Even Energy Comes At a Price—Researchers Finally Quantify What’s Needed for Life

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Even long before the Darwinian notions of "Survival of the Fittest", one question has plagued mankind-what is needed to stay alive? With the uniquity of each species, and every individual within them, it has been a question that has long gone unanswered for the diversity and complexity shrouding a unified explanation. But as technology has advanced, making movement and energy consumption easily calculated tangible data, researchers have come closer and closer to an answer.

Giving a bit of insight into their quest towards the important truth, researchers at the University of California, Santa Cruz opened their notebooks and their lab doors for the public to get in on the data in this week's issue of the journal, Nature.

Their primary subject is a character of complexity himself. Known simply as KE18, part of the answer lies in this endangered Hawaiian monk seal. Captured and banished from his island getaway for his aggressive attacks on more than a dozen members of his species, KE18 is now at the forefront of the research, leading UCSC researchers to a monumental discovery-one that may save his species and many more.

In the wild, KE18's species is on a path to extinction; one that may be entirely attributed to the amount of energy the large marine mammals require to stay alive. Weighing in at just over 200 kilograms, he is a prime example of the best of his species. In the northwestern end of Hawaii's archipelago, the species is dying out. It is reported that four in every five Hawaiian monk seal pups die before reaching adulthood, leading to the species decline by more than 3% a year.

"They end up starving to death" program director at the NOAA Hawaiian Monk Seal Lab in Honolulu, Charles Littnan says. But, KE18 is not like the rest.

Splashing around in the researcher's pool, KE18 displays his newest ornamental trend-an accelerometer fitted to his tail that tracks his every move. And much like the fitness armbands we sport to the gym, that tackle the job of heart-rate monitor, pedometer and even blood-oxygen level monitor, this accelerometer gives researchers an insight into exactly how much energy keeps KE18 alive and thriving.

But he's not the only one.

As the cost of manufacturing accelerometers has greatly declined, thanks to their popularity in the health and fitness industry, where they're predominantly now integrated into mobile phones, ecologists like the team at UCSC have found that they are amazing way to collect data on movement and energy consumption to answer more fundamental and even some of the most complex issues related to an organism's physiology and body chemistry.

In fact, earlier this year polar bears, mountain lions and fish were equipped with the simple devices for the sake of gaining more insight into this research, and even more obscure organisms are finding that they too can contribute to the answer.

In the city of Brest, France researchers at the University of Western Brittany have attached motion sensors to predominantly stationary species like scallops (Pecten maximus}, a species that moves roughly only two minutes out of every day. Though the species may be much simpler than the mammalian research counterparts, the fact that these two minutes of movement which accounts for only 0.13% of their daily activity consumes 17% of their energy makes species like these valuable contributors to the questions we have.

Though the answer is still far from being found, developing methods to collect this accelerometry data and the valuable information gathered from individuals like KE18, are setting researchers on the right path to discovering a key factor of life. A truth that they believe will lead to some of the greatest discoveries of our lifetime.

"We're just at the beginning" lead researcher at UCSC's mammalian physiology lab, and KE18's personal keeper, Terrie Williams says. "It's a really exciting time for wildlife biology.