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Hello, my name is Max Weber and I am a Masters candidate in Marine Biology at Texas A&M University at Galveston. I study deep-sea fish genetics in the lab of Dr. Ron Eytan. Genetics are a powerful tool that can reveal a lot about the fishes that inhabit the deep-sea. One of my areas of research involves the investigation of population size over time in a large number of deep-sea fish species.
We used to think that even though sea surface temperatures change a lot day to day and season to season, that deep-sea temperatures were very stable (cold, but stable!). However, recent long-term monitoring studies have shown evidence of rapid alterations in deep-sea temperatures and other studies on benthic deep-sea communities have shown that those communities are currently being altered as a result of climatic changes.
Historic changes in population size (the number of individuals of a given species in a population) often reveal the effects of major ecological events on the genetic diversity of a population or a species. These fluctuations can be inferred through the use of molecular data. Global climate conditions have varied greatly since the last glacial maxima, approximately 20,000 years ago, leading to changes in global currents, oceanic temperatures, and sea level. Several studies have recently uncovered sharp declines in population sizes of coastal marine fishes attributed to these changes in the marine environment.
My Master’s research focuses on whether fluctuations in the population sizes of deep-sea fishes mirror those found in coastal/shallower water. If I find evidence of recent population expansions in deep-sea fishes, it would suggest that the deep-sea environment is more volatile than previously imagined, however, if I find that the populations of deep-sea fishes are stable, it would suggest that the environment is stable as well. To answer this question, I am using several different methods of analysis to look at DNA sequence data. One method is the Extended Bayesian Skyline Plot (see example below). This presents a visual representation of population size going back in time. Some of my preliminary analyses have revealed major population expansions in recent history. These are exciting results and may help to give us a better idea of how the deep-sea habitat has changed over time.
This is a photo of the lovely hatchetfish, Argyropelecus aculeatus, which lives between 300-6,000 feet deep. It is one of the most common species we capture on our cruises.
This is an Extended Bayesian Skyline Plot (EBSP) showing the population size of Argyropelecus aculeatus over time. It shows that the population had a major expansion followed by continued growth. I am currently working to calibrate a molecular clock that will allow me to assign dates to these changes.
This is a deep-sea dragonfish, Echiostoma barbatum, collected during one of the DEEPEND cruises.
Howdy! My name is Corinne Meinert and I am a Master’s student in marine biology at Texas A&M University in Galveston studying biodiversity of ichthyoplankton in the Northern Gulf of Mexico. When you break the word ‘ichthyoplankton’ down you get ‘ichthyo’ which means fish, and ‘plankton’ which means drifter, so all together the word refers to fish eggs and larval fish that drift in the ocean with the currents. Studying the biodiversity of these little fish is important because it can tell us how healthy the ecosystem is where they live; in general, the higher the diversity of fish, the healthier the ecosystem.
To give you an idea of how small these fish are, below is a picture of a snake mackerel (Gempylus serpens) on my finger:
In the lab, we use microscopes to visually identify our fish samples to the family level. For some families, such as tunas, billfish, and dolphinfish, we use genetics to identify the fish to species level. Over the past two years, we have collected and identified over 18,000 larval fish and have found a total of 99 different families. The most abundant families we have found are lanternfish (Myctophidae) and jacks (Carangidae), when combined, these two families make up of 25% of our total catch. Below are a few pictures of different families of fish we have collected (note: the third one is a tuna with another tuna inside of its stomach!):
We still have a lot to learn about larval fish. Understanding how abundant they are and where they live can help us make better management decisions for the future. If you want to learn more about ichthyoplankton and biodiversity, here are a few good webpages and videos to get started:
Information on ichthyoplankton: https://swfsc.noaa.gov/textblock.aspx?Division=FRD&id=6210
Information on biodiversity: https://www.youtube.com/watch?v=GK_vRtHJZu4
A compilation of other fish (and one invertebrate!) caught during DEEPEND sampling:
Blog by Sebastian Velez, Master's Student at Wilkes Honors College, Florida Atlantic University, Jupiter, FL
When you walk into a restaurant and order sushi, or a fish dinner, do you ever contemplate the series of events that led to that fish arriving onto your plate? Probably not…you’re hungry, but the odds that that particular animal would make it to a harvestable size are astounding. I’ll give you an example. A 10-year-old red snapper in the Gulf of Mexico can produce approximately 60million eggs annually. Of those 60 million eggs, only 450 individuals will reach a size of 5cm. At this size they are still susceptible to predation, starvation, and advection away from suitable habitats. My name is Sebastian Velez and I’m a Master’s student in Biology at Florida Atlantic University, studying juvenile snappers and groupers in the Northern Gulf of Mexico collected during the DEEPEND Cruises. I am particularly interested in what happens to these organisms when they are wafted far out to sea, off the continental shelf in areas where depths can reach 1500m.
This is a juvenile Red Snapper, Lutjanus campechanus. This species supports multimillion dollar recreational and commercial fisheries in the Gulf of Mexico.
Now this concept of advection away from suitable habitat is something that occurs as a result of the life history of snappers and groupers. Both families form seasonal spawning aggregations, at which point the resulting larvae are wafted out to sea for 20-50 days, and begin settling on nearshore habitats. The currents responsible for this dispersal include; the Mississippi River Discharge Plume, The Loop Current, and a series of cyclonic and anticyclonic eddies. But every once in a while these larvae get wafted a bit too far offshore. Literally hundreds of kilometers away from their preferred habitats and so the question is; what happens to these animals when they are so far from shore?
The literature is very vague as to what happens with these expatriates, with most accounts only stating that this phenomena takes place and they most likely die as a result of starvation or predation. Thanks to the DEEPEND cruises, we have found that the biodiversity of these expatriates within both families was impressive, with some of the most notable species being; Goliath Grouper, Snowy Grouper, Nassau Grouper, Red Snapper, Vermillion Snapper, Grey Snapper, and Queen Snapper. Our study also suggests that a few members within these families have the ability to stall their settlement, specifically the Wenchman snapper. Individuals were often found ranging from 14-47mm in standard length, lengths usually attributed to newly settled individuals. We also found new depth records for Red and Wenchman Snapper down to 1500m, well past their normal distributions, most likely in an attempt to find suitable habitat where none exists.
This is an unidentified member of the Subfamily Liopropomatinae, Liopropoma sp. Another type of grouper with vivid colorations and often referred to as basslets, these are very popular in the aquarium trade.
These fishes represent multi-million dollar industries in the form of commercial and recreational fisheries. Understanding the biology and life history of exploited species is imperative in informing future management decisions. The pelagic stages of these species have historically been very hard to sample, thus leaving a gap in the associated knowledge. The processes by which these individuals are dispersed represent a potential mechanism in the connectivity between populations and could help managers forecast future drops in stock abundance.
An unidentified individual from Subfamily Epinephilinae. These are your classic groupers. Examples would be Nassau and Goliath Groupers.
Hey, have you ever heard of a heteropod? You may have heard that term associated with terrestrial spiders, but what I am talking about is a group of very special marine snails! Hi, I’m Kris Clark, a graduate student from the University of South Florida College of Marine Science, studying marine gastropod molluscs collected from the DEEPEND cruises. My little creatures are within the Superfamily, Pterotracheoidea. These floating sea snails, commonly called heteropods or sea elephants (albeit they are generally small), are found throughout the world’s oceans in tropical and subtropical waters where they have adapted to pelagic (open sea) living. I like the name sea elephant as it describes their resemblance to an elephant’s trunk. These animals have an extended proboscis or nose-like feature that terminates with their mouth. The term heteropod was coined for these little beasts back in the 1800’s when they were first realized. The term was used because of the evolutionary development of their swimming fin from their ancestral foot – hetero meaning “different” or “other”.
There are three family groups that are categorized by the type (or lack) of a shell. Atlantidae have a full shell where the animal can fully retract inside. Carinariidae have only a very tiny partial shell that covers their visceral mass and gills. And lastly, the Pterotracheidae lack a shell entirely. All heteropods have mostly transparent bodies, have an evolved foot that now serves as a swimming fin, have a mobile proboscis for feeding, and have spherically gelatinous eyes for locating prey. They feed on copepods, polychaetes, brine shrimp, salps, tiny crustacea, jellyfish, pteropods, and other heteropods.
Most people have not ever heard of heteropods. And that’s not surprising. This group of sea-life is still understudied, however more investigations are developing, including mine. One important and interesting finding about heteropods is that there are a lot of them in the oceans. And since they are found in every ocean and are very abundant it is estimated that these swimming snails are highly important to the ocean foodweb – mainly fishes rely on the heteropods to eat, and larger prey eat these fishes, and so on. So heteropods post an important position in the food hierarchy in the ocean system. Many other compelling attributes have been discovered about little heteropods… keep in touch with our future articles for more curious discoveries!
Want to learn more now? Check out these fun videos of swimming Pterotracheoidea…
Left to right: back: Jessica, Alex, Michelle, Cori, Travis, Jillian, and Nina; front: Jason and Rich
HAPPY 4th of JULY!
Scientists still get to celebrate while we’re out at sea! Check out our tattoos! :)
Today is our last day of sampling. We started bright and early again at 6am. It rained a bit, but it was accompanied by a full rainbow arching over the boat. Nice way to start off the morning!
You guys are probably wondering how we collect all of the larval fish I showed you on the last blog post. Well, we deploy a bongo net off the back of the boat and a neuston net off the side. Both nets are brought on board and the samples are washed down into the codends. The contents of the codends are rinsed/poured and put into our sample jars. The samples are brought into the wet lab for a closer look and a potential photo. Some of the larger specimens (e.g., tunas, swordfish) are frozen for genetic analyses.
I set up a GoPro around the boat to show you guys how we sample at each station. Let’s take a look of some of our scientists at work:
Bongo nets and the sunset last night. Neuston net.
Rich is collecting water for the YSI and for the food web study. Nina is reading the water's temperature, salinity, and dissolved oxygen.
Rich, Nina, Jillian, and Jason are retrieving the bongo nets. Everyone's rinsing down the nets, while Michelle is recording the
Jillian is pouring her plankton sample out of the codend. Jason and Nina are rinsing the bongo nets.
Nina and Jessica are putting the sample into the jar. Jessica is looking at a larval tuna under the microscope/taking a picture.
Alex and Cori just retrieved the neuston net. Jillian, Alex, Cori, and Travis are sorting the neuston net sample.
Jason and Travis sorting through Sargassum. Jason and Alex looking at our catch!
Dr. Michelle Sluis is the PI on the cruise. She is recording the data for each tow (e.g., start time, location, etc.) in the pictures above.
Hope you enjoyed the pictures!
Last night we cruised towards our southern transect. We arrived at our first station and began sampling at sunrise (6am). We've hit 10 stations so far today! We collected many of our targeted species and more!
On the boat, we use a camera attached to our microscope to help us take pictures of the tiny fish. Here's some of our catch:
Alex found a siphonophore.
Cori, Travis and Jillian on deck and ready for the next tow!
All smiles here!
My name is Nina Pruzinsky. I’m out in the northern Gulf of Mexico with Texas A&M sampling for fish larvae on the R/V Pelican. We’ll be out here from July 1-5th. The scientists onboard include: Dr. Michelle Sluis (TAMUG), Jessica Lee (TAMUG), Travis Richards (TAMUG), Cori Meinert (TAMUG), Jillian Gilmartin (TAMUG), Alex Southernland (TAMUG), Jason Mostowy (TAMUG), Richard Jones (FAU) and Nina Pruzinsky (NSU).
We left the port at LUMCON at midnight on June 30th and traveled to the first station (Station 48) during the night. We started our sampling around 10am yesterday. We finished nine stations during the day and did two night tows. During the day we are using a neuston net and bongo nets to sample for larval fish. The neuston net tows for 10 minutes at the surface and the bongo nets sample to about 100 m depth. At night, we only tow the neuston net. This way, we can compare the differences between day and night tows at the same station. Additionally, Alex is sampling for gelatinous zooplankton (jellyfish) for genetic analyses, Jillian is Gtowing another plankton net to look at the community structure of zooplankton, and Travis is collecting water samples in order to characterize the food web in the Gulf.
Yesterday we caught tunas, billfish, dolphinfish, flyingfish, eel larvae, remora, frogfish, triggerfish, pufferfish, rough scad, lanternfish (at night) and more! Check out the pictures below! As you can see, all of our fish are extremely small!
Today we started sampling at sunrise around 6am and have completed three stations. We already caught some tuna and dolphinfish larvae!
Stay tuned for more pictures and updates on the cruise!
R/V Pelican before depature.
Larval dolphinfish (mahi-mahi).
Michelle and Cori preparing the neuston net.
Jillian setting up the plankton net along with the bongo nets.
We also were able to dip net a juvenile tuna last night for my thesis!
Another day at sea – one of our last for this cruise.
My name is Laura Timm and I am a PhD student at Florida International University. This is my fourth DEEPEND cruise and the data we collect from it will contribute to the last chapter of my dissertation.
I work on crustacean genetics. Specifically, I use the DNA of a few shrimp species to describe diversity and characterize how (or if) it is moving within the Gulf. These two things, diversity and gene flow, provide a lot of insight into the health and resilience of these target species. Most of my work with DEEPEND has focused on three shrimp: Acanthephyra purpurea is a bright red color and produces a bioluminescent spew to scare off predators.
Systellaspis debilis is also red (though younger ones can look orange), but with tiny light-producing organs called photophores polka-dotting its body.
Sergia robusta can be dark red or even purple and has photophores around its mouth and tail.
To me, all three are uniquely beautiful.
My research focuses on questions related to genetic diversity, which is a good metric for species health. Where is the most diversity found? Has this changed since 2011? How is diversity distributed? Is some genetic diversity unique to certain places? Answers to these questions provide unprecedented insight into how the Gulf copes with disturbances.
Now, a little perspective.
We trawl with a MOC10 net. It is very large. Every person on the ship could go stand in the frame of the net. However, when compared to the size of the ocean, it is tiny – it has been described as the equivalent of investigating terrestrial diversity using just a butterfly net. Yet, we still catch thousands of shrimp. Of these thousands of shrimp, a few hundred are targeted (A. purpurea, S. debilis, S. robusta). Of these hundreds, 96 are sequenced (this is due to the sequencing process; I can only sequence 96 at a time). The genomes of these species have not been sequenced, so I target a few thousand base pairs of DNA. A few thousand base pairs out of billions of base pairs. About 100 shrimp out of hundreds, hundreds out of thousands, thousands out of every shrimp in the Gulf. This tiny amount of data (which, in the history of science, is unprecedentedly large) can tell us so much about the animals living in the Gulf and how they came to be there and whether they are likely to survive whatever comes next.
Written by Tess Rivenbark
My name is Tess Rivenbark and I am representing the Optical Oceanography Lab at the University of South Florida College of Marine Science. Most of the scientists here focus on biology, but my job is to collect data that ties this biology to the physical processes happening in the ocean, looking at different types of particles in the water.
With the CTD, I collect water samples and then filter them to measure chlorophyll and colored dissolved organic materials. Here is a picture of the CTD as it is being deployed from the ship. We send it down to 1500 meters collecting water samples along the way at various depths and measuring the physical properties of water such as temperature, salinity, and dissolved oxygen.
Another instrument I use, a spectral backscattering sensor, is known to the other scientists as the "fish disco" because it emits multi-colored lights. It measures how these lights bounce, or scatter, off of particles in the water.
My last instrument, a handheld spectral radiometer, measures the sunlight that reflects off the water. This is the same thing that many satellites orbiting the earth, like the Aqua MODIS, are measuring. We use the data we collect out here on the water to help understand what the satellite measurements tell us about the particles in the water. The two photos below show this instrument in use at sea and below that is a satellite image showing the concentration of chlorophyll with our proposed cruise track and sample stations plotted on top.
For centuries, sailors and scientists have observed birds landing on ships. A ship out at sea is like a moving island in the ocean. Various birds may seek refuge on ships, especially when storms occur, or are attracted to the lights of the ship at night. It makes sense that many of these birds are sea birds, but a number of land birds may make migrations across ocean areas or get blown out to sea by storms along the coast. Given the several storms during our cruise, it is no surprise we have had a number of birds land on or fly close to our ship, while it was 100-150 miles off the coast of Louisiana, Mississippi, and Alabama. So, here is a short rundown of the birds we have seen recently…
Purple Gallinule – spent a couple days resting on one of the deck cranes until it took off.
Louisiana Waterthrush – this wood warbler took refuge in a corner of the deck for a while before flying away.
Northern Oriole – just showed up on the ship superstructure, rested for an hour, and took off.
Cattle Egrets – we have had several stay around the ship, with a flock of 14 circling the ship one morning.
Bobolink – a few individuals flew around the boat this morning and one perched on the anchor chains and other structures on the bow.
Barn Swallows – One morning just before another squall, there was a flock of approximately 100 circling the ship from 5-6 AM. A flock of about 8 flew by the ship yesterday after several days of clear weather. This morning 3 were perched on some fixtures.
We also had a very large flock of a small birds that might have been American Goldfinches, but it was too dark at 4-5 AM to see them clearly.
Coastal birds we have also seen far out at sea include…
Osprey – one landed on a container on the forward deck, sat for a few minutes, and then left when it was disturbed by a crew member.
Brown Pelicans – three juveniles paddled along with the ship and flew short stretches to catch up again.
Caspian Tern and Royal Terns – one Caspian and two Royals sought a perch on a part of the stern of the ship during a rain storm.
Laughing Gulls – 3 juveniles and 1 adult stayed around the boat for a day during and immediately after a storm.
Studying the animals in the deep sea within their natural habitat is very difficult. It often requires sophisticated instruments or equipment and scientists have to be careful to make sure that they don’t disturb the animals they are studying. During the DEEPEND cruises, we use sound to study how animals move through the ocean and the daily movement patterns as they go up and down from the surface at night to the deep sea during the day. Using sonars, we can create a picture of where the animals are by measuring how much sound they reflect. While this gives scientists a broad picture of where the animals are, it does not provide enough detail to look at the individuals within the layers.
During this cruise, we have been using a new tool to study fish and invertebrates down in the depths of the ocean. We have attached an autonomous sonar (WBAT- WideBand Autonomous Transceiver) on to the MOCNESS (see photo above) to look at the animals that are near the net. This new sonar provides much higher resolution data at small scales, kind of like an underwater magnifying glass. With this new instrument we can look at the individuals that are being collected by the MOCNESS and then compare this back to what we see on the ship’s sonar. So far we have noticed that the animals do not seem to avoid the net as we expected they would.
This is my first research cruise in over ten years, and I am quite excited by the great opportunity. I once went out to sea fairly routinely when I worked at Harbor Branch Oceanographic Institution (HBOI), but the goals were much different then. This time for DEEPEND, we focus on the pelagic mid water column organisms in the Gulf of Mexico, which remains a fairly new habitat for me to explore.
My role for DEEPEND on this DP05 cruise is to ensure proper collection of new bacterioplankton samples from Gulf of Mexico seawater at various depths. I am basically following the same procedures as past cruises for consistency.
The main instrument for collecting water is the CTD (conductivity, temperature, and depth) which is loaded with a rosette (circular arrangement) of twelve Niskin bottles that can each hold 12 L. These traditional aquatic water collectors close at precise depths which I can control from the ship. R/V Point Sur crew member, Marshall Karmanec, helped get me accustomed to running and deploying the CTD on this cruise. With the controls, I can designate where and when bottles are opened at specific depths. Once the bottles are filled and back on deck, I am able to drain 4-5 L of seawater and bring them into the lab. I share a filtering station corner of the ship’s lab with FWC/USF technician Tess Rivenbark. While most of the other DEEPEND scientists are identifying charismatic deepwater megafauna, I filter marine microbiomes onto special sterile 0.45 micron filters. “Sterile” is the operative word here, since the lab is not the optimal place for traditional “microbiology” methods. Essentially I am preserving the communities on the filter by careful handling, freezing and recording, so they can all be brought back intact to my molecular lab at the NSU Oceanographic Center for DNA extractions and sequencing that will eventually illuminate the distribution and dynamics bacterioplankton in much greater detail.
The CTD also measures where the very important oxygen minimum and chlorophyll maximum zones occur vertically within the water column. These zones represent important parameters for oceanographic work since they can delimit where food chains begin or end, where maximum photosynthesis (the production of oxygen from cyanobacteria) happens, and we also have found distinct microbial communities (also known as “microbiomes”) associated with each zone. With DEEPEND postdoctoral scientist Cole Easson, we have been characterizing these microbiomes from past cruises, and our current results point to significant depth stratification of microbiomes in DEEPEND Year 1 data, which among other interesting findings will be submitted in a forthcoming manuscript. This year 3 sampling adds to the temporal dimension of the project and is also very exciting.
On every cruise, it’s tradition to send decorated Styrofoam cups down on one of the instruments to shrink them. Styrofoam is mostly air, so when cups made of Styrofoam are sent to the depths, as the pressure increases with depth, the air inside the cups is compressed, and the cups shrink accordingly. Once they shrink, they stay that way, as Styrofoam isn’t particularly flexible – it doesn’t expand again when it comes to the surface. This year, we received a set of beautifully decorated cups from Theresa McCaffrey’s Advanced Art Classes at Tualatin High School. Ruth Musgraves, who developed and runs our Creep into the DEEPEND summer camps (http://whaletimes.org/?p=2186) has a daughter in one of these art classes, and they heard about the shrinking cups through her. They send out a box of cups, and the artwork is quite amazing, as you can see in the photos below. The best part is that they made some cups for us as well.
I’m really thrilled about that, because I’m pretty much still at the stick figure level when it comes to my artistic endeavors.
There is a pretty careful protocol that we must follow to package the cups, so that the cups shrink without collapsing inside of each other as they shrink at different rates. If two cups shrink together, one inside of the other, they’re almost impossible to get apart without breaking one. They must be loaded in mesh bags with open ends facing each other, with each row separated by tie wraps so they don’t float together and collapse together.
We can load 14 cups per bag, and two bags per CTD rosette. The CTD rosette is deployed to collect water samples at various depths, monitoring conductivity (C – as a measurement of salinity) and temperature (T) as a function of depth (D). We have to be careful that the bags do not interfere with any of the sensors or closing mechanisms on the bottles, so we never load more than two bags per deployment.