Biodiversity and Biooptics 2020 Expedition

The ctenophore Bolinopsis infundibulum is one of the targeted species for this expedition. Photo by Steve Haddock

MBARI Expedition #483

Expedition goal: During this cruise, we will conduct ROV and scuba dives to aid our research into the biochemical, physiological, and genetic adaptations that midwater organisms have evolved to help them survive and diversify in the deep sea.

Expedition dates: January 28 – February 2, 2020

Ship: R/V Western Flyer

Research technology:  ROV Doc Ricketts

Expedition chief scientist: Steven Haddock

For the next six days, the MBARI Biodiversity and Biooptics Lab, led by Steve Haddock, will be at sea on the research vessel Western Flyer, exploring the organisms that inhabit the midwater of the Pacific between Monterey and San Diego. We will use the remotely operated vehicle Doc Ricketts, midwater trawling, and with blue-water scuba diving to observe and collect organisms from the shallow surface waters to the seafloor.

This expedition is a bit different from our normal operations. While we have regular collections off the Monterey Coast, and several expeditions off Baja California, it is rare that we can obtain samples along a North-South transect across the important biogeographic transition from northern to southern California. Many benthic or shoreline species show distribution patterns along these shores, but it is not clear how well we can resolve such differences in drifting and deep-sea animals.

Of special interest on this trip will be the population genetics of several midwater comb jellies. Our goal is to understand how organisms of different species are related to one another, and how the genetics of a single species varies within a population. Various species can be found from (relatively) warm surface waters with low hydrostatic pressure, all the way down to the low temperature, high-pressure environment of the deep seafloor. We have species from tropics and polar regions and samples from this cruise will help fill in gaps for understanding diversity.

How different species of ctenophores have evolved to live and thrive under great differences in pressure and temperature is a focus of investigation for our NSF-funded DEEPC Project (DEEPC stands for “Diversity, Ecology, and EcoPhysiology of Ctenophores”). We will also gather samples and observations for our ongoing NSF SiphWeb grant, which looks at evolution of predation by gelatinous siphonophores and their prey. We are looking forward to getting a glimpse at nearby, but potentially different communities and understanding their diversity.

Updates from researchers on the R/V Western Flyer:

Sunday, February 2, 2020

From Shannon Johnson:

Today was an exciting day because we thought we were going to be weathered out at first (GALE WATCH, NO!). Luck was on our side in the ‘hole of hope’ and the wind and waves enabled us to collect five species of ctenophores that we are currently studying. This is an important site for our population genetics work because we have collections of animals from the Monterey Bay, Hawaii, and the Gulf of California, but animals from Southern and Central California will help to fill in where we have sampling gaps. These data will allow us to understand how ctenophores move throughout the world ocean.

First, we launched the ROV and almost right away, we found not one but three Deiopea comb jellies! This was amazing because Deiopea are rare, and we have been studying them from Hawaii and Monterey Bay, so it was good to have samples from Southern California. While the ROV was still underwater, we set off for a blue-water SCUBA dive, which was incredible. We were just off Catalina Island, and the water was clean, clear, and bright blue. We felt like we could see for miles. This was a dramatic change from diving in the very productive Monterey Bay, where the water is often thick with algal blooms. As soon as we began our dive, we saw hundreds of ctenophores! It was like swimming in a beautiful, sparkly soup. We saw many Eurhamphaea vexilligera, Pleurobrachia bachei, Cestum, Leucothea, and several species of Beroe. We were busy well into the night, photographing and dissecting our precious samples. Days like today remind me how lucky we are to work on such interesting, amazing creatures.

From Manabu Bessho:

I am a postdoc working with Steve Haddock. My scientific interests are bioluminescence and evolution. Bioluminescence is one of the most remarkable phenomena that occurs in the ocean. More than three-quarters of animals in the water column and more than a quarter on the deep seafloor can produce light by themselves. The special low-light camera deployed on the ROV is highly sensitive and enables us to observe bioluminescence in an animal’s natural conditions. I am looking forward to discovering new species that have bioluminescent capabilities.

On this expedition, I am mainly focusing on bioluminescent deep-sea corals. Corals (Class Anthozoa) are a diverse group of animals. Luminous groups are scattered across the anthozoan tree of life. This raises the question, “Has bioluminescence evolved multiple times independently or once (or a few), then lost many times?” To discover the answer, I study the biochemistry of corals. For example, if bioluminescence evolved independently, the chemical mechanisms will be different from each other; if it evolved once, the mechanism will be shared among descendants. During the cruise, I have been testing corals brought up from the bottom of the ocean to see if they glow in the darkroom. Then I extract a variety of enzymes and organic compounds and analyze them.

That’s a wrap! Other highlights from the cruise:

Updates from researchers on the R/V Western Flyer:

Saturday, February 1, 2020
Kyra Schlining

As with the ctenophores, siphonophores are found from the ocean surface to the seafloor. Also like the ctenophores, many siphonophores are bioluminescent which makes them prime targets for the science team to investigate. Siphonophores range in size from 10 millimeters to 30 meters (less than half an inch to almost 100 feet)—longer than a blue whale! They are important midwater predators, deploying long curtains of stinging tentacles to prey upon a variety of crustaceans and fish. These gelatinous animals are exceptionally fragile and easily fall to pieces, so they must be collected carefully with the ROV.

More information about siphonophores here.

From Alex Lapides:

While I work in Steve Haddock’s lab, I also work in the Video Lab. The Video Lab is responsible for managing the incoming video data from each ROV dive, as well as providing expert-level annotations of each organism seen on the dives. This is my first cruise since I started in the Video Lab, and I can really tell that my identification skills have been improving. It’s gratifying to have a better sense of what lives where in the water column, and to have a global knowledge of all the animals that we see. Today we dove in a deep basin in the Channel Islands of Southern California. This site is much further south than the usual dives in the greater Monterey Bay area. I was fascinated by how different the species composition was—organisms that we rarely see up north were common here, and vice versa. I appreciate being out here getting a firsthand perspective of the habitats I study, and I always look forward to my next opportunity to do so.

From Julia Chavarry:

I am interested in how human impacts influence marine food webs. I am currently investigating how often animals eat plastic, and the potential effects of climate change on deep-sea communities. The R/V Western Flyer is helping me collect species that will allow me to define their role in deep-sea food webs and the rate at which they consume plastic.

From Liz Hetherington:

I am a postdoctoral researcher in Anela Choy’s Lab at Scripps Institution of Oceanography. I am primarily interested in predator-prey relationships in open ocean (pelagic) food webs. My current research focuses on understanding the diets and feeding ecology of siphonophores, a clade of colonial hydrozoans (phylum Cnidaria). However, siphonophores, like many other gelatinous animals, are fragile. This makes it difficult to collect them, and as a result they are understudied compared to many hard-bodied animals.

During this expedition, we have collected many siphonophores using the ROV Doc Ricketts and blue-water dives. I process the samples on deck by photographing them and freezing the tissue. Primarily, I am analyzing stable carbon and nitrogen isotopes, which can give us clues about the diets and feeding ecology of these animals. I am also interested in how siphonophores fit into the overarching structure of the pelagic community. I am collecting a suite of other zooplankton and micronekton from trawl samples to examine prey available to siphonophores and overall food web structure. This research will provide insights into the ‘jelly web,’ or the gelatinous component of food webs that is understudied but likely plays an important role transferring energy through the food web.

Updates from researchers on the R/V Western Flyer:

Thursday, January 30, 2020
Kyra Schlining

The scientific team aboard the R/V Western Flyer this week is focused on learning more about the gelatinous creatures that inhabit the open midwaters of the ocean. This is the largest, and yet least understood, habitat on our planet. Most of the researchers are specifically studying ctenophores or siphonophores, or both. In today’s report we’ll focus on the ctenophores.

Ctenophores, or comb jellies, are characterized by having eight rows of cilia which are primarily used for locomotion. Comb jellies don’t sting, but have sticky tentacles for capturing prey. They eat crustaceans and other small zooplankton, although some species prefer to eat other ctenophores! Other predators of comb jellies include jellyfish, sea turtles, and fish. They are transparent and often colorless, however when light diffracts off the comb rows it creates striking rainbow patterns. Many also exhibit brilliant bioluminescent displays when disturbed. The research team is taking a closer look at these bioluminescent properties, as well as, making progress toward a worldwide ctenophore survey. Ctenophores are extremely delicate and we are learning a lot more about them by using ROV cameras and advance collection methods than we ever could in the past by using net trawls.

Ctenophores can be found in marine environments, from the poles to the tropics, and from the surface to the deepest parts of the ocean, yet very little is known about how they have evolved to survive such a wide range in temperature, oxygen, light, and pressure. That is another part of what the team is working to uncover. To do this, the researchers are using a variety of new tools and techniques including high-pressure instruments, optical oxygen microsensors, genome-scale sequencing, protein purification, and gene cloning and expression in the lab. The greater challenge is how to also conduct experiments in the animal’s natural environment.

For more information see:

Ctenophores: the story of evolution in the oceans

How comb jellies adapted to life in the deep sea

MBARI cruise participants

Other cruise participants:

Tiffany Bachtel, The Evergreen State College
Anela Choy, Julia Cavarry, and Liz Hetherington, Scripps Institution of Oceanography, University of California, San Diego
Lauren Mellenthin, Yale University