Hi all,

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
                                                                                                          flowmeter data.

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!
-Nina

Hi guys!

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:

Dolphinfish larva.

Swordfish larva.

Billfish larva.

Tuna larva.

Frogfish larva.

Alex found a siphonophore.

Cori, Travis and Jillian on deck and ready for the next tow! 

All smiles here!

-Nina

Hello everyone,

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).

Tuna larvae.

Triggerfish larvae.

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!

Cheers!
Nina

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 Rosanna Milligan

It’s the end of another successful cruise and we’ve collected thousands of animals and taken hundreds of physical and chemical measurements across the northern Gulf of Mexico. My job is now to take these data, integrate them with the data from our previous research cruises, and analyze them all to try to find patterns in them that will help us understand how the deep pelagic fish communities are structured.

Understanding how animals are distributed through different environments is one of the key questions in ecology, because the answers can tell us important information about which areas might be particularly valuable. This might be because they contain particularly high biodiversity and are important to conserve, or they might be areas that might contain particularly high abundances of animals that we might want to target for fisheries or drug development for example.

While it’s easy to imagine different terrestrial environments, like deserts, forests or mountain ranges, it’s much harder to imagine what the different environments that might exist in the open oceans are, because, frankly, one patch of seawater looks much the same as any other at first glance. But, when we start looking with scientific instruments like CTDs, or using satellite imagery, we can start to see how the oceans are structured by gradients and boundaries in the physical and chemical properties of the oceans like temperature, salinity or water currents. However, we still don’t really understand is how much this environmental variability influences the animals that live in the deep pelagic oceans. Do they care about different conditions or are they happy to live anywhere? Are they just pushed around randomly by water currents or do they actively swim against them to stay in the best locations?

CTD Instrument used to measure the physical properties of water and to collect water samples from different depths.

Our work with the DEEPEND project is starting to disentangle some of these ideas. For example, we’ve been working hard to figure out how to identify different water masses in the Gulf of Mexico in an ecologically-meaningful way, and separate out how and why different water types affect different deep-sea animals and their distribution patterns. We’re working with teams of geneticists, chemists and oceanographers too, to match up all the different research strands into a coherent story. All of this will be really important in understanding how resilient or vulnerable different organisms might be to human impacts in the Gulf of Mexico, in case something like the Deepwater Horizon disaster ever happens again.

So all the work we do at sea is really just scratching the surface of the work we do when we get back. We’ve got lots more work to do and many more questions to answer!

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. 

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.

We had just finished shrinking all the cups, and the CTD was down, cupless this time, when a squall came through, and 10 foot swells came along with it.  The CTD had to be brought to the surface immediately, and it was quite a dangerous recovery trying to keep the CTD from swinging like a pendulum with safety lines.  As you can see, the cups are just attached by tie wraps, and in those seas, the bag might have snapped off or cups damaged when the protective frame around the rosette was pulled next to the ship to prevent swinging.   We lucked out on that one!   

Written by: Matt Woodstock – DEEPEND graduate student, Nova Southeastern University

Hello, my name is Matt Woodstock and I am a graduate student at Nova Southeastern University working with the DEEPEND Consortium. This is my first time on a research cruise and I wanted to share a bit of my experience so far. Our ship, the R/V Point Sur, is equipped with all the supplies we need to do our science.
 

 
Pictured here (Left to Right): Gray Lawson (Technician), Joe Lopez, Travis Richards, Laura Timm, Tracey Sutton, Jon Moore, and Rosanna Boyle

 My job aboard the ship is to help Travis Richards (PhD student at Texas A&M Galveston) pull tissue samples for genetic sequencing. An average day for us begins early in the morning, hauling nets in from the tow the night before. We sort through each sample, dividing the fishes, crustaceans, squids, and jellyfishes.

 
Pictured here (Left to Right): Tammy Frank, Tracey Sutton, Mike Vecchione

After being identified by our experts, the animals are measured, weighed, and organized so they can be sent to different labs that study each species. We are currently freezing animals for stable isotope analysis, polycyclic aromatic hydrocarbon (PAH) analysis, and parasite analysis (my thesis study).

 A Red Velvet Whalefish, Barbourisia rufa, caught between 600-1000 m that was sampled for stable isotope and genetic sequencing

Three Helmet Jellyfish, Periphylla periphylla, caught in an oblique tow (0-1500 m) is a deep-sea bioluminescent jellyfish

Other animals are persevered and sent to several different labs for later studies. We do this twice a day (day and night) and observe differences in the distribution of animals on a diurnal cycle. Occasionally we will take a break from our sample processing to see anything cool happening on the deck. This morning, we saw the sunrise.

Hello everyone!

Well, our first day of sampling was a success! We managed to deploy the MOCNESS twice at Station B081 (check out our home page to follow the ship!). While retrieving the night trawl we saw a lot of bioluminescence in the water which turned out to be pyrosomes, Pyrosoma atlantica, seen in the picture below. Each pyrosome is a colony of animals called tunicates which related to sea squirts. They form a tube which can pump water to allow them to vertically migrate. The longest species of pyrosome can get up to 20 m in length! We also saw some flyingfish which were being chased and eaten by dolphins!

Today we continued on to B082 and completed two additional successful trawls. Below are some images from the team processing the catch.

Here several of us are emptying the codends and sorting the catch.

Once we've sorted the catch, our team of taxonomic experts identify each organism to species. From front to back we have Dr. Tracey Sutton, Nova Southeastern University who specializes in fish identification, Dr. Jon Moore, Florida Atlantic University who also specializes in fish identification, Dr. Tammy Frank, Nova Southeastern University who specialized in shrimp identification, and last but not least, Mike Vecchione, NOAA's National Systematics Lab specializes in squid identification.

Here, Laura Timm, PhD student at Florida International University takes the species identified by Dr. Frank and samples them to run genetic analyses back in her lab after the cruise.

Travis Richards (foreground) is a PhD student at Texas A&M Galveston whose research involves stable isotope analysis, however, on this cruise he is taking tissue samples for the fish genetics team with the help of NSU graduate student, Matthew Woodstock (middle). I'm at the end of the line in this picture measuring fish lengths.

Our DEEPEND mascot, Squirt, hangs out with us in the lab making sure we're doing our job! You'll see more of him this week on instagram - @deepend_gom

The acoustics team have detected some very large animals under the ship. They will be blogging all about their new gear and what they are "seeing" with sound later this week!

Thank you for following our blog and stay tuned for more!

April

by Mike Vecchione

We are at sea. We finally got under way at 11:00 last night. We were ready at 9 PM but had to wait for two container ships to come in and get safely docked before we could go past them. One belonged to Dole and the other to Chiquita. Both were loaded with bananas. We literally had to wait for a couple of banana boats!

We made good time last night because the wind came around astern and we surfed our way out here. "Here" is almost at our first station and quite close to the  wreck of the Deepwater Horizon. Seas have been running 6-8 ft (moderately unpleasant) but now they are beginning to settle down and we should be able to begin sampling this evening. We are finally out in Sargassum and water that you can see through, a big contrast with Gulfport. There was a dolphin feeding in the lights of the ship before we left and you could not see it until it broke the surface. We are surrounded by huge oil rigs in the distance. There is an support ship practicing with its very impressive water cannons for fighting fires on the rigs. There are flying fishes around but most of the birds I have seen are land birds that were blown offshore by the storm. We are all looking forward to working tonight.

Figure 1. Screen shot of the ship's navigation computer, showing oil rigs around our location.

Figure 2. Water cannons from a oil-rig support ship, presumably a fire-fighting drill.

We spent part of Friday getting the lab set up and everything tied down, the acoustics group moved their heavy gear onboard and worked feverishly to get everything connected, our MOCNESS tech got the MOCNESS frame put together so that we could attach the nets, all in time for a Friday night departure.  And …… here we sit.  The winds are howling, and we have whitecaps (little waves) in the harbor.   What howling winds and whitecaps in the harbor mean is 10-15 foot waves and even stronger (perhaps shrieking) winds on the open ocean.  Our options were to try and get out anyway, spend three days bouncing around in horrible weather with most of the scientific party seasick, and finally completing the 20 hour transit in 60 hours for an early evening arrival on station Monday night, or spending several days at the dock, leaving Sunday night, and spending 20 hours transit for an early evening arrival on station Monday night.  Being scientists, we of course considered the pros and cons of each option, and since option 1 had no pros, we settled on option 2.  

Written by: Dr. Tammy Frank

Hi Everyone!  Quick update that the DEEPEND team is currently staging/getting underway for our 5th DEEPEND cruise of our project!  Stay tuned for blog updates as well as updates to the shiptracker on the home page as coordinates are available.  You can also watch where our glider is moving in the GoM and we are planning to retrieve it later in the cruise.  The team will be returning to port by May13th.  Stay tuned!  We here on land are excited to see what they discover this trip!

We are pleased to present you with the fourth in a series of teaching and learning modules developed by the DEEPEND (Deep-Pelagic Nekton Dynamics) Consortium and their consultants. Whenever possible, the lessons will focus specifically on events of the Gulf of Mexico or work from the DEEPEND scientists.

All modules in this series aim to engage students in grades 6 through 12 in STEM disciplines, while promoting student learning of the marine environment. We hope these lessons enable teachers to address student misconceptions and apprehensions regarding the unique organisms and properties of marine ecosystems. We intend for these modules to be a guide for teaching. Teachers are welcome to use the lessons in any order, use just portions of lessons, and may modify the lessons as they wish. Furthermore, educators may share these lessons with other school districts and teachers; however, please do not receive monetary gain for lessons in any of the modules.

You can download the module and view our other modules here; http://outreach.deependconsortium.org/index.php/education/resources/lesson-plans

The saying “all good things must come to an end” is a cliché I do not want to use, but it is the only saying that will give my DEEPEND Teacher at Sea experience any justice. This amazing journey has shown me things I have never seen or experienced before.  Many things that I discovered on this trip could no way have been taught in a classroom by a lecturer.  The first-hand accounts I have discovered produced a new found passion for the deep sea.  I plan on building on the things I have learned and I plan on sharing them with my family, friends, and my COAST students at Cutler Bay Middle School. 

I want to thank Dr. Sutton, Dr. Judkins, Dr. Moore, and Dr. Cook for allowing me to participate on this incredible journey, and for keeping me laughing throughout the trip!  Thank you to my lab partner Mike and all the scientist on board the Point Sur that have helped me learn the lab routine.  You all truly made me feel like a part of the team from the start. 

I want to thank Mr. and Mrs. Martinez, Mr. Bas, Mr. Callahan, Mrs. Mills, Ms. Carnall, Mr. Squirrell and my brother Jason for taking great care of my fish tanks, getting my classroom ready for the excited students Monday morning, and for getting things ready for an exciting school year!  I want to thank my principal, Mr. Pfeiffer, for allowing me to continue my education and participate as the DEEPEND Teacher at Sea.

My COASTIES, we have so much to talk about when I return!  I have plenty of stories and pictures to share that I am sure you all will also grow a new found passion for the deep sea just as I have.

I want to give a special thanks to my family, especially my daughter who was sad to see me leave, but understood how important this trip was.  I love you very much!

This trip has been everything I could have imagined!  Thank you for allowing me to share my experiences with you.  I hope you had as great of a time reading my blogs, as I had creating them.

Signing off,

Chris Valdes, Teacher at Sea

With only a couple days left in the trip, I am still amazed by the different creatures we continue to examine.  Some are big and some are small; but all are unique.  This trip has opened my eyes to deep sea organisms and the adaptations they have evolved in order to survive in such a harsh environment.  

Some animals use bio-luminescent photophores that give off a fantastic light show.  Some animals are very scary looking with gigantic teeth and over sized mouths.  Many have very large eyes that are able to take in the faintness of light in the ocean’s depths.  Some animals are colored red because this color is almost invisible in deep dark waters, so these animals use it to their stealthy advantage.  Some creatures use parts of the body as a lure to attract its prey and others swim around until they find something to eat. Some of these creatures have very long tentacles and others are missing some of the traditional fins that are present on their shallow water counterparts.  

These animals have really adapted well to live so far below the surface. These past two weeks I have grown an appreciation and fascination with the deep sea!

Since tomorrow is our last day at sea, I wanted to share some pictures of the creatures I have been able to examine while aboard the Point Sur.  I hope you enjoy them as much as I did discovering them!

Chris Valdes, Teacher at Sea

Bio-acoustics is a major component to the DEEPEND research.  Whereas the MOCNESS net collects physical organisms, the bio-acoustical team collect sound samples.  They are then able to use that data and transform the auditory world in to a visual one. 

 “It’s like a fish finder on steroids”, explains Ben from Florida International University, as he describes the system.  He is able to use the data to determine not only biomass, but he is able to identify different species while creating taxonomic data from sound. He is able to send different vertical sound frequencies and pulse lengths through the water to identify individual fish and crustaceans. He is also able to use target areas of interests to get multiple reads in order to create a well-documented profile of the target.  Ben is also able to record migration patterns of different organisms and is hoping to determine why certain patterns exist.

In the early hours of the morning, before the sun has started to rise, a mass migration of pelagic organisms begins its descent to the mesopelagic zone. The cycle reverses itself in the evening, as many crustaceans and fish species migrate back towards the surface to feed through the night. Using multiple frequency scientific echosounders (sonars), scientists can discriminate between taxonomic groups using a technique known as decibel differencing. This is made possible by the unique “acoustic fingerprint,” or echo that each group of organism produces when pinged at different frequencies. In the figure below you can see these taxonomic groups highlighted in different colors, and their corresponding migration pattern recorded over a 24hr period in the Northern Gulf of Mexico.

Although the focus of the trip is to study the deep scattering layer and the diel migration patterns of the organisms that form it, chance sightings of larger fish can occur. In this echogram a school of larger animals were observed swimming through an area of high biomass (brighter color = higher concentration of organisms), which could indicate foraging! (Pictured below)

Chris Valdes, Teacher at Sea

The CTD Rosette is one of the major pieces of lab equipment that we have on aboard the Point Sur. The CTD Rosette measures the water’s conductivity, temperature, and density.  Additional sensors have been added that will also record oxygen, florescence, and pH levels.  The CTD travels as deep as 1,500m, but will take different readings at the preset depths needed by the scientists.  When the CTD reaches that specific depth, one of the grey chambers (niskin bottles) will open, fill and close with water from that depth in the water column.

Shaojie and I getting the CTD ready to drop in to the Gulf.

Lindsay and Shaojie watching the CTD drop to 1,500m.

A thumbs up for success. 

Lindsay, from NOVA Southeastern University, is interested in the filtered microbes that are found in the water.  These microbes are used by the anglerfish to “light up” their lure through bioluminescent.  She would like to draw the connection between where and how the anglerfish acquire the bacteria in the water, since the anglerfish is not born with it.

Lindsay in the lab.

Shaojie, from University of South Florida College of Marine Science, uses the CTD for other readings.  He is interested in the chlorophyll levels that are only found in the top 2 levels of the targeted depth.   He is using the data to help Travis get an idea of the amount of phytoplankton in the water.  

Shaojie in the lab.

To demonstrate the crushing pressure of the depths below the surface, we tied a bag of Styrofoam cups the CTD before it was deployed to 1,500m.  At that depth the weight of the water that is above the CTD is so heavy that is causes pressure changes.  The pressure shrunk our Styrofoam cups and turned them into “mini-cups”.  We all took the time to create souvenirs for our friends and family.  I think it is a really cool souvenir from a place so deep in the ocean!

Cups before they were lowered to the depths below.

Look how much they shrunk!

On each side is a cup that was not lowered into the Gulf.

Chris Valdes, Teacher at Sea