[Originally posted to MBA Student Oceanography Club (SOC)]
Elephant seals are amazing creatures. It
is easy to see them on the shore and imagine that they are slow and
lazy. Other than the brief brush ups among the males (see the video
above), they didn’t seem to do much when we were visiting, but in
reality they are well adapted for an extreme lifestyle.
For example, though they appear to laze on the beach for months at a
time, they do so without eating or drinking any food or water. Males
can be on the beach for as long as three months, and may lose up to a
third of their body weight during that time. To make up for that lost
weight, elephant seals must be voracious and efficient eaters, so when
it comes time to head to sea, they go right to the best fishing ground –
in the middle of the Pacific north of Hawaii for females, and up near
the Aleutian Islands for males – where they gorge on squid and fish.
The seals return to our coast twice a year, and may cover well over
10,000 miles in a year.
Each year they’ll spend 8-10 months at sea, 90% of which they are
underwater. They dive continuously, rarely spending more than five
minutes at the surface between dives. They even dive while sleeping,
taking 15-30 minute naps without breathing. While foraging, they can
dive for almost two hours at a time, and reach depths of nearly a mile.
At those depths, the pressure is tremendous; any air in their lungs
would quickly dissolve into their blood, causing major problems as it
turned back into gas when they resurfaced. To solve that problem, they
actually exhale, completely emptying their lungs, before they dive.
Without air in their lungs, they have a host of other physiological
adaptations that help ensure that they have enough oxygen so that they
don’t pass out while they are under water. For one, they have blood
extremely rich in hemoglobin, the protein that binds oxygen and gives
blood its red color. Similar proteins in their muscles allow them to
stock their tissues with large amounts of oxygen. When diving, they
also lower their metabolism, slowing their heart rate and stopping blood
flow to the skin to reduce oxygen consumption.
With such intense feats of swimming and diving, it's no wonder that they like to relax when they come to shore.
[Originally posted to MBA Student Oceanography Club (SOC)]
In our December meeting, we talked a lot
about the use of technology in research, and while it is true that many
scientists are always using the greatest advancements in technology and
engineering, some of us use simpler tools. I thought I would share the
items I used for one of my experiments to contrast with the
submersibles, satellite sensors, and DNA sequencers used by many of my
colleagues.
Tools I used to test how corals grow in different environments*:
Mask, snorkel and fins to work underwater, where I collected coral fragments and deployed blocks.
Cement blocks to anchor corals in specific places on the reef.
Glue to attach corals to the cement blocks (OK, so I actually used really expensive glue that hardens underwater).
Ziplock bags to bring coral fragments to the lab where I attached them to blocks and measured them.
Cooler to take blocks with corals attached out to the field at the beginning of the experiment.
Ruler to measure the length of the coral fragments at the beginning and end of the experiment.
I did fly in a plane to get to my study site, moved everything around
in a small boat and used a GPS so that I could locate the corals that I
put out on the reef, so my experiment did rely on some fancy
technology. However, creativity and what you have on hand are often the
only limits to what you can use for science. In the past I’ve used
lots of household items in my research, including kitchen pot scrubbing
pads, floor tiles, chopsticks, spoons, straws, coffee filters, plastic
cups, popsicle sticks, corn meal, paint brushes, cable ties, duct tape,
Tupperware, nails, sand paper and fishing weights.
Lots of scientists use low-tech items. A friend of mine used a
shark-shaped pool toy to observe how fish behave in the presence of a
predator, and the video below shows two of my friends using butter
knives and an aquarium net to catch coral crabs without destroying the
coral!
Copyright Statement :
