SeaWeb - Science: Did You Know?

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Turtle Tears?

Sea turtles have salt excretion glands behind their eyes, which makes it appear as though they are crying. These glands give sea turtles the ability to ingest saltwater without getting dehydrated.

You can spot the difference between seals and sea lions in four easy steps

Though they share many traits, seals and sea lions belong to two distinct families. Seals belong to the family Phocidae considered “true seals” while sea lions are classified under the family Otariidae, or “eared seals.” While you might find either of these Pinnipeds off the coast of Northern California, a trained observer can look for these four characteristics to distinguish between the two marine mammals:

Ears: Sea lions have visible external ear flaps whereas seals have small ear holes known as pinnae.
Front flipper: Sea lions have long, mostly hairless flippers with short nails whereas seals have short, fur-covered flippers with long claws.
Hind Flippers: Sea lions have flexible hind flippers that can be rotated forward to “walk” on land whereas seals have a single hind flipper that points backward to “worm” or “galluph” forward on land.
Whiskers: Sea lion whiskers are smooth whereas most seal whiskers are crimped or beaded.

Christmas tree worms use their bright feathery plumes for respiration and to gather food

These aptly named tube dwelling creatures live in tropical waters around the world anchored to corals. The cautious critters quickly retreat into their burrow when disturbed, slowly reemerging to extend their colorful plumes soon after. The polychaete worms use their distinctive filamentous fans to filter oxygen and tiny food particles and plankton from the water column.

All of the reefs surrounding Guadeloupe are threatened by human activities.

The World Resource Institute’s Reefs at Risk analysis classified almost every reef within the 400 km² area surrounding the islands as threatened by overfishing. The report estimated that eighty five percent of the reefs in the surrounding waters are threatened by coastal development while roughly twenty five percent of reefs are threatened by marine-based pollution. Additional anthropogenic threats include agricultural pollution, urban pollution and sediment runoff from deforestation.

Source: Reefs at Risk in the Caribbean >>

Seagrasses

Seagrasses occupy only 0.1% of the seafloor, yet are responsible for 12% of the organic carbon buried in the ocean, which helps reduce greenhouse gases.

The estimated coverage of seagrasses globally is between 300,000 and 600,000 square kilometres (186,000 square miles and 372,000 square miles).

A hectare of seagrass absorbs 1.2 kilograms of nutrients per year, equivalent to the treated effluent from 200 people.

Over a billion people live within 50 km of a seagrass meadow. Millions of people obtain their protein from animals that live in seagrasses.

More information about seagrasses >>