mlmlblog – Page 16 – MLML Student Life

Diving the MLML Seawater Intakes

October 25, 2013October 13, 2020mlmlblog

By Diane Wyse, Physical Oceanography Lab

Earlier this week I volunteered to dive on the MLML seawater intakes, located about 200 m due west of the Monterey Bay Aquarium Research Institute (MBARI) and 17 m below the surface. The intakes supply seawater to multiple sites around Moss Landing, including the aquarium room at MLML, the Test Tank at MBARI, and the live tanks at Phil’s Fish Market.

Location of the intake pipes offshore. Image: MLML/Google Earth (2013)

The purpose of the dive was to attach a surface float to a subsurface float located at a depth of about 15 feet. A secondary objective was to visually inspect the intakes, which can be viewed in the video below.

The view from approximately above the intakes. Photo: Diane Wyse (2013) — The view of Moss Landing from approximately above the intakes. Photo: Diane Wyse (2013)

So how do you find an intake system 50 ft below the water?

To execute the operation, Assistant Dive Safety Officer Scott Gabara and I took a whaler from the MLML Small Boats with the assistance of boat driver Catherine Drake. We used the best GPS coordinates previously called upon to locate the intakes, then threw a spotter surface float attached to a line and weight that unraveled to the seafloor. We followed that line to the bottom and practiced our circle search skills until we found the first of the two intakes. While anchoring the search line I saw a pipefish, a couple flatfish, and not much else. During our descent and ascent we spotted half a dozen sea nettles, but on the sandy bottom it appeared pretty desolate. The intakes, on the other hand, provide a hard substrate for sessile invertebrates and their predators to form a lively little oasis in the sand. The first thing you notice when you come upon the intakes are the large white Metridium anemones. If you take a closer look at the video, around 15 seconds in, you can spot a little octopus scurrying for cover. After inspecting the first intake we moved to the second, that’s right, completely submerged by sand, with the line extending up to the subsurface float. Though the video is short you can see some of the organisms residing on the line include seastars, Metridium, caprellids or “skeleton shrimp”, and my favorite marine invertebrate: nudibranchs. Hermissenda (opalescent) nudibranchs, to be exact. I wish I had a chance to take still photos while I was out there, but we had a job to do. We successfully tied the surface float to the line and removed old line, thus making it much easier for future divers to study sediment movement and perform maintenance on the intake pipes.

I'll admit had another motivation for volunteering for the dive. Beyond helping out and increasing my scientific diving experience, I was curious about the system. In 2011 and 2012 I worked as a research assistant for CeNCOOS, and helped maintain the oceanographic instruments at the MLML shore lab and ensure that the public data portal was operational. That system is dependent upon water flowing in from the intakes. I learned even more about the seawater system in my chemical oceanography class, so it was really cool to see the pipes from under the sea. The visibility for most of the dive was much better than it seems in this video, as we spent most of the time working further up in the water column away from the fluffy layer composed of detritus and fine-grain sand.

When my dive buddy and I returned to the surface we met back up with our boat, reeled in the line for the first float, and cruised back to the harbor. Another day, another successful dive!

Divers Diane Wyse and Scott Gabara with the new surface float for the seawater system. Photo: Catherine Drake (2013)

A Sandy Situation

October 20, 2013October 13, 2020mlmlblog

By Scott Gabara

We want to go with the flow when it comes to supplying seawater to Moss Landing Marine Labs. The incoming water is used for research and husbandry so we keep a close eye on and maintain our seawater intake system. In efforts to better understand why sand has been building up around our intakes over the years our diving safety officer, Diana Steller, and a new student, Angela Zepp, have started to take cores of the sediment in that area. We hope to learn more about the sand movement and/or retention from cores by continually taking them and comparing the sediment size over time. Sand seasonally moves onshore and offshore during the summer and winter seasons, respectively. We hope to learn why this buildup is occurring over time.

Tidepooling Take Two

October 17, 2013October 13, 2020mlmlblog

By Diane Wyse, Physical Oceanography Lab

Earlier this week, three graduate student volunteers and I ventured to Bay View Academy in Monterey to talk with the fourth grade class about trophic levels and intertidal zonation. I had the unique opportunity to lead the trip again this year, you can learn about the first iteration of this trip in one of my very first posts for the Drop-In.

Sara Worden, Heather Kramp, Dorota Szuta, and Diane Wyse lead a classroom safety briefing and intertidal lesson. Photo: Erika McPhee-Shaw (2013)

I volunteered for the trip again this year because it is the sort of educational outreach experience that to me really embodies the spirit of MLML; sharing resources and experiences from multiple labs and teaching in our beautiful marine backyard. The student volunteers represented the Physical Oceanography Lab, the Phycology Lab (Sara Worden), the Benthic Ecology Lab (Dorota Szuta), and the Ichthyology Lab (Heather Kramp). Another reason I volunteered again? Try passing up an opportunity to geek out science on one of the prettiest beaches in the world. Yeah, it’s tough to do.

Benthic Ecology Lab student Dorota Szuta teaches a group of fourth grade girls about intertidal invertebrates. Photo: Diane Wyse (2013)

Working off an intertidal food web lesson plan developed by the Teaching Enhancement Program at MLML, the grad student volunteers introduced the fourth grade class to the organisms in tidepools at Asilomar State Beach. We were impressed by the knowledge the students shared with us that their teacher Alicia Doolittle had introduced in previous lessons. At the beach it was hard to tell who was more excited to explore the intertidal – the elementary students, grad students, or even the parent chaperones!

Ichthyology Lab student Heather Kramp shows some intertidal organisms to an interested chaperone and the youngest field trip participant. Photo: Diane Wyse (2013)

This year’s trip was especially cool for me as my graduate advisor, Dr Erika McPhee-Shaw, who serves as a board member for Bay View Academy, was along for the trip and helped to photo-document the field lessons. I’ll admit it was a bit intimidating to be on the other side of things – here’s a highly-regarded physical oceanographer who has taught me equations of motion, coastal dynamics, and guided me through the steps of a Master’s research thesis, and here I am fielding questions about the inner workings of the ocean to a class of fourth graders while she listens in the audience. It reinforced something I’ve learned time and again through graduate school, that the more simply and elegantly you can describe a complicated process, the more completely you understand it. With the students’ healthy appetite for knowledge our conversation ventured from why ocean water is blue to a comparison of ecological zonation on a beach versus a mountain.

Recognize those t-shirts? The 2013 Open House t-shirts were designed by our very own Dorota Szuta! Photo: Alicia Doolittle (2013)

From the closing discussion it was clear that invertebrates were the crowd favorite: the hermit crabs, the purple pisaster (ochre) seastar, even the tunicates were getting some love thanks to the students’ curiosity about the round little chordates. Will student leaders from MLML lead the trip again? You better believe it!

Government Shutdown Causes Heartbreak and Hardship for Scientists

October 15, 2013October 13, 2020mlmlblog

By Dorota Szuta, Benthic Ecology Lab

A research team at MLML has been conducting research in the Antarctic for many years, but this year their plans may be shutdown. View of the Antarctic, photo by Clint Collins.

To be honest, I was sure this would have been over by now. When the government shutdown first started, I didn’t think it could reasonably last more than a couple of days. Even now in the second week, many people are still not seeing serious ramifications of the shutdown in their own lives. I, however, am feeling its effects greatly.

I started the Moss Landing Marine Lab graduate program last year after working as a research assistant in the Benthic Ecology Lab for a couple of years. My thesis work focuses on changes in Antarctic bottom-dwelling communities along a depth gradient, under the guidance of Dr. Stacy Kim. I've taken this current semester off from coursework in order to go to Antarctica to do field work for three months. Despite not being in any classes, I’ve been surprisingly busy getting ready for the trip. In order to physically qualify to work in Antartica, there are a series of medical tests everyone must pass involving EKG’s, full dental x-rays, blood work, and vaccinations. The diving we were planning on doing in Antarctica is deep, in sub-zero temperatures, and under a thick sheet of ice—considerably different than diving here in the Monterey Bay, so I had a lot of dive training to complete. Our team (you can read more about our work here: http://scini-penguin.mlml.calstate.edu/) was scheduled to live in a field camp where we would be collecting data through a hole in the ice with our remotely operated vehicle (ROV) called SCINI, so since the summer we’ve been testing its functioning and practicing driving it. Needless to say, our engineers have been busy.

View from under the ice to a hole where divers can enter and exit to perform underwater research. Photo by Clint Collins

If you’ve been following the news at all, you know what happens next in the story. The government shutdown means the National Science Foundation (NSF) is not operating, which means that the US Antarctic Program switches to "caretaker mode" and all science is suspended (you can read the announcement here: http://www.usap.gov/). Plane flights are canceled, ships en route are turning around, cargo is stopped, and almost everyone who is already down there has to be flown home. The waste of resources and funds this cancellation represents is monumental, but the additional cost in ruined research and scuttled projects makes it an irreparable loss.

Missing out on the research trip of a lifetime is frustrating and heartbreaking for me. However, my independent research won’t take too hard of a hit; while I was planning on collecting samples for my thesis work this season, I will be able to complete my thesis with data collected in previous years. What is much worse is the implication for the hundreds of larger projects that were to be conducted this season, such as our team's work on Antarctic food webs, numerous climate change studies, or research on life in subglacial lakes. Many studies conducted in Antarctica measure change over time, so one season of missing data can disproportionately compromise the scientific integrity of a sustained project.

Penguins — View of penguins in the Antarctic, subject of a lot of research that is suspended until further notice. Photo by Clint Collins.

But what if the government shutdown ends soon? Can’t we still go? Well, as we’re settling into fall here in the northern hemisphere, spring is in full bloom in the southern hemisphere. In Antarctica, the research season is a narrow window in the summer, roughly October through February. And the window for diving is even narrower since an annual plankton bloom towards the start of summer means bad visibility by December. Sure, it’s possible that the government shutdown will end tomorrow and the US Antarctic Program will be back up and running. (But take that with a grain of salt— the shutdown itself has really changed my view on what is possible). There is a chance that we will still have part of a field season, although it may look pretty different from what was originally planned. The logistics of conducting research in Antarctica are complicated (think airplanes and helicopters, icebreaker ships, and international cooperation) and are planned out months and even years in advance. To suddenly stop everything and attempt to restart it weeks (or months?) later will be even more complicated. Whether any scientific research is going to happen this season, or whether it will be moved to next year, or whether it will be cancelled completely, is unknown.

So things are up in the air and we wait. After a year of planning, everything was halted just three weeks before our departure date. Our bags are packed and sitting on a pallet just waiting for theoretical shipment. So for now, I’ll be at the lab doing research for my thesis. But only the kind you can do with books and scientific papers.

Ballast Water Creature Counting

October 7, 2013October 13, 2020mlmlblog

By Liz Lam

The Golden Bear Facility at the Cal Maritime Academy is the site of all our ballast treatment testing. Photo: CMA

Although I’m only a first-year graduate student here at Moss Landing, I’ve had the pleasure of working on the ballast water testing team with the Biological Oceanography lab for over a year now. Aquatic invasive species have become an increasingly large problem across the globe and one of the ways organisms make their way to non-native waters is through the ballast tanks of ships. The IMO (International Maritime Organization) is now requiring all ships to reduce the number of live zooplankters in their ballast tanks to only 10 in every 1000 liters. Since most zooplankton are microscopic, you can imagine that this is an incredibly challenging thing to accomplish!

Samples are carefully collected so we can compare the treated water with the control. Photo: GBF Staff

But another huge challenge that our team directly faces is determining whether certain treatment methods have worked. How do we do this? With some good old fashioned counting! First, samples are filtered through a net that catches only organisms that are greater than 50 um in size (which is the size class we count by eye). Then, 5 mL of that sample are pipetted into a serpentine tray, which allows us to count what is in the sample row by row. We can then look under a microscope and manually count every single living zooplankton found in that 5 mL sample. This is sometimes known as the "poke and prod" method, since we may not even be sure if a zooplankter is alive or dead until after we've poked them with a small poker stick. Afterwards, we can use our 5 mL sample counts to extrapolate how many total organisms were found in 1000 liters of the treated water and determine whether the treatment method passed.

Counters use microscopes and serpentine trays to count every zooplankter in a 5mL sample. Photo: Kevin Reynolds

In order to make sure our zooplankton counts are as reliable as possible, we have to count samples multiple times. Although the work is time consuming and sometimes back-straining, it’s fun and fascinating to discover all of the tiny, microscopic organisms found in just a few drops of water. Everytime I count a new sample, I wonder what kind of alien-like creatures I’ll find swimming around!

The Coriolis Force: Or Why Toilets Flush the Same Everywhere

October 5, 2013October 13, 2020mlmlblog

Like many of you readers out there, I seem to overlook the small things in life. One of those is what direction the water in my toilet rotates in when it flushes. Why does this matter? Well, if you are like me, you have likely grown up hearing that toilet water in the Northern Hemisphere flushes in a different direction than toilet water in the Southern Hemisphere. That is to say that when Australians use the toilet in America, they will aptly notice that the water is flowing in the opposite direction.

Well I learned this past Thursday in Physical Oceanography, that is not the case!

As it turns out, toilet water flushes down in the same direction in both the Northern and Southern hemisphere. Why is that? Well, like almost everything else in the world, it is due to physics. Why though, did this rumor about flushing in different directions start? As it turns out, it too is based in physics, but it is just inaccurate.

The Coriolis force is a deflection of moving objects when they are viewed on a rotating reference frame. Well, the Earth is a rotating surface, therefore objects that move in the Northern Hemisphere are deflected towards the right and objects that move in the Southern Hemisphere are deflected to the left. It is this force that the rumor is based on. However, whoever started this wives tale didn't take their Physical Oceanography class very seriously because this only applies to objects that move for a time period of over a day (since that is how long it takes for the Earth to rotate completely) and for a distance to the order of kilometers.

Since toilets do not take over a day to flush and the water in a toilet is moving in a space that is less than even a meter across, it is safe to say that the Coriolis force does not affect what direction the water flushes down a toilet. Next time you flush, just know that the water moves down that toilet in the same direction as it does when a kangaroo uses a toilet in Australia as well.

99 bottles of fish on the wall? Try 200,000!

September 29, 2013October 13, 2020mlmlblog

By Kristin Walovich

Fellow grad student Catarina Pien and I were lucky enough to visit to the California Academy of Science in San Francisco to check out their extensive museum collection, home to nearly 1.2 million specimens! We were on a mission to observe a variety of sharks, rays and chimaeras and to bring back specimens on loan from the South African Museum. We were greeted on a foggy San Francisco Friday by Dave Catania, the senior collections manager for the Department of Ichthyology.

The California Academy of Science (CAS) Department of Ichthyology houses one of the largest and most important research collections of fish in the world. There are nearly 200,000 jars of preserved fish in the collection, representing nearly 11,000 different species. That is more than a third of fish known to science!

By looking up the unique identification number assigned by CAS, our guide Dave was able to bring us a whole cart of jars filled with old and unique animals. Catarina is working on a project to describe the sharks and rays from Oman, a country to the south east of Saudi Arabia. She photographed several specimens, including this Gulper Shark, to compare to other specimens from the region.

This species of Gulper Shark (Centrophorus granulosus sp.) is found worldwide, living at depths of over 3,000 feet.

Just like a library, scientists can check out specimens from the museum like a book on loan. I was lucky enough to do just that with a new species of chimaera from the South African Museum. Chimaeras, or ghost sharks, are deep water fish with a skeleton made of cartilage, making them close relatives of sharks and rays.

When a new species is discovered a single animal is chosen, called the holotype, to represent the entire species. From this one animal I will record dozens of body measurements, take photographs and make observations in order to identify this chimaera to other scientists. After the specimen is described it will be added to a museum collection like the one at CAS for other scientists to observe in the future, a process called accession.

Proper identification and detailed observations are very important when describing a species. Take for example these two species of small catsharks from the Indo-Pacific Ocean. They are very similar in size, color and shape, but because they are available for scientists to look at, subtle differences start to emerge. Without detailed records and a holotype, identifying sharks (or any animal for that matter) can be difficult.

With jars in hand and our camera memory cards full, we make our way back to Moss Landing Marine Labs for more photos, notes and measurements.

Sea otters participate in coastal restoration

September 16, 2013October 13, 2020mlmlblog

by Jackie Lindsey, Vertebrate Ecology Lab

There's a new reason to love the world's smallest marine mammal species - so let's talk sea otters!

These voracious predators are again making headlines in the science world as a new paper comes hot off the (virtual) presses. Hughes et al. (2013) published an article in PNAS entitled "Recovery of a top predator mediates negative eutrophic effects on seagrass". This paper is truly a local collaboration, with scientists from UCSC's Long Marine Lab, the Elkhorn Slough reserve, USGS, CSU Monterey Bay, and MBARI.

The headline? Sea otters may have saved the Elkhorn Slough seagrass habitat by doing what they do so well: eating crabs.

Photo credit: Ron Eby http://www.vcstar.com/photos/2013/aug/26/307245/

To fully understand the premise of the paper, here's a little ecology review:

When we think about the health of a marine ecosystem, we often think of two major ways that the system could be controlled.

1) Top down: A classic example of top down control is sea otters consuming urchins in a kelp forest. These three trophic levels depend heavily on one another, so that if the sea otters in the kelp forest are removed by a predator (humans or killer whales) and can no longer keep the sea urchin population in check, the urchins will become overpopulated and consume so much of their prey (the kelp) that the kelp disappears, taking with it other creatures in the ecosystem that depend upon it. If the sea otters are returned to the system, they consume enough sea urchins that the kelp is released from predation pressure, and the ecosystem can return to normal balanced levels. Here's a figure by Estes et al. (1998) to illustrate this classic example. Focus on the cartoons and the arrow sizes to track who eats what in each scenario.

2) Bottom up: Think of bottom up control like the workings of a traditional garden. If you over-fertilize your tomato plants and they start to die off as a result, this bottom up forcing will impact the aphids that depend on the tomato plant for food, and in turn their ladybug predators.

Ladybugs consuming aphids on a tomato plant http://extension.umd.edu/growit/photos-aphids

Was that example not "marine" enough for you? Let's get back to the sea otter news!

It is well known that Elkhorn Slough, an estuary located right next to MLML, is a nutrient-loaded system due to nearby agricultural activity. In the past, biologists noticed that nutrient loading was having a negative impact on the estuarine reserve's seagrass beds, when algal epiphytes bloomed and overtook the seagrass. (That's bottom up control!) Hughes et al. showed that in the last 30 years, that trend of declining seagrass beds was reversed, even as agricultural runoff increased!

How?? Hughes et al. noticed that another thing happened about 30 years ago: southern sea otter populations recovered to the point that otters began colonizing Elkhorn Slough habitats. Was this a coincidence? The authors think that this is an example of an interaction between top down and bottom up control.

Figure 2a from Hughes et al 2013 — Figure 2a from Hughes et al. 2013

Hughes et al. (2013) demonstrated that the interaction between sea otters and their prey species in Elkhorn slough created a 4-level trophic cascade that released the seagrass from top down control pressures, allowing it to flourish even in the presence of high nutrient loads. In short, the sea otters ate the crabs, which in turn consumed less algal epiphyte grazers (snails, slugs), which in turn consumed more algal epiphytes (blanketing the seagrass), which allowed the seagrass to grow. This well-timed trophic cascade was lucky for the seagrass, and all other marine critters that depend on it for habitat in Elkhorn Slough.

The sea otters are helping to restore our coastline, and you can too! Just five days until California's Coastal Cleanup Day, and it's not to late to volunteer!

My citations, in case you want to do a little more reading,:

Brent B. Hughes, Ron Eby, Eric Van Dyke, M. Tim Tinker, Corina I. Marks, Kenneth S. Johnson, and Kerstin Wasson (2013) Recovery of a top predator mediates negative eutrophic effects on seagrass. PNAS: 1302805110v1-201302805.

Estes JA, Tinker MT, Williams TM, Doak DF (1998) Killer whale predation on sea otters linking oceanic and nearshore ecosystems. Science 282(5388): 473-476

How long is that tail?

September 8, 2013October 15, 2020mlmlblog

By Jessica Jang

On Labor Day weekend, Moss Landing Marine Laboratories' own Pacific Shark Research Center (PSRC) had the opportunity to dissect a 14.7 feet long common thresher shark (Alopias vulpinus). The female shark was found washed up on the beach on Moss Landing already dead.

Program Director, Dave Ebert, PSRC students, and UROC students posing with the thresher shark — Program Director Dave Ebert, PSRC students, and Undergraduate Research Opportunities Center (UROC) students posing with the thresher shark

The PSRC is part of the National Shark Research Consortium for the West Coast. Currently there are 7 students enrolled in this department led by the program director, Dr. David Ebert, also a MLML alumni, and a handful of undergraduate volunteers from San Jose State University and California State University: Monterey Bay all who are ready to learn more about elasmobranchs!

The students were pretty amazed to see such small teeth on such a large shark. The teeth on this animal say a lot about what it eats. Schooling fish such as sardines and anchovies, as well as cephalopods are its preferred prey. Thresher sharks are part of the mackerel shark order (Lamniformes) and excel at speed and long distances. A few examples of this order include, the white shark (Carcharodon carcharias), the makos, shorfin mako (Isurus oxyrinchus), longfin mako (Isurus paucus), the salmon shark (Lamna ditropis), and the porbeagle shark (Lamna nasus). These species in particular are endothermic, meaning that they can thermoregulate their own body temperature to several degrees warmer than the ocean water, allowing better foraging opportunities.

They also have big eyes to find prey and large gill slits for oxygen. Since these species are pelagic species, they require a lot of oxygen to keep moving. Lamniformes (mackeral sharks) breathe through ram ventilation, where the animal swims while opening its mouth. These species require constant motion or else they'll drown. However, some sharks have adapted to living life on the bottom, and can actively pump water pass their gills with their spiracles, which are tiny holes usually located behind the eyes on the shark. In larger oceanic species, the spiracles have lost its ability to pump water.

The dissection was a very exciting and rare opportunity, since thresher sharks are pelagic predatory fish, that spend their lives in the open ocean. There are currently only three known species of thresher sharks, the common (Alopias vulpinus), pelagic (Alopias pelagicus), and the big-eye thresher (Alopias superciliosus).

Previously it was thought that thresher sharks used to swing their tails around to catch their prey. However, a new study this summer show that they actually use their long caudal tails to stun their prey. Scientists managed to catch footage of the pelagic thresher shark (Alopias pelagicus) in action.

Students were able to take morphometric data of the shark by measuring everything from body length and fin lengths, counting the vertebrae, and noting of any visible scars or injuries.

Dave Ebert instructing PSRC students how to measure the shark

One noticeable wound was the large propeller strike that was near the end of her body.

Wound found on the shark, possibly from a propeller.

They also took tissue samples of the shark's muscles, reproductive organs, and liver to detect mercury levels. Since sharks are apex predators, meaning they eat at top of the food chain, toxins and heavy metals can bioaccumulate which can cause detrimental health problems if they are in high concentrations. Stay tuned to see if we found something revealing on what may have caused her death.

New Recruits to Moss Landing

September 7, 2013October 13, 2020mlmlblog

By Heather Fulton-Bennett, Phycology Lab

The fall semester has brought the return to classes, gorgeous weather, and most excitingly, a new crop of students to Moss Landing Marine Labs. This year we welcomed 15 new marine scientists to 8 of the labs, and their past adventures and new ideas for theses are inspiring already. Potential thesis projects range from molecular ecology of invertebrates in Indonesia to sediment movement at the head of the Monterey Submarine Canyon to the life history strategies of deep sea sharks.

New students meet for orientation with staff and student body officers

Check out the Meet the Students page to see how they came to Moss Landing Marine Labs, and check back as several of the new students will be writing for the Drop-In in the future!

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By Diane Wyse, Physical Oceanography Lab

By Scott Gabara

By Diane Wyse, Physical Oceanography Lab

By Dorota Szuta, Benthic Ecology Lab

By Liz Lam

By Kristin Walovich

by Jackie Lindsey, Vertebrate Ecology Lab

By Jessica Jang

By Heather Fulton-Bennett, Phycology Lab