Galapagos Fur Seals Gain Foothold In Warming Peru
Author: Terry Wade
ISLA FOCA, Peru - Taking advantage of warmer seas, fur seals from the Galapagos Islands have established a full-fledged colony on the Pacific Coast of Peru, some 900 miles from their normal habitat, local scientists say.
Though the fur seals have been spotted sporadically for several years along the northwest coast of South America, the scientists in the last few months have gathered evidence adult seals are mating and having babies in Peru.
Carlos Yaipen-Llanos, a veterinarian and marine biologist at the Orca research center in Peru, believes climate change has allowed the fur seals to expand beyond their traditional home.
"This is a unique species that used to live exclusively in the Galapagos Islands of Ecuador," he said after luring a baby out of a cave on the rocky island by barking to imitate its parents' calls.
"The scientific importance of the Galapagos fur seals establishing a resident colony in Peru is that the animals have extended their range and found a new habitat. This is associated with warmer water temperatures."
According to data from Peru's geophysics institute, water temperature readings taken every January over the last decade near Isla Foca have varied from 17 degrees Celsius (63 Fahrenheit) in 2000 to 23 Celsius (74 F) last month. Temperatures in the Galapagos are around 25 Celsius (77 F).
The colony of about 30 fur seals lives on Isla Foca, a tiny island populated by birds such as blue-footed gaviotas and pelicans, along with another larger mammal, the South American sea lion. The craggy island is near the city of Paita, about 700 miles north of Lima, Peru's capital.
The Galapagos fur seal is believed to be the smallest of its kind in the world, with an adult male weighing about 110 pounds (50 kg) and 5 feet 3 inches in length.
They move fast in the water, but waddle slowly on land -- across jagged ledges covered in white bird droppings that give the whole area the pungent smell of ammonia.
Galapagos fur seals tend to feed at night in the open seas and are smaller than sea lions, which grow to 9 feet in length.
WAITING FOR GENETIC EVIDENCE
Some marine biologists said the fur seals Yaipen-Llanos has been observing might in fact be another species, the South American fur seal, which thrives in Chile and Southern Peru, where upwelling in the chilly Humboldt Current creates the world's most productive fishery.
"Unless genetic evidence is provided, I don't think anyone can claim with much substance that these are Galapagos animals," Fritz Trillmich, a biologist at Germany's Bielefeld University who studies fur seals, said by email.
But Yaipen-Llanos, who is still analyzing genetic data for release later this year, said the Galapagos fur seals have noticeably louder and higher pitched calls than South American fur seals, as well as different coloring, stature, fur, anatomy and behaviors that he has seen in the field and on rescues of injured animals.
"The Galapagos fur seal is highly specialized. It often feeds on squid and mollusks typical of warmer temperatures, while the South American fur seal eats cold water species like anchovies," he said.
Northern Peru, popular with tourists because of its exposure to equatorial waters, sits near where the Humboldt Current veers west away from the continent.
It is an unpredictable region, where severe weather anomalies develop in years of El Nino, the periodic spiking of equatorial water temperatures in the Pacific.
The island appears to be affected by two phenomena -- a broader warming trend and El Ninos.
"That area of Peru is especially susceptible to temperature variation, with the interface between (cold and warm) currents moving back and forth," said Bill Patzert, an oceanographer at NASA's Jet Propulsion Lab in California.
EXPANDING BEYOND DARWIN'S ISLANDS?
When a strong El Nino forms in the central Pacific, easterly winds can overtake weakening westerly ones and send warmer waters east to slam into the South American coast, right around Ecuador and Northern Peru.
During a robust El Nino, rains can cause floods along Peru's desert coast and its anchovy stocks plummet as phytoplankton levels drop in the sea. The current El Nino has caused some flooding, but is weaker than the severe anomaly of 1997/1998 that triggered catastrophes globally.
Sara Purga, a biologist at Peru's Instituto del Mar, a government run marine lab, said average sea surface temperatures near Isla Foca have risen over the last five decades.
"This warming could generate the arrival (in Peru) of tropical species from Ecuador, mainly species such as turtles, tropical birds and colorful fish that we don't have," she said.
For Yaipen-Llanos, the Galapagos fur seal's move into a new habitat suggests swifts changes are occurring in the Earth's environment, with or without El Nino.
He wonders if fur seals from the Galapagos, where Charles Darwin collected evidence for his theory of evolution, will establish other colonies on the coasts of Peru, Ecuador or Colombia.
"With warming up along the continent, the likelihood increases that more colonies of Galapagos fur seals could be set up here," Yaipen-Llanos said.
(Editing by Dana Ford and Eric Beech)