Elephant seals take over beach left vacant by US shutdown

An understaffed stretch of California coastline has new residents: nearly 100 elephant seals and their pups

Alissa Greenbergin Point Reyes, California

Sat 2 Feb 2019 11.00 GMTLast modified on Tue 5 Feb 2019 13.00 GMT

During the US government shutdown, understaffed national parks were overrun by careless visitors. But at one spot in California, the absence of rangers meant a takeover by a horde of a different sort: a massive group of boisterous elephant seals.

Almost 100 females and their pups, plus a handful of three-ton males, have made a temporary home at the popular Drakes Beach at Point Reyes national seashore, 30 miles north of San Francisco. They have spilled into the parking lot, sheltering under picnic tables and crushing wooden railings under their weight. Their presence means that the beach is now off-limit to humans.

After working so hard to bring the pinnipeds back from extinction, closing the beach and access road was an easy decision, said John Dell’Osso, the head of interpretation and resource education at Point Reyes. “They’re at a critical time: the pups have been born there, they’re nursing. We’re not going to disrupt that process.”

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Seals help plug Antarctic water mystery

August 24, 2016

Elephant seals have helped scientists to demonstrate that fresh water from Antarctic's melting ice shelves slows the processes responsible for the formation of deep-water ocean currents that regulate global temperatures.

The study, led by Dr Guy Williams from the Institute of Marine and Antarctic Studies and Antarctic Climate and Ecosystems CRC, is published today in Nature Communications.

Macquarie's Professor Rob Harcourt from the Department of Biological Sciences is the Facility Leader for the elephant seal IMOS Animal Tracking program through which the data is collected.

Dr Williams said the findings raised questions about potential future changes in global ocean circulation patterns.

"Antarctica and the Southern Ocean are like a beating heart, producing deep and powerful currents of cold water that drive global ocean mixing and regulate atmospheric temperatures," Dr Williams said.

"These currents begin with intense sea ice formation around the Antarctic continent in winter, which creates cold, salty and dense water that sinks and flows away from the continent in large volumes.

"If this production of Antarctic bottom water weakens, it leads to changes in global ocean circulation patterns that can, in turn, lead to changes in the global climate."

In 2011, the same team of researchers discovered a fourth source of Antarctic Bottom Water off Cape Darnley in East Antarctica.

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Molting elephant seals add mercury to coastal seawater

Researchers traces elevated mercury levels in coastal seawater near Año Nuevo State Reserve to hair shed by elephant seals in annual molt

Date:  September 7, 2015

Source:  University of California - Santa Cruz

Summary:  As fish-eating predators at the top of the marine food chain, elephant seals accumulate high concentrations of mercury in their bodies. A new study shows that elephant seals shed significant amounts of mercury during molting, resulting in elevated concentrations of the toxic metal in coastal waters near the elephant seal rookery at Año Nuevo State Reserve.

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Benefits of being fat (but not too fat) for deep-diving elephant seals

Date:

November 5, 2014

Source:

University of California - Santa Cruz

Summary:

Researchers using a new type of tracking device on female elephant seals have discovered that adding body fat helps the seals dive more efficiently by changing their buoyancy. The study looked at the swimming efficiency of elephant seals during their feeding dives and how that changed in the course of months-long migrations at sea as the seals put on more fat.

Read on ...

Elephant Seals Seen Traveling Oceans for Food

Elephant seals travel through the entire northeast Pacific Ocean on foraging trips in search of prey, newly released tracking data shows.

These findings highlight the adaptability of elephant seals, suggesting that they may be able to withstand environmental perturbations such as climate change because the population is not dependent on a single foraging strategy.

The study, published yesterday, May 15, in the journal PLoS ONE, is one of the largest datasets on the species, including nearly 300 animals, revealing their migrations and diving behavior in unprecedented detail.

The researchers found that individual seals pursue a variety of different foraging strategies, but most of them target one oceanographic feature in particular — a boundary zone between two large rotating ocean currents, or gyres.

Continued:  http://www.livescience.com/20371-elephant-seals-traveling-oceans-food.html