You might have read this week about how our oceans are changing. A recent report by federal scientists confirmed what many fishermen already knew: the fish are on the move. Warmer waters are pushing species like cod, haddock and winter flounder further north, causing New England fishermen to have to go farther out to sea to get their traditional catch. Dr. Mike Sieracki from the Bigelow Laboratory for Ocean Sciences in West Boothbay Maine, has gone farther afield to study the effect of climate change. He's currently off the coast of Malta in the Mediterranean, doing a stint aboard a research sailing vessel which this year began a three-year circumnavigation of the world to study the acidification of the ocean. He spoke earlier with MPBN's Tom Porter.

Dr. Mike Sieracki: So I'm on "Tara" which is a French sailing schooner which is on a voyage around the world, the voyage of discovery, and I joined her in Malta, about a week ago, and I'll be on for a total of three weeks, on the legs from Malta to Tripoli, and then Tripoli to Dubrovnik, Croatia.

Tom Porter : Can you give us an idea of the scale of the expedition? What's the big picture? Where's it going to go on to? And who's on the boat?

MS: The boat is a round-the-world expedition, it's going to go for three years and it started in September in France going through the Mediterranean in the first year and we'll finish the first year in Cape Town, South Africa, and the secondnd year we'll take it through the southern Ocean, the South Atlantic and them across the Pacific to Australia, and the third year we'll take it from Australia up through the Pacific north, up around Alaska and through the Northwest passage back to Boston, and then over to France.

TP: And that'll be in 2012.

MS: Yes.

SP: So how is it working? Have you teams of international scientists rotating
throughout the voyage and who's organized the expedition?

MS: So the expedition is organized by a private foundation that's owned by Agnes B, which is a clothing style company in France and the Tara ship is built for expedition, it was in the Arctic for a two-year expedition where it was frozen into the ice and it was very successful. Now it's the rotation of scientists, there are about 15 people on board, five crew, five scientists, and five media people, so there's a heavy emphasis on public outreach and education. And we're trying to learn about the oceans in terms of the plankton of the ocean, using new molecular methods looking at DNA and imaging of the microbes in the ocean, and at the same time teaching the world about the state of the ocean and what the microbes are telling us about that.

TP: Why are plankton so important?

MS: So, you might know that the oceans cover 70 percent of the earth's surface and the plankton are biology of the ocean that keeps things going. Not only do they form the base of the food chain but they also control the chemistry, especially of the atmosphere, so they have a large impact on the oxygen and carbon in the atmosphere. Every other breath you take comes from phyto-plankton in the ocean, the oxygen comes from phytoplankton, so they're crucial to maintaining the life support systems of earth.

TP: And what effect does it appear that climate change could be having on the plankton and what are the implications for the rest of us?

MS: The newest concern has to do with ocean acidification. All the CO2 that we're putting into the atmosphere from burning fossil fuels is causing the ocean PH to start to change and that could have a more direct impact and it's one of the things we're going to be measuring on the Tara expedition.

TP: Now you're out there in Mediterranean at the moment, but back here in Maine we're seeing evidence of global warming in the ocean. We were just hearing about how warmer waters in the gulf of Maine are driving a lot fish away from the coast. Also scientists here are finding out that ocean acidification is posing a threat to clams and other bivalve populations. What are you noticing out there in terms of the impact climate change is having on marine life?

MS: Well, there are some things that we've seen changes in like terrapods which are little shelled animals, and their shells get absolved by the lower PH levels of acidification. We're also worried about corals, we're worred about any of the calcium-forming organisms like shellfish, but there's very little research on what the effects of PH are on these organisms, because we never really thought it would be possible to change the PH of the ocean.

TP: This expedition really seems to exploring new ground and blazing a trail in terms of the scope and depth of the work it's doing.

MS: Yeah it really is. There was a previous round-the-world trip but it really stayed in tropical waters and this expedition is really going to sample the important and interesting areas of the ocean including both the southern and northern polar regions.