Wednesday, October 15, 2008
A Changing Ecosystem
Our study of creatures on the bottom of the sea has been done every year for 45 years. In fact, it is the longest series of data for fish, in the world. Why is this important? I asked Dr. Michael Fogarty, head of the Ecosystems Assessment Program, at the Northeast Fisheries Sciences Center in Woods Hole, MA.
Mr. T: This is the longest uninterrupted time series of a trawl survey anywhere in the world. Is that important?
Dr. Fogarty: Really important because the changes that we are observing occur over long periods of time due to fishing and climate and other factors, so we need to track these changes to see how individual fish species are doing and to see how the ecosystem itself is responding to these changes.
Mr. T: What have you found?
We have found overall in the 45 years that we have been doing this survey, the number of fish has remained the same, but the types of fish have changed. In Georges bank, we would have mostly cod, flounder in the past, now we have small sharks, skates, which are relative of the rays.
Mr. T: What does that mean in terms of the ecosystem?
Dr. Fogarty: It has changed the entire food web because, for example, these small sharks we are seeing are ferocious predators. Because these dog-fish prey on other species, they keep the fish we usually like to eat down in number
Mr. T: Why is that happening?
Dr. Fogarty: Our hypotheseis is that because the some fish have been hurt by too much fishing, the other fish have come in to take their place.
I thought about that for a while. It means this ecosystem has been effected by something called Overfishing and something called climate change. I started wondering about all the different factors that might have effected the environment we are studying. There are so many! Let's look at some of the may things that human beings have done that have changed this ecosystem in the 45 years we have been doing this study. Dr. Fogarty and I talked about this and then we created talked about this mini website for you. Click each problem area to learn more.
Remember the other day when I tried to use a sextant to fix our position? I could not even get close, so today, I took a lesson with one of the NOAA Corps officers on board, Lieutenant Junior Grade Andrew Seaman. Click here to come along.
Elsewhere on the ship, Snuggy and Zee paid a visit to the dive locker on the ship. This is the area on the ship where SCUBA gear is stored. We are not using SCUBA on this trip, but it was fun to visit the locker and see all the gear. Snuggy and Zee learned that the crew can actually fill up the air bottles they need right on the ship. They have all the equipment they need to do work underwater right here on the ship.
We had a fire drill yesterday. I know you are all familiar with fire drills, because we have them at school. When we do them at school, we often practice evacuating the building and calling the fire department. Well, at sea, things work a little differently. We have to get away from danger, but then, we have to practice putting out the fire as well. After all, there is no fire department to call way out here! Click here for a video.
Finally, so many of you asked about dangerous creatures that we have caught. This torpedo ray does have an electrical charge to it. The ray can zap you if you are not careful. I used rubber gloves to keep from getting hurt. The hardest part was holding the thing while we took the picture. I kept dropping it becuase it was so slimy!
AT: I have not been frightened by anything on the ship or in the sea that we have seen. The hag-fish did seem gross. Very gross. Other than that, no.
Hi SP, I enjoy Korean food very much and have eaten lots of crab roe. It does not gross me out at all. Thanks for writing.
NV, Zee and Snuggy are just fine. Thanks for asking.
Mrs. B's Class: I'm glad you liked the blog. We found the dead whale 100 miles or so off of Cape Cod. There are no sea snakes here. The water is too cold. I'm kind of glad about that!
Hello Mrs. Graham's Class. I am staying nice and warm. Even working on deck, it is not too cold. We could stay out for several more weeks without a problem. Do you know what we use to make electricity? See if you can figure that out. We have to go back to port before we run out of that.
Mrs. Christie Blick's Class: Very interesting. Our chief Scientists says that they can tell the whales don't like barnicles because whales without them don't behave in quite the same way.
Hello to Mrs. Coughlin's Class, Mrs. Berubi's Class. I'm glad you like the blog.
NN, I'll be back next week. Because the crew and I, as well as a few birds are the only land-creatures we have seen out this far! Thanks for writing.
Hi Jennnifer. Thanks for your kind words and thanks for checking in on the blog.