It Was The Perfect Fish Study — Until Nature Messed It Up

hen the San Clemente Dam in Carmel Valley gets demolished next year, steelhead trout will get 25 miles of an open-water, upriver swim to find their spawning sites – something the seafaring fish haven’t had since the 106-foot-high dam was built in 1921. For scientists, the dam removal project presented the chance to study the threatened Central Coast trout before, and after, the river restoration. The setup seemed ideal: scientists could take advantage of the meticulously planned project to design simple studies that would yield high-quality research data.

But, to borrow a line from Steinbeck, the best laid plans of mice and men often go awry. Especially in scientific studies that need nature to cooperate. This year’s drought turned simple research projects into long lessons about the ways scientists have to adapt to save their studies when real life intervenes.

“It’s typical of field projects to start with one design and then have nature throws curveballs at it,” said David Boughton, a research ecologist at NOAA’s Southwest Fisheries Science Center in Santa Cruz. “But this took it to a whole new level.”

In the elegant original design, Boughton’s research group planned to put tiny tracking devices, called PIT tags, in 1,000 young trout. When the fish migrated out to sea, antenna strung across the lower river would catch and record the unique electronic IDs implanted in the fish. If those trout came back next year, the antennae would pick up that data, too. The scientists also intended to trace the fish that stayed behind in the upstream pools and tributaries. (A still-mysterious fact of trout life is that some smolt develop saltwater adaptions to swim in the sea as steeelhead while others remain riverbound and lead the freshwater life of a rainbow trout. So studying the fish that stay behind could give scientists clues about why trout “choose” the river or the ocean.)

agging those fish should have been the easy part of the study. The Sleepy Hollow steelhead rearing facility (SHSRF) crouches alongside the Carmel River, not far below the San Clemente Dam. The facility is a long, concrete channel built with riffles, pools, and overhanging branches, to mimic a natural creek. And every year, an average of 16,000 young fish are rescued from isolated pools in the river, relocated here to eat krill and grow until they’re ready to smolt.

The fish are generally released when seasonal rains raise water levels enough for the river to flow all the way to the ocean again. In drawing up the plans, you could look at the facility’s history and think of those trout as a study group just waiting to be tagged. But if you looked at last year’s weather, you’ll see where things started to go wrong.

“PIT-tagging was a first step to answer the question: Is the rearing facility producing viable smolt that migrate to the ocean, survive, and return?” Boughton said. “Then it got complicated.”

The fish rearing facility depends on water diverted from the river, and the river needs to flow at least five cubic feet per second for the facility to operate. Unfortunately, 2013 was a very dry year. Almost double the average amount of fish were rescued and taken to Sleep Hollow. Then, when the winter rains never came, the Carmel River dribbled downstream at three cubic feet per second, a flow rate that wouldn’t sustain the fish in the facility. The 10,000 young trout that survived had to be turned out in September to make do with whatever deep pools of water could be found.

“If there’s a way that nature can get in the middle of a good field study, it will,” Boughton said.

The researchers scrambled to find a place to tag, feed, and grow 1,000 of those turned-out fish until the river levels rose. Fortunately, there were big tanks available at the Southwest Fisheries Science Center in Santa Cruz. The situation wasn’t ideal because now the tagged and untagged fish wouldn’t be reared under the same conditions, and that could affect the study results. But at least the fish had a place to stay until smolting, which typically occurs during April and May. The Sleepy Hollow-reared fish were usually released earlier than that. So things should have gone, well, swimmingly. But they didn’t.

Boughton and his collaborators soon found out their fish had to leave the Santa Cruz tanks in February. Other researchers had booked those tanks for their studies and they expected them to be empty when they arrived. Once again, the trout were out. With hardly any rain all winter, the Carmel River was still at abysmally low levels. Still, there was no other option. The tagged trout went back to the river, too.

Finally, almost four inches of rain fell in February, and another three inches poured down in March. Not much, but that was a deluge compared to the previous dry months. At the Sleepy Hollow weir, water district gauges showed the river was flowing at more than 200 cubic feet per second at the beginning of February. The steelhead rode the rising river all the way to the lower valley — where they abruptly ran aground.

“The water just disappeared into the ground,” said Brian LeNeve, president of the Carmel Valley Steelhead Association. Despite the big surge, when the river ran to the lower valley, the aquifers were so depleted that the water was promptly sucked into the ground. The river never made it to the ocean. Neither did the fish.

Once again, the fish rescuers rallied, schlepping the steelhead upstream to deeper water. The fish with tags were measured, sampled, and counted.

“We have now a record of all the PIT-tagged fish rescued in lower district,” Boughton said. “We also know that some trout moved at least 5 miles downstream, a definite ‘decision‘ to head to the ocean. The interesting part will come next year, to see who makes it downstream or not.”

The researchers still had to go looking for the tagged trout that didn’t head for the ocean, the ones that stayed behind in the deep, bedrock pools. That presented a problem. Normally, the fish are rescued in shallow water using a mild electrical current that stuns them enough to be easily caught in nets. Once the fish have been moved or sampled, they can quickly be recovered and released. But that technique doesn’t work well in deep pools. So the scientists spent many frustrating hours trying to corral those fish with seine nets, 50-by-4-foot nets that catch easily on anything in stream –that is anything except fish at the bottom, which frequently escaped.

espite all the curveballs, Boughton says, they did eventually collect good data. The results haven’t been completely analyzed yet, but Boughton said he’s more pleased with the study than he expected to be.

“You try to design a study so that, whatever happens, you’ll get some answers,” Boughton said. “The corollary to that is: when nature does surprise you, it’s trying to tell you something. After all that, I’m just not sure what’s trying to tell us here.”

American Kestrel Population Drops Dramatically, And Without Fanfare

t’s late afternoon – an auspicious hunting time for birds of prey – and I’m leaning against a chain link fence watching the roofline of an abandoned building. Somewhere up there, I hope, an American kestrel will emerge from her nest.

Instead of a female emerging from the building, a male kestrel circles overhead, a small, determined shadow against the blue sky, before perching on a high branch of a nearby redwood tree. Through my binoculars I can see a hapless rodent dangling from his talons. Seconds later, a slight scrabbling noise draws my attention back to the building. I’m just in time to see the female kestrel slip out from under the eaves before she flies up to join her mate; the prey he’s delivering is a sure sign that eggs are in the nest.

An empty building in a residential neighborhood seems an unlikely place for kestrels to build a nest. The four-ounce falcons typically choose tree hollows to raise their young. But these birds of prey have a reputation for being adaptable. And finding the birds’ nesting site – anywhere – was encouraging for Zach Michelson and Teague Scott, volunteer researchers with the Santa Cruz Predatory Bird Research Group, who are investigating the local status of kestrels in response to reports that the falcon’s numbers are in a nationwide decline.

“No one has specifically studied the birds in this area. We want to lay the groundwork for repeatable surveys with our research,” said Michelson. “It’s only by following these kestrels year after year that we can find out if there are population changes, and if anything can be done to help.”

Zach Michelson (left) and Teague Scott, volunteer researchers with the Santa Cruz Predatory Bird Research Group, affiliated with UC Santa Cruz, watch for kestrels.

n a national level, the American kestrel (Falco sparverius) population has been plummeting. Records from the North American Breeding Bird Survey, a massive annual data collection effort for more than 400 bird species overseen by the U.S. Geological Survey (USGS) and the Canadian Wildlife Service, show the kestrels have declined by an estimated one and a half percent each year between 1966 and 2010. The long-term loss is almost 50 percent of the population. That’s a big drop for a bird considered abundant in North America.

Almost one third of the estimated four million birds in the global breeding population live in the United States, according to Partners in Flight, a nonprofit organization for landbird conservation. Some migrate seasonally, while others stay all year in areas with more hospitable climates, such as Santa Cruz. But over the decades the number of birds reported during breeding survey counts, hawk migrations, and the National Audubon Society’s Christmas Bird Count have dropped, occasionally precipitously.

In coastal California there’s been a 68 percent decrease across 106 routes monitored by the Breeding Bird Survey from 1966 to 2008. But the kestrels’ decline isn’t uniformly distributed across the country. For reasons that aren’t clear, the birds’ numbers are increasing around the central states and parts of Mexico, according to numbers gathered in the same survey.

A handful of things could be causing the lower kestrel numbers, bird biologists say, including increased predation by Cooper’s hawks, continued exposure to pesticides, and competition at nesting sites by European starlings. The land-clearing practices of “clean farming” may also get rid of the trees and brush that help make good places for the birds to nest and hunt. Even invasive plant species may be a factor if they grow too high on grasslands that once provided the short ground cover kestrels need to hover hunt, the birds’ unique style of flying in place over one hunting spot.

It’s just not easy to get a handle on kestrels.

“It’s hard to follow these cool little birds; they’re so fluid in their movement,” says kestrel researcher Elizabeth Wommack, a PhD graduate from the University of California at Berkeley’s department of integrative biology. Wommack, also a seven-plus year volunteer with the Golden Gate Raptor Observatory, has been studying kestrels across the continent to learn more about their population genetics. “The kestrels we’re seeing in California now could have been in Oregon or even Alaska. These birds are affected by weather and changes in their habitat, too.”

All the different ways of collecting information about them – breeding bird surveys, migratory bird counts, tracking birds with leg bands, nest box studies, or her own genetic studies – only gets researchers so far, she says. They all have information gaps. “The way I understand it, the Santa Cruz study sounds like it’s going to help fill in one of these gaps at the local level,” Wommack says.

american kestrel on light — A male kestrel perches on a light on the UC Santa Cruz campus. (Photo courtesy Zach Michelson)

ith my binoculars trained on the tall branches of the Redwood’s “feeding perch,” I see the female snatch the rodent away from her mate. Then she neatly dives down to the building. With a flash of russet feathers, she executes an aerobatic maneuver and tucks up under the roof ledge. The male remains on his perch for a few minutes, preening and preparing for his next hunting foray.

The field biologists have been watching this place for weeks. Before the birds chose this nesting spot, they followed pre-breeding rituals of kestrel behavior during which the male offered a selection of nesting sites. Once that choice was made, the birds picked a feeding perch where the male would bring prey to his mate before egg laying began. Breeding pairs can lay anywhere from four to seven eggs. Unlike other birds of prey, the kestrels take turns on nest duty. Incubation takes about 30 days. The hatchlings will be ready to fledge the nest another month later.

Michelson and Scott mapped out 12 study sites scattered throughout Santa Cruz County, based on historical sightings of birds in the area. They chose the most likely habitats to host kestrels using local information accumulated by the Santa Cruz Bird Club on breeding and wintering territories, and other suitable and accessible habitat patches. They also searched through virtual databases such as eBird and the Monterey Bird Board, as well as records accumulated by the Santa Cruz Bird Club, to choose the most likely habitats to host kestrels. “But there was no really long-term data to look at,” Michelson says. “So it wasn’t easy to put together a picture of the kestrel population here.”

In January and February they surveyed their selected spots for kestrels. By April, they had four breeding pairs in their sights – two more pairs than had last been noted in 2008. Then, in June and July, they returned to the same locations to follow the nesting process.

“We’ve been chasing birds all over the county,” Michelson says. In addition to the pair that nested in the vacant building — near Schwan Lake — they’ve also been following a breeding pair at the Moore Creek Preserve on the western end of town, and another set along the San Lorenzo River. The kestrels need about one square mile to have enough hunting available to support a nestful of hatchlings.

As they followed the birds, the biologists noticed these kestrels make do with the habitat at their disposal. The Moore Creek Preserve birds have an ideal location with acres of open grassland near their nest. But at the San Lorenzo site, close to the downtown area, the male kestrel has to commute; he arrives from several different directions each day to present insects, rodents, or the occasional snake, to his mate.

“Making huge flights to get prey may be how the birds are making up for lack of interconnectivity of their habitat,” Michelson says. When the birds live near people, their prey is more likely to be in fields some distance away.

But that adaptability may come at a cost. Studies show that closely fitting in to human habitats leads to higher stress levels in kestrels. Under more stress, more females abandon their nests too early resulting in young that don’t survive.

‘We can’t yet say if the Santa Cruz kestrel population is in trouble,” says Scott. “There could be lots of other breeding pairs where we aren’t surveying. That kind of analysis requires long-term data – maybe five or 10 years’ worth.”

female american kestrel — A female kestrel takes off from her favorite perch. (Photo by Teague Scott)

ven long-term data sets can be deceiving. The year-to-year fluctuations in commonly-found bird populations can mask critical turning points in species numbers, says Jessica Stanton, a USGS conservation biologist who spoke in early July at the North American Congress for Conservation Biology. So Stanton, along with USGS ecologist Wayne Thogmartin at the Upper Midwest Environmental Sciences center in Wisconsin, developed “risk metrics” to evaluate population numbers. These risk metrics forecast the probability of a species declining to 50 percent of its current abundance, or becoming rare within any given bird conservation region (BCR) in the near future. (The BCRs are defined by the North American Bird Conservation Initiative as “ecologically distinct regions in North America with similar bird communities, habitats, and resource management issues.”)

When Stanton applied the risk model to North American Breeding Bird Survey numbers for kestrels collected between the years of 1970 to 2012, she found a continent-wide declining trend across almost all of the bird conservation regions. In California, kestrel numbers decreased in 15 of in the 28 BCRs that Stanton analyzed.

Although Stanton says she wouldn’t call it a downward slide, and the results aren’t meant as hard predictions, the risk analysis suggest that American kestrels could be in decline even though they’re not recognized as species of concern at regional or federal management levels . The next step is to go out and get data to try and see what’s happening.

“Our study is simple,” says Teague Scott. “But bird behavior is complex. We don’t make assumptions about what we see. We wait to see what the birds show us, and we do that repeatedly – and repeatably – over time.”

The three of us look up in time to catch the male taking off from the redwood tree. He makes one swift pass over the field next door before rapidly gaining altitude, beyond the range of our binoculars. He’s “specking out,” says Michelson, to places and things only kestrels know for sure.

‘Slow Coast’ Will Stay Slow with Newly Protected Lands

You can color more green on your Central Coast conservation map.

Last month the federal Bureau of Land Management (BLM) took over the Coast Dairies property, a spectacular swath of land that spans Highway 1 just 8 miles south of the elephant seal enclave of Ano Nuevo State Park near Santa Cruz. The big parcel touches part of the CEMEX Redwoods property, creating a connection between 14,282 acres of conservation land that hasn’t been open to the public for more than a hundred years. If all goes according to BLM plans, two hiking trails may be cleared for public use by the end of the year and many more are expected to open in the future.

Much of the 6,800-acre Coast Dairies site has been closed to the public since two Swiss families combined their land grant properties in 1902 to graze cattle, run a dairy and raise crops. When the original landowners returned to their native country, the resource-rich land was still leased out for agricultural use. Then, in the 1970s, PG&E optioned the land to put a nuclear power plant on the ocean bluffs just north of Davenport — that is, until a seismic survey showed the area wasn’t stable enough for that.

Oddly, that survey didn’t stop a developer from picking up the property with plans to build 139 luxury homes. To stop the land from becoming a subdivision, almost every major land conservation group in the San Francisco Bay area — and some beyond — stepped in to preserve this green swath of territory.

It’s been a long battle to save the land that surrounds the town of Davenport, the epicenter of the “Slow Coast,” a term locals coined to convey a quieter way of life that prevails along the scenic stretch from Santa Cruz to Half Moon Bay.

“It’s taken about 114 years of effort on the part of a lot of people,” said Reed Holderman, executive director of Los Altos-based Sempervirens Fund. “We’re almost back to having the self-sustaining land it was more than a century ago.”

A mother holds her daughter's hand as they view the Pacific Ocean from a cliff along Coast Dairies. Photo: William Poole/Trust for Public Land. — A mother holds her daughter’s hand as they view the Pacific Ocean from a cliff along Coast Dairies. Photo: William Poole/Trust for Public Land.

On April 16, it became official. Trust for Public Land, a San Francisco-based nonprofit that helps communities conserve land nationwide, transferred 5,750 acres to BLM. Before the land can be opened for public use, a long-term management plan needs to be put in place. But Hollister BLM manager Rick Cooper said he hoped to get people hiking on the Liddell Creek and Molina Pasture trails before the start of next year.

Although the original Coast Dairies deed covered around 6,800 acres, some of that land has already been parceled out. More than 400 acres, mostly on the ocean side of Highway 1, was transferred to the California State Parks in 2006. Another 700-plus acres remains under the ownership of the Coast Dairies & Land Company for agricultural use, according to the BLM.

A 2012 California Coastal Commission report that was prepared in preparation for this land transfer noted:

“This is an important property, not only for its range of resources and associated values, but also in terms of its sheer size and its relationship to the north Santa Cruz County coast viewshed and open space values. The north Santa Cruz coast area represents the grandeur of a bygone (in many places) agrarian wilderness in California …”

A stunning view from Coast Dairies land looking out over the green pastures, coastal bluffs and the ocean beyond. Photo by Jim Pickering/BLM.

Now preserved, the property puts a big green patch along the coast. Five significantly-sized open spaces surround the Coast Dairies land: Big Basin Redwoods State Park, the Bonny Doon Ecological Preserve, Henry Cowell Redwoods State Park, Wilder Ranch State Park,and the CEMEX Redwoods. A wildlife corridor traversed by mountain lions, coyotes, deer, and countless other creatures is also better connected.

With the CEMEX Redwoods property sitting on the northeast shoulder of the Coast Dairies land, another 8,532 acres could be added to recreational opportunities, too. More than 70 miles of unpaved roads criss-cross the parcel, which runs up Empire Grade from Highway 1. It has a tree line spiked with Douglas fir, redwoods, live oak, Pacific madrones, and the endangered Anderson’s manzanita. The acreage is also home to the California red-legged frog, federally endangered plant species such as the Santa Cruz wallflower, and two insects only found in these hills: the Mount Hermon June beetle and the Zayante band-winged grasshopper.

A freshwater creek nestled in the oak woodlands of the Coast Dairies land. Photo by Jim Pickering/BLM

A coalition of groups rallied to help the Sempervirens Fund and the Peninsula Open Space Trust take title to the CEMEX land (but not the cement plant) for $30 million after its last owners, the Mexico-based CEMEX company, shuttered operations in 2010. But unlike the Coast Dairies deal, this property is slated to stay in private hands. So, a conservation easement needs to be obtained before plans for public access can move ahead.

“It’s important for wildlife, but it’s also important for people,” said Holderman, also the former executive director of the Trust for Public Lands. “To be able to go from the ocean up to the top of Empire Grade is a long and beautiful hike through a redwood forest. It took me two hours to mountain bike down.”

Mountain lion kitten taken on the property. Photo: Paul Houghtaling, 2013

Although the Coast Dairies land has many special conditions attached to its transfer (such as not allowing commercial logging or fracking) no one wants to take any chances on what the future may bring. The Conservation Lands Foundation, headquartered in Colorado, is also pushing for National Monument status. With that status comes a level of visibility that conservationists hope will provide protection if budget cuts arise. Advocates are optimistic because the Stornetta Public Lands near Point Arena were designated as a National Monument in March and they led to a similarly successful pitch for Fort Ord in Monterey in 2012.

“It deserves national attention,” said Holderman. “It’s like nowhere else. There are species that travel thousands of miles to get here — whales, marbled murrelets, elephant seals — and it’s right in our backyard.”

Tule Elk Relocated As Numbers Rebound

It’s spring and tule elk are on the move in Santa Clara County. It’s not a migration, though. Instead, a herd in the San Antonio Valley Ecological Preserve is expanding with the help of wildlife experts, some sturdy trailers, and a relocation plan for excess elk in the San Luis National Wildlife Refuge in Los Banos.

Although moving can be a stressful under any circumstances — for man or beast — the fact that there are too many tule elk anywhere in California is cause for celebration. Not so long ago, there were almost too few of these native elk to count.

These animals take up a lot of room,” said Joe Hobbs, a senior environmental scientist for the the California Department of Fish and Wildlife (CDFW). “Although it’s a big state, it also has a large population (of people). When an animal that big goes from the brink of extinction to living on the landscape in herds, it’s a huge achievement.”

A hood was used to keep the elk calm for their safety as well as staff. Photo: CDFW

A half million tule elk, native only to California, once roamed from Mendocino to the Tehachapi Mountains near Bakersfield. Hobbs said the “homegrown elk” are the smallest of the three subspecies found in the state, weighing anywhere from 400-pound cows to the beefier, 1,000-pound bulls. (The other two subspecies that can be found in California are the Roosevelt, which ranges along the coastal Pacific Northwest, and the Rocky Mountain elk found in northeasterly areas.)

But when the Gold Coast population spiked in the mid-1800s, tule elk were almost hunted and pushed out of existence. Oddly enough, the remaining elk were spared largely through the conservation efforts started by cattle baron Henry Miller, who took a liking to them despite draining prime foraging areas of marshland to make way for profitable farmland.

Now, about 4,200 of the iconic elk roam around California. By CDFW accounts, there are 22 herds grazing on state-run preserves and national parks. But the elk have shown no reverence for fence lines or private property.

“They’ll go wherever they want,” said Hobbs.

Elk were kept cool and ice and water. Photo: CDFW

So, over the years, herds have been shuffled around the state to maintain good relations between the elk and ranchers. At least 1,500 of the roaming ruminants have been relocated since 1975, according to CDFW records. Even Miller — the man who lobbied so hard to save the species — reportedly removed tule elk from his ranch lands to preserve his property from their trampling ways.

The most recent reshuffling of elk herds happened at the end of March. For two long days, teams that included wildlife workers from the CDFW and the U.S. Fish and Wildlife Service used helicopters, nets, and on-their-feet expertise to capture 15 bulls, 16 cows, and five calves on the Los Banos reserve.

Before the animals were trailered to new grazing grounds, biologists recorded body weights and collected samples of blood, hair, skin, and teeth. Among other things, that data is used to monitor herd health and analyze DNA for evidence of interbreeding. Then the animals were trucked to one of three areas within a reasonable driving distance: the San Antonio Valley Ecological Reserve in Santa Clara County (north of Mount Hamilton), the Carrizo Plains Ecological Reserve in San Luis Obispo County, and the Wind Wolves Preserve in Kern County.

We try to spread the elk around,” said Hobbs. “Before their numbers went up, we were down to a handful of animals, so genetic diversity was really low to start with. If we let herds continue to grow in isolation, it would cause increasing genetic loss.”

Wildlife workers put a tule elk on the scales after capture at the San Luis National Wildlife Refuge in San Joaquin Valley. Photo: CDFW

It’s no surprise that moving the elk is a huge logistical challenge. To tip the odds in their favor, wildlife managers schedule such events for the cooler winter months, after the bulls have shed their antlers and before most cows have calves. Younger elk, between one to three years of age, are targeted because they’re easier to integrate into existing herds.

Nine bulls were delivered to San Antonio Valley, a 3,000-acre preserve on the eastern edge of the Henry W. Coe State Park. They’ll mingle with an existing herd of about 150 tule elk that were reintroduced to the area a few decades ago. As part of a smaller herd, the new bulls will have an easier time getting enough to eat, despite drought conditions that have made it harder for grazing animals to find good forage.

A young tule elk takes off into new territory, while another waits its turn to exit the trailer. (Not at San Antonio Valley). Photo: CDFW

Young tule elk bull released in San Antonio Valley Ecological Preserve. Photo: CDFW

Now that the number of tule elk are on the upswing, Hobbs said the state is developing a new management plan for the animals. Mountain lions and coyotes don’t keep the population in check. While wild elk might only make it to their early teens, cows leading less stressful lives on managed lands can live into their early 20’s and produce a calf every year. Although birth control has been tested in some herds, it’s not a foolproof method. Most herds are now managed by relocation or culling with a set number of hunting licenses allocated each year, depending on the population and location.

But culling and relocation options don’t exist for managing all the tule elk herds. The animals in the 500-plus herd at Point Reyes have to stay put. There, a microscopic predator that causes chronic wasting, called Johne’s disease, prohibits any of the elk from being shipped outside the area. The tiny foe, the Mycobacterium avium ss. paratuberculosis, infects the intestinal lining of cattle and other ruminants such as elk, deer, and sheep. The hardy bacteria is shed in manure and then can persist in the soil for years. Even though the disease was discovered in cattle more than a century ago, there is still no cure for it. So no one wants to risk moving the disease around the state along with the elk.

Still, the success story is the fact that tule elk remain in Central California, said Hobbs. Now the goal is to keep the herds going and minimize conflict wherever they roam.

Tule elk released on the Carrizo Plains Ecological Reserve in San Luis Obispo County. Photo: CDFW

San Antonio Valley Ecological Preserve is not open to the public except for special events. The San Luis National Wildlife Refuge in Los Banos is open year-round and tule elk can be seen via the auto-tour route.Tule elk can also be viewed at CDFW’s Grizzly Island Wildlife Area, the Tupman Tule Elk State Preserve, and Point Reyes National Seashore.

Explaining the Cosco Busan Spill’s Toxic Effects: Scientists Report A Link Between Oil and Fish Heart Health

When the Cosco Busan spilled oil into the Bay in 2007, the toxic toll on wildlife came as no surprise. More than six thousand birds died after the spill, with grebes, cormorants, and murres among the hardest hit. Within two years the herring population collapsed, too. The cause of death for the oil-coated birds seemed obvious. But the way the fish died wasn’t as clear.

Scientists suspected the fish had heart problems. After other oil spills, scientists had seen fish with barely beating hearts. But until about a month ago, no one knew why.

Now, seven years after the Busan spill, a group of scientists led by Barbara Block at the Hopkins Marine Station in Monterey have discovered the exact chemical pathway that makes oil such an insidious toxin -– and it has implications beyond fish health to humans as well.

“Two groups of scientists have been working together,” Block said. “Others showed evidence that oil causes the heart damage. Now we’ve shown how that oil exposure delays the timing of the on-off switch in the heart.”

At first, even “fingerprinting” the tanker oil as the cause of herring problems in the Bay was a huge challenge, said John Incardona, a toxicologist with the fisheries division of the National Oceanic and Atmospheric Administration. The Bay Area has lots of potential sources of oil in its water, like storm water runoff, local refineries, and automobile exhaust. The Richmond-San Rafael Bridge, with its base at Point San Quentin and the San Rafael Bay by the Marin Rod and Gun Club, looms over one of the biggest herring spawning sites.

Researchers at the Bodega Bay Laboratory had been studying herring populations in the area for years, though, and knew what to look for.

“We had sites that had healthy spawning within the last 10 years, so we could show that immediately after the oil spill there was a dramatic drop in herring numbers,” Incardona said.

Pacific herring are a sentinel species for oil spill damage. Once a year California’s largest population of herring come into San Francisco Bay to spawn. Arriving between November and March, the females make their way from open ocean to intertidal and shallow subtidal areas, where they expel super-sticky eggs on eelgrass, rocks, pier pilings and boat hulls. The Cosco Busan spilled the oil on November 7, just before the spawning season started.

After the San Francisco Bay spill, experts estimated that up to 29 percent of the next winter’s herring spawn was lost. The following year, 2009, the spawning biomass was the lowest on record and prompted the California Fish and Game Commission to close the commercial herring season. The numbers finally started to recover in 2010. But scientists aren’t sure the damage is over.

Clues to the heart maladies caused by oil have been floating around for a long time. In 2000, Gary Cherr and a team of researchers at the Bodega Bay Laboratory showed that creosote (an oil-based wood preservative) causes slower heart beats and swelling around the heart in herring eggs stuck on creosote-treated pier pilings.

Then, scientists who studied the salmon population after the 1989 Exxon Valdez spill in Prince William Sound found fish embryos there had slower heart rates, too – a condition called bradycardia. Many of the embryos also developed heart chambers with the wrong shape. Not surprisingly, these fish couldn’t swim as fast and became easier prey as they matured.

When the Deepwater Horizon pipeline broke – spewing sweet crude oil into prime spawning grounds for tuna – Block was studying tuna and their highly efficient use of oxygen. As questions cropped up about damages to fish in the Gulf of Mexico, she turned to the big fish for answers.

“Tuna are the Olympians of the sea,” Block said. “They can go from cruising speed to hunting in an instant, all under the stress of cold water.”

When the outside environment changes, the inside of a body has to compensate. If you’re a big fish and swimming fast, it takes a well-adapted circulatory system to keep going despite dramatic changes in temperature or pressure. Sort of like trying to run really fast up and down the Swiss Alps, without slacking your pace. More importantly, because of its athletic capabilities tuna turned out to be just the right fish to study.

A fish’s heart beat

This video, from John Incardona’s 2014 paper in the Proceedings of the National Academy of Sciences, compares the heartbeats of normal embryos and those exposed to oil in three different tuna species. The first fish shown is the normal embryo, the second is one exposed to oil. In each case, there is an observable arrhythmia.

With a special microscope, researchers watched the inner workings of individual heart cells in developing bluefin and yellowfin tuna. They compared normal young fish with those that were exposed to the breakdown products of oil – called polycyclic aromatic hydrocarbons (PAHs) – and discovered that these smaller chemical compounds block the pathway linking the electrical impulses in heart cells to muscle contractions. Without that link, called excitation-contraction coupling, cells literally can’t conduct a beat.

It takes a series of tightly orchestrated events to make a heart cell contract and relax with a regular rhythm. The process relies on the synchronized movement of sodium, calcium, and potassium ions through specific channels that lead in and out of a cell. If the timing of anything is off, the heart muscle cells – called cardiomyocytes – might miss a beat. In an embryo there aren’t many cells to begin with, so every cell needs to be in working order.

Before a heartbeat begins, sodium moves into a cell and starts an electrical current that acts like an “on” switch. When sodium channels are open, the switch turns “on” and that triggers the release of calcium from storehouses inside the cell. In turn, calcium trips the switch for the cell machinery that causes contractions.

But what contracts must also relax. It takes an outward flow of potassium ions to switch cells “off,” letting the muscle cell relax and get ready for the next round of action. When PAHs get into cardiac cells they clog those critical outward-bound potassium channels. The cell gets locked into a constant state of “on.” Without a way to relax and recover, the heart gets progressively slower.

The tuna’s need for speed means that it’s built with more of these potassium channels than most fish – and most other species. So when the scientists peered into the heart cells of young tuna, they found enough of the right channels to study. “If we’d looked at a mouse we might have missed this mechanism,” said Block.

PAHs also create another problem for heart cells. Block and her colleagues discovered that once the potassium channel is plugged and the cell is stuck “on,” the tide of calcium ions released inside the cells doesn’t rise as high as it should. The precise mechanism for this isn’t yet clear, but the end result is that lower calcium levels inside the cell lead to weaker contractions – a double whammy for a heart cell that’s already slowing down.

Next, Block wants to figure out precisely why calcium levels drop in these cardiac cells. She’d also like to find out what happens in other species – people, for instance. The same sorts of oil breakdown products that are toxic to fish in water also cause air pollution. Although there are well-known associations between human heart disease and air pollution, Block noted that no one is hunting – yet – for a similar mechanism.

“These potassium channels are well known in pharmacology,” Block said. “Every drug in America has to be tested to make sure it doesn’t affect these channels and cause heart attacks. If this oil was a drug – we’d throw it out.”

But funding for additional studies is scarce once damages have been assessed after a spill.

The $2.4 million settlement money for damage to the fish population has been targeted for eelgrass restoration, a plan that should also be a boon to other species.

Learning more about what happens to the fish in the long haul would help fisheries management, said Cherr. It might improve human health, too.

Bottlenose Dolphins Move North Into the Bay, Creating a Research Puzzle

About 60 coastal bottlenose dolphins have been spotted traveling from Southern California to the waters off Bodega Bay, pushing the northern limit of their range and leaving the scientists who study them with a mystery: Long distance migrations aren’t unusual for marine mammals, but these dolphins aren’t making seasonal swims. Instead, says Bill Keener, a marine mammal biologist at Golden Gate Cetacean Research, the dolphins seem to be traveling up and down the coast without any sort of schedule.

Scientists have tracked the long-range swimmers with telephoto lenses by using close-up photos of the unique nicks and notches on the silhouette of each dolphin’s dorsal fin to compile a catalog of dolphin IDs. The questions arose when San Francisco Bay researchers checked their images against photo entries in a catalog kept by scientists farther down the coast, and discovered a lot of matching images.

“Finding 10 percent of the entire West Coast stock here is kind of unexpected,” Keener said. “But we also don’t know what is spurring them to keep moving.”

Dolphin skulls dating from long, long ago have been dredged up from San Francisco Bay. But in modern times, dolphins weren’t sighted north of Point Concepción – the land that juts into the Pacific just west of Santa Barbara – until the 1982 El Niño carried warm currents and a supply of fish up the coast. Then, the gregarious cetaceans were spotted off the San Mateo coast. When the water turned cool again, some of the dolphins stayed instead of retreating to their old stomping grounds in Southern California.

About six years ago the bottlenose dolphins started to show up regularly in the Bay, said Izzy Szczepaniak, a marine biologist at GGCR. Reports of the coast-hugging cetaceans came from the Golden Gate Bridge and Redwood City. Dolphins got stuck in the shallow waters of Colma Creek and again in the mudflats south of San Francisco Airport.

“We don’t know how far they can travel in a day,” said Mark Cotter, field director for the California Coastal Dolphin Project and vice president of Okeanis, a nonprofit marine mammal research organization based in Moss Landing. That said, Cotter knows that the animals can show some hustle: One August day in 2011, two dolphins called Rambo and Oro were sighted off the Golden Gate Bridge by Keener and Szczepaniak, and then two days later Cotter saw the same pair swimming in Monterey Bay.

The dolphin they call “Smootch” could be the poster dolphin for the northward range expansion. Her dorsal fin photo has been in the California Dolphin Online Catalog (CDOC) for decades. She was first photo-tagged in 1984 by San Diego researchers. Since then she’s been photographed in six sites – once with a calf to give researchers a clue about her gender – ranging from Ensenada, Mexico to Bodega Bay. Smootch’s swims are the longest distance ever recorded for a coastal bottlenose dolphin.

“This is not a migration. These dolphins are moving weekly and they aren’t always taking short trips,” said R.H. Defran, a San Diego researcher who has studied the dolphins for decades. He is organizing CDOC into an online resource that will make it easier for researchers to collaborate and find answers for the dolphins’ puzzling lifestyle.

The California dolphins do things differently than their Atlantic Seaboard counterparts. On the East Coast and in the Gulf of Mexico the dolphins lead a more residential lifestyle, staying in smaller schools and rarely straying from the bays and estuaries that provide mullet, squid, and small flatfish to eat.

Here, the dolphins’ habit is to move up and down the coast until they find food, said Defran. Then they hang around and exploit it. When the food thins out, the dolphins continue on elsewhere. It may be that the chance to make a living over a longer distance is a better option than sharing food over a shorter distance. “We can’t yet say what drives the dolphins’ micromanagement decisions about food,” he said. “But, they wouldn’t do it if it didn’t pay off.”

Although the dolphins have strong food preferences they are also behaviorally “plastic,” meaning they are good at adapting to new circumstances, Defran said. Dolphins will team up to herd schools of anchovies or herrings. They’ll break off into groups of two or three to chase down halibut, rockfish, or capelin. They can also “kerplunk” – smacking their fluke or fins on the water to stun larger fish. Researchers even photographed dolphins dining on Chinook salmon in the Bay.

But food may not be the only reason for the dolphins’ northward movement. It could be about culture, said Defran. The dolphins have a “fission-fusion society” in which bonds are very fluid. Most of the animals have probably crossed paths at some point. Defran theorizes that the abrupt range expansion resulting from the El Nino exposed older members of some social groups to the sustainability of more northern waters. In turn, these more senior dolphins may have exerted some influence over the geographic preferences of younger generations. There’s good evidence that dolphins develop cultural preferences. In Western Australia the dolphins use sponges to protect their sensitive chins when they forage and they pass that skill from mother to daughter.

With more photos and collaboration among colleagues up and down the coast, the scientists hope to understand why the dolphins are moving so much. The CDOC may also help figure out another surprising phenomenon among these coastal dolphins: porpicide.

For reasons that researchers don’t yet understand, dolphins have been ganging up on harbor porpoises and causing enough blunt force trauma to drown the smaller cetaceans. In 2008-2009 there was a significant increase in porpoise strandings; almost half of those were associated with blunt force trauma consistent with dolphin attacks, based on necropsies performed at The Marine Mammal Center in Sausalito. One episode was caught on video by Cotter’s colleagues from Monterey Bay. If they were able to get photographs that showed the same dolphins were involved in porpoise attacks, that might suggest that aggression was part of a cultural transmission, a behavior that could be shared – and spread – among dolphins.

Although scientists figure there are about 500 coastal dolphins in California, the catalog can never be definitive. Dorsal fins aren’t like fingerprints. The animals get fin notches from a variety of sources: rubbing on pier pilings, brief entanglements with fishing lines, or social interactions – scars from rake marks – with each other. Some dolphins are “smooth”; they don’t have any unique marks that can be tracked, while others may have notches that change over the years. Smootch added a new notch to her fin in 2012 but is still, fortunately, identifiable by her original fin profile taken in 1984.

The photo IDs for the Bay Area dolphins should be integrated into the CDOC before the end of this summer. Then the next step is to see if there are any other long-distance swimmers like Smootch, said Szczepaniak. He’s looking forward to catching sight of Smootch again, too.

Citizen scientists can send bottlenose dolphin sightings in the Bay Area to Golden Gate Cetacean Research by going to www.ggcetacean.org and filling out the sightings report form.

Counting Harbor Porpoises with Carbon Currency

ara Gallagher spends a lot of time on the Golden Gate Bridge, scanning the cold waters below for evidence to solve a really challenging math problem.

Gallagher, a graduate student at San Francisco State University who collaborates with Golden Gate Cetacean Research, knows the Bay’s porpoise population is rebounding, from zero as recently as a decade ago to at least 600. Although all those porpoises aren’t fishing for food in the Bay at the same time – they likely come and go from the larger population of about 2,500-3,000 along the outer coast – the inland waters have clearly become popular with the porpoises. What she wants to know is: What does that mean about the Bay ecosystem itself, and how could you start to tell?

What’s Causing the Dry Weather — And When Will It End?

In the 150-plus years that we’ve been tracking rainfall in Northern California, it’s never been this dry. It was the driest December in many places, and this week’s drizzle wasn’t enough to keep San Francisco from its driest-ever January. And if there’s an end in sight to the big-picture weather pattern that’s led to the drought, forecasters haven’t spotted it.

“When will it end? That’s the million dollar question,” says Logan Johnson, the meteorological warning coordinator at the National Weather Service Forecast Office in Monterey. “We don’t have any observations to compare with what’s happening now.”

The dry weather has been caused by a high-pressure ridge of air that rises four miles above the Earth’s surface and stretches from Canada to Mexico. The air on top weighs heavily on the air below, causing it to sink under its own weight. As the air gets closer to the Earth, it circles away in a clockwise pattern that pushes colder, northern air to the East and draws warm air from the south up toward the West. As long as the ridge stays put, it blocks the air underneath – our air – from rising, cooling, and condensing to give us rain or snow. The precipitation we need keeps getting shunted away. And while ridging is a common part of California’s weather pattern in both summer and winter, the ridge usually builds for a few weeks then breaks down as storms move through. Not this time.

The “ridiculously resilient ridge,” a term coined by Stanford graduate student Daniel Swain, has hung over us for more than a year. Its persistence has everyone puzzled. Even though a few 10-day forecasts have included the possibility of rain showers, the sunshine keeps showing up.

“In essence, these pressure systems are like eddies in a stream and can stay in place for long periods of time,” Johnson says. Ridge-busting storms usually ride into the West Coast with the polar jet stream – often described as a powerful ribbon of air that travels from west to east at even higher levels in the atmosphere. But the jet stream has shifted upward from its typical winter path, now hugging the northern boundary of the anchored mass of air and taking the storms with it. While that accounts for where the storms went, no one is quite sure why this particular high-pressure ridge won’t budge.

Despite all our technological advances, predicting weather can be a tricky thing. Johnson sits at a bank of computer screens, each monitor flashing with undulating bright lines, multicolored grids, or dream-like swirls of colors that depict recordings of air pressures, temperatures, and water vapor from sites around the Bay Area. Remote radar images come from the station on top of Mount Umunhum, the fourth-highest peak in the Santa Cruz Mountains. Data is collected from a weather balloon launched from the Oakland airport every morning. And twice a day the National Weather Service, based in Silver Springs, Maryland, sends long-range reports that the Monterey meteorologists interpret according to local conditions. But it still comes down to feeding all that information into mathematical equations, or models, that use the history of weather patterns to forecast what will happen in the future. And in forecasting the ridge, there’s that problem again: “No one has ever seen this before,” Johnson says.

It’s hard to pin down the long-range forecasts. Weather modeling follows the chaos theory, developed by Massachusetts Institute of Technology professor Edward Lorenz, which says it’s difficult to predict weather beyond two or three weeks with any accuracy. In a 10-day forecast, any incorrect factor in the mathematical models gets amplified during that time frame and all those incorrect assumptions can add up to another day without rain.

While the resilient ridge means Johnson and his colleagues haven’t had to revise the forecast much this winter, the 24/7 forecasting station still has plenty to do. “Even though the weather looks the same, new information is always streaming in,” says Johnson. Two meteorologists work the public affairs section in eight-hour shifts while a hydrometeorological technician handles media inquiries and monitors the reporting instruments to make sure everything is reading correctly. One section is dedicated to aviation and ocean traffic. Every six hours the Monterey forecasters issue reports to the airports in San Francisco, Oakland, Santa Rosa, Salinas, and Monterey. With the high-density population around San Francisco Airport and the potential for international air-traffic jams when the fog rolls in, it’s critical to get the weather details right. The San Francisco Bay is also one of the world’s biggest shipping ports and recreational sailing vessels ply the same waterways as massive ocean tankers. Normally this is the busiest time of year because storms are coming in. But there’s no storm watch now. The forecasters are still tracking fire weather.

For up-to-the-minute weather reports Bay Area residents can follow the National Weather Service on Twitter @NWSBayArea or join the weather-watching community on the US National Weather Service San Francisco Bay Area Facebook page.