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A glimpse into the shifting community structure of a Southern California kelp forest and the benefits of long-term monitoring

July 29, 2020September 23, 2020mlmlblog

By Lauren Parker, MLML Ichthyology Lab

I can’t tell you how much I miss spending the majority of my day underwater. It’s difficult to communicate the feeling it gives you; the feeling that you have somehow been given the opportunity to glimpse another world, one that most people never get to see. As a marine scientist spending a select few glorious (for the most part) hours in that world, I am tasked with collecting data. I record pages and pages of species codes and numbers, I count things and I measure them. I take copious amounts of photos.

I was a research SCUBA diver for the Partnership for the Interdisciplinary Studies of Coastal Oceans (PISCO) at the University of California, Santa Barbara (UCSB), monitoring the kelp forest around the northern Channel Islands in Southern California. Most of my days were spent waking up before the sun, loading dive gear into the boat, racing dolphins and dodging migrating whales across the Santa Barbara Channel so that we could dive all day long. We’d race the sunset back to the harbor just to do it all again the next day.

The 2017 PISCO team on board NOAA's Shearwater.

UCSB’s PISCO team has been monitoring the kelp forest in the Channel Islands since 1999. While changes over the long-term are the principle focus of organizations such as PISCO, short-term variability in ecosystem structure can provide insight into the potential effects of future ocean conditions, particularly in the context of a swiftly changing climate.

While my time with PISCO represents just a snapshot of the continually evolving story of the kelp forest ecosystem, I was witness to several distinct changes in the kelp forest community in my five seasons of diving. I watched sea star populations decline markedly and sunflower sea stars disappear completely. I watched the invasive alga, Sargassum horneri, replace the native giant kelp at Catalina Island and then quickly spread to the northern Channel Islands. More and more often we recorded species not normally seen on our surveys.

Decline in Sea Stars

I began surveying the kelp forest in 2013, just before the anomalous rise in sea surface temperatures across the North Pacific Ocean, known as the “warm blob,” appeared along the west coast. For a more in-depth explanation of the “warm blob” check out this link. 2013 was also the last year during which I saw a sunflower sea star.

Me with a sunflower sea star, Pycnopodia helianthoides, on my head in 2013.

Sunflower sea stars can grow up to meter in diameter, and can have 24+ arms as adults. They are also voracious predators, feeding on a variety of invertebrates and even other sea stars. Sunflower sea stars were seemingly the first casualty in what came to be a mass mortality event over the next few years. Sea Star Wasting Disease (SSWD) caused the death of many types of sea stars and scientists are still studying the disease’s origins and what triggered the outbreak. Sunflower stars play an integral role in the kelp forest ecosystem. As sunflower stars became functionally extinct, purple urchin numbers increased dramatically, which in turn caused a marked decline in kelp abundance, though not as prevalent a decline as that of macroalgae populations in central and northern California. While noted as an important player in the kelp forest, research on sunflower sea stars is unfortunately minimal due to a lack of commercial importance.

A large number of other sea star species were heavily impacted by SSWD. The ochre sea star, the giant-spined sea star, and the short-spined sea star are larger and more abundant species, so their decline was particularly apparent. These and several other sea stars, totaling around twenty different species, were decimated by SSWD. Infected individuals looked like they were slowly dissolving, many of them missing limbs and they were often covered in white, fleshy lesions.

Invasion of Sargassum

Sargassum horneri, nicknamed devil weed, is an invasive seaweed native to eastern Asia and a relatively new resident in California waters. Discovered in 2003 in Long Beach harbor, it has since invaded and become established throughout Southern California, taking a particularly firm grip in the Channel Islands. S. horneri has become the subject of several studies aimed at understanding it’s invasibility, particularly its ability to outcompete native algae. In the northern Channel Islands, at Anacapa Island in particular, the level of invasion has been linked to the level of management, where marine protected area type and the length of protection strongly influence invasibility. Results indicate that marine invasions are complex but that protection does play a key role in resistance. Check out this paper for more information. Adequate marine management is imperative in a changing climate, particularly since marine invasions are forecasted to increase with changes in ocean climate.

Diving deep into a bed of S. horneri at Catalina Island, CA.

An increase in ocean temperatures is often accompanied by some odd animals showing up in strange places. This became particularly apparent during the “blob” years of 2014 through 2018 when a variety of organisms began pushing the limits of their typical temperature envelopes and causing an uproar wherever they were spotted. Thousands of pelagic red crabs began making a regular appearance each field season. Finescale triggerfish began showing up on the same transects as lingcod, a comparably much colder water fish. A goldspotted sand bass, normally a resident of the waters from Cedros Island southward off the coast of Baja California, showed up on a fishing vessel in the Channel Islands. Basking sharks began patrolling the waters of the channel and green sea turtles were glimpsed at Santa Cruz Island. These examples represent only a portion of what seemed out of the ordinary during my time with PISCO. However, an increasingly changing ocean climate is likely to foster shifts in species ranges that will cause a lot more strange animals to show up in weird places. If you happen to see any such animals, such as the sheephead and spiny lobsters that have shown up in Carmel, check out the Strange Fish in Weird Places website and let the scientists know what you saw.

A pelagic red crab, Pleuroncodes planipes, at Santa Cruz Island.

Return of top predators

Not all of the changes I witnessed were negative, although that might depend on who you ask. Recent years have shown what seems to be a recovery of top predators in the kelp forest ecosystem. Yep. You guessed it. Sharks. White shark populations have made a significant comeback, with higher numbers of both adult and juvenile populations reported along the California coast, likely the result of increased protections in the last couple of decades. While white sharks do pose a threat to crowded beaches and various other ocean pastimes, such as surfing and freediving, they are a vital component of the marine ecosystem and their increase in numbers, while making us ocean goers slightly more uneasy, should be celebrated.

These events by no means indicate a clear trend for the future of the kelp forest, however they do highlight what can happen in a drastically changing climate. Recent years, including those in which I was an active PISCO diver, were what can be termed a perfect storm of events. Periodically warmer waters caused by an El Niño event were coupled with the “warm blob”, a marine heatwave that caused unseasonably warm waters for an extended period along the west coast of the United States. Prolonged elevated temperatures caused innumerable marine impacts, and likely had a hand in the ones discussed here.

More frequent and more intense storms and heat waves, like the “blob”, higher levels of pollution, and other anthropogenic impacts that result from climate change are threatening ecologically and economically important marine systems, worldwide. Scientists in recent years have begun to confirm that kelp systems, globally, are in decline. The need for long-term monitoring of ecosystems is necessary now, more than ever, to assess and understand the changes that are happening right before our eyes.

Could seaweed be a pollution solution?

July 16, 2020September 23, 2020mlmlblog

By Shelby Penn, MLML Phycology Lab

As a child, I remember spending hours collecting trash from the street ditch, woods, and ravine around my house. It was something that I felt very strongly about even as an 8-year old. I’ve never been able to understand how someone could just throw their trash out the car window without a second thought. Today, as an avid outdoor enthusiast, tour guide, and lover of all things nature, or as I like to call it “neature”, helping out mother nature has now become a passion and life-long pursuit.

Chemical pollution is a huge problem across the globe and many contaminants are released into the natural environment daily. Concern over chemical pollution can be dated back as far as the 13th century when England’s King Edward I wanted to use penalties to reduce air pollution if the residents of London did not stop burning coal. This threat, however, had little effect, and it was not until after the industrial revolution that the concern of pollution resurfaced.

Living among emperor penguins: 2019 field expedition to Antarctica

July 9, 2020September 23, 2020mlmlblog

How does pollution ‘coral’ate with coral bleaching in American Samoa?

July 2, 2020October 14, 2020mlmlblog

By Melissa Naugle, CSUMB Logan Lab & MLML Invertebrate Ecology Lab

You may have heard stories about the Great Barrier Reef and coral reefs worldwide that are succumbing to ‘coral bleaching.’ Maybe you’ve seen the pictures of stark white corals devoid of the fish and other creatures that make a reef healthy and colorful. But what exactly is coral bleaching and what is it like to study it?

When corals bleach, they lose their symbiotic partner, microscopic algae called zooxanthellae. Zooxanthellae provide the majority of the coral’s diet by converting energy from the sun into food for the coral. As a response to stressful changes in their surroundings, zooxanthellae will abandon their coral host, leaving behind a pale and hungry coral skeleton. Often, the corals never recover their zooxanthellae and die of starvation.

Improving soil health on farms: better for the farmer, better for the planet

June 25, 2020October 16, 2020mlmlblog

by Stefanie Kortman, CSUMB Haffa Lab

The author collecting soil greenhouse gas measurements on a farm during a cover crop season.

My research in sustainable agriculture practices was born from two passions: my love of food and my concern for protecting and preserving natural resources. I came into my role as an agricultural scientist in the world-renowned farming valleys of the Monterey Bay region. (One of these valleys—the Salinas Valley—is even called “The Salad Bowl of the World” for all the produce it exports.) In my work, I examine how different farm management practices influence soil and the production of greenhouse gas emissions, such as carbon dioxide, methane, and nitrous oxide. Before I started my research, I never thought of soil as a source of greenhouse gas emissions and didn’t know how the process of growing food can cause more to go into our atmosphere than are naturally produced in the soil by microorganisms. I have come to learn that agriculture is in fact an important source of human-induced greenhouse gases. It’s estimated to contribute 19–29% of total greenhouse gas emissions, while transportation accounts for 14%. With agriculture soil management heralded as a top solution for drawing down global carbon dioxide levels to mitigate climate change, farmers are increasingly expected to adopt practices that reduce emissions and store, or sequester, carbon in soil while still providing our growing population with essential food products. The solution is in the soil. My goal is to help show farmers how to keep their soil healthy. It benefits both their farming and the environment.

Farm-to-Water, Farm-to-Air

What happens on farms does not always stay on farms. When farmers apply fertilizer and water to soil, plants don’t use all of it. Microscopic organisms (aka “microbes”) in the soil transform excess nutrients into other forms, such as gas emissions. One such gas is nitrous oxide, or “laughing gas”—the same gas dentists use for sedating patients. But nitrous oxide production from agriculture is no laughing matter; this potent greenhouse gas is 300 times more effective than carbon dioxide at trapping heat on Earth. Most nitrous oxide emissions caused by humans come from agriculture—mainly from applying more nitrogen fertilizer to the soil than plants can use.

Left: Monitoring soil greenhouse gas emissions on a farm participating in a 3-year Healthy Soils Program grant funded by the California Department of Agriculture. Right: Dark, rich soil with crop residues on the surface at a farm that has practiced management focused on soil health for over 30 years.

Agricultural runoff can carry topsoil and nutrients that pollute waterways and degrade aquatic ecosystems.

Nutrients can also be transported in water (think salt in water) down through the soil and into groundwater or out of farms through drainage channels that carry this “runoff” into rivers, streams, estuaries, and eventually the ocean. This can lead to contamination of drinking water, pollution of waterways, and negative impacts within aquatic ecosystems. Runoff often encourages the growth of harmful algae that use up the dissolved oxygen in the water and create “dead zones”. Thankfully, there are many opportunities for improving farm management practices and reducing air and water pollution.

Good for the Soil, Good for the Farmer

Improving crop production, reducing losses of topsoil and nitrogen, and storing carbon in soil are all achievable opportunities of soil-health focused farming, and it all comes down to the basis of managing soil health: soil aggregates. Soil aggregates are little clumps of soil bound by secretions from roots and enzymes from microbes, both of which act like glue to hold soil particles together. They improve soil structure by creating little pockets of space between clumps, which helps keep water in place so plants can use it. This, in turn, reduces topsoil erosion and runoff. When soil can hold more water, less irrigation is needed, and minimizing erosion and runoff reduces the loss of nitrogen and precious topsoil from farms. These little clumps also keep carbon locked away, or sequestered, and help promote conditions that reduce nitrous oxide production.

Practices that improve soil aggregate stability, and thus soil health, include planting cover crops and reducing tillage. Cover crops are crops that are planted in the winter or spring and provide many benefits to soil, including adding plant-usable nitrogen, keeping soil in place, extending roots into the soil to create pathways for water to move through, and much more. Common cover crops are legumes—such as hairy vetch, fava beans, and clover—and grasses—such as rye, oats and buckwheat. Reducing disturbance to the soil by minimizing tillage helps maintain soil aggregates that take time to build. These methods can help farmers promote healthy soil and reduce greenhouse gas emissions.

Left: Hand-applying compost on a farm to improve soil structure is one of many techniques to promote soil health in agroecosystems. Right: Cover crops promote soil health by keeping the soil planted which prevents erosion, improve soil's physical and biological properties, supplies nutrients, suppress weeds, and improves the availability of water.

The future of food production is dependent on soil health-based farm management, but not all methods work for every farm or region. Researchers like me partner with farmers to monitor the impacts different crop and soil management practices have on soil health and crop production and learn which techniques work best for different situations. Through these collaborative efforts we can assess the efficacy and practicality of different management practices in terms of improving soil health and maintaining a successful farm business. The future of farming depends on partnerships to achieve the greatest benefit for feeding a growing population and protecting the resources that make this planet so unique. I am proud to be working for a better future.

Saving sea turtles from cold stunning

June 12, 2020October 14, 2020mlmlblog

By Daphne Shen, MLML Vertebrate Ecology Lab

Every October, animal rehabilitation facilities around the northeast gear up for another sea turtle cold stun season. Cold stunning for sea turtles is similar to hypothermia for people, and typically occurs in November and December. As the ocean temperature drops below about 10°C (50°F), a sea turtle’s body shuts down. Since they are cold-blooded, their body temperatures are close to that of the surrounding water. Once they get too cold, sea turtles become lethargic and are no longer able to swim or eat, and end up at the mercy of the currents.

These turtles, usually juveniles, wash up on beaches around Cape Cod, Massachusetts, and Long Island, New York. They can be found traveling up the East Coast with the Gulf Stream and spending their summers feeding in the waters off the coast of New England. As the water cools down, sea turtles should instinctively migrate back south towards Florida and the Caribbean. The problem is that many animals get caught in bays and can’t figure out how to navigate back to the open ocean, eventually succumbing to cold stunning when the water rapidly cools.

A picture is worth a thousand words: using underwater photography to predict coral reef recovery

May 25, 2020October 14, 2020mlmlblog

By Caroline Rodriguez, MLML Invertebrate Ecology Lab & CSUMB Logan Lab

If you have seen photos of coral reefs, you probably agree that coral reefs are beautiful, colorful seascapes. Coral reefs are indeed picturesque, but they are also extremely important to humans for a number of reasons. Coral reefs protect coastlines from storm surges and erosion, support local economies through tourism, and uphold diverse ecosystems that sustain important fisheries. The services of reefs are valued at $375 billion per year and 25% of fish depend on these key habitats.

Despite their economic and ecological value, coral reefs around the world are dying. Pollution and overfishing contribute to coral decline, but increasing ocean temperatures from greenhouse gas emissions is the most severe threat to coral reefs.

Go Fish? Fisheries management in the face of climate change

May 18, 2020September 23, 2020mlmlblog

By Katie Neylan, MLML Ichthyology Lab

As a graduate student in the Moss Landing Marine Labs (MLML) Ichthyology Lab, I spend a lot of time thinking about fish. Over the years, I have become aware of the importance of effective resource management. Healthy fish stocks are crucial as they are a main protein source for over three billion people globally. To ensure that there will be fish in the ocean for future generations, we must ask ourselves how our ocean resources are managed and how our fisheries will be affected by climate change.

One of the earliest forms of fisheries management consisted of exclusive fishing grounds. People would only fish in designated boundaries. This gave fishermen incentive to only fish for what was needed in order to conserve the population for future years. Most countries in the world have now switched to more modern policies. Today, fisheries managers make decisions that are informed by scientists to determine catch limits, gear restrictions, and no-fish zones (marine reserves), to name a few. The goal of these restrictions is to prevent overfishing and ensure fish stocks are healthy for long-term harvesting. However, the effects of climate change add another layer of complexity to the management of marine resources.

CSI: Marine Mammal 🐋 – A day in the life of an MLML stranding responder

May 11, 2020September 29, 2020mlmlblog

By Lauren Cooley, MLML Vertebrate Ecology Lab

The hotline rang at 2pm and I quickly ran across the lab to grab the phone, excited to find out what new adventure awaited me. “Moss Landing Marine Laboratories Stranding Network, this is Lauren,” I answered. The caller had been out for a walk on Del Monte Beach in Monterey, California and had stumbled upon a deceased California sea lion. He relayed to me his location and a brief description of the animal. I thanked him for reporting the sea lion to our hotline, packed up my equipment and headed out the door, excited for another glamorous (or maybe not) day of marine mammal field work!

🚨BREAKING NEWS🚨: Stressed graduate student studies stressed fish

May 6, 2020October 14, 2020mlmlblog

By Alora Yarbrough, MLML Ichthyology Lab

What stresses you out? As a 24-year-old graduate student, I use the phrase “I’m stressed” at least once a day. I’m sure most readers can relate. Between classes, thesis deadlines, work, and rent, there are a lot of things that make my cortisol levels rise daily.

A blackeye goby next to its hole. Photo taken by Kristin Saksa at Stillwater Cove, Pebble Beach.

My personal stressors inspired me to study how stress affects a common Monterey Bay fish: the blackeye goby (Rhinogobiops nicholsii). I know what you’re thinking… what could possibly stress out a fish? Didn’t Sebastian from The Little Mermaid sing a whole song about how “life under the sea is better than anything they got up there?” Well, it turns out there are a lot of things that cause a fish’s heart to race and cortisol to spike. Anything from predators being nearby to a slight increase in temperature is enough to set off a full stress response.

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