Gerick's Outreach Blog

Tuesday, January 5, 2010

Science and (low) Technology

[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.

* You can learn more about what my research was about at: http://www.gsbergsma.com/research-interests/dissertation

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!

Tuesday, November 10, 2009

Goodbye Great White

[Originally posted to MBA Student Oceanography Club (SOC)]

The aquarium recently released the captive white shark that had been on display, but don't shed too many tears for her. As sad as it is to see her go, just think that now she can roam the entire Pacific, perhaps taking a much needed vacation to Hawaii before coming back to visit our local beaches again. At least that is what researchers have found that many other great whites have done:

http://www.washingtonpost.com/wp-dyn/content/article/2009/11/03/AR200911...

Researchers at the Monterey Bay Aquarium, Stanford University, and other organizations have been tracking these sharks for a decade now, and have found that great whites travel widely, but regularly return to our coast. Even so, the recently released shark will still regularly call to let us know how she's doing. For example, a couple of weeks ago she let us know that she was visiting the Monterey Canyon:

http://montereybayaquarium.typepad.com/sea_notes/2009/11/white-peacock.html

If you want to follow the latest news on the tagged great whites (or tuna, turtles, marine mammals or other pelagic predators for that matter), check out the Tagging of Pacific Predators web site:

http://www.topp.org/species/white_shark

Click on the "Near real-time tracking" button on the map to see where different animals are located. Our girl is listed under "Juvenile White Shark" with the ptt # 95118 and TOPP ID # 3309004. She is currently hanging out with the surfers near Santa Barbara.

Saturday, October 17, 2009

Salps in the bay

[Originally posted to MBA Student Oceanography Club (SOC)]

During our kayak trip, we saw some pretty cool organisms. Among the more unique were salps, the gelatinous creatures that were swimming everywhere. Salps are tunicates, marine chordates identified by their rigid tunic (also known as a test). Most tunicates, commonly known as sea squirts, are sessile, meaning they live permanently in one place firmly attached to the bottom. The 24 species of salps, however, have adopted a free-swimming, pelagic lifestyle. All are transparent, tubular, gelatinous animals that swim via jet propulsion as they pass water through their bodies.

Salps feed continuously on plankton and detritus as they swim. A mucus net captures particles suspended in the water that passes through the salp’s body. The net is constantly renewed, and cilia move the mucus like a conveyor belt into the gut. They are very efficient feeders, and some of the fastest growing of all multicellular animals; one species can increase its body size by as much as 20% per hour! Salps also reproduce rapidly, with generation times of several days. Because of their rapid reproduction and incredible growth rates, when phytoplankton is abundant, salps can form massive blooms. They can swarm by the millions or even billions until they filter out most of the plankton in the surrounding water, at which point the populations crash.

We likely witnessed such a bloom during our kayak trip. The species that we saw in the bay was probably Cyclosalpa affinis. Cyclosalpa can consume approximately half of their body mass in 24 hours, increase in body size by about 25% a day, and reproduce quickly, explaining the huge number that were present in the bay for several days. Like other salps, Cyclosalpa have a complex life cycle that alternates between solitary, asexually reproducing generations, and aggregate, sexually reproducing generations. The solitary phase, called an oozoid (shown in photo 1), buds chains of aggregate salps, called blastozooids (the arrow in photo 2 shows the budding chain coming from an oozoid). In some species, this chain can be up to 15 feet long. In Cyclosalpa, however, the aggregate salps form rings of individuals (shown in photo 3). The aggregate individuals remain attached while swimming and feeding, growing and reproducing as a unit. The aggregate salps are sequential hermaphrodites, starting life as females, and becoming males when they grow larger. Chains of small female salps will therefore mate with chains of larger male salps, and embryos are gestated within the female’s body wall. The embryos develop into solitary salps and are released, beginning the cycle anew.

Salps are an important part of the pelagic ecosystem. They are food for many predators, including jellyfish, fish, sea turtles and birds, and host a number of other organisms, including parasitic crustaceans and fish (the arrow in photo 3 shows a parasitic amphipod residing in a blastozooid). The fecal pellets formed from their prodigious feeding are also a major source of food for mid-water and deep-sea creatures.

Salp Oozoid