Understanding Early Diagenesis: A Two-Part Story

By Catherine Drake, Invertebrate Zoology Lab

Part One

Sedimentation is the process by which particles sink and accumulate on the seafloor. Layers upon layers of these settled materials tell the story of the oceans and climate from which they originated. Alterations to these sediments from compaction, bioturbation, and microbial respiration form sedimentary rocks through an action termed diagenesis.  A better comprehension of diagenesis is needed to translate the sedimentary record into clues that help explain past events. To better understand these processes, students at MLML take the MS 274 “Advanced Topics in Oceanography” course.  This class, taught by Dr. Ivano Aiello and Dr. Kenneth Coale, examines the factors that affect sedimentation and subsequent diagenesis in Monterey Bay.

A major driver of sedimentation is the ocean “biological pump.” This is the fixation of carbon by phytoplankton and the subsequent transport of plankton debris to depth.  Over time, these sediments undergo diagenesis as more sediments are deposited and compacted or consumed and disturbed by organisms. The process of diagenesis mimics many of the same processes as we observe in a compost pile, but occurs much slower.

The ocean biological pump. (Source: http://www.nature.com/nature/journal/v407/n6805/full/407685a0.html)

To study which organisms drive the biological pump in Monterey Bay, the MS 274 class constructed sediment traps. To build the array, we first mastered the technique of splicing rope together, which held our sediment traps to a mooring approximately 30 feet from the seafloor.  Then, we attached a subsurface float that held eight replicate sediment traps just above the sediments.  On top of the array, we fastened a surface float to aid in recovery.  The purpose of the array was to catch fresh material that we could compare to materials in the sediments.

Emily Donham and Catherine Drake learning to splice rope to use for our sediment trap array. Photo by: Diane Wyse

Dr. Kenneth Coale drew a schematic for our sediment array. Photo by: Diane Wyse

On September 24, 2012, we boarded the R/V John H. Martin and set a course for a location in Monterey Bay that was approximately 60 feet deep and deployed our sediment trap array.  The traps were left for two weeks before they were retrieved on October 8, 2012.  In addition, we collected sediment cores from the trap location from the R/V Point Sur in order to retrieve older material from comparison.

Once in the lab, we conducted scanning electron microscopy (SEM), elemental analysis and petrographic microscopy to characterize both fresh and deposited materials.  Stay tuned for part two, where we present and interpret our findings!

The MS 274 class waits aboard the R/V John H. Martin to reach the sediment trap deployment site. Photo by: Catherine Drake

Diving Adventures in Big Creek

By Catherine Drake, Invertebrate Zoology Lab

For many graduate students at MLML, diving is an essential component to their thesis work, whether it involves collecting samples, obtaining data, or making observations about subtidal ecosystems.  Students must be research dive certified in order to perform these science-related activities.  Here at the lab, we have an excellent research diving program run by our research faculty member and Diving Safety Officer (DSO) Diana Steller. Through this program, students have the option of taking the course either during the fall semester or during a two-week intensive course in the summer.

DSO Diana Steller gives the ok after a tough beach entry at Big Creek. Photo by Maria Kyong.

Having gotten my open water certification earlier this spring, I was excited to take the summer research diving class.  For the first week, we practiced a series of underwater skills and swim tests to ensure that we felt comfortable in the water.  There are certain basic scientific skills that must be practiced and perfected to become certified in research diving. These skills include laying out a transect tape and taking observations along the tape.  To master this, we all studied the local fish, invertebrates, and seaweeds to take surveys within the kelp bed for an organization called Reef Check.

I give the ok signal as I practice a Reef Check survey at Breakwater in Cannery Row. Photo by Scott Gabara.

The following week, we caravanned south to Big Creek State Marine Reserve; while there, we camped in the redwoods and dove consecutively for four days.  We would wake up each morning bright and early, eat breakfast to fuel us for the first dive of the day, and then head to the beach.  Diana and Assistant DSO Scott Gabara would brief us on the dives, we’d suit up and enter the water ready to take data.  After our first dive, we’d sit on the beach with our lunches and warm up in the sun before heading out for our second dive.  Once we completed our second dive, we would wade into the large creek (hence the campsite’s namesake), wash off our gear and relax.

Diana Steller gives a brief on the dive site. Information in this meeting includes beach entry strategies, transect locations, and allowed depths and dive times. Photo by Maria Kyong.

The kelp canopy and sub-canopy are magnificent habitats at Big Creek.  As I swam out to the location of each transect, I’d get entangled in giant kelp (Macrocystis pyrifera) and feather boa kelp (Egregia menziesii), and would use bull kelp (Nereocystis luetkeana) as an anchor when being pushed around by the swell.  Once we descended, the seafloor was inundated with Pterogophora californica and Laminaria setchelii, so much so that I could not see the bedrock below.  To obtain data for Reef Check, we placed the transect under the sub-canopy and crawled our way through the kelp to count stipes, look for inverts, and point our flashlights at unsuspecting rockfish.

Light can barely penetrate the dense canopy of Macrocystis pyrifera and Nereocystis luetkeana. Photo by Marina Kyong.

I noticed that during any dive, something can and will go wrong, especially when you have transect tapes, slates, compasses, dive computers connected to you as you maneuver underwater.  The most important lesson I learned from Diana on this trip was that it’s how you react to these situations that determines your competence and confidence as a research diver.  If you stay calm and remember to always breathe while your mask fills with water, you get caught in kelp, your datasheet falls off your slate, and the surge inverts you, then you are definitely ready for research diving!

Dive buddies pair up for one last picture after our last, and deepest, dive of the week. Photo by Maria Kyong.

Our awesome summer research diving class! Photo by Maria Kyong.

Friends of MLML Host Screening of “Otter 501″

By Catherine Drake, Invertebrate Zoology Lab

One great aspect of being a student at Moss Landing Marine Labs is Friends of MLML, an organization designed to inform the public about MLML through tours and events, as well as help students with their research by providing scholarships. Friends of MLML put on events every other month that are free to the public. Last night was one such event: the screening of the film “Otter 501” presented by Sea Studios Foundation.

Otter 501 being rehabilitated at the Monterey Bay Aquarium.

This film revolved around a stranded otter pup, Otter 501, and the young woman who found the pup, Katie Pofahl. The film depicts Otter 501’s journey toward rehabilitation at the Monterey Bay Aquarium. Although her training on how to hunt was initially slow, Otter 501 learned the tricks to diving and finding prey from her adoptive otter mother, Toola. The film then shows Otter 501’s subsequent release into Elkhorn Slough, located about a mile north of MLML.

Otter 501 and her adoptive mother, Toola.

Following the movie, those who came to the event had a Q&A with Katie, who was also the narrator of the film. When asked if there were any updates on Otter 501’s whereabouts, Katie and fellow researchers present in the audience happily reported that she was spotted that very day in the Slough, interacting with a male!

For more information on events hosted by Friends of MLML, visit their Events page.

For more information about “Otter 501″ visit their Facebook page.

The Early Bird Gets the Fish in this Case (and a Great Tide-Pooling Experience)

By Catherine Drake, Invertebrate Zoology Lab

In early June, I went camping with my family in Southern California at El Moro Campground, a part of Crystal Cove State Park. While there one day, I was excited to learn that there was going to be a -1.8 foot tide at 6 am. So, the next morning, my mom and I woke up bright and early and made our way to Corona del Mar Beach.

Corona del Mar Beach at a -1.8 foot tide early one June morning. Photo by Catherine Drake.

The last time I visited Corona del Mar Beach, which is a relatively unknown tide-pooling location, was about two years ago. I noticed that in this two-year span, this particular rocky intertidal ecosystem changed drastically: the mussel beds expanded, less surfgrass canopied the habitat, and both crustose coralline and red algae filled the void. Ochre sea stars, once abundant on the northern part of the beach, are now flourishing about 100 yards south for better access to the mussel beds.

A flourishing mussel bed (Mytilus sp.) in the rocky intertidal.  Photo by Catherine Drake.

A shore crab (Pachygrapsus sp.) eats a limpet as it moves through the intertidal. Photo by Catherine Drake.

A uniquely neon green anemone (Anthopleura sp.). Photo by Catherine Drake.

This was by far my favorite tide-pooling experience. I spotted organisms I had never seen in the rocky intertidal before, such as a Hopkin’s rose nudibranch (Okenia rosacea). I also was witness to feeding behaviors I had not previously seen, such as a crab eating a limpet as it traversed the rocks, and an egret moving within a tide pool with such delicacy to find its prey, an oblivious fish.

An egret prevails in its hunt for breakfast. Photo by Catherine Drake.

Being Resourceful, the MLML Grad Student Way

By Catherine Drake, Invertebrate Zoology Lab

Sometimes when sampling, you have to be resourceful.  Not everything will go according to plan (an instrument might break or a sampling method may not work), which is why problem solving is a great skill for any scientist to have.  Such mishaps can even be humorous, as I found with my trip to Catalina Island with the Biological Oceanography lab two weeks ago.

The city of Avalon on beautiful Catalina Island.

We set out for Catalina Island in the early morning of Sunday, May 6^th to meet the TS Golden Bear as it traveled around the island on its way southward.  Two of our crew boarded a small boat and made their out to the ship, while the rest of us explored the beautiful island.  While on the ship, the others worked on the treatment of the ship’s ballast water, took samples, and brought them back to the island.  Then, it was time for us to start our zooplankton counts.

The issue we faced was that we had no facility to conduct out counts in, so we had to improvise.  Time for us to put our problem solving caps on!  We went into the hotel room and started to stare at all the objects—furniture, cabinets, shelves, etc.—to figure out how we could setup our counting stations.  Our final configurations worked like a charm!  My setup comprised of an ironing board, a wicker chair, and a microscope.  And although the stations weren’t conventional, we were still able to get the data, and had fun in the process.

My microscope setup for my zooplankton counts.

Diving into the Deep

By Catherine Drake, Invertebrate Zoology Lab

My family and I have been going to the beach since before I could even walk. I’ve been snorkeling, boogie boarding, and building sandcastles for most of my life. But there is one method of enjoying the ocean that, until a couple of weeks ago, I had not yet tried: scuba diving. When I moved up to the central coast to attend MLML almost nine months ago, I knew that I wanted to get my open water diving certification. That way, eventually I could take the research diving course taught by Dr. Diana Steller. Also, I would ideally like to incorporate diving into my thesis, so I wanted to ensure that I could feel comfortable in such a novel environment.

To get your open water certification through PADI (Professional Association of Diving Instructors), you need to go on four dives. So, on Saturday April 14th, we set out for Stillwater Cove in Pebble Beach with all our dive gear and kayaks. I filled up my kayak with my tank, BC, weight belt, and snorkeling gear, clipped it all in and set off into the cove. On Sunday, we got on a boat in Monterey Harbor and set out into the bay. Our first site was at Red House, with a couple curious otters watching us as we jumped off the boat into the water. Then we moved over to Octopus Reef, for our final dive of the certification process.

My kayak getting filled with all of my dive gear to go diving in Stillwater Cove.

During our dives, I saw multiple species of sea stars, including a Pycnopodia helianthoides that was almost a meter wide. In addition, I found some nudibranchs, a giant decorator crab, and a gumboot chiton. I didn’t see any fish until halfway through my last dive; I was practicing a compass heading and happened to look up, only to find I was in the middle of a school of fish. I just hung out there and watched them as they watched me.

Getting our kayaks ready for launching into Stillwater Cove.

My dive buddies, instructors, and I on the boat just before our final two dives.

Before my diving experiences, I was nervous that I would become too afraid to be able to dive. Surprisingly, the only time I was scared during the whole weekend was when I first slid off my kayak into the water before beginning my first dive. I had not yet put on my BC, so I was just floating in my seven mm wetsuit; I slid down my mask and looked into the water. All I could see were my flippers, and below that was a green abyss. My first thought was, “what if there is a shark below me?” and I became anxious. But then I took a deep breath to calm down, put on my BC, and dove into the depths below into this new, unfamiliar and amazing world. It was an amazing experience, and I can’t wait to go diving again now that I’m certified!

 

The Ballast Water Balancing Act

By Catherine Drake, Invertebrate Zoology Lab

Docked in the Carquinez Strait, an offshoot of the San Pablo Bay in the city of Vallejo, is the TS Golden Bear.  It is a training ship for the California Maritime Academy, which—like MLML—is a campus of the California State University.  The Biological Oceanography lab at MLML utilizes the ship for ballast water research.  As ships traverse the globe, they pick up ballast water from one area and release it back into the ocean once they reach their destination.  Ships uptake seawater into their ballast tanks to optimize balance and streamlining when traveling a great distance.  During this process, potentially invasive planktonic organisms are brought into the tanks and transported by being held in the ballast tank during travels.  As these organisms are released back into the ocean, they are now introduced into a new environment.

The TS Golden Bear, which houses the laboratory and is the source of ballast water used in the research conducted by the MLML Biological Oceanography lab.

Ships take in seawater and store it in ballast tanks in order to remain balanced as they glide through the oceans. Then, they discharge the ballast water as they enter a port or harbor.

This can pose a problem, as some plankton can become invasive, meaning that they can outcompete native organisms in a habitat.  According to Ruiz, et al., shipping is considered the largest transfer mechanism for coastal invasions.   As a result, regulations developed by IMO (International Maritime Organization) are implemented to reduce invasive plankton.  One of their requirements forces ships to reduce the number of live zooplankton to 10 live zooplankters per 1000 liters after the water has been treated with a kill-factor (toxic reagents, oxygen reduction, UV light, heat, etc).  “Though the challenge of coming up with an effective but environmentally safe kill factor is still up and coming, so are the methods to determining the quality of the treatment system,” says Julie Kuo, a student in the Biological Oceanography Lab.  Consequently, this has enhanced the collaboration between engineers, and scientists to construct standard operating procedures to determine the quality of a treatment system based on IMO regulations.

Copepods, tintinnids, rotifers, and cladocera are all zooplankton that can be found in ballast water.

Enter Dr. Welshmeyer and the Biological Oceanography lab: the purpose of their project is to count the number of live zooplankton alive before and after the treatment.  This process is used to determine whether or not the treatment tested on the Golden Bear is successful at meeting the IMO regulations.  As we boarded the ship, we carried microscopes and coffee down through the ship to a room that was designated as our lab.  In the 8 by 15 foot room, we setup our microscopes and began counting zooplankton.  That particular day, we were counting pre-treated water, which was full of zooplankton swimming around; this included tintinnids, copepods, rotifers, and nauplii.  After our counts of the live and dead zooplankton, we extrapolated that there were anywhere from 100,000 to 200,000 live organisms per cubic meter; up to 60% were alive in an untreated sample that was concentrated from one cubic meter of water from the Carquinez Strait.  So, treatment systems have to be incredibly affective in order to kill all but ten zooplankton in ballast water!

Julie Kuo, a graduate student in the Biological Oceanography lab at MLML, counts the number of zooplankton in a sample of pre-treated ballast water.

Invertebrate Spotlight: Sunflower Star

By Catherine Drake, Invertebrate Zoology Lab

One great aspect of being a graduate student in the invertebrate zoology lab at MLML is that we get the chance to take care of various invertebrates in our aquarium room.  Currently, we have anemones, mussels, crabs, and sea stars living in our tanks.  One of the sea stars, called a sunflower star (Pycnopodia helianthoides), is special and gets its own tank for a number of reasons.  Firstly, the sunflower star is the largest sea star in the world, and can grow up to one meter in length.  Sunflower stars generally have 15 to 24 arms, which is more arms than any other species.  They are also the heaviest sea star and can weigh up to 5 kilograms, which is about 11 pounds.  So we like to give our big star plenty of room to roam around – sunflower stars are fast and can move up to one meter per minute!

Many sunflower stars (Pycnopodia helianthoides) living in a kelp forest. Sunflower stars are the largest sea star and can be many different colors.

Below is a video of our sunflower star, and you will be able to see various distinctive features.  Along its arms are tube feet, which operate by hydraulic pressure and are part of the water vascular system that facilitates respiration, movement, and feeding.  Sunflower stars generally have about 15,000 tube feet!  In the center of the body, you can see a white spot, or madreporite, which is a water filter for the vascular system.  The blue nodules on the sea star are called pedicellaria, which are pincers on the body wall and are used for protection; if you put your hand on them, it feels like Velcro!

 

Dozens of Diatoms

By Catherine Drake, Invertebrate Zoology Lab

The last field trip of the fall semester for the Geological Oceanography class was to the Monterey Formation on Toro Road in the Salinas Basin. As we drove up through the hills on the winding road, we came across a grayish cliff that must have spanned about a mile down the road. The students got out of the car, and as we walked along the road, we noted the striations and laminations within the sedimentary layers. What’s especially interesting about these layers is that they are biogenic sediments: they consist of organic particles, usually in the form of skeletal fragments of marine organisms.

The Monterey Formation consists of an incalculable amount of diatoms, which are a type of phytoplankton and are primary producers, meaning they take up carbon dioxide while. Diatoms have siliceous tests, meaning that their cell walls are silica based; so, when diatoms die, they become part of a siliceous ooze and get deposited on the seafloor. Considering that diatoms usually range from 2 to 200 μm and the Monterey Formation spanned almost a mile, which means that there were hundreds of millions of diatoms at the time! Primary production must have been incredibly high during that time period, which was approximately between 11 and 3 million years ago.

Diatoms are phytoplankton that produce oxygen through primary production.

Invertebrate Spotlight: Christmas Tree Worms

By Catherine Drake, Invertebrate Zoology Lab

For those of you vertebrates who still have their holiday decorations up, here is an invertebrate you might enjoy learning about: the Christmas tree worm.  These polychaetes, Spirobranchus giganteus, are tube-building worms that have two “crowns” in the shape of Christmas trees, hence their name.

Many Christmas tree worms assembled together.

These appendages are an extension of their mouth and catch prey that swims by and then transport it by cilia to the worm’s mouth.  Additionally, the appendages act as part of the worm’s respiratory system, and are thus commonly referred to as gills.  Christmas tree worms are generally found in tropical waters and live within corals in calcareous tubes formed by the worms.

The appendages on these polycheates aid in the catching of prey.