Changing Seas

California's north-central coast is famous for its natural splendor. Here, on the very edge of the North American continent, steep cliffs meet the vast Pacific Ocean. Only 50 miles northwest of San Francisco's famous Golden Gate Bridge, yet light years away from the hustle and bustle of the human world, lies a magical underwater island few people have ever heard of. It's sensory overload. I've never seen so much color, I didn't know where to look. Pinks, purples, oranges, even blues and greens, it's just mind blowing. Every single square inch of reef is covered by some sort of invertebrate. In some places you've got sponges growing on top of corals on top of anemones. There was the biggest school of fish that I've ever seen. Anywhere. It's truly amazing. This is the Cordell Bank - an underwater oasis that is an ecological Eden. It is a shallow bank located at the edge of the continental shelf. Cordell Bank is the seabird capital of the Northern Hemisphere. Seabirders come from all over the world. Europe, Asia, Africa, just to do pelagic seabird trips out to Cordell Bank. It's been documented that whales and seabirds will migrate from thousands of miles away to feed at Cordell Bank because the ocean there is so productive. We receive birds from New Zealand, turtles from Indonesia, albatross from Hawaii, they all come here to feed. Something's got to be right for all of these birds, these whales to come here. What makes this unique location so special? And what is done to research and protect this place? Major funding for this program was provided by the Batchelor Foundation, encouraging people to preserve and protect America's underwater resources. And by The William J. & Tina Rosenberg Foundation, The Do Unto Others Trust, and by the following. Hidden beneath a surface that is often shrouded in fog, the Cordell Bank is located 20 miles due west of the Point Reyes Lighthouse. It is a pretty spectacular place in that it has the bank, which is about four miles across by about nine and a half miles long, which comes up a couple hundred feet from the soft sediment of the continental shelf. So, you've got this feature, in the middle of all of the soft sediment that provides hard substrate for organisms to live on. The shallowest point is 115 feet. But from there, it drops. Most of the shallow area on the bank is between 130 and 160 feet. For centuries, this underwater gem lay hidden beneath the waves. George Davidson, who worked for the U.S. Coast Survey, was the first to discover the bank in 1853 - shortly after California became part of the United States. Sixteen years later he sent out the accomplished surveyor Edward Cordell to map the bank, which would later be named after him. And then from that point forward, it was a landmark for mariners who are coming back into San Francisco Bay. But it would be more than a century later before anyone else decided to further explore the area. In 1977, divers with the non-profit research association Cordell Expeditions began to look beneath the surface. We need to give a lot of that credit to Dr. Bob Schmieder. He started diving out there with a group of volunteer divers for almost 10 years, recording just the spectacular biodiversity that's down on the bank. And for those of us who just look at the surface of the water from the shore, we would have no idea that that was out there. Bob brought those images back and went to Washington, D.C. and this was right when the Marine Sanctuary Program was getting started and he said, "You know, this is really a place that deserves to be recognized and deserves to be protected because it's such a spectacular place." Acknowledging its ecological importance, the National Oceanic and Atmospheric Administration established the Cordell Bank National Marine Sanctuary in May of 1989. The big driver was the prohibition of oil and gas exploration, which is one of our primary regulations. We also have regulations that prohibit the disturbance of the seabed. In 2015, the sanctuary boundaries were expanded to areas surrounding the bank. The sanctuary includes part of the continental shelf, from the deep slope habitat and then to the north, a prominent submarine feature called Bodega Canyon. It's all below the surface so it's really hidden from view and I think people are shocked when they learn that right off the California coast there's this area of incredible underwater beauty. National Marine Sanctuaries are important to protect, not just for people to visit and to see, but also because of the habitats that they protect. At Cordell Bank National Marine Sanctuary our science program is to understand the resources in the sanctuary and understand how they might be changing so that we can provide the best science information available for the best conservation. Since 2004, experts regularly conduct research at sea as part of ACCESS, which is short for "Applied California Current Ecosystems Studies." It's a collaboration between Greater Farrallones National Marine Sanctuary, Cordell Bank National Marine Sanctuary, and Point Blue Conservation Science. So, it's unique in that it's a public - private partnership and we each bring some resources and expertise together, and we're able to do much more than we could independently. And the object is to study the ocean health and that ocean ecosystem in the sanctuaries. We try and sample the same time frame every year so that we can look at changes over time. And to do that we survey three times a year, usually around May, July and September for six to ten days at a time. We want to hit the beginning of upwelling, the middle of upwelling, and right after upwelling. Wind-driven coastal upwelling is a physical process and North America's Pacific coastline is one of four major upwelling regions in the world. We have a persistent north wind blowing down the coast of California. And you would think that wind would drag the water along with it, well it does, but we're living on an earth that's rotating, and so the surface layer of the ocean, the top 100 feet or something, is pushed offshore and you have to replace that water with something, so you replace it with water from underneath. That cold water welling up from the deep is rich in nutrients. These nutrients fuel tiny surface-dwelling ocean plants known as phytoplankton, which form the base of the marine food chain. It's like when you put plant food to your lawn, upwelling works like that. It upwells strongest and most persistently in Point Arena, and then it flows south and as it does that the phytoplankton develops. It takes about three to five days for a good phytoplankton bloom. And the water will change colors-starts looking green or maybe a little brown, typically green. And by the time that's happened the water's moved 100 miles down the coast, which happens to be where Cordell Bank is. And there are a lot of organisms, krill for example, they will feed on these drifting plants. And of course they're eaten by fish and the fish are eaten by seals or the whales can be eating krill directly. So it's a whole ecosystem building up from those drifting plants. That is really the driver if you will. What makes Cordell Bank and many other places along the west coast of California so productive that then draws organisms from all over the Pacific to come and feed in this area. The ACCESS research team studies how the various oceanographic conditions influence the distribution and abundance of animals. When we are at sea we have two teams. A team that works on the flying bridge of the vessel. We have two marine mammal observers, one on each side. So, that's a humpback whale. And they're scanning in a 90-degree quadrant on their side for marine mammals. Then we have one seabird observer on one side and she's scanning her 90-degree quadrat as well, and one data recorder. So when they see a seabird or marine mammal they call out a series of codes. Common murre one, zone two, water. That gets entered into the computer with a GPS location. Our area here is actually probably one of the best places on the west coast for foraging birds and mammals. We observe humpback whales and blue whales and fin whales, grey whales. And seabirds like western gulls, common murres, shearwaters, storm petrels. Some of those are resident birds that breed in this area, but some of them migrate from thousands of miles away to feed in the productive waters here.

We get species from all over the Pacific including

Indonesia, New Zealand, Alaska, Hawaii. For example, albatross will have chicks on the nest in the Northwest Hawaiian Islands, they will come all the way to Cordell Bank to find food, and then they turn around and go back, and then they feed their chick all within the breeding season coming all the way to Cordell Bank and going all the way back to the Hawaiian Islands. And they'll do that several times throughout the nesting season. It's really the best restaurant on the west coast. We can be working and suddenly there's a breaching whale right next to us. Or we're working and we see an ocean sunfish and those are pretty amazing fish to see. We have these predetermined transect lines that we survey repeatedly each time we go out. The spacing of the lines are so that we don't double count things, but we want to have them close enough together so that we're doing a full coverage. The boat stops at multiple stations along these transect lines so experts can sample the water column. The second team works on the back deck. We're sampling for the prey, the zooplankton and the krill and the fish. And the stations are selected so that we can sample all across the continental shelf, and then the shelf break, and then we sample beyond the shelf break. The shelf break is an important feature for seabirds and marine mammals feeding. A lot of the food gets concentrated when the water upwells there, so that's a hot spot for seabirds and marine mammals. We deploy several nets, a larger net that we use to monitor zooplankton in the upper water column. And one time on every line, we deploy a really large net, and we send that net about 200 meters depth to sample for krill. And that goes back to the lab where all the krill get counted and sized and identified, there's a couple different species that we have. All the zooplankton goes to a specialist who will sort that sample and identify all the organisms in that sample. And so we're able to kind of quantify the water that we filter with the net and how much plankton is in that net and so we get an estimate of the prey availability to the seabirds and marine mammals. We sample the prey directly using nets or indirectly using hydroacoustics. So this computer is the hydroacoustic computer. Here we have a fancy fish-finder. And we- that operates at three different frequencies, and what it allows us to do is identify where fish, or where the krill concentrate. And then we're also doing oceanographic sampling. So look at the temperature and salinity and oxygen in the water. And the objective is to understand the ocean ecosystem health. So we're looking at the distribution and abundance of the predators, the seabirds, and the marine mammals. We look at the prey availability through the zooplankton, the krill and the fish, and then we look at the physical conditions in the ocean. By compiling these various layers experts gain a better understanding of how everything in the ecosystem ties together. And that's really how we can identify those hots spots of where we can allow certain things to happen, where we really shouldn't be allowing certain things to happen. While the sanctuary is actively protecting local resources, it still faces global stressors that might threaten the area in the future. One concern is lowered dissolved oxygen levels in the water caused by climate change. While low oxygen levels can occur naturally, human impacts have increased the frequency and severity of low-oxygen zones worldwide. If there were a really reduced level of oxygen at Cordell Bank like they've seen in other places like in Oregon, it could be really detrimental to the animals, the organisms that live on the bank, so we've been monitoring hypoxia, which means low oxygen, at Cordell Bank for the past few years. We haven't seen a huge die off, but we want to be monitoring and be able to catch things before we get to that point. The ACCESS research team, together with experts from the University of California, Davis Bodega Marine Laboratory, use a variety of sensors to measure the dissolved oxygen levels throughout the sanctuary. Under normal conditions, surface waters are saturated with dissolved oxygen from the atmosphere. Dead surface-dwelling plants and animals sink to the depths and use up oxygen during decomposition, making the water that upwells from the deep naturally low in dissolved oxygen. The animals that live down at depth in Cordell Bank, it's been millennia - ages that they've lived there, they've adapted to it and everything works fine. The concern of course is if we change that. As ocean surface temperatures rise with global climate change, the amount of dissolved oxygen the water can hold goes down. It also becomes more difficult for the oxygen to reach the colder, deep-water layers. The surface of the ocean gets warmer and it becomes more stratified. So you need more energy to mix up the cold water and the warm water and that also means that you will mix the oxygen from the surface down to depth more slowly. As a result of that, the oxygen at depth gets a bit lower. Meanwhile you're decomposing just as much material, but you're not topping it off with oxygen as rapidly if you have surface warming. We do see episodes every year of hypoxia on the shelf. In one case we had a report from a fisherman collecting crab that the crab were dead. So it can get low enough to cause impact. At this stage that's an unusual event, but that is the fear we have for the future if climate change continues to decrease the oxygen of the deep water in the ocean. Another climate change related impact affecting the oceans worldwide is ocean acidification an increase in the acidity of the water caused by rising carbon dioxide levels. Ocean acidification is the change in the ocean chemistry which makes carbonate less available to animals that build shells and it can cause their shells to dissolve, or they may have more difficulty building shells, it may be a stressful environment for them. So, this could really affect the entire food chain. So we are starting to see impacts especially on some of the larval forms that are out there and they're extremely vulnerable in the early stages of their life. If acidification started to impact things like krill who use the carbon to form their carapace, if those krill were to go away, salmon would be negatively impacted. Our whole ecosystem would kind of get tilted, if these impacts of ocean acidification continue. It would affect everything from the plankton in our local ecosystem to the top predators, like the whales and seabirds. To measure the acidity of the water in the sanctuary, University of California Davis Ph.D. Candidate Carina Fish collects water samples during the ACCESS research trips. And that helps us understand how changes in the water column have been going on for the past, say, decade or so. Carina is also studying how ocean acidification may impact a species of deep sea corals that was recently discovered in the depths of the Bodega Canyon, which lies north of the Cordell Bank. Named after their skeleton, bamboo corals are long lived and slow growing. We've seen them as deep as 1800 meters. It's very cold and it is also very dark. The water down there is probably around like four degrees celsius. They rely solely on the marine snow falling from above as their food source. Marine snow is made up of dead phyto and zooplankton - tiny marine plants and animals that are sinking down into the deep. We're not seeing - the polyps would be on top of the skeleton, so this is just the actual bone-like structure of them. And the reason why I'm so particularly interested in the skeleton is because it has a lot of history that it records in it. So the chemistry of this organic node, this black part here, records the life cycle of the coral and also the environment in which it grew up in and the diet that it ate. They're going to be anywhere from like 100 years old to 400 years old. So that's actually the beauty of deep sea corals. It's not just the past maybe decade or so that we've been monitoring. They give us a nice 400-year record. The fear is that as ocean acidification worsens in the upper layers of the ocean, it will impact the zooplankton the corals rely on as a food source. It could either be there are less amount of the available food or it could be the nutritional value of that food sinking down isn't as high. So that's what I'm investigating currently. The corals rely on the plankton, and the plankton rely on the ocean conditions. And so if you're able to understand the oceanographic conditions that you're seeing, the plankton communities that you're seeing, and the corals themselves, you can actually understand better holistically what the ecosystem is doing. It's really important as stewards of the sanctuary for us to be able to know how the sanctuary's doing. What are the status and trends, so that we can make decisions about management that we can use to better protect the resources in the sanctuary. As with any remote or deep place in the ocean, much is left to explore inside the Cordell Bank National Marine Sanctuary. There is a whole lot to discover. 'Cause every time we go down there, we find organisms that have never been described. Until a local group of technical divers became interested in exploring the site, there had been almost zero scuba diving on Cordell Bank, since the Cordell Expeditions team first explored it in the 1970s. Lots of helium. POV's good. It had kind of become like this mythical place. Everybody had heard about it. It was supposed to be amazing. It was impossible to get to. And so we always talked about diving it. BAUE, or Bay Area Underwater Explorers, is a local affiliate group to a global organization called Global Underwater Explorers. One of the things that drives us all is just the urge to explore. Documenting underwater life, and basically sharing that with the world so that they realize there's a reason to conserve what's under there. Diving on the Cordell Bank requires a highly specialized skill set, due to the challenging depths, currents, weather conditions, and remoteness of the site. It take's special training, practice and more importantly being very familiar with the type of conditions that are out there. Most of the divers have ten or so years of experience doing these kinds of dives on the California coast. It's typically very cold, low to mid 50s Fahrenheit. We need the wind and waves to be safe enough to get the divers on and off the boat, and probably the biggest unpredictable factor is the fog. The fog can move in without any notice. And so all of our diving is done live boating. There's a down line to get the divers to the structure, they will go wherever the dive is going to take them. And then when they're on their way back up they'll shoot a marker buoy so that we can tag that marker buoy and then follow them wherever the currents would take them and pick them up. In 2013, after years of research, planning and preparation, the BAUE team was ready to dive in. We worked closely with NOAA, and the Cordell National Marine Sanctuary team in particular, really to identify not just the regulatory steps required to go out there, but also to identify a mutually beneficial goal. They are a great group of individuals who have been collecting important information from the top of Cordell Bank for us, and it's been really a fantastic partnership. We've collected images, videos, species, samples. That first year, we got three days in a row of perfect conditions for diving and it was everything that we imagined and so much more. And we got out to the bank and it was like, "Wow! I can't believe we're actually here." As soon as we dropped in the water and we're coming on the bottom and I see just fish as far as the eye can see, in every single direction. You're like a kid in the candy store. It's of upmost importance that the public understands that these places exist and efforts to protect these places really do have a meaningful impact. Our hope is that by some of the work that we've done we can help kind of create that awareness for people that aren't necessarily going to get to see it themselves. California's Cordell Bank is a national treasure - one dedicated individuals and organizations are working hard to explore, understand, and protect for many generations to come. As a marine sanctuary, that's really our mission, is to maintain these ocean areas in the best possible condition that we can. Major funding for this program was provided by the Batchelor Foundation, encouraging people to preserve and protect America's underwater resources. And by The William J. & Tina Rosenberg Foundation, The Do Unto Others Trust, and by the following.