Davidson Seamount Explorers

The Davidson Seamount Explorers. Click image for larger view.


Ask an Explorer

Questions were sent to the Davidson Seamount team throughout the expedition. Selected questions and answers are offered below.


Randy Kochevar, Co-Principal Investigator of the Davidson Seamount Expedition responds to questions.

Question from Tim D.

Doesn't the pressure difference, associated with the raising the specimen from such great depths, effect the survival of the collected specimens?

The change in pressure can definitely affect the animals that we collect – especially those fishes that have gas-filled swim bladders, which expand as the pressure is decreased. We find that animals from the deep sea are very sensitive to changes in temperature, so we need to keep them very cold if they are to be kept alive.

However, many of the specimens we are collecting out here will be used in studies that don't require that they are living. In fact, many studies on biochemistry, physiology and genetics of these animals require carefully frozen or preserved tissue samples. So before each dive, we try to think about what specimens we are collecting and how they will be used once we get back on shore, so we know how best to collect and care for them on the way to the surface, and in the laboratory on board the ship.


Two questions from Betsy & Dick: Why doesn't the ROV arm hurt the animals it picks up and how is the top of the biobox closed without the animal escaping ?

The Tiburon's mechanical arm is a very sophisticated piece of equipment. The pilot can adjust the pressure it exerts with the claw, so it can crush rock or pick up a delicate basket star without damaging it. We also use a suction sampler, which works a bit like a vacuum cleaner, to catch soft-bodied animals without harming them.

And to answer your second question, the lids of the bio boxes are weighted with lead so they stay closed once an animal has been placed inside.

Is it possible to capture a rat tail to bring back for display at the MBA?

Scientists have found it very difficult to capture ratfish, and they usually don't survive the trip to the surface. Although their swim bladders are mostly filled with fats, there is still enough gas in them to cause problems at shallow depths.

We did deploy a large fish trap on the top of the seamount on our first dive (Saturday, May 18), in hopes of catching some of the larger fishes, but it only contained two crabs and 104 shrimp in it upon recovery three days later.



Question from M. Reed Brooks, Pea Ridge, AR

After reading the short history given in your website (which was excellent, by the way) one thing that struck me was that the early explorers were men of great patience, foresight, and determination. I got to wondering if any of our current exploration team have ever tried repeating some of the experiments performed back in the 1800s, using the tools available back then, and if so, were they successful in achieving the accuracy and precision that our early explorers achieved. Another question would be, given their choice, which experiment would they most like to repeat?

We agree – past explorers did amazing things with much fewer resources. Our explorers still use ships and nets in their descriptive studies, and have visited important historical sites such as the Galapagos Islands. However, we all chose to use modern navigation and computers to enhance our abilities. You have gotten us thinking about what we admire and would like to repeat from the past. Perhaps it would include revisiting basic taxonomy and natural history.

We have also discussed that explorers in the 1800's were using the most modern technology at their time. Yet, for instance, they never saw the animals living on Davidson Seamount. And, until 1933, no one even knew there was a seamount in this area! Imagine what explorers will find that we missed when they revisit this area 200 years from now!



Multiple questions from 58 sixth graders at Wood Middle School.

Geology:

1. What kind of volcano is the Davidson Seamount?
This question is difficult to answer. Davidson Seamount is a unique volcano, formed on an old spreading center. What we learn on this expedition will help us to answer this better in the future.

2. When did it last erupt?
About 12 million years ago.

3. What are the geological features of the volcano?
The most common features are pillow lavas and ash layers.

4. Is this the largest seamount?
No. The largest ones reach nearly to the sea surface. For example, Makarov Seamount, located between Midway Island and Japan, is larger. (Of course, once a volcano rises above the sea surface, it is considered an island rather than a seamount!)

Ecology:

1. Can you estimate the number of different species?
We've seen 18 different fish species so far, several different corals, several different sponges, many different sea stars, crinoids, and sea cucumbers, etc.…If you were to add up the total number of animals we will eventually identify as different species, it would probably be a hundred or so. However, this is just the number of large, obvious animals that we see. When we've zoomed in close on the large gorgonian corals, for instance, we see dozens of different animals living among the branches – suggesting that there are hundreds upon hundreds, or even thousands of different species living there.

2. Will anyone be diving around the top?
Even the top of the seamount is far deeper than SCUBA divers can go, and we aren't equipped (on this trip) to do blue-water diving in the water column above the seamount.

3. Can the exploration of the seamount affect the habitats?
The sampling we are doing does have a local impact, and the ROV occasionally bumps into things like corals. Also, the bright ROV lights may be harmful to some animals used to living in total darkness. However, all of these impacts occur in a very, very tiny area relative to the overall size of the seamount, and the pilots and scientists alike make every possible effort to minimize the impact we might cause. Just a few decades ago, had we wanted to study the animals on Davidson Seamount the method would have been to pull a deep dredge over it, and see what comes up. This would be far more damaging, and much less accurate than using the ROV.

4. What is the temperature range?
The temperature at the top of the seamount is just above freezing – about 2°C (35.6°F). At the sea surface, the ocean temperature is around 14°C (57°F).

5. What are the types of instruments that are going to be used on this expedition?
Although we often think of them as “vessels,” the Western Flyer and the ROV Tiburon are very sophisticated, multi-million dollar pieces of equipment. Working together, these tools give us the ability to navigate around a complex structure like the seamount; to record observations in real time; to make measurements of water conductivity and temperature; and to do all these things in a coordinated way such that all the data can be analyzed and re-analyzed later. Thus, these are the most important instruments we have at our disposal.

General Questions:

Can you tell us more about your observations regarding the association of sperm whales with the seamount?
Experts are not sure if there are two populations of sperm whales on and off the coast of California. If we are able to collect genetic samples from this expedition, we will help to answer this question. We sighted two small groups of sperm whales early this afternoon, but unfortunately were not quite close enough to obtain a skin sample for DNA analysis.

Are there any plans emerging for a more comprehensive management approach to seamounts in California and other parts of the US?
There are currently no plans to specifically protect seamounts. At the present time, none of our nation's seamounts lie within the boundaries of the National Marine Sanctuary system. The Monterey Bay National Marine Sanctuary is updating its management plan, and the public has asked to have the Davidson Seamount protected by the Sanctuary. This expedition will advise us in that consideration.


Questions from Kristina G., Poland

Greetings from Poland. I am reading with great interest the story of your exploration of Davidson seamount. I understand this is the second time scientists have explored the area. Where can I get information about the discoveries made on the first visit to Davidson seamount?
The 2000 expedition was run through the Monterey Bay Aquarium Research Institute, or MBARI. You can learn more on their website, at www.mbari.org.

What were the results of the in-Sanctuary survey on habitat diversity and health?
Unfortunately this survey was postponed due to a fire on board the Research Vessel McArthur. (We've corrected the text on the Davidson website to reflect this.)

Can you tell us more about your observations regarding the association of sperm whales with the seamount?
Experts are not sure if there are two populations of sperm whales on and off the coast of California. With genetic samples from this expedition, we will help to answer this question. We sighted two small groups of sperm whales early this afternoon, but unfortunately were not quite close enough to obtain a skin sample for DNA analysis.

Where can I get information about the other seamounts in California--their depth, status, species composition and threats?
I am unaware of such a resource, if it exists at all. The interest in seamounts, and the ability to explore them is relatively new – so I suspect that beyond basic physical data (i.e., depth, size, etc.), information is probably sparse.

I am familiar with the NSF web site on seamounts, but as a non-scientist, it is difficult to take full advantage of it. I will keep trying though. Are there any plans to create a web site that is perhaps not so technically intimidating?
There are no such plans that I am aware of. However, it might be possible if we find that there is a broad interest among the general public in learning more about seamounts in general.

The NOAA Ocean Explorations site is a wonderful example of an easy to use web site, but I wish it would provide more in-depth information.
It's always difficult to know how much is enough. Because the Web is open to everyone, it becomes very challenging to know who your audience might be, and what their level of background is on any given topic.

Are there any plans emerging for a more comprehensive management approach to seamounts in California and other parts of the US?
We are not aware of any effort nation-wide. Because of the proximity of the Davidson Seamount to the Monterey Bay National Marine Sanctuary, however, this expedition might serve as a first step towards including it and managing it as a national resource.

I am a US lawyer living in Poland currently doing research on deep sea marine biological diversity. As there is growing interest in seamounts and cold-water corals world-wide both as a habitat for commercial fisheries and as a repository of unique species I am proposing to prepare a paper on the subject for the upcoming California and the World Ocean Conference, in Santa Barbara October 27-30. Do you plan to present any of your research findings at the Santa Barbara conference? I am sure you would have a captivated audience.
There are members of the Expedition Team who are planning to attend the conference. However, they have not yet decided whether they will be presenting information related to this expedition.

Who should I ask about the possibility of using any photos for public presentation purposes--not for profit of course?
We will continue to make more images available on the Ocean Exploration website which you are welcome to use for presentations. If you require other images, you can contact me directly (Rkochevar@mbayaq.org) and we can discuss how we might be able to make it happen.


Question from Maia, 8th grader, Santa Cruz, CA

Is there any specific animal or organism that you are hoping to find for any special reason? An indicator species...?
We are particularly interested in large, old corals. We have encountered several different species out here, two of which grow incredibly large! They could be indicators of a spectacular, fragile habitat that needs special protection from human activities such as trawling and grab sampling from the surface.

Another phenomenon we are interested in studying is the occurrence of pelagic (open-ocean) animals near the seamount. It is thought by some that seamounts may act almost like a trap, concentrating these midwater animals as the currents sweep them against the seamount. The halosaur may match this description, as well as a couple of other animals we've observed.


Question from Chris, 8th grader, Santa Cruz, CA

Are there any animals that are unique to the Davidson Seamount?
This is a key question in the minds of our explorers. Unfortunately, it is very difficult to properly document very rare and unique animal specimens. On this trip alone we have seen several different animals that are in the process of being described as new species, and we will be sharing photographs, video footage and specimens with experts to determine just how rare or unique these animals actually are.

~In addition to finding several animals none of us had seen before, we've seen habitats that appear to be very unusual. The vast coral and sponge forests along the crest of the seamount are unlike anything that has ever been described in the deep sea, and have raised several questions about why different animals occur in different places along the ridge crests. Does it have to do with currents or substrate types, or something else we don't know about?


Question from Sean C., 8th grader, Santa Cruz, CA

Do you think any of these animals could help us?
The field of “marine pharmacology,” which searches for medically useful products in marine organisms, has certainly grown in the past several years. Given the diversity of animals we have seen on the seamount, particularly among the sponges, it would not be surprising to discover that some of them offer potentially beneficial compounds.

However, we have much to learn before we start discussing whether or how we might capitalize on the biological richness of the seamount habitats. At the moment, their greatest value is probably in helping to teach us about the astonishing diversity and beauty of life in the oceans. Despite decades of research in the deep oceans, we are just beginning to explore this vast undersea world.


Question from Tony S., 8th grade teacher, Santa Cruz, CA

What has surprised you or any of the team about your experience or findings at Davidson Seamount so far?
There have been several surprises. Some of them have been in seeing animals we've never seen, like the sea toad or the halosaur. Some of them have been in seeing animals in places we wouldn't expect them – like the footage we obtained yesterday of a midwater mollusk drifting only a meter or so above the bottom! And then there have been the subtler surprises, which come only with hours of observation and reflection: The Davidson Seamount is clearly host to several different, distinct habitats. There are forests of corals, and vast fields covered with sponges. Today we saw boulder fields littered with tiny, white anemones – which we hadn't seen on any of the previous five dives. These different habitats appear to occur at specific depths, but depth alone clearly cannot account for the different species compositions. So how can they be so different?


Questions from Tom J., Appleton, WI

Greetings, so many questions, so little space!! Is there any seismic activity to indicate that one day this volcano may someday wake up?
Nope. There hasn't been any seismic activity detected out here, and there hasn't been an eruption on the seamount in 12 million years.

Did you see any whales in the area?
We have seen a pod of sperm whales, a pod of orcas, a humpback whale, several Dall's porpoises, northern right whale dolphin and pacific white-sided dolphins.

And did you see shipwrecks/debris on the sea floor?
We haven't seen any shipwrecks, but we've seen debris on nearly every dive – an old milk bottle, a few soda and beer cans, a newspaper, a rolled-up window shade, several pieces of plastic, and a swatch of fabric.


Question from Jane C.

What do deep-sea red sea coral use as a food source?
Hi Jane! They filter organic material out of the water column, which includes just about any biological material (living or dead) small enough to get stuck on the tentacles of their tiny polyps. We have observed that many of these corals, even the really large specimens, are oriented into the incoming water currents – presumably to ensure that each polyp gets access to the food that drifts by.


Question from Gwen S.

Are there any drawings or graphic representations available of what the “mountain” actually looks like?
Some of the best images we have currently are on the web site. NOAA has also produced a special bathymetric chart on the seamounts, but you'd have to contact them directly to obtain more information.


Question from Mgraz53490@aol.com

Will the animals collected during this expedition be displayed at the Monterey Bay Aquarium? What kind of study will be done on these animals?
Yes, some of the animals we are collecting will be displayed at the aquarium, in the “Mysteries of the Deep” exhibition. Because these animals are new to us, however, we do not know how long we will be able to maintain them alive in captivity.

Those that cannot be kept alive will be used in genetic studies, or kept as preserved specimens to help identify similar individuals we see in the future.

Besides trying to figure out how best to keep deep-sea organisms alive for public display, we are curious about how old they are. For example, we think that some of the large corals we have collected might be hundreds of years old – maybe even older! To answer this question, we will have to use special dating techniques that are based on rates of radioactive decay.


 


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