Mary Ann Wilson

Mary Ann Wilson

Mary Ann Wilson

Aug 182017
 

Homes on Broad Beach

The California Ocean Protection Council and the California Natural Resources Agency have updated statewide guidance on sea-level rise to reflect new advances in ice loss science. Their new report, “Rising Seas in California: An Update on Sea-Level Rise Science,” notes that satellite data of West Antarctica show an increased loss of grounded land ice and accelerated loss of ice shelves, which buttress the grounded ice. If this continues, California’s shores could experience higher sea levels sooner that previously thought.

The problem is that the West Antarctic Ice Sheet lies on bedrock that is below sea level, in contrast to the Greenland Ice Sheet which is above sea level. If global warming is great enough to erode the floating ice that buttresses grounded ice, this would effectively uncork the bottle, unleashing an escalating and irreversible discharge of ice into the ocean. Such a loss could change the earth’s gravitational field and rotation, resulting in a higher rate of sea-level rise along California’s coast than the global average.

The precise magnitude and timing of when this would happen is unknown. But in a best-case scenario, research models show a seal level rise off La Jolla of about 6 inches by 2030 and one foot by 2050; while a worst-case scenario predicts the ocean will rise more than 1 foot by 2030 and 2 feet by 2050. The most extreme water-level increases will come after 2050, when ocean levels off Southern California could reach 2 to ten feet above 2000 levels by 2100.

The concern around an increased rate of sea level rise adds a new layer of legal complexity and overlaps current coastal planning. Even in the absence of sea level rise, poorly planned coastal development can be in harm’s way and affect public interests along the coastline. If not proactively and effectively managed, coastal development has the potential to reduce coastal access and degrade, destroy, and perhaps even privatize shorelines and tidelands.

Which brings us to the Public Trust Doctrine.

The Public Trust Doctrine is an ancient legal doctrine that goes back to Roman Law, under which some waters, tidelands and wildlife resources of the state are held in trust for all of the people, and the state acts as the trustee to protect these resources for present and future generations.

In California, this doctrine extends to the protection of navigable surface waters, to non-navigable tributaries of those waters, to aquatic resources, and to birds and other wildlife. Additionally, the courts have added the right of public access, and protection of the environment and recreation. Most importantly, this common law doctrine allows any person to bring a lawsuit against the state if it fails to fulfill its duty as trustee to manage these protected resources in accordance with the doctrine.  So how will the Public Trust Doctrine apply to private properties facing sea level rise?

In an effort to provide guidance to state and local governments, Stanford University’s Center for Ocean Solutions published two documents: Consensus Statement on the Public Trust Doctrine,  and The Public Trust Doctrine: A Guiding Principle for Governing California’s Coast Under Climate Change in July 2017. Authors included former leaders of the State Lands Commission, the California Coastal Commission, the California Department of Justice, the San Francisco Bay Conservation and Development Commission; as well as representatives of local government and a few academicians. The group met over the course of a year to develop a consensus interpretation of how the Public Trust Doctrine could apply to sea level rise, since it has not been fully fleshed out in the courts.  And because it’s a common law doctrine, the ultimate arbiter will be the courts.

Don Gourlie

One of the co-authors of the consensus statement, Don Gourlie, who is an Early Career Law & Policy Fellow at the Center for Ocean Solutions, reviewed the highlights in a webinar on August 16. He said that one of the main challenges the group focused on was the mean high tide line.

In 1935, the Supreme Court in 1935 defined the coastal property line as the mean high tide line, which is, of course, ambulatory. California courts have held that a coastal landowner’s property boundary continues to change because of the naturally changing location of the mean high tide line. The courts; however, have not reported cases specifically addressing the legal effect of permanent submergence on open ocean coastlines.

The mean high tide line is found by determining the average elevation of all high tides over the course of 18.6 years (one lunar epoch) and surveying where that elevation rests on the shore from time to time. A recalculation is due in 2022, and based on tide gauge data from around the state, it’s expected that the mean high tide elevation will increase a few inches through most parts of the state. When that occurs, the surveyed location of the property boundary will also change. The concern is that because this line in the sand, as it were, is so ambulatory, surveyed locations at any given point in time may not be useful in making long-term decisions about permanent structures.

The group suggested improving the way the mean high tide is located by increasing the number of tide gauges or surveys over a period of time to measure a boundary’s range of movement, and provide more resources for the State Lands Commission and other groups tasked with conducting those boundary determinations.

The mean high water line, or mean high tide line, is the boundary between public tidelands and uplands in California.

Four dynamic processes and how they may change the location of the mean high tide line.

Also, the ambulatory nature of the boundary is not very well understood by either the general public or relevant state agencies. That’s because property rights are assumed to have defined boundaries. Getting that information out there is important, which the group suggested could be done through through legislative discussion as well as disclosures of risks in coastal development permits.

Another problem is that the mean high tide line as a standard is actually challenging to apply on the open coast and not fully protective of public trust resources. The standard was initially developed through the federal courts and was applied in protected bays where there’s not much wave run-up. This and any issues relevant to the use of the mean high tide line on California’s open coast would benefit from discussion at the legislative level.

Local governments are likely worried that property owners will sue for losses due to erosion, inundation, and migration of the mean high tide line. On this, the group entirely agreed that the Public Trust Doctrine—as a background principle of property law in the state—would be a complete and successful defense to taking a claim. “What’s more likely to be challenged,” Gourlie said, “is if the state decides to regulate areas that are currently upland or private property that is likely to become public land in the future due to sea level rise.”

Seawall along Broad Beach

The group also tackled the issue of how permanent structures like seawalls would affect the movement of this boundary. Though there’s no California case on point to this effect, they noted that there are cases in other jurisdictions, as well as principles of property law recognized in California case law, which indicate that the placement of a physical structure that halts erosion or halts landward movement of water does not fix the legal shoreline boundary.

Once public trust tidelands are located, they need to be protected. “Identifying which areas should be included in the public trust is key,” Gourlie said. “Once that’s in place, government agencies should be systematic about considering and analyzing the expected effects of an action or decision on public trust resources; and not grant permanent grants that my adversely impact public land in the future.”

Other highlights:

  • Just as homeowners are required to clear space around their homes for fire prevention, we should protect our dynamic coastlines by not allowing activities that will encourage potential hard armoring of the coastline or the need to defend ourselves from sea level rise especially since this threat can be easily avoided. For activities that don’t take place on public trust land but affect them, decision makers should not undertake or authorize uses of uplands without appropriate safeguards for nearby public trust resources and uses.
  • Decision makers may need to review past decisions in response to new evidence concerning effects on public trust resources and uses and should retain this right to review. It’s also important to not grant permanent rights that may adversely impact public lands in the future.
  • Decision makers must consider and assert public interests in statewide policy making and long-term planning (e.g. creating or revising local coastal programs, local general plans, etc.).
  • Coordination among decision makers is essential, especially when locating shoreline property boundaries, in order to minimize conflict and avoid wasting resources.

 

References

Griggs, G, Árvai, J, Cayan, D, DeConto, R, Fox, J, Fricker, HA, Kopp, RE, Tebaldi, C, Whiteman, EA (California Ocean Protection Council Science Advisory Team Working Group), Rising Seas in California: An Update on Sea-Level Rise Science. California Ocean Science Trust, April 2017.

Sanda Mazza, Extreme sea-level rise could wreak havoc on California coast, experts warn,  April 18, 2017.

Environmental Law Foundation, et al., California’s Public Trust Document.

Center for Ocean Solutions, Story: The Public Trust Doctrine: A Guiding Principle for Governing California’s Coast Under Climate Change,  July 1, 2017

Center for Ocean Solutions, Consensus Statement on the Public Trust Doctrine: A Guiding Principle for Governing California’s Coast Under Climate Change, July 2017

Center for Ocean Solutions, The Public Trust Document: A Guiding Principle for Governing California’s Coast Under Climate Change, July 2017

Don Gourlie, Webinar: Public Trust Doctrine, Coastal Land Use, and Sea Level Rise, August 16, 2017

Images

  1. Homes on Broad Beach, Mary Ann Wilson
  2. Don Gourlie, coastalresilience.org
  3. The mean high water line, The Public Trust Document: A Guiding Principle for Governing California’s Coast Under Climate Change, p. 17
  4. Four dynamic processes, The Public Trust Document: A Guiding Principle for Governing California’s Coast Under Climate Change, p. 18
  5. Seawall along Broad Beach, Mary Ann Wilson
Apr 092017
 

Sea Lions at Pacific Marine Mammal Center, Orange County

This is the second part of a two-part series about the recent unusual mortality events of California sea lion (Zalophus californianus) pups. The first article investigated the reasons why thousands of emaciated pups have been stranded on California beaches. This article highlights the work of nonprofit organizations dedicated to rescuing and rehabilitating them.

 Rescue

A network of rehabilitation centers take in sick and injured marine mammals along California’s coast, and each center has their own jurisdiction: Sea World, serving the San Diego area; Marine Mammal Care Pacific Marine Mammal Center, Orange County; Marine Mammal Care Center Los Angeles, Los Angeles and Long Beach; California Wildlife Center, Malibu; Channel Islands Marine Wildlife Institute, Santa Barbara and Ventura Counties; The Marine Mammal Center, San Luis Obispo through Mendocino counties; and Northcoast Marine Mammal Center, Humboldt and Del Norte Counties.

All centers handles their own rescues except for Marine Mammal Care Center Los Angeles (MMCC). Along with local Animal Control agencies, MMCC relies on Peter Wallerstein, the director and founder of Marine Animal Rescue, which is an organization entirely devoted to the rescue of marine mammals. Their authorized territory extends as far south as Long Beach, west to Catalina Island, and north to Pacific Palisades. Of the 4500 marine mammals they’ve rescued since 1985, 90 to 95 percent are California sea lions. Why so many? One reason may be sheer numbers: Compared to the 300,000 sea lions in California, there are just 39,000 harbor seals— approximately the same ratio as the strandings. Wallerstein estimated that of the 395 rescues they’ve done this year, 30 to 40 were elephant seals, followed by a few harbor seals, fur seals, dolphins, and sea turtles.

The organization’s busiest time of the year is from January to June, when starving sea lion pups lose their fat and become stranded on the beach. In an ominous Facebook post on November 4, 2016, they showed two pups rescued within the last 24 hours and the caption: “Starting early this year.”

Because upper water fish are depleted due to the collapse of the food chain, nursing mothers are forced to dive much deeper than usual. While their pups are small and unhealthy, at least they are alive. The reasons being fat- and calorie-poor fish such as short belly rockfish are generally found deeper in the water column than the fat- and calorie-rich fish like anchovies, sardines, and mackerel.

Peter Wallerstein of Marine Animal Rescue

Since the public plays a big part in rescues of not just stranded sea lions but entangled or beached whales, dolphins, seals, and even sea birds, Peter Wallerstein offered some guidelines for beach-goers who spot a sea lion or any marine mammal in need of assistance.

The first thing to do, he said, is call the Marine Animal Rescue on their 24-hour, toll-free hotline at 1 (800) 39-WHALE anytime day or night, 365 days a year. I told Wallerstein that I had called the center in Malibu two different times, and each time they said they didn’t have enough room. The second time they came and posted signs warning the public to stay away, and then left.

“We try to bring them in even if they don’t have a place for them,” Wallerstein replied. “We’ll bring them to another quiet beach where they can be left alone, and then we’ll keep an eye on them. What’s helpful for that is when we do relocate it, we tag it, and if that animal comes back on the beach, that’s a re-strand and that gives us more power to try to force the center’s hand.”

I found out later that the California Wildlife Center can only take up to 25 sea lion pups, so the response you get depends on where you happen to be and of course, the number of stranded pups there are.

If you spot one and call the nearest center, Wallerstein asked that you stay in the area and maintain contact by phone with the rescuers. “It’s pretty difficult searching both sides of a crowded jetty a quarter mile long to find an animal,” he said.

But keep your distance. “Not only are they federally protected animals, they also bite ten times harder than a dog,” he said. “If they have domoic acid (a neurotoxin that causes amnesic shellfish poisoning), they might have seizures on the beach, or chase lifeguards and trucks.”

If they’re on land, don’t try to get them back to the water. “Once you bring it back into the water, it’s almost a one hundred percent chance they’re going to die,” he said. “If they’re on land, we’re going to come get them and we’re going to bring them to the rehab center. If they go back in the water, then they have absolutely no hope.”

On the other hand, “If they’re trying to get back to the water, never cut off their path. Do not pull it into the water. If it’s weak and emaciated, it won’t survive.”

Don’t feed them. “About a month and a half ago, we found one guy spoon feeding a sea lion,” he said. “Luckily the animal was hypothermic because as soon as it warmed up, it got extremely aggressive. And you don’t want to give sea lion pups that are starving food right away. They need to be hydrated first. You can tell if a sea lion is hydrated by their eyes – if they’re runny, they’re hydrated. You can’t tell if they malnourished because they may be bloated and look fine to you, but that might be a belly full of parasites.” Sea lions are like fish in that they get their fresh water from the food they eat, so the starving pups are also dehydrated. When they’re transporting a pup, they surprisingly give them a dog bowl filled with freshwater, which can determine if they live or die. But they don’t give them food.

Rehabilitation

Mitchell Fong of The Marine Mammal Center

Mitchell Fong, a volunteer with the Marine Mammal Center in Northern California for the past thirteen years, explained that some of the emaciated pups are missing half their normal weight or more. As with humans, when pups are that malnourished, their digestive system can shut down making it impossible for them to digest food. “We often don’t even offer fish initially,” Fong said. “What we’re doing is while we’re tube feeding them, we’re checking to make sure that the animal is truly digesting the food; so if liquid starts coming out of the tube and we see its undigested formula, we know that their stomach is not able to digest the last meal we gave them.”

When starving animals arrive at their facilities, they are often given electrolytes for their first few feedings to help hydrate them. The most severely emaciated sea lions can have the longest progression toward fish—which could include first electrolytes, then Emeraid, a formula containing amino acids, protein, vitamins, minerals, and water. The next step is fish smoothies without salmon oil, then fish smoothies with salmon oil, then whole fish. The fish they use is sustainably harvested herring.

Since I live in Southern California, I visited the Pacific Marine Mammal Center (PMMC) in Orange County in early September to take a look at their facility. Established in 1971, this was the first rehabilitation center for marine mammals in California. They’re also one of the smaller ones and hold up to 135 pups comfortably. They have just thirteen paid staff (some are part-time), but 188 volunteers.

As soon as the patients arrive, they’re weighed. That helps the animal care and veterinarian staff determine medication as well as food intake, since sea lions need to consume up to ten percent of their body weight each day. A physical exam follows. Critical care patients stay in one of two heated pens — where even the floors are heated and blankets are provided.

Michele Hunter & Wendy Leeds of PMMC with Mary Ann Wilson

“When these guys come in, they’re emaciated, they have no fat layer,” said Lead Rescue Coordinator Wendy Leeds, who has worked for the center since 1996. “It’s the fat that’s keeping them warm. So any food that we actually give them, they burn off all those calories just trying to stay warm.”

Procedures are done in the lab, which houses an x-ray machines, a portable ultrasound machine, and an infrared camera that allows them to see deeper abscesses. Emaciated animals are hydrated via subcutaneous injection (subq for short) in which electrolytes are injected right underneath a layer of skin, rather than intravenously, to hydrate them. Depending on the situation, they are also tube fed: While the animal is restrained, a biter is placed inside its mouth, and the tube goes through the biter and then down into its stomach. This way staff can pour or push the formula into its belly, starting them with what they call Formula A, a combination of unflavored Pedialyte, Karo syrup and Nutri-Cal.

Formula B consists of fish added to electrolytes. Each pup has their own individualized formula and the amount of fish added depends on where the pup is at in its recovery process. By the time a pup can handle medium-thick formula, they’re weaned to fish. They start with capelin, a small and lean forage fish which is neither oily not fatty, followed by herring, which is a lot more oily and fatty. It’s the herring that’s bulks them up. Michele Hunter, the director of animal care who has worked there since 1989, said, “In our busy season we go through 800 pounds of fish a day, yeah and it’s roughly a dollar a pound so that’s over eight hundred dollars we’re going through in fish a day.” But, she said, “We always want the highest quality of fish for these animals, because they’re sick animals.”

As they get healthier, the pups are moved to different pens. Each pen has heated floors and can be closed if it gets too cold and windy. The animals that can eat but are still pretty thin are placed in pens with no access to a pool, though they can be brought to a pool on an individual basis. They start eating from bowls of fish. If two animals start eating at the same pace, a shallow pool is placed in the pen and fish are added. It’s a good sign if they start competing together, because ultimately they have to compete for their fish. The goal is for them to graduate to bigger pools with five or ten other animals, throw all their fish in there and let them swim around and compete for fish. If they continue to steadily gain weight, they’re likely to be successful out in the wild.

California sea lions stay with their mothers from six months to a year before they’re weaned. They learn everything from them, including social cues and how to swim. Before bringing in a newborn pup, PMMC staff make sure the mother has not left it on the beach to go out and forage. Because most newborns need to be hand–reared, they come to depend on human interaction and bond with their caregivers who guide them and even teach them to swim. They will not be successful out in the wild, so they are placed in a zoo or aquarium.

The rest are kept wild; staff members and volunteers don’t talk to them, and any kind of interaction is kept to a minimum. The majority of pups are born mid-June, and since the rescues start around January or February, they are already weaned and have eaten fish. Unless the pup has an injury that will prevent them from being release, their chances of being returned to the wild are high.

Katie © The Marine Mammal Center

Case Study: Katie

Katie was spotted on June 21, 2016 at Pirate’s Cove, a beach in San Luis Obispo County. A male sea lion pup, he was named by his rescuer who at the time didn’t know his gender. Katie suffered from ataxia (lack of muscle coordination), a swollen jaw, an open wound on his chin, and malnutrition. His body weight was low but not terribly low with a body weight of around 20 kilograms (44 lbs.).

The Marine Mammal Center, which serves San Luis Obispo through Mendocino counties, has full-service veterinary hospital is in Sausalito, but they also have field offices in San Luis Obispo, Monterey, and Mendocino counties. Katie was brought to the San Louis Obispo office, where they injected subq fluids.

At the same time, they tube-fed him fish mash. They figured he could digest protein since he was not severely emaciated, and his swollen jaw and wound most likely inhibited him from eating fish. They also had to decide whether he could make the four and a half hour drive to their hospital in Sausalito. Based on their observations, they took him first to their office in Monterey Bay and obtained a fecal sample, which allows them to look for things like parasites and diseases.

The next day they transported Katie to the hospital in Sausalito, where the veterinarian staff examined the wound to see what caused it and if the wound itself was causing other problems. To examine him for structural damage, they anesthetized him and did an x-ray. Luckily there wasn’t any.  They put him on antibiotics and pain medication for his swollen jaw and chin wound. While in Sausalito the ataxia cleared up and Katie became quite active. Wong surmised that the wobbling that was initially observed may have been due to either his injury or hunger.

The facility in Sausalito, in contrast to the one in San Luis Obispo, has some deep pools of water so sea lions can swim and go after the fish, rather than eating the fish in small, shallow pools of water. Soon after getting there, they were able to transfer Katie from being tube-fed to eating fish. By the time he was released about a month later, his weight was 37.5 kg – close to double his weight when he was admitted.

Back to the Ocean!

Release

In July 2016, I was fortunate to see Katie and three other rehabilitated sea lions released by the Marine Mammal Center in Morro Bay. When they were let out of their individual cages, they touched noses and waddled to the ocean, as volunteers held boards and made a path for them. As soon as they hit water, one of them jumped up and immediately caught a fish. I was moved to tears.

 

Originally published in Catalina Marine Society’s OceanBights, p. 9

References

Mitchell Fong, volunteer with the Marine Mammal Center, Interview July 26, 2016

Peter Wallerstein, director and founder of Marine Animal Rescue, Presentation at Eco Dive Center in Culver City, August 16, 2016

Michele Hunter, director of animal care & Wendy Leeds, lead rescue coordinator; Pacific Marine Mammal Center, Interview September 4, 2016

 

Images

Sea Lions at Pacific Marine Mammal Center, Orange County: Gordon Kelly

Peter Wallerstein of Marine Animal Rescue: Mary Ann Wilson

Mitchell Fong of The Marine Mammal Center: Mary Ann Wilson

Michele Hunter & Wendy Leeds of PMMC with Mary Ann Wilson: Gordon Kelly

Katie: © The Marine Mammal Center

Back to the Ocean: Mary Ann Wilson

 

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Aug 112016
 
Back to the Ocean!

Back to the Ocean!

On July 16, 2016, the Marine Mammal Center released four rehabilitated California sea lions in Morro Bay. After witnessing dead and dying sea lion pups in 2013 and 2015 on Malibu beaches, I was moved to tears to see these pups so excited to get back in the water. Here are their profiles. Note that the person who first finds the sea lion doesn’t know the animal’s gender but gets to name it.

 

Glenn

Glenn, a female California sea lion pup, was first rescued on February 18, 2016 at Oceano Dunes, San Luis Obispo County and released on April 15, 2016. She was re-rescued on May 4, 2016 at Del Monte Beach, Monterey County.

Reason for rescues: of maternal separation, malnutrition, fishing hooks caught on flipper, Pneumonia.

 

Sunset Willie

Sunset Willie, a female California sea lion pup, was first rescued on February 18, 2016 at Sunset Beach, Santa Cruz County and released on May 9, 2016. She was re-rescued on May 22, 2016 at Monterey Harbor, Monterey County.

Reason for rescues: maternal separation and malnutrition.

 

JaydenJayden, a male California sea lion pup, was rescued on May 20, 2016 at Oceano Dunes, San Luis Obispo County.

Reason for rescue: trauma to both eyes and malnutrition.
Note: Corneal Edema will be cleared up in seawater.

 

KatieKatie, a male California sea lion pup, was rescued on June 21, 2016  at Pirate’s Cove, San Luis Obispo County.

Reason for rescue: Ataxia (lack of muscle coordination), swollen right side of jaw, wound on chin, and malnutrition.

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Here’s the video of their release:

Video of Release: Gordon Kelly

Images

Glenn, Sunset Willie, Jayden, and Katie: courtesy of The Marine Mammal Center

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Jul 222016
 
vaquita

Vaquita caught in fishing nets

Vaquita, which in Spanish means “little cow,” is a rare porpoise and the smallest and most endangered species of the cetacean order. Also called the Gulf of California Harbor porpoise (Phocoena sinus), it was discovered only in 1958, but by 2014 the estimated number of individuals dropped below 100, putting it in imminent danger of extinction. That number was revised to about 60 in May 2016.

Vaquitas are often caught and drowned in gillnets used by illegal fishing operations in marine protected areas within Mexico’s Gulf of California. More than half of the population has been lost in the last three years. The vaquitas are threatened primarily by gillnet fishing for the totoaba fish, another endangered species in the Gulf of California that is hunted for its swim bladder, which is considered a delicacy in China.

On Friday, July 22, 2016, United States President Barack Obama and Mexico’s President Enrique Peña Nieto committed to intensify bilateral cooperation to protect the critically endangered vaquita porpoise. Mexican authorities are banning night fishing and gill nets in an area inhabited by the endangered vaquita marina porpoise in the upper Gulf of California. The national fisheries commission said fishermen in the protected area of the gulf, known as the Sea of Cortez, will also have to leave and return from specially designated docks, to help enforce the measures. It said that gillnets, the use of which was already suspended in the area, are now prohibited permanently.

“The demand for illegal totoaba fish bladders is driving the vaquita’s demise. By strengthening bilateral cooperation, Mexico and the United States are pledging their commitment to save the world’s most endangered marine mammal,” said Dr. Frances Gulland, The Marine Mammal Center’s Senior Scientist and a member of the U.S. Marine Mammal Commission. “Enforcing a permanent ban on gillnets, developing alternative fishing gear, and increasing awareness among potential sellers and buyers of totoaba bladders will give the vaquita the greatest chance of survival.”

In March 2016, Dr. Gulland performed necropsies on three dead vaquitas that were discovered in the northern Gulf of California, determining their death as “trauma, entanglement.”

 

References

Associated Press, Mexico bans night fishing, gillnets for vaquita porpoise, July 20, 2016

Marine Mammal Center, www.marinemammalcenter.org

World Wildlife Federation, http://www.worldwildlife.org/species/vaquita

Image

Vaquita, World Wildlife Federation, http://wwf.panda.org/what_we_do/endangered_species/cetaceans/about/vaquita/

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Apr 102016
 
Westward Beach, Point Dume, Malibu April 12, 2015

Westward Beach, Point Dume, Malibu April 12, 2015

On a Sunday morning in March 2013, I spotted three dead California sea lion pups and two dying pups on the beach just south-east of the cliffs in Point Dume, Malibu. I called the Marine Mammal Care Center for help but they were overwhelmed and could not assist the pups. Two years later in April of 2015, I saw two dying sea lion pups just north-west of the cliffs. Someone called the CA Wildlife Center, and a representative came and put up signs that warned people to stay away and then left, saying there was no room for them.

During both years the National Oceanic and Atmospheric Administration (NOAA) declared an Unusual Mortality Event (UME) for California sea lions (Zalophus californianus). In 2013, more than 1600 California sea lions were stranded alive along the Southern California coastline and admitted to rehabilitation facilities in January, February, March, and April.  Seeing some strandings is normal, particularly from mid-April to mid-May, when most pups are weaned and begin foraging on their own. Pups remain with their mothers for the first 10-11 months of their life and become independent around May of the year after their birth. This coincides with the peak upwelling period in the California Current System (CCS) when primary productivity is at its maximum. If the upwelling fails, we may witness an UME. That’s what happened in 2009—a huge mortality event took place between May and August, a period characterized by the strongest negative upwelling observed in 40 years, resulting in unchar­acteristically warm sea surface temperatures.

Figure 1: Annual California Sea Lion Strandings

Figure 1: Annual California Sea Lion Strandings

But 2013 was unique because most of the strandings occurred in the first four months of the year and were located mainly in Southern California (see Figure 1).

This pattern not only repeated itself in 2015, but worsened. The strandings in 2015 occurred along the same stretch of coastline as they did in 2013, mostly from Santa Barbara through San Diego Counties.  But the total strandings during the first five months of 2015 totaled 3340 (see Figure 2), more than doubling the 1262 strandings during the same period in 2013. Moreover, the strandings in 2015 was more than ten times the average stranding level for the same five-month period from 2004 to 2012.’

Figure 2: California Sea Lion Pup and Yearling Strandings

Figure 2: California Sea Lion Pup and Yearling Strandings

The UME status allowed for the establishment of a panel of experts to determine the cause of the mortality. What the investigation found in both years was “a change in the availability of sea lion prey, especially sardines, a high-value food source for nursing mothers. Sardine spawning grounds shifted further offshore in 2012 and 2013,  and while other prey were available (market squid and rockfish), these may not have provided adequate nutrition in the milk of sea lion mothers supporting pups or for newly-weaned pups foraging on their own.”

Mark Lowry, a National Oceanic and Atmospheric Administration biologist, has collected sea lion scat from San Nicolas and San Clemente islands each season since 1981. Through the years, he has identified 133 different species, seven of which are commonly found in sea lions’ diets. The common prey are market squid and six kinds of fish—anchovies, sardines, two different kinds of mackerel, short belly rockfish, and pacific hake.

Of these forage, sardine and anchovy are fat- and calorie-rich while rockfish and squid are fat- and calorie-poor.  Lowry, who has completed his analyses of 2013 samples as well as the 2015 winter and spring samples, said in February 2016 that in 2013 and 2015, anchovy and sardine pretty much dropped out of their diet. As a result, the sea lions’ diet became incredibly diversified. Evidence of common fish include market squid, some hake—though hake is also down from what they normally eat, and short belly rockfish. “But mostly they’re targeting a group of non-common squid and octopus and non-common fish,” Lowry said. The spring 2015 samples showed the highest levels of non-common cephalopod—squid and octopus—and non-common fish he had seen in a long time.

Of the 127 non-common species found in their diet, 40-60 different species were seen in samples taken from San Nicholas Island in 2015. At San Clemente Island, where Lowry collects fewer samples, 40-45 non-common species were found. Two kinds of mackerel, Jack and Pacific, have increased at San Clemente but not at San Nicholas Island.

In April 2015, Lowry told the Los Angeles Times that he had found “mystery stuff — gooey bits of substance you’d expect from a diet of jellyfish or tube worms.” Though yet to be verified, his analysis now shows they were pyrosomes—free-floating colonial tunicates which are closely related to salp. “That’s very unusual,” Lowry said. “It’s the first time I’ve ever seen those. What that says is that sea lions can’t find what they normally eat, so they’re eating whatever they come across.”

In a report published by Royal Society Open Science, Sam McClatchie, Supervisory Oceanographer for Southwest Fisheries Science Center, predicted the temporal sequence of pup weights between 2004 and 2013 based on two variables: the relative abundance of sardine and anchovy, and the relative abundances of rockfish and squid.  When rockfish and squid are more abundant than sardine and anchovy, sea lion mortality increases. The six most common items in their diet are shown below with their corresponding calorie and fat content.

 

Sharon Melin, a wildlife biologist with the NOAA Fisheries National Marine Mammal Laboratory, tracks sea lion pups’ weight gain and growth, and correlates them with inferred diet of mothers. From an analysis of scats from females collected from breeding sites between June and September over eight years, she defined four different diet types and what years the types were dominant.

  • Diet 1: low percentage of market squid and a high percentage of Pacific sardine (2002, 2005).
  • Diet 2: dominated by market squid and Pacific hake (2000, 2001, 2010, 2011).
  • Diet 3: comprised mostly of northern anchovy and Pacific sardine (2003).
  • Diet 4: dominated by market squid and rockfish (2009, 2012).

Average pup weights tended to be heavier in years represented by Diets 1 and 3, average in years with Diet 2, and the lightest pups occurred in 2009 and 2012 with Diet 4.

During three weeks of fieldwork on San Miguel Island in April 2015, Melin observed the sea lions traveling farther and diving deeper to find food. That’s generally not a problem for males since they can go wherever the food is. After the breeding season, some males migrate north as far as Alaska. But a mother is tied to the rookery island until her pup is weaned almost a year later. Females generally remain within 90 miles (150 km) of the breeding rookeries.

California sea lion females give birth to a single pup between May and June in large rookeries on offshore islands along California and Baja Mexico. The main US breeding rookeries are located on the Channel Islands and California sea lion pups are born on the islands of San Miguel, San Clemente, San Nicholas and Santa Barbara. Once a mother begins foraging for food, a sea lion pup will usually nurse, on average, every third day. While she’s away collecting food, she produces milk while her pup waits on shore and fasts. When she returns, she locates her pups with a “pup attraction call,” which is established shortly after birth when the mother and pup call to one another and the pup imprints on its mother’s distinct call. They also recognize each other by scent.

Lactating female California sea lions consume approximately 11% of their body mass in food per day. In addition, because lactating females are usually also pregnant during nine months of the 11-month lactation period, a diet that is insufficient to support both lactation and gestation may result in the resorption of the fetus or a premature birth.

In December 2014, Melin’s team satellite tagged twelve adult female-pup pairs. What they found was while many stayed around the island through much of December, by January they started seeing females taking off and not returning, which was indicative of their pups dying. So out of the original twelve, by March only six were still coming to San Miguel Island, and they were consistently diving to 400, 500, 600 meters.

This diving requires extraordinary physiology. To dive this deep, sea lions’ lungs collapse at about 225 meters down and then re-expand at the same depth upon ascent. This technique not only staves off decompression sickness, by keeping nitrogen out of the bloodstream, but also reduces the amount of oxygen delivered from their lungs to their bloodstream—preserving the oxygen within the sea lion’s upper airways. When they head back to the surface, the preserved oxygen re-expands into the lungs and prevents the sea lion from blacking out in the shallows.

“To have half of our sample diving into those kind of depths is unusual,” Melin said in a NOAA Fisheries podcast last April by which time only four females-pup pairs remained. “These females that were doing this deep diving, they were going very deep and they were going out into very deep water. They were also the four females whose pups are still alive, and we were able to capture their pups. And although their pups were not giant, healthy pups, they were alive.”

Lowry’s 2015 winter and spring findings concur. Short belly rockfish, one of the common fish showing up in his samples, are generally found deeper in the water column than anchovies, sardines, and mackerel. Furthermore, a lot of the non-common fish that were found live on or near the bottom of the ocean, like flat fish and different species of rock fish, as well as cusk eels—a group of marine bony fishes.

A downward trend for sardine abundance has been going on for a decade, and over a large area (five degrees of latitude). McClatchie’s report, which uses data from the Southwest Fisheries Science Center’s Rockfish Recruitment and Ecosystem Assessment Survey (RREAS), shows that during the decade from 2004 to 2014, market squid and rockfish increased, while sardine and anchovy fell to very low numbers off central and southern California, and around San Miguel Island in northern California where sea lions breed.

According to the Pacific Fishery Management Council (PFMC), which develops regulations for fisheries in the U.S. off the West Coast, the sardine biomass (the estimated weight of a stock of fish) reached a peak of 1.3 million metric tons in 2006, then dropped to an estimated 97,000 metric tons in 2015, a decline of more than 90% and significantly below the 150,000 metric ton threshold for this directed fishery. In April of 2015, the Pacific Fishery Management Council announced the closure of the 2015-16 U.S. Pacific sardine fishery, beginning July 1.

Sardine populations rise and fall naturally, cycling as ocean temperatures shift. But, says Tim Essington, a University of Washington professor of aquatic and fishery sciences, “Fishing makes the troughs deeper.” In a paper published in March, Essington showed that overfishing worsens the magnitude and frequency of the cyclical declines of sardines and other forage fish, such as anchovies.

His March 2015 study showed for the first time that fishing likely worsens population collapses in species of forage fish, including herring, anchovies and sardines.  To prevent complete collapse, the study recommended the use of risk-based management tools that would track a fishery’s numbers and halt fishing when they dipped too low. This strategy has the potential to not only ensure more fish for the sea lions, but long term stability in the fishing industry. Using simulations of this management strategy, researchers determined that by suspending fishing when a population falls below half of its long-term average, 64 percent of collapses could be prevented and average catch would be reduced by only two percent in the long term. Based on scientific recommendations by the Lenfest Forage Fish Task Force, Oceana suggests increasing the threshold for pacific sardines from 150,000 metric tons to at least 640,000 metric tons.

At the April 2015 PFMC meeting, assessment author Dr. Kevin Hill presented a Southwest Fisheries Science Center analysis of what the sardine population might look like in the absence of fishing (see Figure 3).  While it is clear that, with the lack of recruitment, the population would have declined greatly even in the absence of fishing, Hill’s analysis showed the population would have been four times higher in 2015 without fishing; that is, approximately 400,000 metric tons (purple line, ‘no fishing’) versus the current estimated 96,688 metric tons (blue line ‘2015 update’). Moreover, sardine harvests exceeded Maximum Sustainable Yield levels during the decline.

Figure 3: Sardine Stock Biomass

Figure 3: Sardine Stock Biomass

The U.S. population of California sea lions is currently estimated to be 300,000 animals, all on the Pacific coast. From an estimated population of about 10,000 animals in the 1950s, their numbers have grown rapidly since 1972 when the Marine Mammal Protection Act was implemented. Lowry, who also conducts annual aerial surveys of California’s pinniped populations, told the LA Times that the sea lion population is increasing at a rate of about 5.1% per year.

Unfortunately, we now have a large sea lion population coupled with a decline in food quality near breeding colonies. Until high-quality food increases again in the Southern California Bight, pup emaciation may become the norm.

Originally published in Catalina Marine Society’s OceanBights, p. 4 

References

Melin SR, et al, Unprecedented mortality of California sea lion pups associated with anomalous oceanographic conditions along the central California coast in 2009, California Cooperative Oceanic Fisheries Investigations Reports. 51: 182-194.

NOAA Fisheries, West Coast Region, 2015 Elevated California Sea Lions Strandings in California: FAQs

NOAA Fisheries, 2013-2016 California Sea Lion Unusual Mortality Event in California

Mark S. Lowry, Research Biologist, Marine Mammal and Turtle Division, Interview February 22, 2016

Louis Sahagun, Scat may contain clues to marine mammals’ Southern California deaths, Los Angeles Times, May 13, 2016

Sam McClatchie et al, Food limitation of sea lion pups and the decline of forage off central and southern California, Royal Society open science, DOI: 10.1098/rsos.150628. March 2, 2016

NOAA Fishwatch, Pacific Mackeral

Sharon Melin et al,California sea lions: An indicator for integrated ecosystem assessment of the California current system, California Cooperative Oceanic Fisheries Investigations Reports. 53: 140-152. 2012

NOAA Fisheries, Transcript: Sea Lion Strandings – The View from the Rookery, April 13, 2015

AMMPA California Sea Lion Fact Sheet

Winship et al., Food Consumption by Sea Lions: Existing Data and Techniques, Sea Lions of the World, DOI: http://doi.org/10.4027/slw.2006

Rich Press, NOAA Fisheries Science Writer, NOAA Fisheries, Transcript: Sea Lion Strandings – The View from the Rookery, April 30, 2015

Birgitte I. McDonald, Paul J. Ponganis, Lung collapse in the diving sea lion: hold the nitrogen and save the oxygen, Biol. Lett. 2012 8 1047-1049; DOI: 10.1098/rsbl.2012.0743. November 12, 2012

Pacific Fishery Management Council, Council Votes to Close 2015-2016 Pacific Sardine Fishery, April 13th, 2015

T.E. Essington et al, Fishing amplifies forage fish population collapses. Proceedings of the National Academy of Sciences of the USA. 2015;10.1073/pnas. April 6, 2015

Lenfest Forage Fish Task Force, Little Fish, Big Impact, April 2012

Oceana, Letter to Ms. Eileen Sobeck, Assistant Administrator for Fisheries, May 21, 2015, Agenda Item B.1.b Supplemental Open Public Comment 2

Washington Department of Fish and Wildlife, Conservation, California Sea Lion Fact Sheet

Images:

Emaciated California sea lion pup, D. Gordon Kelly, Westward Beach, Point Dume, Malibu, April 12, 2015

Figure 1, Annual California Sea Lion Strandings: NOAA Fisheries, West Coast Region, 2015 Elevated California Sea Lions Strandings in California: FAQs, Figure 1

Figure 2, California Sea Lion Pup and Yearling Strandings: NOAA Fisheries, 2013-2016 California Sea Lion Unusual Mortality Event in California, California Sea Lion Strandings

Figure 3, Sardine Stock Biomass: K.T. Hill et al, NOAA Fisheries, SWFSC-FRD, Assessment of the Pacific Sardine Resource in 2015 for USA Management in 2015-16, Fishery Impacts, Slide 12

 

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Nov 032015
 
The bongo net (shown here) has been the standard CalCOFI sampler since 1978. Ships retrieve the nets at an oblique angle to collect fish larvae. CalCOFI sampling and equipment specifications must meet and follow rigorous standards

The bongo net (shown here) has been the standard CalCOFI sampler since 1978. Ships retrieve the nets at an oblique angle to collect fish larvae. CalCOFI sampling and equipment specifications must meet and follow rigorous standards.

Two independent long-term time series show four decades of declines within fish populations in the California Current, with no sign of reversal.

The data set from the California Cooperative Oceanic Fisheries (CalCOFI) and the data set from the power plant cooling water intakes (PPI) were taken from five sites along the California Coastline. Both sets exhibited dramatic declines from the 1970s to the 2000s: 78% for fishes entrapped by the power plants and 72% for the overall abundance of larval fishes in the CalCOFI time series.

“It is notable that these two very distinct data sets tell us that the larval fish populations collected by CalCOFI and near shore fish species observed by PPI data are both declining at nearly the same rates,” said Scripps researcher John McGowan, one of the authors of the study published in Marine Ecology Progress Series on October 28, 2015.

Overall, fishes with an affinity for cool-water conditions, such as northern anchovy, Pacific hake, and several rockfish and midwater fish species are among the most abundant in the California ecosystem. These have declined most dramatically off southern California with initial declines deepening after the 1989 to 1990 regime shift, when warm waters intensified, severely reducing the productivity of many coastal species.

The study’s conclusion: One of the most striking aspects of this study is the strong coherence between these two independent time series and the nearshore and offshore fish communities that they represent. Cool-water marine ecosystems are generally more productive than warm-water ecosystems, and it is apparent that changing ocean conditions have produced far more losers than winners across a range of fish communities in the southern California Current System over the past 40 years. Without the CalCOFI and PPI time series, such dramatic changes would likely not have been possible to document, as they are not observed so clearly in the commercial fishery data. Whether this is due to a movement of cool-water species northward or an overall decline throughout the California Current is a key question for future investigation.

 

References
J. Anthony Koslow,Eric F. Miller, John A. McGowan, Dramatic declines in coastal and oceanic fish communities off California

Mario Aguilera, California’s Fish Populations Are Declining, Oct 29, 2015

Jason Waite, Climate Change and the Central California Current System

 

Images

The bongo net (shown here) has been the standard CalCOFI sampler since 1978, CalCOFI

Dec 292014
 

Back in April 2011, my friend and I were diving off Casino Point on Santa Catalina Island in chilly waters when we looked up and saw four large black fish. They were about four to five feet long, cruising slowly in around 20 feet of water at the edge of the kelp. To my friend they looked like underwater cows; to me they seemed more like mellow hippies on floating motorcycles. Whatever they were, I was in awe of them. We were told they were giant sea bass (GSB), Stereolepis gigas, which return to the waters off Catalina Island every summer, and we were the first to see them that year.

Measuring 8.9ft, this giant sea bass is the largest ever seen.

Measuring 8.9ft, this giant sea bass is the largest ever seen.

These apex predators have had a rough time, being nearly fished to extinction until saved by legislation. Commercial fishing of giant sea bass began in Southern California in1870 when fish were taken with hand lines. But as the take declined between 1915 and 1920, fishermen switched to gill nets, temporarily increasing catch. Commercial landings peaked in 1932 at 115 tonnes but then decreased rapidly. By 1935 most commercial fishing had shifted to Mexico. And by 1980 commercial landings in California waters had declined to 5 tonnes.
In 1981, the California State Legislature banned commercial and recreational fishing for giant sea bass, but still allowed commercial fishermen to retain and sell two fish per trip if caught incidentally in a gill net or trammel net. This law also limited the amount of giant sea bass that could be taken in Mexican waters and landed in California. The law was amended in 1988, reducing the incidental take to one fish in California waters.
After the moratorium was enacted in 1981, catches decreased substantially. From 1983 to 1992, incidental catches remained low, ranging from 1.7 to 5.9 tonnes.

But the moratorium didn’t prohibit fishing over giant sea bass habitats where they could be caught incidentally. Entangled giant sea bass that would exceed the catch limit if landed were discarded at sea or distributed among fishing boats.

Larry Allen

Larry Allen

Other fish have also suffered from nets and overfishing.  Soup fin sharks became scarce in the early 1940s, while leopard sharks declined in the mid-1980s. In a drastic move to save the fish, gill nets were banned as of 1994 from within three miles of southern California’s mainland.  This regulation signaled a turning point for fish populations. In a presentation given this past October, Dr. Larry Allen, biology department chair at CSUN, said the Proposition 132 ban on gill nets is what turned the tide for many commercially fished species.  “We’ve seen a response of halibut, a response of giant sea bass that we’ve published, a response of leopard sharks and soup fin sharks and a variety of other large elasmobranchs which seem to have gotten some relief from commercial fishing.”

Dr. Allen worked for 20 years before seeing a juvenile giant sea bass in 1993. His first observation:

“Last year while trawling in Newport Bay on a sampling trip for Cal Fish and Game’s BENES program targeting local sport fishes, something memorable happened…Almost as soon as the trawl had hit the deck, my chief research assistant, Motz (Tom Grothues), began yelling something about a black sea bass. I was on the back deck in an instant grumbling in disbelief. I had never seen or heard of a black (or now, more properly, a giant) sea bass being taken from inside Newport Bay in all of my 20 years of experience there. But, sure enough, there it was. An absolutely gorgeous little fish about 6 inches long. It was reddish-bronze in color with jet-black circular spots and huge black fins…From the likes of this tiny, elegant fish — the largest, the eldest, and most magnificent of our nearshore fish species will emerge.” (Western Outdoors News, 1993)

He was right.  A scientific monitoring program conducted quarterly by SCUBA divers with the Vantuna Research Group (see OceanBights Vol. 3 No 1) didn’t report any along Palos Verdes Point from 1974 to 2001. The giants were finally seen there from 2002–2004. That’s when Allen decided it was time to begin a study of giant sea bass. But his article entitled “The decline and recovery of four predatory fishes from the Southern California Bight” was turned down by Science, Nature and PNAS, because “there was one reviewer that simply didn’t believe our data. He thought we made it up,” Allen said. It was finally published 2008 in Marine Biology.

Juvenile giant sea bass

Juvenile giant sea bass

Giant sea bass start life as brightly colored orange juveniles with large black spots, and ride the sand riffles in shallow water. According to Allen, the juveniles gorge on opossum shrimp, while the darker adults eat pretty much anything they want including fairly large spiny lobsters which they are more than capable of sucking out of their crevices with their large, gaping mouths. As the only “megacarnivore” inhabiting the kelp beds in southern California, they also consume Pacific mackerel, ocean whitefish, midshipmen, stingrays, white croakers, small sharks, crabs, and mantis shrimp.

Historically, giant sea bass were distributed from Humboldt Bay to southern Baja California and the Sea of Cortez with populations concentrated south of Point Conception in shallow rocky reefs.  According to Allen, the current primary range is Pt. Conception south to about Punta Abreojos, Baja Mexico and in the northern Gulf of California (north of the Midriff Islands). “We think they occur off the coastline of southern Baja California, but if they occur there, they are probably in deep water — say 200 to 400 feet,” Allen said. “We also think they or their larvae migrate around the tip of Baja joining the populations on either side of the peninsula, based on anecdotal and personal observations as well as genetic data.”

Very little is known about giant sea bass, but their increasing numbers enable better research on lifespan, size, mating and population diversity. In recent years, scientists have determined that the Stereolepis gigas are not even related to sea bass. They’re in a completely different group of fish, the wreckfish (Polyprionidae) which are very distantly related to groupers.

To estimate age, Allen counted the number of annuli on otoliths from 64 heads, obtained from the Santa Barbara Fish Market between January 2010 and May 2013. These fish were incidentally caught by fishermen working between the Northern Channel Islands and northern Baja Mexico. When he counts the rings he places a dot on each ring to ensure accuracy. Then he figures out how much bomb radiocarbon it has, and fits that into the calibration curve of bomb radiocarbon present in the Eastern Pacific. Bomb radiocarbon was produced from atmospheric nuclear testing in the 1950s and shows a very distinct pattern in most oceans, as the atmospheric fallout worked its way into the bony structures of all fishes and invertebrates. In 2012 Larry Allen and Allen Andrews were the first to validate annual growth rings for one individual and provide a verified maximum age, 76 years, for giant sea bass using bomb radiocarbon validating techniques.

JR Clark and Parker House

JR Clark and Parker House

Wild, live fish are being studied at Catalina. Two of Allen’s students, JR Clark and Parker House, received WIES Wrigley Institute Summer Graduate Fellowships and spent three months diving off Catalina Island, first locating the giants’ aggregations, then trying to determine their size, densities, and mating behavior. They also hope to learn what impact their return will have on kelp bed fish populations. Grants and $6,000 dollars in crowd funding help to pay for the students’ underwater hydro-acoustic equipment and sea scooters.

To find the minimum population size around the entire island, they chose eight sites: four where they thought they’d see giants and four where they thought they wouldn’t see them, and did the back side as well as front side. Those eight sites were Johnson’s Rocks, Little Geiger, Empire Landing, Twin/Goat (between Goat Harbor and Twin Rocks), Italian Gardens, Casino Point, The Vee’s, and Little Harbor. There were 4 periods within roughly two-week long windows that sampling was conducted.

Sites with the most individuals and biomass were Little Harbor, Goat Harbor, and the Vee’s. At the Vee’s they saw an aggregation of 24 individuals in two different sampling periods. To accurately size giants underwater, the students use length-calibrated lasers and a GoPro video camera mounted on top of SeaDoo SeaScooters. Two laser beams calibrated four inches apart are pointed directly (90 degrees broadside) at an individual fish so that the laser dots are visible in the video. Stills are later extracted from video and then measured using a software program. Using length to weight relationships, biomass is determined for different areas.

Parker House and JR Clark underwater

Parker House and JR Clark underwater

Their calculated average biomass for the eight sites was 36.29kg/1000m2, which was higher than expected. House said this was due to the unexpected and very large aggregation at the Vee’s. The most individuals observed were 36 counted during the sampling period from July 15 to July 23, 2014. The least were seen during June with only nine individuals. The giants ranged from 0.9 to 2.7 meters while the majority were around 1.3 m (4.2 feet) in length.  The International Game Fish Association all-tackle world record for this species is 563 pounds 8 ounces, caught at Anacapa Island in 1968. But the largest one seen this summer was 2.7 meters or 8.9 feet and weighed at least 325 kilograms or 800 lbs, and is the largest ever measured.

“It was relatively easy to count the individuals as many stayed in a general area,” House said. “Many of them have different characteristics; some had many parasites on their face, or scars on their fins or sides, or blotches so you can more easily identify one fish from another, although they do change color.  Some would be near us and would show a certain color pattern, but once they moved away, you would see these patterns change. We think the changing of color pattern may be a signal for mating as well as communication to the other individuals.”

“Many fishes change color when they are ready to mate,” Clark added. “A good example is the kelp bass, which presents a yellow or orangey mask when males are in the spawning season. We have seen some color change, from a light to dark color type change. This has been previously described as a spawning type activity in giant sea bass.”

Parker House riding a SeaDoo SeaScooter

Parker House riding a SeaDoo SeaScooter

Another way to identify spawning and courting behaviors is by their sound. The students had just gotten down to one of their sites when they heard a BOOM — the sound of a very loud bass drum.  “The first time I heard it I thought something was wrong with my tank,” House said. “So I checked my pressure gauge to see if it had dropped, but it wasn’t us. We looked around and a giant sea bass was coming straight to us, and then he checked us out and took off. We think the sound could be either a call to try and get us away because they were courting in that area, or to see if we were potential mates.”

Spawning in giant sea bass has only been seen in an aquarium where there are just two individuals. Because of their size and the enormous amount of eggs the females carry — up to 60 million — GSB are thought to be group spawners, but Clark believes that they are pair spawners because they are frequently seen in pairs, even when they are in large aggregations.

Giant sea bass sounds are recorded by a hydrophone.

Listening in on a hydrophone.

The students use the sounds giant sea bass make to distinguish one fish from another and also to measure the density of giants in a specific area. Clark uses a DSG-Ocean Acoustic Datalogger, which is an omnidirectional hydrophone (underwater microphone) that can record data over many days. He distinguishes giant sea bass sounds from other fish by looking at the decibel range and sound frequency they produce and comparing them with giant sea bass sounds recorded in an aquarium. This enables him to analyze mating strategies and describe spawning behavior of giant sea bass in detail. “Although there may be some echoing in the sounds produced in the aquarium it will allow me to ground truth sounds and get a general decibel range to work with,” he said.

Whatever the giants spawning behavior is, their genetic diversity is small. Allen and Andrews used mitochondrial and nuclear microsatellite techniques to determine genetic diversity. They found all the giant sea bass, those in the northern Gulf of California, as well as off Southern California and Baja, were closely related. They’re basically one panmictic group — a panmictic population is one where all individuals are potential partners. “Our estimate is 152 breeding females, with maybe an upper limit of 500 and a range of 84 to 539,” Allen said. “So we’re dealing with a fish that’s not genetically diverse anymore; relatives are breeding with another, and we don’t know what that says to the ultimate sustainability of these populations. Sobering.”

A pair of giants

A pair of giants

However, the king of the kelp forest has returned. Recently a Giant Sea Bass Count was organized by researchers at the University of California, Santa Barbara and California State University, Northridge.  Recreational divers could report any sightings around Southern California during the first week of August. Giant Sea Bass sightings numbered 23. Their results can be seen at seasketch.org. Green dots indicate sightings and black X’s show where people reported that they dove but saw no Giant Sea Bass.

Next year’s giant sea bass count will probably be in early August, but check and “like” the Facebook page, The Giant Sea Bass Collective, to get updates.

Originally published in Catalina Marine Society’s OceanBights, p. 3, and reprinted in California Diver.


References

Giant Sea Bass, Stereolepis gigas

Dr. Larry Allen, “The Return of Giant Sea Bass off California,” Presentation at California State University, Fullerton; Wednesday, October 8, 2014

Holly A. Hawk & Larry G. Allen, Age and Growth of the Giant Sea Bass, Stereolepis gigas

IUCN Red List Data, Stereolepis gigas

California Department of Fish and Game, Giant Sea Bass

Current Results, Sharks, Seabass Rebound After Fishing Banned

Dr. Larry Allen, Target Species Profiles: Giant (black) Sea Bass (Stereolepis gigas)

Larry Parker House, CSUN marine biology graduate student, interview September 8, 2014

Brian (JR) Clark, CSUN marine biology graduate student, interview September 24, 2014

Images:

  1. A pair of giants: Parker H. House
  2. Largest giant sea bass ever measured at 8.9ft and 800+ lbs.: Parker H. House
  3. June 1906: world record at 428 lbs.: Library of Congress, Digital Collections
  4. Dr. Larry Allen: Mary Ann Wilson
  5. Juvenile giant sea bass: Phil Garner
  6. JR Clark and Parker House: CSUN Students Dive Into Marine Research on Catalina Island
  7. Parker House riding a SeaDoo SeaScooter: J.R. Clark
  8. Parker House and JR Clark: Parker H. House
  9. Listening in on a hydrophone: Parker H. House
Sep 072014
 
Sep 022014
 
PCH

View of the Pacific Ocean from Pacific Coast Highway.

In a new five-year project, UCLA researchers will make the first detailed models predicting how climbing temperatures will affect the coastal climate in four eastern boundary upwelling systems, or EBUSes, which are off the coasts California and Oregon, Peru and Chile, southern Africa, and Spain and northern Africa. The project is supported by a $2 million grant received this month from the National Science Foundation.

Current global climate models provide sketchy predictions of changes for EBUS areas, partly because the regions are such narrow slices of the globe. To overcome that flaw, the research team will develop the first fine-tuned model of the EBUSes to simulate the complex interaction between the ocean and the atmosphere, identify the difference between the natural variations in the ecosystems and variations due to climate change, and predict whether changes in cloud cover will allow in more or less sunlight and warmth.

Read article here.

Image: Mary Ann Wilson

Aug 222014
 
The shell pictured here is a victim of acidification. The normally-protective shell had become so thin and fragile, it is transparent.

The shell pictured here is a victim of acidification. The normally-protective shell had become so thin and fragile, it is transparent.

The significance of our ocean’s impact on greenhouse gas begins with the earliest ocean four billion years ago, when all the atmospheric carbon was absorbed and allowed the earth to cool enough for life to begin. In our modern era, as atmospheric carbon dioxide levels go up, the ocean absorbs more carbon dioxide to stay in balance. Currently the ocean is holding 50 times more carbon than the atmosphere and is slowing the rate of climate change by absorbing about 30 percent of carbon dioxide from cement production and other activities.

But there’s an important side effect. When carbon dioxide reacts with seawater, carbonic acid is formed—the same weak acid found in soda. Carbonic acid releases negatively charged hydrogen ions, which lowers the pH level of seawater. Although ocean water is still alkaline, the term “acidification” refers to a gradual shift toward the acidic end of the scale. The pH scale ranges from 0 to 14; 7 is neutral, lower numbers are acidic and higher numbers are alkaline. Over the past 300 million years, ocean pH has averaged about 8.2, but since preindustrial times it has dropped 0.1 to a current average of 8.1. This may not sound like much, but the pH scale is logarithmic, so that a pH of 7 is about ten times more acidic than a pH of 8. Thus, this drop represents a 25-percent increase in acidity over the past two centuries.

Servicing the Santa Monica Bay Observatory mooring’s antenna

Servicing the Santa Monica Bay Observatory mooring’s antenna

There are several reactions that occur between carbon dioxide (CO2), water (H2O), carbonic acid (H2CO3), bicarbonate ion (HCO3-), and carbonate ion (CO32-). But over the long term ocean acidification leads to a decrease in the concentration of carbonate ions in seawater. Together with calcium ions they form the basic building blocks of carbonate skeletons and shells. The decline of carbonite ions impacts the ability of many marine organisms such as corals, marine plankton, and shellfish to build or even maintain their shells.

There are two main forms of calcium carbonate used by marine creatures: calcite and aragonite. Calcite is used by phytoplankton, foraminifera, and coccolithophore algae. Aragonite is used by corals, shellfish, pteropods, and heteropods. When additional calcite and aragonite cannot be dissolved in water, that water is said to be supersaturated; when they can be dissolved, the water is said to be undersaturated for those minerals. Animals that need calcium carbonate are better in supersaturated water as obtaining that mineral from the surrounding water is easier. The saturation of these minerals in seawater decreases with depth, and the transition point between supersaturated and undersaturated conditions is referred to as the saturation horizon. Because aragonite dissolves more easily than calcite, aragonite is the first to be impacted by ocean acidification. For example, one might find the saturation horizon for calcite at 150 meters or even deeper, but for aragonite it would be at 100 meters.

Currently, nearly all of the surface ocean waters are substantially supersaturated with regard to aragonite and calcite. However, more carbon dioxide dissolving in the ocean has caused the saturation horizon for these minerals to shift closer to the surface by 50-200 meters as compared to the 1800s. As the ocean becomes more acidic, the upper shell-friendly layer becomes thinner.

Distribution of the depths of the undersaturated water (aragonite saturation < 1.0; pH < 7.75) on the continental shelf of western North America from Queen Charlotte Sound, Canada, to San Gregorio Baja California Sur, Mexico. On transect line 5, the corrosive water reaches all the way to the surface in the inshore waters near the coast. The black dots represent station locations.

Distribution of the depths of the undersaturated water (aragonite saturation < 1.0; pH < 7.75) on the continental shelf of western North America from Queen Charlotte Sound, Canada, to San Gregorio Baja California Sur, Mexico. On transect line 5, the corrosive water reaches all the way to the surface in the inshore waters near the coast. The black dots represent station locations.

The saturation horizon is much closer to the surface in regions where upwelling occurs, such as along the West Coast from British Columbia to Mexico. That’s because deep water in the North Pacific is naturally rich in CO2, since the deep water has been out of contact with the surface for 1200 to 1500 years. As water travels along the oceanic conveyer belt, it accumulates CO2 through natural respiration processes that break down sinking organic matter, generating CO2 just as humans do when they breathe. Under normal conditions (and even more so under La Niña conditions), winds blow from north to south during spring and summer months along the West Coast creating an effect known as the Ekman Transport, which in turn moves surface water away from the coastline. This warm surface water is then replaced by colder water upwelled from depths between 100 and 300 meters. This deep nutrient-rich water traditionally makes for robust fishery production. However, the naturally highly acidic water is now augmented with man-made carbon dioxide, making this carbon-rich water even more acidic.

In the Northeastern Pacific, corrosive waters are already shoaling into the euphotic zone during upwelling. In 2007 Richard Feely and a team of scientists found undersaturated seawater with respect to aragonite reaching depths of about 40 to 120 meters. In one transect less than 20 miles from shore near the California-Oregon border, the saturation horizon had shoaled all the way to the surface. Without the contribution of anthropogenic CO2, the aragonite saturation horizon would be about 50 meters deeper.

Because of this, the Pacific Northwest oyster-growing industry nearly collapsed before Feely and other scientists were able to help devise strategies and monitoring protocols. In 2007, the Whiskey Creek Shellfish Hatchery in Oregon lost millions of oyster larvae and later discovered that the larvae were being bathed in acidic waters drawn in by intake pipes. Oyster larvae are particularly sensitive in their first few days of life such that carbon dioxide alters shell formation rates, energy usage and, ultimately, their growth and survival. Now, the Whiskey Creek hatchery tries to balance the acidity of its waters by adding soda ash. Costs have increased and production has never fully recovered.

Island Scallops, a shellfish producer in the Georgia Straight near Vancouver, lost all its scallops over a 3-year period from 2010 to 2012, during which time pH levels had dipped to 7.3. CEO Rob Saunders said that this level of pH in the water was something he hadn’t seen in his 35 years of shellfish farming. The loss amounted to 10 million dollars and a third of their workforce (20 people).

No less troubling is the impact of acidification on the food chain. This year, a NOAA-led research team found evidence that acidity off the West Coast has been dissolving the shells of pteropods at double the rate since the pre-industrial era. These tiny free-swimming marine snails make up 45 percent of the diet of pink salmon and are also a food source for herring and mackerel. The highest percentage of sampled pteropods with dissolving shells were found from northern Washington to central California, where 53 percent had severely dissolved shells.

Compared to Southern California, the water north of Point Conception comes from deeper depths up to the surface where the upwelling is stronger and lasts longer—from spring to fall. Because the direction of the coastline changes (from north-south to east-west) south of Point Conception, a weaker upwelling occurs in Southern California from February to May. The same NOAA-led research team found evidence of corrosive waters shoaling to depths of about 20-50 meters in the coastal waters off Washington, Oregon, and northern California; and to depths of about 60-120 meters off southern California.

Anita Leinweber on board the R/V Seaworld.

Anita Leinweber on board the R/V Seaworld.

This has been the pattern for at least the past ten years, according to Dr. Anita Leinweber, a researcher at UCLA who has been measuring acidification levels in Santa Monica Bay for more than a decade. In a 2013 study, Leinweber and co-author Nicolas Gruber published six-year trends for pH and the aragonite saturation state in the Santa Monica Bay from 2003 to 2008. They found that the saturation horizon there reaches 130 meters on average. As the aragonite saturation state changes, this shoaling is exacerbated and the horizon could climb 20 meters by 2050 to reach an average depth of 110 meters.

Median trends for pH are also decreasing by an average of about -0.004 per year between 100 and 250 meters. These trends in Santa Monica Bay are larger in magnitude than most of those reported so far — for example, about -0.003 pH units per year in Monterey Bay. They are also slightly larger than those expected on the basis of the recent trends in atmospheric CO2. The study also noted that the saturation horizon reached its highest point—the top 30 meters—during the height of the upwelling season in April and May. Lower pH and aragonite saturation states were observed during winters when La Niña conditions prevailed, which makes sense given that La Niña conditions intensify upwelling conditions.

At the time of the study’s publication, no statistically significant linear trends had emerged in the upper 100 meters. But this past April, Leinwebier saw a statistically significant trend in surface pH, calculated from additional data which extended to 2013. The pH values in the top meter had been decreasing by about 0.003 per year. (Calculations were not yet complete for other depths.)

Dr. Leinweber and Takeyoshi Nagai attaching water-sampling bottle

Dr. Leinweber and Takeyoshi Nagai attaching water-sampling bottle

“We have evidence already that ocean acidification is happening,” Leinweber said. “It’s not something that we’re making up or something that we know has to come at some point. We actually see it.”

As alluded to above, the effects of ocean acidification will vary with location. For its part, the Catalina Marine Society is acquiring pH and other ocean chemistry data at specific depths near Santa Catalina Island with its depth-profiling program. These data will enable us to determine where the water comes from, where the phytoplankton reside, the acidity of Santa Catalina water, and how much oxygen is available to marine fauna. The goal is to obtain sufficiently dense records to compare to similar data collected in Los Angeles Harbor (by the Southern California Marine Institute), Point Loma (Scripps Institution of Oceanography), Santa Monica Bay, and off the Santa Barbara coast (University of California, Santa Barbara), as well as understand the physical processes operating around the island and develop expectations for what climate change and ocean acidification will bring. The new data will supplement what was previously collected at a single depth (18 m) near Two Harbors, Catalina. Those data, which include pH levels from May 19, 2012 through November 17, 2013, are available to researchers and students at http://www.catalinamarinesociety.org/Scientificmooring.html

Originally published in Catalina Marine Society’s OceanBights, p. 3.

References

Intergovernmental Panel on Climate Change, Climate Change 2013: The Physical Science Basis, Chapter 3, Observation: Ocean

pH Scale, Introduction and Definitions

European Project on Ocean Acidification, FAQs about Ocean Acidification, Ocean carbon chemistry and pH

Skeptical Science, Ocean acidification: global warming’s evil twin

Nicolas Gruber, Claudine Hauri, Zouhair Lachkar, Damian Loher, Thomas L. Frölicher, Gian‐Kasper Plattner; Rapid Progression of Ocean Acidification in the California Current System

NOAA OAR Special Report, Scientific Summary of Ocean Acidification in Washington State Marine Waters

Richard A. Feely, Christopher L. Sabine, J. Martin Hernandez-Ayon, Debby Ianson, Burke Hales; Evidence for upwelling of corrosive “acidified” water onto the Continental Shelf

Kenneth R. Weiss, Los Angeles Times; Oceans’ rising acidity a threat to shellfish — and humans

Brooks Hays, 10 million scallops dead in Canada thanks to overly acidic water

CBC News, Acidic ocean deadly for Vancouver Island scallop industry

N. Bednaršek, R. A. Feely, J. C. P. Reum, B. Peterson, J. Menkel, S. R. Alin and B. Hales; Limacina helicina shell dissolution as an indicator of declining habitat suitability owing to ocean acidification in the California Current Ecosystem

Leinweber and N. Gruber, Variability and trends of ocean acidification in the Southern California Current System: A time series from Santa Monica Bay

Anita Leinweber, Institute of Geophysics and Planetary Physics and Department of Atmospheric and Oceanic Sciences, University of California, Los Angeles, California, interview May 17, 2014.

Catalina Marine Society, Measuring Catalina’s Ocean, Flyer for Boaters

Images:

  1. The shell pictured here is a victim of acidification: NOAA, Ocean Acidification
  2. Servicing the Santa Monica Bay Observatory mooring’s antenna: Anita Leinweber
  3. Distribution of the depths of the undersaturated water: Richard Feeley, Evidence for upwelling of corrosive “acidified” water onto the Continental Shelf
  4. Anita Leinweber on board the R/V Seaworld.: Anita Leinweber
  5. Dr. Leinweber and Takeyoshi Nagai attaching water-sampling bottle