Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Lasers shed light on the inner workings of the giant larvacean

04.05.2017

New laser technology is allowing MBARI scientists to look into the structure of giant larvaceans-tadpole-like marine animals that are important players in ocean ecosystems. In a recent paper in Science Advances, MBARI researchers described a new method for measuring the flow of seawater through larvaceans and other gelatinous animals. The results will help scientists understand how much carbon dioxide the oceans are absorbing from the atmosphere.

Larvaceans play a significant role in moving carbon from the upper part of the ocean down into the deep sea. They build balloon-like mucus structures called "houses," which concentrate food by filtering tiny particles out of the surrounding seawater. These particles contain organic carbon, some of which originated as carbon dioxide in the atmosphere.


This is an illustration of MBARI's MiniROV using the Deep Particle Image Velocimitry (DeepPIV) system system to illuminate a giant larvacean.

Credit: Kim Fulton-Bennett (c) 2017 MBARI

Over time their filters become overloaded with particles, and the larvacean abandons its house. The discarded houses collapse and sink rapidly to the seafloor, carrying carbon into the deep sea. Once on the seafloor, this carbon is consumed by animals or buried in seafloor sediment. The buried carbon is likely to be removed from the atmosphere for millions of years.

Because giant larvaceans are just centimeters in length, but build houses that can be a meter across, they are a challenge to study. Intact larvacean houses are nearly impossible to collect in a net or jar, or to contain in a laboratory aquarium. Once they drift into a solid net or wall, the houses fall apart.

Instead of trying to build a tank large enough to harbor a giant larvacean and its house, MBARI Postdoctoral Fellow Kakani Katija has been investigating ways to study larvaceans in the open ocean, using a technique called particle image velocimetry (PIV). PIV systems have been used in laboratories for decades to observe and measure complex water-flow patterns such as currents, swirls, and eddies.

In 2015 Katija set out to adapt a PIV system for use in the deep sea. Her "DeepPIV" system consists of a laser that emits a thin sheet of light and a video camera that records tiny particles in the water, which are lit up by the laser as they pass through this sheet of light. Working with MBARI engineers Alana Sherman, Dale Graves, and Chad Kecy, Katija mounted the laser and video camera on MBARI's MiniROV, a small remotely operated vehicle (ROV).

Later that year Katija joined Senior Scientist Bruce Robison and the rest of the DeepPIV team in their first field test, using the MiniROV to dive 1,200 meters (4,000 feet) below the surface of Monterey Bay.

When the team spotted their first giant larvacean, the ROV pilot turned on the lasers, switched off the ROV's lights, and held the ROV in position while a sheet of laser light scanned through the larvacean's body and house. Some of the scientists on the cruise had studied giant larvaceans for years, but when the laser switched on, suddenly they could see chambers and passageways in the larvacean's house that they never knew existed.

"We were all shocked by how well it worked," said Katija. "There was a lot of oohing and aahing in the control room. It wasn't just the scientists who were shocked and amazed--it was everyone on the research vessel."

Robison commented, "DeepPIV allowed us to look inside a complex structure that we had only seen from the outside before. As a result, we learned more about giant larvaceans during a single dive than we had in the previous couple of decades."

Eventually Katija was able to videotape the flow of particles within the houses of 24 giant larvaceans over the course of 13 different ROV dives. Analyzing the footage from these dives, Katija measured how fast the particles were moving. From this information she could calculate how much water the larvaceans were filtering through their houses.

Katija's calculations showed that each giant larvacean in Monterey Bay could filter up to 76 liters (20 gallons) of water per hour. This is four times higher than previous estimates for giant larvaceans and five times higher than filtering rates by other gelatinous open-ocean filter feeders, such as salps.

Coupling her filtering estimates with MBARI's long-term data on the abundance of giant larvaceans at various depths, Katija calculated the total volume of water filtered by giant larvaceans in Monterey Bay. During the spring months, when they are most abundant, Katija estimated that larvaceans could filter all the water between 100 and 300 meters in Monterey Bay in as little as 13 days. That's the equivalent of 500 Olympic-sized swimming pools per hour.

Katija's research shows that larvaceans play an even larger role than scientists had previously thought in removing carbon from the surface ocean. In her paper, she noted that DeepPIV could also be used to measure filtration rates of other midwater animals. These data will help scientists understand how much carbon deep-sea animals are removing from the oceans and (indirectly) from the atmosphere. Such information is vital for improving computer models of climate change.

Following up on her initial success with the DeepPIV, Katija has been collaborating with MBARI biologist Jim Barry to understand how deep-sea corals and sponges gather tiny food particles carried by ocean currents. "Now that DeepPIV is available to the oceanographic community," Katija said, "it opens up all kinds of possibilities."

###

Original journal article:

Katija, K., Sherlock, R.E., Sherman, A D, Robison, B. H. (2017). New technology reveals the role of giant larvaceans in oceanic carbon cycling. Science Advances, 3: doi: e1602374

Online news release with images: http://www.mbari.org/lasers-shed-light-on-the-inner-workings-of-the-giant-larvacean/

MBARI YouTube video on this research: https://youtu.be/0fCnHyxYVMw

Media Contact

Kim Fulton-Bennett
kfb@mbari.org
831-775-1835

 @MBARI_news

http://www.mbari.org 

Kim Fulton-Bennett | EurekAlert!

Further reports about: Aquarium Bay Aquarium Research MBARI deep sea seafloor tiny particles video camera

More articles from Life Sciences:

nachricht At last, butterflies get a bigger, better evolutionary tree
16.02.2018 | Florida Museum of Natural History

nachricht New treatment strategies for chronic kidney disease from the animal kingdom
16.02.2018 | Veterinärmedizinische Universität Wien

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Demonstration of a single molecule piezoelectric effect

Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale

Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...

Im Focus: Hybrid optics bring color imaging using ultrathin metalenses into focus

For photographers and scientists, lenses are lifesavers. They reflect and refract light, making possible the imaging systems that drive discovery through the microscope and preserve history through cameras.

But today's glass-based lenses are bulky and resist miniaturization. Next-generation technologies, such as ultrathin cameras or tiny microscopes, require...

Im Focus: Stem cell divisions in the adult brain seen for the first time

Scientists from the University of Zurich have succeeded for the first time in tracking individual stem cells and their neuronal progeny over months within the intact adult brain. This study sheds light on how new neurons are produced throughout life.

The generation of new nerve cells was once thought to taper off at the end of embryonic development. However, recent research has shown that the adult brain...

Im Focus: Interference as a new method for cooling quantum devices

Theoretical physicists propose to use negative interference to control heat flow in quantum devices. Study published in Physical Review Letters

Quantum computer parts are sensitive and need to be cooled to very low temperatures. Their tiny size makes them particularly susceptible to a temperature...

Im Focus: Autonomous 3D scanner supports individual manufacturing processes

Let’s say the armrest is broken in your vintage car. As things stand, you would need a lot of luck and persistence to find the right spare part. But in the world of Industrie 4.0 and production with batch sizes of one, you can simply scan the armrest and print it out. This is made possible by the first ever 3D scanner capable of working autonomously and in real time. The autonomous scanning system will be on display at the Hannover Messe Preview on February 6 and at the Hannover Messe proper from April 23 to 27, 2018 (Hall 6, Booth A30).

Part of the charm of vintage cars is that they stopped making them long ago, so it is special when you do see one out on the roads. If something breaks or...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

2nd International Conference on High Temperature Shape Memory Alloys (HTSMAs)

15.02.2018 | Event News

Aachen DC Grid Summit 2018

13.02.2018 | Event News

How Global Climate Policy Can Learn from the Energy Transition

12.02.2018 | Event News

 
Latest News

Fingerprints of quantum entanglement

16.02.2018 | Information Technology

'Living bandages': NUST MISIS scientists develop biocompatible anti-burn nanofibers

16.02.2018 | Health and Medicine

Hubble sees Neptune's mysterious shrinking storm

16.02.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>