World class deep diver
The Elephant Seal
With content provided by Jessica Meir and Paul Ponganis.
Reviewed October 27, 2009 by Jessica Meir, Birgitte McDonald,
and Paul Ponganis.
Photographer - g-na. License granted according to Creative Commons Attribution-Noncommercial 2.0 Generic
It begins in November with the arrival of the serious contenders, the behemoth males that come from the sea.
They arrive early, to fight for beachfront property and attract large harems. Soon-to-be mothers arrive next and their pups a few days later.
In Januaries of recent years, more than 100,000 elephant seals appear on California beaches during the breeding season. Over the year, individuals come-and-go according to a complex schedule that masks how much of their lives they spend at sea, in places that were unknown even two decades ago.
Decline, recovery and future - Every northern elephant seal is a descendant of just 100 or so individuals that remained at the end of the 19th century after hunting had reduced their numbers.
In his account from 1874, whaler and naturalist Charles Scammon reported that a "fat bull, taken at Santa Barbara Island ... in 1852, was eighteen feet long, and yielded two hundred and ten gallons of oil" . Elephant seals, and more significantly whales, were once valuable sources of oil for lamps and machines.
The last elephant seals were saved by the coincidence of their extreme scarcity, international conservation efforts and development of alternative fuels at the start of our fossil fuel-based economy.
They have been a conservation success story, but there are new concerns about their continued success. Climate change is expected to affect a part of the world we've just begun to explore - the deeper parts of the ocean where elephant seals spend most of their time hunting for food.
The fossil fuels that saved their blubber a century ago may be altering their food supply.
Extreme capabilities, extreme solutions - In the mid-1990s, satellite-based tracking tools became affordable enough to let biologists follow these animals.
Elephant seals turned out to be one of the world's deepest-diving and farthest migrating air-breathing mammals.
Some were diving nearly a mile under and staying down for as long as two hours.
They were spending most of their time hunting at unusual depths where human impacts on fish stocks and habitat were just beginning to be realized.
How these animals dive so deep is still a secret. Scientists don't know enough about these animals yet because the numbers don't add up. Elephant seals stay down longer than their known oxygen supply should allow.
Researchers Paul Ponganis and Jessica Meir want to know how they do it. Are these animals carrying more oxygen than we think? Do they have novel ways to stretch their oxygen supplies?
Jessica and Paul’s recent research has revealed that elephant seals can tolerate much lower levels of oxygen than humans. Humans lose consciousness with more than a quarter of their oxygen supply left, while elephant seals operate down to nearly zero. This capability is particularly interesting because it may translate into better ways to help people survive stroke, heart attack, and organ transplant surgery.
Research raises our awareness of the needs of these animals and informs efforts at conservation. Knowledge of the behavior and physiology of this animal is vital to understanding its role within complex ecosystems. Furthermore, this research has potential benefits to human health.
Continue and learn more about these animals.
In the U.S., a grad student is a student who is going to school beyond graduating from a four-year college or university with a bachelor's degree. Even though graduate studies happen at many of the very same colleges and universities that offer undergraduate degrees, graduate students are said to be attending "graduate school" instead of college like undergraduates. There is no consistent difference between a school called a college vs. a university.
What degree is earned? In graduate school, a two or three year program usually leads to a master's degree and 3-6 years beyond that leads to a doctoral degree or Ph.D. Master's and doctoral degrees are considered "advanced" degrees. Many programs require a master's degree before continuing on to pursue a doctoral degree. Graduate studies in business, medicine and law also occur after obtaining a bachelor's degree from a four-year college, but they are often in separate programs leading to professional degrees. People who earn a Ph.D. or doctoral degree are typically not medical doctors, although a medical doctor can also have a doctoral degree. The length of the program for master's and doctoral degrees varies by program, school, and individual.
What fields offer master's and doctoral degrees? Many fields in sciences, engineering, humanities (literature, social studies, education) and the arts offer advanced degrees. Applied field such as studio art do not usually offer the doctoral degree although academic fields such as art history do.
What does a graduate degree do for you?
It varies, but the experience builds specialized skills, expertise and judgment in a specific area of study.
- Many jobs require particular graduate degrees. Businesses often require particular graduate degrees for particular positions. Specific graduate degrees are also required to obtain licensing required to do business.
- In a practical sense, you build important transferable skills and knowledge in graduate school.
- You learn nuts and bolts about your area of expertise that you will not learn on the job. This often involves coursework at the graduate level. For example, human anatomy and the use of differential equations are not learned on the job.
- You gain the skills to conduct independent research - to analyze a situation, write professional quality reports, and give advice on matters that have important consequences.
- You gain practical skills in how to approach a research question or problem - how to break down a problem, to organize field activities, coordinate and work with teams of people, conduct or manage lab work, give professional presentations, and more.
- You learn about common, expected and regulated practices in business.
- You develop a sense for the limits of your expertise relative to others. You know who the experts are, where to find them, and when to say you don't know.
- You develop a sense for what others have already done and solved, so you save time and resources and don't reinvent the wheel. Your knowledge is current and up-to-date in your field.
- You learn how to find out new things as you need them. You know how to learn on your own and how to find outside resources when it is more efficient.
- You have access to internship and other opportunities that allow you to gain skills and knowledge about a particular business, governmental agency, or non-governmental organization that hires graduate students with particular degrees. It allows you to make contacts with people who might want to hire you after you graduate. It gives you an insight into the kinds of things that are best learned on-the-job.
- A person with a master's degree is expected to be able to conduct research, and to defend their work in writing and in person. This is the terminal degree required by many jobs. It is also the degree that allows you to teach in many community colleges.
- A person with a doctoral degree is expected to break new ground in their research - to answer questions that no one has every answered to extend the body of human knowledge. Many large businesses rely on the specialized knowledge of at least a few people with this degree. The doctoral degree qualifies you to become a professor in a four-year college or university.