whales, remained a mystery.

Unlike toothed whales, baleen whales do not have enlarged canals in their jaws where specialized fats sit. While toothed whales use echolocation to find prey, baleen whales generally graze on zooplankton, and so some scientists have speculated that baleen whales may not need such a sophisticated auditory system. But a new study by scientists at Woods Hole Oceanographic Institution (WHOI), published April 10, 2012, in The Anatomical Record, has shown that some baleen whales also have fats leading to their ears. (more…)

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Evolving to Fight Epidemics: Weakness Can Be an Advantage

*Less resistance can sometimes be better than more–at least in a freshwater lake*

When battling a deadly parasite epidemic, less resistance can sometimes be better than more, a new study suggests.

A freshwater zooplankton species known as Daphnia dentifera endures periodic epidemics of a virulent yeast parasite that can infect more than 60 percent of the Daphnia population.

During these epidemics, the Daphnia population evolves quickly, balancing infection resistance and reproduction. (more…)

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Explosive Evolution Need Not Follow Mass Extinctions

In the wake of a mass extinction like the one that occurred 445 million years ago, a common assumption is that surviving species tend to proliferate quickly into new forms, having outlived many of their competitors.

But new research shows that tiny marine organisms called graptoloids did not begin to rapidly develop new physical traits until about 2 million years after competing species became extinct. (more…)

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