15 November, 1995



November 15, 1995

Location: Bransfield Strait. Sea Beaming/Sea Floor Mapping

Update: Larry Lawver, the Chief Scientist from Texas called me from the wet lab at 7:00 AM. I was startled from bed and answered the phone on the first ring. He said, Are you awake? I said Yes, mostly out of surprise and disorientation rather than being awake He said, "We just brought up a dredge and we have some really interesting stuff. You have to come down!

From the excitement in his voice, I knew that something really intriguing was lying on the back deck. I pulled on some clothes and boots, grabbed my camera and headed down to the deck. When I got there I was met by a sea of orange float coats. I felt like I was at an opening for some big event.

I knew when I had gone to bed that the OSU team had planned a dredge this morning near one of the suspected hydrothermal vents. I was half expecting to see some interesting volcanic rocks, or possible a part of a hydrothermal vent chimney. Instead, on a piece of white map paper are a collection of fish, sea stars, and worms laying on a piece of paper. It was like a mini fish market. Everyone on the ship made their way down to the wet lab, including the Captain and most of the crew. Photos were taken with the catch. Everyone was caught up in the excitement. It is unusual to find living organisms in dredges of the sea floor. Typically all that is collected by the dredge is rocks.

By 8:00 the scene had calmed down. Since I am the only biologist aboard, I happily became responsible for collecting, logging and preserving the samples. It was great! I really felt comfortable with the task and thrilled to be given the responsibi lity. I have had a good educational background and quite a bit of experience working with fresh water organisms. I felt a bit anxious as we began, because I knew that I was preserving these specimens for future research, and their might be a scientist one day cursing or praising our preservation techniques.

This was my first opportunity to work with salt water organisms. What is parcticularly interesting is that these organisms were collected at a depth of nearly one mile. Deep water organisms are referred to as benthic organisms. One of the research ass istants from OSU, Chris Schneller helped log and preserve all the organisms. After about three hours we had logged, packaged and preserved 23 specimens.

All of the organisms were deep water species, but none were specifically hydrothermal based organisms. One characteristic typical of animals from hydrothermal vents is that their biology is based upon sulfur. Hydrothermal vent animals smell like hydr ogen sulfide (rotten eggs) because of the sulfur in their environments. We collected three fish, worms, sea stars, nematodes and sponges off the rocks. It was a fantastic experience. Although these animals look similar to their fresh water relatives, the cold and high pressure conditions at the sea floor produces some inter esting variations, parcticularly in the larger organisms.

The gills and internal organs of the fish were void of any color. They were white with no evidence of red blood within their circulatory system. I saw no evidence which would indicate the presence of an air bladder. Buoyancy appeared to be controlle d by fat bladders on the pectoral fins. The body shape was tubular with a broad flat head. The two largest fish appeared to be the same species. The third fish was similar in shape to a tadpole. It had no caudal, or dorsal fins. Its circular in shap e was positioned in the middle of the front of the head. The jaw was not a dominant feature.

The sea stars had most of their appendages severed, although one had three of the five nearly intact. I have to email one of the Marine Biologists at the University of Delaware to see if he wants them sent to him at the completion of the cruise. If he does want them we have to secure the proper permits to transport them to the US. Other wise, they will be transported to OSU for their Marine Biologists.

We also sent down a deep submersible still camera. The photos show some of the small organisms on the rocks on the sea floor. They turned out extremely well considering the age of the equipment. The last time photos had been taken with this parcticul ar camera was in 1982. Mark Wiederspahn from Texas was responsible for its operation on the cruise. In the first days of the cruise out of Chile, I helped Mark clean and setup the camera and strobe. Small areas of the metal pressure housing in the area of the O rings was pitted from rust. There was considerable concern that the O rings which seal out the water housing might fail. Mark carefully cleaned all the metal surfaces and replaced the O rings.

The camera and strobe were cleaned and checked. Fresh batteries were placed in both units. The mechanisms were tested on the deck without film, and all systems seemed to work properly. Since we had only one battery for the strobe, there was no prete sting in the water. The photos from the vent area were the test, and the equipment worked well.

We continued our sea floor mapping for the remainder of the morning and headed to an intriguing region of the Bransfield Strait near a volcano to take a core sample of the sediments in a flat basin near the volcano.

Dr. Ben Sloan from the University of Texas and Amelia Shevenell, a senior at Hamilton College, were again responsible for the coring operation. The technique for using the corer seams to have been mastered by the coring crew. A beautiful sediment cor e was retrieved on the first attempt. Ben and Amelia spent about 6 hours taking samples of the core for further analysis at their universities.

Ben was hysterical about his post coring encounter with the birds that fly along with the ship. He described a scene that Hitchcock would have been hard pressed to imagine. As he tried to shovel the unneeded sediments overboard using a shovel, the birds flew near miss bombing missions at him. He could barely get the mud over the side due to what seemed to be an orchestrated assault.

After a short while Ben decided to take matters into his own hands and he returned fire on the oncoming bird squadrons using a water hose on deck. These were savvy foes and they lured his fire toward the side of the ship. Instead of hitting his troublesome antagonists with the stream of water, the ocean wind allied with the birds blowing back the steam into a spray that blew toward to the head of unsuspecting Amelia. What started out as a simple task of tossing some sediments overboard had evolved into an Antarctic Elvis and Costello style ship comedy with Ben and Amelia as its stars.

We left the coring site and set a course for an evening of ZAPS work. We continued our survey of the sea floor in the area with Captain Joe at the helm. All of the ships navigators are excellent sailors, but Captain Joe seems to see the Palmer as an ice yacht rather than an ice breaker. He thrilled us with a circuitous course through the bergs at sunset. It was a captivating evening ballet of ice and the light of the setting sun choreographed by Captain Joe at the helm.

ANNOUNCEMENT: Technically we have been having a bit of trouble with the servers that we manage the Antarctic Link Project from. As a result, some of the updates have been a bit slow at being posted. Without the help of Bob Manthey and Eric Truett man aging the page in the states, it would be impossible for me to post the updates as efficiently as they have been.

Due to some problems in Cyberspace we would request that you look for the Antarctic Link Page at one of the following two ULR locations. http://www.wctc.net/~bmanthey/antarc.htm or http://dns.worldweb.net/~etruett/antarctic.htm

These servers are stable sites and as a result you will see more frequent updates, and hopefully in a about a week photos taken while on the cruise.

We would also like to create a database of email addresses of those visiting the web page, so that information about future projects on this web site can be posted to you as well as opportunities for polar science curriculum materials. Also, we would like to be able to demonstrate to NSF and our sponsors the diversity of the audience that has been visiting our web page.

I look forward to your continued questions, I would appreciate any comments about the page as well.

QUESTIONS:

WFPHS95: The ocean in the region of the South Scotia Sea and the Bransfield Strait ranges in depth from about 4500 meters forming deep flat plains to steep abrupt volcanic mountains and ridges that are at a depth of about 500 meters below the surface. The sea floor has plains, valleys, ridges, hills and mountains just like the surface of the earth. The primary differences is that on the sea floor, the forces of erosion are very slow, so the features are more stark and rough on the sea floor.

Scientists are able to measure the rate and direction of these deep ocean plates by using and array of special geographical positioning Instruments that are anchored to the sea floor. These instruments record their geographic position using satellit e positioning. A special radio transmits the instruments position to the scientist. The instruments are placed on either side of a fault on two opposing plates. The change in the geographic position of the plates is used to determine the rate and direc tion of motion. Plates typically move centimeters to tens of centimeters a year.

From the data that we have, the hydrothermal vents in this area are miles to tens of miles apart.

The atmospheric pressure here changes hourly. We have had a high of 1005.5 millibars and a low of 948.2 millibars. In a single day it is not unusual to have a change of 2 to 3% in the air pressure.

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