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March 16th, 2011:

Saving Hawaiian Monk Seals

I have never been to Hawaii. Okay, that’s not entirely true. I went when I was 4 with my family. I remember sitting on the beach and playing in the sand. I can’t tell you which beach or which island… it may as well have been Any Beach, USA. I’ve decided this visit doesn’t count.


Though I have never experienced Hawaii, I have always been fascinated by the islands. Specifically, I have always been interested in the Hawaiian monk seal. You see, I have my master’s degree in marine biology and I study seal diet. I had grand plans to study the Hawaiian Monk seal in graduate schoolbut unfortunately, it never came to fruition. I ended up studying the diet of Greyseals, off the coast of Maine. However, I now have an opportunity to go to Hawaii and study the Hawaiian monk seal. But, first, do you know why they are so important?

With a population of around 1,100 animals, the Hawaiian monk seal is the most endangered pinniped (seal/sea lion) in the U.S. and one of the most endangered marine mammals in the world. There were two other species of monk seals, the Caribbean monk seal, which has been declared extinct, and the Mediterranean monk seal — considered the most endangered pinniped in the world with a population of  less than 600 remaining. With only around 1,100 Hawaiian monk seals left and the population decreasing at 4% a year, this charismatic and important marine mammal may not survive much longer.

The monk seal, hunted by humans to near extinction in the 1800’s, has struggled to rebound. The majority of the seals live in the North West Hawaiian Islands, mainly between French Frigate Shoals and Midway Island. The monk seal has been fully protected for the past few decades; their primary habitat in the North West Hawaiian Islands has been protected for several years. NOAA has permanent research stations dedicated to studying this species and partners with many other organizations such as the University of Hawaii and The Marine Mammal Center.

Sadly, the monk seal is still not recovering. It is thought that the main reason for this lack of recovery is that most monk seal pups are dying of starvation. They have a less than 1 in 5 chance of making it to adulthood. This is probably due a shift in the availability of food and to competition for fish resources from other seals and other species such as sharks. If a monk seal pup can make it past the first few years of life he has a much better chance at surviving. But many young pups can’t seem to compete well enough to get the fish, cephalopods and invertebrates they need.

There is some good news. There is one small group of monk seals in the Main Hawaiian Islands whose population is increasing. What we need to do is to fully understand the biology and ecology of this small population so we can better monitor its growth. This increased understanding will be used to develop effective strategies to allow seals and humans to coexist in the Main Hawaiian Islands. The foraging ecology of these animals is a critical component to understanding the prey and habitat needed by the only growing population of Hawaiian monk seals.

I study seal diet. For this opportunity, in partnership with the Hawaii Institute of Marine Biology, University of Hawaii at Manoa and NOAA, we will use the latest technology in the field of marine mammal dietary studies to try and determine what the Main Hawaiian Island monk seal population is eating. We will collect seal scat (poop), a non-invasive sample collection method that causes minimal disturbance to the animals. (Yup, that’s right. I study seal poop. Don’t judge.)

In researching seal diet, we look for fish bones in the seal scat to see what the seals are eating. Sometimes certain fish species do not show up in the scat because their bones are so fragile. I will bring the scat samples back to the lab and analyze the them for prey item DNA. This method will give us more sensitive data on monk seal diet than we have been able to obtain in the past, thus giving us more insight into the diet of the Hawaiian monk seal in the Main Hawaiian Islands. Understanding the diet of marine mammals is tough to do since foraging is difficult to observe, so any information we can gain about this subject matter is valuable and will contribute to the conservation of the species.

Monk seals have been called “living fossils” because they are considered to be on the order of 14-16 million years old. We certainly don’t want to watch them become extinct! We hope that gaining insight into the diet of the small increasing Main Hawaiian Islands monk seal population will help us understand this species better and help to conserve a highly endangered species, before it is too late.

Help Dash go to Hawaii! The expedition is funded by the National Geographic Channel, but she needs to win a place from a program called Expedition Granted. To learn more, go to Expedition Granted and VOTE FOR DASH. To learn more about Dash, check out her blog.