Friday, May 30, 2014

Molting in May

 A sunny day on the beach. This young male couldn't resist pestering a female who wanted to be left alone.
 This tail looked especially ragged.
 A lot of youngsters, especially males, played in the water.
 Get rid of that nasty old brown skin!
Most were happy just to rest on the sand.

Saturday, May 17, 2014

Sea turtles and domoic acid

Wildlife biologist Heather Harris presented her work on how leatherback sea turtles are affected by domoic acid, the toxin produced by harmful algal blooms. That's kind of surprising, because the jellyfish they eat aren't thought of as being affected by domoic acid. But it turns out, they are.

She doesn't get to see many, but occasionally one washes up on the beach.She was here in 2012 when a tagged female died and turned up on our beach. As a veterinarian, she has been working on turtle health. She necropsied this one and found that she died of a bacterial infection caused by intestinal perforations. She had high concentrations of domoic acid in her urine and gastrointestinal contents. The question to Heather was: where did the DA come from?

Leatherback sea turtles migrate along our Central Coast. While they are here in the fall, they are eating a lot of jellyfish, to bulk up for their long migration across the Pacific Ocean. They weigh more than 1,000 lbs., so they eat huge amounts of jellyfish.

Shellfish, filter feeders such as mussels, bioaccumulate DA, but leatherback sea turtles don't eat them. She needed to look for DA in jellyfish. In 2010, that's what she did. She found DA in nearly every jelly of four different species that she sampled.

"Jellies may add a new dimension to offshore harmful algal blooms," she said.

"Human impacts affect the ocean. We are all connected. Anything we do to alter the environment affects us all."

More of Heather's work is posted on Oikonos.

Monday, May 12, 2014

Small nose, big plans

Visitors are confused by seeing so many seals on the beach, but no adult males with the iconic nose. These youngsters are about as big as are on the beach right now.
 This one's five years old. They may be very mature, but they are big and healthy. There weren't any entangled seals on the crowded beach. Good to see them looking so hearty.
This two-year-old doesn't seem to notice the five-year-old lying on him. Perhaps that big boy is giving him dreams to aspire to in the future.

Staying cool

The seals found ways to stay cool on this hot day.A lot of them were in the water.
Others stayed on the cool wet sand at the water's edge. I've heard that going in the water can retard their molt.
They certainly wouldn't want to impede natural processes! These young males are probably five years old, judging by their proboscis development.