After our informative tour of the AUV Lab, we got started on a couple of mini research projects. For the rest of the day each of us learned about either biodiversity and its various indices and methods of calculation, or the various zones of the intertidal, the variety of invasive species and their effects, or the history and conservation of the Boston Harbor. We presented our findings to the rest of the group the morning after a short and hectic 4th of July hiatus from Sea Grant. Following our presentations and an early lunch we went down to the harbor to look at some plates an MIT Sea Grant member had used for his Master’s. As we pulled out the first plate we were astonished by a writhing mass of sea life.

The writhing mass.

As we looked closer we found 16 species in the two plates we pulled up only a couple of meters apart. These included the predictable mussel Mytilus edulis, the barnacle Balanus balanoides, and the sea squirt Ciona intestinalis, commonly known as a sea vase. We were surprised to see hundreds of the invasive skeleton shrimp Caprella mutica, which gave the impression that the entire plate was writhing. After we had our fill of writhing shrimp and tunicates we pushed the plate back into the water and tested the water for dissolved oxygen, (using both a probe and a winkle test!) salinity, (using a hydrometer, the probe and a refractometer!), pH and temperature. After we had recorded our data we packed up and headed home.

WINKLING! 

Sea Lettuce!

Anenome!

Probing and poking…

Clam Worm

On the third, we were given an excellent opportunity to visit the MIT AUV Lab – conveniently located in the same building as the Sea Grant program.  After a quick elevator ride and a jaunt down the hall way, we arrived  in what appeared to be a small museum. Decommissioned AUVs  hung from the ceiling or sat with wires exposed.

There we met Mike Soroka, who, while taking generous gulps of iced coffee, proceeded to take us through the history of MIT’s AUVs.

But what is an AUV? The acronym AUV stands for Autonomous Underwater Vehicle, used by marine scientists to go where they cannot.  Not to be confused with ROVs (which require a driver/operator), AUVs can be given specific tasks to complete without super vision.

The first vehicle we saw (and on of the first made in the MIT AUV lab) was the original Odyssey, made to go under Antarctic ice. This was something no ROV was able to do, since they required cable tethers and had short range.  But the Odyssey had one sixth the weight  and twice the range of all other vehicles and was able to go under the ice successfully in January 1993.

As AUVs became more sophisticated, more problems had to be addressed.  Turning, maintaining depth and position, resistance to pressure in deep ocean scenarios, etc.   The AUV lab managed to come up with an elegant solution to the problem of maintain depth and position. Instead of having a torpedo like fixed thruster at the back, the Odyssey IV has four in different locations.  Two are  fixed, cross-body thrusters which allow the Odyssey to move sideways without turning or moving vertically.  The other two bisect the body and are able to rotate – giving the AUV  four degrees of freedom and the ability to “hover” in the water.

Unfortunately, even with a high tech computer that measures exactly where each thruster is on its rotation, accidents can happen. Some times one thruster can get a little faster than another, which causes the AUV to “freak out”, as Mike put it, and pin itself to the ocean floor.

A good example of the autonomy and precision of AUVs  would be the AUV Odyssey IV ‘s pipe inspection. People in charge of oil rigs normally warn marine scientists to stay away from rigs because all the drilling and welding noise messes up the machines acustic instruments.  These instruments are vital for navigation, since GPS doesn’t work under water.  However, the Odyssey IV is different – it has a camera it can use for navigation.  To convince the oil workers  that was safe for the AUV to be there, the AUV Lab guys commanded the Odyssey to find the pipe, maintain a specific depth and distance away and drive three circles around it -only using its camera to navigate. The Odyssey IV performed it flawlessly and convinced the people in charge.  Here is  the demo video. A bad example would be crashing. Unfortunately the  Odyssey IV we saw was decommissioned after a boat landed on it while trying to pick it up with an on-board crane.

Mike Soroka also showed us the new AUVs they are working on: new, more specialized incarnations of the REX II  reef explorer.  The REX II itself is pretty cool. They managed to fix the problem of navigation by just attaching a giant buoy  to the top that houses a GPS navigation system.  Here are some highlights from some of it’s missions.

Further into the future, AUVs could navigate their own boat deployment systems, untie themselves from docks and go on missions -all by themselves.

The AUV lab was a truly excellent way to take a break from our mini research projects.

-Carolann

Hello Everyone,

Welcome to The Intertidal Times. Today is the second day of operation Sea Grant Ocean Summer Science Internship 2012. Yesterday we got started off with a bang. The team assembled at MIT at 9 o’clock sharp for introductions and to talk about the project we will be undertaking over the next four weeks, sampling and collecting data on The Boston Harbor Islands. Our team consists of our fearless leader, Kate, and the interns; Jeffrey, Pavlina, Carolann and myself (Isabelle.) After getting to know each we jumped right into the wilds of taxonomy in an effort to prepare ourselves for those species that we might encounter in the field. Tunicates, Arthropods, Copepods, and algae were discussed at length and the probability of finding each species during our sampling was calculated before we broke for lunch. After lunch Kate decided that it would be inhumane to make us identify different species of barnacles on a full stomach, so she whisked us off for a field trip down to Rowes Wharf on the Boston Harbor. 

For those of you who may not have noticed it is the Forth of July this week, which means that Boston is packed with people from around the country here to partake in our festivities and revel in our history. We managed to wend our way, without getting lost or run over by large groups of tourists, towards the waterfront to the research vessel The Song of The Whale. Kate has recently come back from a cruise aboard The Song of The Whale where she was tracking and listening to Right Whales. We were invited aboard to take a look around. The vessel was in a state of uproar since the crew is readying her to depart on a cruise to Iceland following the whales as they go. Jake, a crew member of The Song of The Whale and a friend of Kate’s, showed us around the boat; We got to see the hydrophones that they use to listen to whale songs and Jake talked to us about the different frequencies that whales use to communicate with each other and the properties of sound underwater.

Then it was on to the Lobster Lab at the New England Aquarium where we got a tour and learned about lobster shell disease and how what a lobster eats can effect its shell color. We also got to she the jelly culture lab, where they breed jellyfish, and the Right Whale research facility, where they conduct assays on whale fecal matter to detect stress hormones. Afterwards we walked around the Aquarium for awhile and looked at the fur seals and visited the sharks and rays. After an exhausting but informative and fun day we made our way back to MIT to collect our stuff excited about the next four weeks of marine science.

Yay science!

-Isabelle

Holding lobsters at the lab.

European Lobster. While believed not to get shell rot as badly as the American Lobster, the European Lobster gets it even worse.

Blue American Lobster.

An albino American Lobster. Researchers feed these lobsters a special diet to keep them white because it is easier to detect shell disease on white lobsters than on colored ones.