Researchers from the National Oceanic Atmospheric Administration (NOAA) have discovered that thousands of sea lion pups from the coast of California are starving because their mothers are not consuming enough high-quality food.

It has been many years since the researchers have been searching for clues of why baby sea lions are starving. The pups have been suffering for years but nobody was able to understand that, and now, their situation is getting worse.

A study suggests that mothers are eating the oceanic equivalent of “junk food”. Credit: NOAA

In a new study published March 2 in the journal Royal Society Open Science, researchers could finally find the answer to this situation. They explained that it is all caused the pups’ mothers.

Female sea lions are not eating enough high-quality food which is directly affecting their babies. They do not get high octane fuel of sorts in their diet, causing them to starve and end up in an emaciated state.

The reason behind the mothers’ malnutrition is unknown and sadly, scientists believe that this is a trend that will neither reverse itself easily nor anytime soon.

Sardines and anchovy vs. rockfish and squid

Sea lions diet consists of a wide variety of fish and squid, with sardines and anchovies being their most favorite – and also the most nutritional and high in calories – and rockfish and squid being their least favorite and the junk food.

When sardines and anchovy go through natural environmentally-driven fluctuations, the sea lions health is directly affected.

Scientists analyzed data on the availability of forage fish in California sea lion habitats and found that sea lion mothers are being forced to eat rockfish and squid since sardines and anchovy populations are basically disappearing.

The scientists’ theory to explain why these fish are disappearing says that they are moving north to cooler waters since the waters off the coasts of California are getting warmer than usual, which results from the El Niño phenomenon.

More babies to feed

However, warmer waters are not the only explanation for the problem.

Sea lion population has risen from 50,000 to 340,000 over the past 40 years, which means that there are more sea lions hunting for food to feed more babies, leading their prey to become scarcer.

There is not enough food to feed this quantity of sea lions, so pups weight is lowering raising concern among biologists.

Now, people working on various animal centers have assigned themselves the duty of taking care of these babies.

Source: Royal Society