PRESENTER 1: Next we have Carol Ladd up, also from EcoFOCI. A federal researcher, she's talking to us on the US Arctic and ecosystem, defined by seasonal sea ice and what happens when the summer sea ice is gone? 

CAROL LADD: So this is kind of a follow on to all of the stuff that Phyllis was talking about. A big part of our focus has been on the Bering Sea. We are also doing a lot of work in the Arctic, so I'm going to talk a little bit about that work. So this, like the Bering Sea, is a system driven by sea ice. 

Early in the spring, as ice starts to thin, we see an ice algae bloom at the base of the sea ice. And ice algae tends to be very clumpy, and falls to the bottom as the ice starts to retreat. And it feeds a very rich benthic ecosystem. As the ice retreats, we start seeing an open water phytoplankton bloom, which then uses up all the nutrients in the surface layer. And we end up with the subsurface bloom. 

So the two different kinds of phytoplankton influence the ecosystem in different ways. And they're both dependent on the timing, and extent of the ice. So the ice also influences-- in addition to kind of the base of the food chain, it also influences the distributions of commercially valuable fish, endangered species, and subsistence hunting in the region. So it's incredibly important, and we need to understand how this ecosystem is going to change as this ice continues to decrease. 

So Phyllis showed this map earlier. I'm focusing on the northern part, North of the Bering Strait. And we are up there every summer collecting shipboard data. And we have an extensive array of moorings up there, some of which have been out there for 10 years or longer now. The shipboard data gives us only ice-free conditions typically, and the moorings give us year-round data. 

In the center here, we have an example of some of the types of data that we collect on our moorings. Often our moorings are also located with acoustic moorings, provided by the Marine Mammal Lab. So we're out there at the same time collecting the physical data, at the same time that the Marine Mammal people are collecting data showing the timing and distribution of mammal migrations and that type of thing. 

And a lot of the mammals out there are endangered, and are also subsistence resources for the region. And we also work very closely with the Innovative Technology group at PMEL, and the engineering group in developing new technologies that allow us to measure underneath the ice, and particularly at the ice ocean interface, which is so hard to understand and get data under. 

So I said the ice is decreasing. This is just a look at satellite data showing just how fast this ice is decreasing. So the colored map here, is the trend in the length of the open water season. So if we define the open water season as any time that ice concentration is less than 30%, we can look at how long that ice part of that open water season is each summer. And the trend, you can see the colors. So warm colors are up here three days per year, over the last couple of decades. 

And I've shown the location of our moorings out there, and I'll focus a little bit on that C2 mooring, which is our longest time series in the region. And the time series at the bottom here, shows the trend, just at that C2 location. And we're looking at a difference, early in the record in the early 1990s, it was somewhere on the order of 80 to 100 days of open water every summer. 

Now we're up to close to 200 days of open water, so the ice is retreating earlier in the spring, coming back later in the fall and it's influencing a lot of the ecosystem. So it's a really rapid change. So that's influencing the bottom temperatures in the region, but with all of the temperatures. 

But this was just a look at our bottom temperature record from that C2 mooring. So you can see that there's-- so these black lines are the record, from 2010 to 2060. There is a lot of variability during the summer. It's freezing temperatures during the winter. If we had 2017 on top of that, the ice retreated very early in 2017. And we got that extreme warming early in the year, higher than we had ever seen before. And that heat in the water column stayed throughout the summer. 

In 2018, the ice stuck around longer, and came and went during the spring of 2018. We didn't see that really extreme warming in the early spring, but we did see the highest temperatures we've observed by October. So really, really kind of outside of our range of what we've measured previously. 

And so on our moorings, we also measure nutrients. This is work by Calvin Mordy. Here I'm showing on the left, is the nitrate measured at our M8 mooring location down here in the northern Bering Sea. You can see there is a lot of interannual variability there. 

And so that's fall nitrate. If you look at the following spring nitrate at our C2 mooring, you can see-- so the bottom axis here is the fall nitrate at M8. And the side is the spring nitrate at C2. And you can see there is a very nice relationship between the two, other than this one outlier in the winter of 2011, 2012, which was due to very weak transport in that area. 

From our array of moorings here, our three moorings, we can calculate the transport across that line. And that's what this plot up here is. The green dots are the monthly average transports and the black line is a three month running mean. And you can see that transport has kind of changed in these last couple of years. 

We're seeing stronger northward transport than we've seen before. That's associated with stronger northward winds, and more frequent episodes of northward winds. And you can also see this winter of 2011, 2012 and again, in '12-'13, which-- especially this year of 2012-- was that year of maximum ice, which is associated with the direction of the winds and all of that. 

Over here is where we had lower transport during the winters, and that's part of the reason for that outlier there, where the nutrients from the Northern Bering Sea did not make it to the Chukchi Sea, to our location in the Chukchi Sea in time for the spring bloom that year. So all of this kind of ties together, in enforcing the ecosystem of a region. I think that's all I've got. Thank you. 

[CLAPPING]