Cambrian: Opinion

Elephant seal youngsters have the beach at Piedras Blancas to themselves right now

All the adult seals have left the beach, leaving it to the youngsters. It’s Fall Haul-Out time!

All seals migrate twice annually, as far as the Aleutian Islands or the west Pacific. Some travel as far as 5,000 miles each time, some not so far. It’s a demanding schedule.

The short migration is after the breeding season. Females leave in February or March and return in April and May. When they leave in May, they don’t return until the following January, when they come back to have their pups.

Males leave in March and April, returning in July and August. They are gone now, feeding and gaining weight for their return in November to contend for females in the breeding season.

Return of the young of the year

The pups that were born in January and February and left in March return in the fall, survivors of their first migration. They are the young of the year, and are the smallest seals on the beach.

Look for them among the older seals. The young of the year usually aren’t much bigger than the 200 pounds or so that they weighed when they left the beach in March and April. Surviving is the measure of success. They’ll gain weight later.

The older, bigger seals at Piedras Blancas for the haul-out are generally not older than five years.

Size alone is a good indicator of age, but check nose development on the largest seals. Males start growing that long appendage, which gives them their name at about 5 years old, so it’s an indicator of size among sub-adults.

Females don’t grow the nose, so it’s no way to tell on them. As adults, males are always larger than females, but until the male nose starts to grow, young males and females are difficult to tell apart.

Shark attacks increase

Fall is also shark feeding season along the Central Coast. Sharks are thought to be born or hatched in warm Southern California and Mexico waters, then migrate north as they grow and mature. Baby sharks eat fish, but when they are about 9 feet long, they transition over to eating marine mammals, like elephant seals.

Shark attacks on otters have increased about 30 percent in recent years.

Not much to eat on an otter, which the sharks spit out. The carcass then washes up on the beach, which is how we find out about it.

But a nice chubby elephant seal juvenile, with a couple hundred pounds of blubber, makes a good meal — and a less dangerous meal for a shark than attacking a full-grown bull that could turn around and attack a shark.

Younger sharks, that usually stay in warmer waters, have been observed recently in Monterey Bay. Scientists are studying whether warming ocean temperatures are influencing the fish to move to places where the water temperature suits them.

The Blob, a mass of warm water that developed off the coast in 2013, caused changes in the fish species. The warm surface temperatures of the following El Nino years also disrupted marine ecosystems.

Every seal on the beach is a survivor of a dangerous and, to us, still mysterious ocean world. Visit the viewpoint and welcome them back.

Christine Heinrichs is a certified California naturalist who writes about wildlife.
Related stories from San Luis Obispo Tribune

  Comments