Christopher Tait: Where am I? April 1, 2017

 NOAA Teacher at Sea

Christopher Tait

Aboard NOAA Ship Reuben Lasker

March 21 – April 7, 2017

Mission: Spring Coastal Pelagic Species Survey

Geographic Area of Cruise: Pacific Ocean from San Diego, CA to San Francisco, CA

Date: April 1, 2017

Weather Data from the Bridge

Time 8:51 PDT,

Current Location: South West of Santa Rosa Island, Latitude 33.37N Longitude -120.7 W

Air Temperature 13.4 oC  (56.1 oF)

Water Temperature 13.1 oC  (55.5 oF)

Wind Speed 12 kts

Barometric pressure 1013.98 hPa

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Science and Technology Log

Oceans cover 71% of the surface of Earth and 99% of the livable space (Figure 1).  The Coastal Pelagic Survey is taking several approaches to map the distribution of anchovy, sardine, and other target species within the epipelagic zone.  This zone is the thin surface layer extending to the depths light penetrates the ocean, which is approximately 200 meters near California.  The epipelagic zone in some coastal areas is very productive due to the upwelling of nutrient rich water causing an abundance of primary production by phytoplankton.  Besides the net trawling and acoustic transects, the researchers are using samples of fish eggs and ichthyoplankton (ichthyo = fish, plankton = drifting) to determine locations of spawning. This voyage is mostly surveying over the continental shelf and I am amazed at the diversity of organisms we have found thus far.  In this modern era of exploration of the vastly unknown deeper regions, I can only imagine the species still to be discovered!

 

Figure 1: Ocean Layers

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(c) Knight, J.D., 1998, Sea and Sky, http://www.seasky.org/deep-sea/ocean-layers.html

CUFES:

A CUFES (Continuous Underway Fish Egg Sampler) system is used to determine the location of fish eggs as we travel transects on a continuous daily basis (Figure 2).  Water from 3 meters below the surface is pulled into the boat at 640 L/min. and poured through a filter to collect fish eggs and other plankton.  The collected samples are analyzed every 30 minutes to determine a density of eggs and which species are spawning.  The collected samples are further analyzed at NOAA’s SWFSC (Southwest Fisheries Science Center) in La Jolla, CA.

Figure 2: CUFES Schematic

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CUFES schematic.

 

Figure 3: Preliminary Results of CUFES Survey

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Preliminary results of the CUFES survey. The CUFES data is overlaid on sea surface temperatures measured by satellite.

The CUFES data is overlaid on sea surface temperatures measured by satellite.

PairoVET Tow & Bongo Tow

A PairoVET (paired vertical egg tow) sample is collected using a pair of small, fine mesh nets dropped to 70 meters deep and vertically towed to the surface to collect fish eggs and zooplankton in the water column at predetermined locations along our transects every 20 nautical miles. This is generally the depths that sardine release their eggs. The Bongo net gets its name because the nets are the size of bongo drums (Figure 4 & 5).  This is a plankton tow that is pulled alongside the ship and occurs every 40 nautical miles.  The net is dropped to a depth of 210 meters and pulled up at a 45 degree angle to get a more complete sample of the ichthyoplankton and zooplankton throughout the water column at location.

 Figure 4: Bongo net in center of image and PairoVET on the right.

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Bongo net in center of image and PairoVET on the right.

Figure 5: Bongo going overboard.

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Bongo going overboard.

Figure 6: Preserving the Bongo Sample for later analysis.

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TAS Chris Tait preserves the Bongo Sample for later analysis

CTD: Conductivity, Temperature and Depth Probe

The scientists use a CTD (conductivity-temperature-depth) probe to measure the physical properties of the seawater throughout the water column that biologic samples are being taken (Figure 7). Conductivity is used to calculate the salinity of the water. These physical properties are very important in determining the types of organisms that are present at varying locations.

 Figure 7: CTD (Conductivity Temperature Depth) Analysis

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CTD (Conductivity Temperature Depth) analysis

Personal Log

One of the great mysteries of waking up is answering the question of “where am I?”  After a long evening of trawling for fish and keeping an eye on where you are, you go to bed.  Exhausted, the boat rocks you to sleep.  When I wake up the first thing I do is, jump out of bed and run out onto the front deck.  Some days, there is ocean for as far as the eye can see, some days a mysterious island (Figure 8) in the distance and sometimes there is the mainland (Figure 9)!  I run to grab my phone when mainland is in sight to get a couple of phone calls out to family.

 Figure 8: The mysterious island turns out to be Anacapa Island, which is part of the Channel Islands National Park.  The waters surrounding the park are part of a national marine sanctuary.

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Anacapa Island, one of the Channel Islands

 

Figure 9: Sunrise over Santa Barbara.  Time for me to make a call home!

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Sunrise over Santa Barbara

In the Dry Lab there is a computer with a map showing where we are currently located, a red track line showing where we have been and transect lines displaying where we will soon be (Figure 10).  On our acoustic transects, we follow the parallel lines to mow the lawn and find the location of the CPS (coastal pelagic species) from their echoes.  When we trawl, we break transect and go to places that showed promise in the acoustic backscatter.  

 Figure 10: Without tracking our location on the computer I would feel totally lost! The blue lines are where we plan to go, and the red lines show where we’ve actually gone.

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Blue lines show where we plan to go, and the red lines show where we’ve actually gone.

Catch of the Day

As I get ready for my night shift, I feel this anticipation to discover what species we are going to find!  Every day brings a new catch of the day!

Grey Smoothhound Shark (Mustelus californicus): This small coastal shark feeds on small invertebrates and fish.

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Gray Smoothhound Shark (Mustelus californicus)

Needle Fish (Family Belonidae):  This large needle fish is coastal piscivorous fish, meaning they specialize at eating other fish. They have a mouth full of tiny needle like teeth to prevent a slippery fish from getting away.

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Needle Fish (Family Belonidae)

Northern Anchovy (Engraulis mordax): This is one of our target species on this survey.  Anchovy have the potential to form massive schools and have a tremendous impact of the ecology of the California Current Ecosystem.  They feed on zooplankton, provide food for other fish, sea birds, and marine mammals.  They are also an important fishery which have the potential to be over fished if not properly managed.

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Northern Anchovy (Engraulis mordax)

Pacific Sardine (Sardinops sagax, top specimen) and Pacific Mackerel (Scomber japonicas, bottom two specimens): These two species are also part of the Coastal Pelagic Species community, which this survey are targeting.  The sardine is another very important fish due to their ability to form tremendous schools, impacting plankton through feeding, providing food for larger predators, and they are a valuable fishery.  Sardine populations have the ability to boom and crash, and the cause is still not fully understood.  The Pacific mackerel is a species that has been populous at times of lower sardine and anchovy abundance.

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Pacific Sardine (Sardinops sagax), top, and Pacific Mackeral (Scomber japonicus), bottom two

Pacific Sardine (Sardinops sagax) and Pacific Mackeral (Scomber japonicus)

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Close-up of Pacific Mackerel (Scomber japonicus)

Pacific Mackeral (Scomber japonicus)

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Pacific Mackerel (Scomber japonicus)

Jack Mackerel (Trachurus symmetricus) and Larval Rockfish (Sebastes sp.): Jack Mackerel is another target species of the Coastal Pelagic Survey.

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Jack Mackerel (Trachurus symmetricus) and a larval rockfish (Sebastes sp.)

June Teisan, Ichthyo-WHAT? Ichthyoplankton! May 6, 2015

NOAA Teacher at Sea
June Teisan
Aboard NOAA Ship Oregon II
May 1 – 15, 2015

Mission: SEAMAP Plankton Study
Geographical area of cruise: Gulf of Mexico
Date: Wednesday, May 6, 2015

Weather Data from the Bridge:
12:00 hours; Partly cloudy skies; Wind 080 (WNW) 9 knots; Air temp 25.8C; Water temp 25.7C; Wave height 3-4 ft.

Science and Technology Log:

From my very first shift the day we left port at Pascagoula, I’ve been out on the ship’s deck deploying nets and processing samples. Samples of what, you ask? Ichthyoplankton! Ichthyo-What? Ichthyoplankton are the eggs and larvae of fish, and are typically found less than 200 meters below the surface, in the “sunlit” zone of the water column. We have 40 testing sites or “stations” ahead during this cruise, as shown below.

SEAMAP_OregonII

The blue area holds the SEAMAP Plankton stations we plan to sample on the first leg of the spring cruise. The other stations will be sampled on the second leg May 17-31.

 

With my noon to midnight teammates Pam Bond and Jonathan Jackson, and the invaluable Oregon II deck crew to operate the winches, I’ve learned to draw samples from the Gulf with specially developed equipment: the Bongo net, Neuston net, MiniBongo net, and S-10 Neutson net, and the CTD sampler.

The Bongo and its smaller cousin the MiniBongo are designed with funnel-shaped nets that collect samples into a cylinder at the end of the net. Once the nets are sprayed down to chase the last of the biomass into the PVC cylinder or “codend”, we take the cylinders to the processing table to sieve the biomass, transfer that to the glass lab jars, and fill with preservative solution.

The Neuston net is affixed to a large metal rectangle and is pulled along the surface of the water for a ten minute time segment. The mesh of the Neuston is not as fine as the Bongo, so smaller plankton slip through and larger organisms are gathered.

 Once the samples are gathered they must be sieved, transferred into lab jars, and preserved. Immediately after collecting the samples, we walk the buckets holding the codend cylinders to the back deck where the processing table holds the equipment and solutions we need for this part of the process.

Personal Log:

I’ve been on board the Oregon II for five days, and I am deeply impressed by many facets of this scientific journey.

  • The level of dedication, professionalism, and passion of the NOAA science team: This work is high caliber data gathering in sometimes grueling conditions, with monotonous waiting periods in close quarters; but the good humor, dedication to best practice field science, and mutual respect and support among the team is always evident.
  • The complexity of running a working research vessel: From the Commanding Officer down the chain, each crew member has their jobs and each person is vital to the success of the excursion.
  • The importance of the work: Our fisheries are a vital food source; to manage the stocks and avoid overfishing we need data to make management decisions that ensure a healthy ecosystem.
  • The beauty and jaw-dropping magnificence of the Gulf: This vast expanse of water – teeming with life, driving weather patterns, supplying us with food and fuel – is a sight beyond words.

Finally, here’s a shout out for Teacher Appreciation Week! Kudos to all my colleagues across the country and especially to the teaching staff at Harper Woods Schools in Harper Woods, Michigan for all you do everyday!

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And a special hello for the students in Mrs. Wesley’s class all the way from the Gulf of Mexico!

Carol Schnaiter: Our First Day of Work, June 10, 2014

NOAA Teacher at Sea

Carol Schnaiter

Aboard NOAA Ship Oregon II

June 6 – 21, 2014

Mission: SEAMAP Summer Groundfish Survey

Gulf of Mexico

June 10-11, 2014

South wind  10 to 15 knots

Seas (waves) 3 to 4 feet

Partly cloudy

My home away from home for a few weeks!

My home away from home for a few weeks!

Science and Technology Log

On June 9th we arrived at our first station. There are over 120 stations on this survey in the Gulf of Mexico. Unfortunately I was not able to participate in the first station. (More on that later)

When we arrive at the station the ship’s crew is very busy. The deck crew put trawling nets into the water and down to the bottom to catch fish, shrimp, and other organisms. Once these nets are back at the surface the crew uses cranes to lift them to the deck where the scientists can work on the catch. When the nets are in the water the ship must slow down, so the nets do not rip.

After the nets are raised the organisms collected in the nets are emptied into buckets. The scientists then weigh the buckets on a scale. To make sure they are only weighing the organisms, they first weigh the bucket when it is empty.

Weighing the catch

The basket must be weighed before we sort it.

Next everything goes into the “wet” lab. It is called a wet lab because this area has water available and it is where the organisms are poured out on to a long conveyor belt, sorted, and washed off.

Catch on the conveyor belt

Everything is poured onto the conveyor belt to be sorted.

First, everything is sorted by species. Then everything is counted, measured, weighed, and sometimes the gender and maturity are calculated. All of this is recorded into computers.

Some of the species are very tiny and others are large, but everything is counted.  Many of them look alike so the scientists need to be careful when sorting everything.

The scientists on the Oregon II know many of the names of what they catch, but they also use books, charts, and the computer to look up information to make sure.

Sometimes someone in the lab back on shore may be doing research on a certain species and if that species is found it will be tagged, bagged and sent back to the lab.

The CTD’s and bongo net tows are conducted from the forward well deck (check the first blog if you forgot what those do).

The bongo nets are used to collect ichthyoplankton and so the mesh on these nets is very tight, sometimes as small as 0.333 millimeters. These samples are placed into jars and will be examined back in the lab on land later.

Material from bongo net

This is what we collect using the bongo nets. Photo by Chrissy Stepongzi

By time everything is finished, it is time for the next station and everything starts over again.

The work that the Oregon II does is very important. This survey has been conducted twice a year since the early 1970’s and the information collected can show the scientists what is happening under the surface of the water.

The survey helps to monitor the population and health of everything, plus shows any interactions with the environment that may be happening.

Personal Log:

You may have noticed that I mentioned I could not participate in most of the first day’s work, I was seasick and I spent a lot of time in my stateroom.

State Room

State Room

Thank goodness for the medics and Chief Steward on the ship. Walter, the Chief Steward, sliced up fresh ginger for me to suck on, while Officer Rachel Pryor gave me sugar coated ginger to chew on.

The two trained medics, Lead Fisherman Chris and Fisherman James, both were great help and were all very concerned. Kim, the lead scientist, and my bunk mate, Chrissy, checked in on me throughout the night. I am so grateful for everyone that helped. I am now drinking a lot of water and Gatorade to stay hydrated.

As soon as I felt better I was able to help in the wet lab by sorting, counting, weighing, and measuring organisms that were pulled up. We found some really cool things, like this Atlantic Sharpnose shark that Robin Gropp is holding.

Atlantic Sharpnose Shark

Atlantic Sharpnose Shark

The Atlantic Sharpnose Shark can grow to be 3.9 feet long and can live 10-12 years. It is a relatively small shark, compared to others.

The Common Terns (seabirds) follow the ship when we are trawling hoping to find a free meal. They sit on the ship’s rig that holds the nets waiting for food. The Common Tern is the most widespread tern and can be found by many large bodies of water. They are mostly white with a little black.

Common Terns waiting for dinner!

Common Terns waiting for dinner!

Taniya Wallace and Andre Debose are the two scientists on the night shift (midnight to noon) and they are extremely knowledgeable and explain everything to me. I am learning a lot of new words and I am even getting better at telling one fish from another.

Andre and Taniya holding the stingray.

Andre and Taniya holding the stingray.

The Southern Stingray that Andre is holding is just one of the amazing creatures we caught. We also brought up a Blackedge moray, a Texas Clearnose Skate, a sea hare, red snapper, jellyfish, pufferfish, sea horse, and many more. I can’t wait to share all of my photos next school year!

He may not look dangerous, but he could really hurt you!

He may not look dangerous, but he could really hurt you!

I am working the midnight to noon shift and it is strange to “wake-up” at midnight and eat supper (the cooks save a plate if you ask) and then go to work. Again, the food is wonderful. Last night I had the best prime rib and mashed potatoes!

Everyone on the ship is so helpful and friendly. I enjoy listening to where everyone is from and why they decided to make the Oregon II their home.

On the Oregon II

Here I am enjoying the beautiful view from the bow. Photo by Rebecca Rosado

Emilisa Saunders: Away We Go! May 13, 2013

NOAA Teacher st Sea
Emilisa Saunders
Aboard NOAA Ship Oregon II
May 14th – 30th, 2013

Mission: SEAMAP Plankton Study
Geographical area of cruise: Gulf of Mexico
Date: Monday, May 13th, 2013

Science and Technology Log:

Boarding the Oregon II

Me and the Oregon II (and the silly crewmember in the background). Photo by Kaela Gartman

I’m finally aboard the Oregon II!

Today I got a sneak preview from the lead scientist, Andy, of the labs and some of the equipment that we’ll be using to collect plankton once we’re underway.  There are three labs where we’ll be doing science for the next 17 days: the dry lab, the wet lab, and the chem lab.  The dry lab, where I’m sitting and typing right now, is a room with computers that are used to remotely monitor the depths of the nets once they have been dropped, and to record data about those drops.  The wet lab is where samples of plankton are preserved in jars to be sent back to shore and studied.  The chem lab is where chlorophyll is separated from plankton samples.

I got to see the CTD, which is a unit that collects water at specific depths in order to measure physical characteristics of the water, such as salinity, fluorescence, temperature, and dissolved oxygen.  I’m looking forward to learning more about this physical data and why it is important once we are underway.

CTD

The CTD collects water samples for testing

Andy also showed me the nets we will use to collect plankton.  All of the nets are large and heavy and are raised and lowered by winches that are operated by the ship’s crew.  The first is a Bongo net.  If you’ve ever seen bongo drums, you can get a sense of what this unit looks like: two side-by-side nets with round openings.  The nets themselves are shaped like cones, and we’ll attach a bottle called a cod end on the end of each to capture all of the plankton from the nets.  Then there are two Neuston nets, which have large, rectangular openings.  The regular Neuston net will be towed along the surface, and the Subsurface Neuston will be towed in a pattern at various depths, as will the Bongo.  The unit that I am most excited about is the MOCNESS.  This big frame holds up to ten nets, which can be opened and closed at certain depths; that way, we can collect samples from various depths and monitor plankton at separate locations and at specific depths in the water column.  In the other nets, you know what you get and where it came from, but not how deep it was.

Bongo nets

Bongo nets

Subsurface Neuston

Subsurface Neuston Net

The water column is an idea that scientists use to think about and study the ocean from top to bottom, or from the surface to the ocean floor.  When you think about the water column, imagine the ocean as an aquarium, and you’re looking into it and seeing the organisms that live at different depths and what the water is like at those depths.

The reason that the MOCNESS is so exciting to me is that it reminds us that the water in the ocean is not just a uniform mixture all throughout; different creatures live at different depths, and in different numbers at those depths.  It’s easy to imagine that creatures that are benthic – meaning, they live on the ocean floor – will vary depending on where they are in the world and how deep the ocean floor is in that spot.  It’s harder to imagine that pelagic organisms – those that live in the water column, neither at the very surface, nor at the bottom or at the shore – will also vary greatly depending on depth and location.  The water itself is different as well; the temperature of the water and the amount of salt, light and oxygen changes with depth.

Challenge Yourself:  Here’s a challenge for my Nature Exchange Traders: go on into the Nature Exchange and explain the terms water column, benthic and pelagic to earn some bonus points.  Tell them Emmi sent you!

NOAA Oregon II

The journey begins! Photo by Kaela Gartman

Personal Log

Flying over Alabama on the descent into Mobile on Sunday, I was struck by how much water there was everywhere below me.  Everywhere I looked, there were slow, meandering rivers, sparkling ponds, lakes and streams.  At times when I thought I was looking down on a forest, I saw the sun reflecting off of water blanketing the ground beneath the trees and shrubs.  I was even struck by the number of puddles in parking lots and lining the streets.  I kept thinking that, living in the desert, I’m just not used to seeing so much water – and I hadn’t even reached the harbor yet!  It was as if I was being slowly introduced to the world that I’m about to live in for the next 17 days.

I’ve been aboard the Oregon II at dock for just a few hours now, and I’m already overwhelmed with fascination, excitement, curiosity, and anticipation.  I started the morning at my hotel feeling very nervous, knowing that I was about to experience a rush of newness: new people, places, sights, sounds, rules, routines, you name it.  I told myself just to take a deep breath and take it in one thing at a time, and that really helped me to enjoy the experience.  Now the nerves are mostly gone and I’m just very much looking forward to the ship’s departure tomorrow afternoon!

To my great fortune, I’ve already found everyone I’ve met to be incredibly kind and friendly.  I got to meet some of the NOAA lab scientists who study the plankton that is collected from the Gulf, as well as field scientists Alonzo and Glenn, with whom I’ll be working the night shift on the Oregon II.  Last but not least is Andy, the lead scientist for this cruise, who helped plan logistics for my arrival, gave me a tour of the ship and helped me get situated on board.

The folks I’ve met on board are from all over the United States.  Some of them came to Pascagoula to work for NOAA to study the effects of the Deepwater Horizon oil spill; some came as part of their graduate school studies.   Everyone I’ve met either has or is pursuing an advanced degree, so the intelligence on board the ship is impressive.  As challenging as it can be to for the scientists to be away from home for more than a hundred days out of the year, all of them have some level of appreciation for doing field work.  Not all of the scientists who study plankton in Pascagoula are able to leave the lab to go on the cruises, so I am even more grateful that I have the honor of taking part.  I’m also extremely grateful to learn that I will be of help to the team.  Because of limited staffing and budgets, the science team depends on teachers, like me, to provide extra sets of hands during the field work.

Stateroom 5

My stateroom on the Oregon II

I’ll be staying in Stateroom 5 for this cruise, which I’ll share with a volunteer scientist named Jana.  “Stateroom” is the word used for a bedroom on a ship.  The stateroom is small, as expected, but it actually feels like it’s the perfect size.  All of my belongings are unpacked in drawers and cabinets, and they all fit just fine.  There’s a bunk with two beds, a sink, and three storage cabinets.  Two of the cabinets are entirely for our use, and one mostly holds safety gear and flotation devices.  There is enough floor space that I could lay on the floor and do snow angels, so there will be plenty of room to move around.  I don’t expect to be spending all that much time in the stateroom once we are underway.

Time has taken on a whole new meaning in the past two days.  Yesterday morning I left Las Vegas in the Pacific Time Zone and flew to Atlanta in the Eastern Time Zone, then to Mobile in the Central Time Zone.  It was almost like time travel.  After we embark tomorrow, I’ll start my work schedule, which will have me on duty from midnight to noon every day.  Work goes on around the clock on NOAA vessels.  This schedule will take some getting used to, but as a morning person, I am excited that I’ll be awake and active for my favorite part of the day, and I’ll get to watch the sun rise.  Right now, I’m attempting to stay awake for my entire first night on the ship so that I can get on my work schedule right away.  To add another level of confusion to my sense of time, ship crews observe 24-hour military time instead of using AM and PM.  Numbers are difficult for me and don’t come naturally, so this will take some getting used to.

Military time

The clocks on the ship show the 24-hour military time system.

Just being on the ship feels quite surreal.  As I write this at 23:33hrs, there are just a handful of people on board, and we are still at dock.  Every once in a while some subtle movement reminds me that this is a ship in the water, but mostly it feels like solid ground.  I know that will change once we get moving.  Aside from the obvious signs, there are other little reminders that this is a ship, where everything must be secured for rougher waters.  Computers and monitors are strapped and bolted to the tables, there are gripper pads spread out on tables and in drawers, and every door, from drawers and cabinets to staterooms, has to be latched shut and unlatched to open, and open doors have to be secured with a hook so that they don’t slam shut when the ship shifts.   There’s also a constant hum of noise on the Oregon II.  I’m interested to see how loud it is when we’re actually moving!

The adventures in science begin tomorrow!

Sunset at Dock

Sunset at dock, from the dry lab of the ship

Did you know?

Bluefin tuna plankton are a type of ichthyoplankton, which comes from the Greek words for “fish drifters.”  For those of you in Nevada, think of our state fossil, the ichthyosaurus, which means “fish lizard!”

Dave Grant: The Straits of Florida, March 3, 2012

NOAA Teacher at Sea
Dave Grant
Aboard NOAA Ship Ronald H. Brown
February 15 – March 5, 2012

Mission: Western Boundary Time Series
Geographical Area: Sub-Tropical Atlantic, off the Coast of the Bahamas
Date: March 3, 2012

Weather Data from the Bridge

Position:30 deg 37 min North Latitude & 79 deg 29 min West Longitude
Windspeed: 30 knots
Wind Direction: North
Air Temperature: 14.1 deg C / 57.4 deg F
Water Temperature: 25.6 deg C / 78.4 deg F
Atm Pressure: 1007.2 mb
Water Depth:740 meters / 2428 feet
Cloud Cover: 85%
Cloud Type: Cumulonimbus and Stratus

Science/Technology Log:

Entering the  Gulf Stream and Straits of Florida

“There is in the world no other such majestic flow of waters.
Its current is more rapid than the Mississippi or the Amazon.
Its waters, as far out from the Gulf as the Carolina coasts, are of an indigo blue.
They are so distinctly marked that their line of junction with the common sea-water
may be traced by the eye.”

Matthew Maury – The Physical Geography of the Sea

 While our cruise could hardly be called leisurely, most sampling has been spread out between sites, sometimes involving day-long periods on station while the CTD and moorings are recovered from great depths (5,000 meters). However, Chief Scientist Dr. Baringer regularly reminds us that west of the Bahamas in the Gulf Stream transect, our stations are in much shallower water (≤800 meters) and close together (The Florida Straits are only about 50 miles wide), so we should anticipate increased activity on deck and in the lab. In addition to the hydrology measurements, we will deploy a specialized net to sample those minute creatures that live at the surface film of the water – the neuston.

The Neuston net is deployed for a 10-minute tow.

The Neuston net is deployed for a 10-minute tow.

Now that we have crossed the Bahama Banks and are on-station, the routine is, as expected, very condensed, and there is little time to rest. What I did not anticipate was the great flow of the Gulf Stream and the challenge to the crew to keep the Brown on our East-West transect line as the current forces us north.  Additionally, as Wordsworth wrote, “with ships the sea was sprinkled far and wide”  and  we had to avoid many other craft, including another research ship sampling in the same area.

Ben Franklin is famous for having produced the first chart of this great Western Boundary Current, but naval officer Matthew Maury – America’s Scientist of the Sea – and author of what is recognized as the first oceanography text, best described it.  Remarkably, in The Physical Geography of the Sea, first published in 1855, he anticipates the significance of this major climate study project and summarizes it in a short and often-quoted paragraph:

“There is a river in the ocean. In the severest of droughts it never fails,
and in the mightiest floods it never overflows.
Its banks and its bottom are of cold water, while its current is of warm.
The Gulf of Mexico is its fountain, and its mouth is the Arctic seas.
It is the Gulf Stream.”

 

Gulf Stream water

CTD data from the Straits of Florida
1. Note that temperature (Red) decreases steadily with depth from about 26-degrees C at the surface,
to less than 10-degrees C at 700 meters. (Most of the ocean’s waters are cool where not warmed by sunlight).
2. Dissolved Oxygen (Green) varies considerably from a maximum at the surface, with a sharp decline at about 100 meters, and a more gradual decline to about 700 meters. (Phytoplankton in surface water produce excess oxygen through photosynthesis during daylight hours. At night and below about 100 meters, respiration predominates and organisms reduce the level of dissolved oxygen.)
3. Salinity (Blue) is related to atmospheric processes (Precipitation and Evaporation) and also varies according to depth, being saltiest at about 150 meters.

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“Ron Brown: Phone Home!”

At Midnight, just within sight of the beam of the Jupiter Inlet Lighthouse (And to the relief of the home-sick sailors on board – “Finally –  after  more than two weeks, we are within the range of cell phone towers!”) we began our studies of the Straits of Florida and the Gulf Stream. Nine stations in rapid order – standing-by for a CTD cast, and then turning into the current to set the neuston net for a ten-minute tow.

The purpose of the net is to sample creatures that live on or visit the interface between air and water, so the mouth of the net is only half submerged. Neuston comes from the Greek for swimming and in warm waters a variety of invertebrates and even some young mesopelagic fishes rise within a few centimeters of the surface at night to filter phytoplankton and bacteria, and feed upon other zooplankton and even drowned terrestrial insects that have been blown out to sea.

On the upper side of this water/atmosphere interface, a smaller variety of floating invertebrates, notably Physalia  and Velella (Portuguese man-of-war and By-the-wind-sailor) use gas-filled buoyancy chambers or surface tension to ride the winds and currents. This much smaller group of seafarers is further classified by oceanographers as Pleuston.

Prior to this cruise, my experience with such a sampling device was limited – Years ago, spending miserable nights sailing in choppy seas off of Sandy Hook, NJ searching  for fishes eggs and larva rising to the surface after dark; and later, much more enjoyable times studying water striders – peculiar insects that spend their lives utilizing surface tension to skate along the surface of Cape Cod ponds.

Our CTD and net casts are complicated by rising winds and chop, but some great samples were retrieved. Once the net is recovered, we rinse it down with the seawater hose, collect everything from the bottle at the cod end, rinse off and separate the great mass of weed (Sargassum) and pickle the neuston in bottles of alcohol for analysis back at the lab.

Midnight shift: Recovering the net by moonlight.

Midnight shift: Recovering the net by moonlight.

Midnight shift: Recovering the net by moonlight.

Midnight shift: Recovering the net by moonlight.

Since much of the zooplankton community rises closer to the surface at night where phytoplankton is more concentrated and the chances of being preyed upon are slimmer, there are some noticeable differences in the samples taken then and during daylight hours. Unavoidably, both samples contain great quantities of Sargassum but the weed-colored carapaces of the different crustaceans are a clue to which specimens are from the Sargassum community and which are not.

Gulfweed Shrimp - Latreutes

Gulfweed Shrimp – Latreutes

We hit the jackpot early; snaring a variety of invertebrates and fishes, including the extraordinarily well-camouflaged Sargassum fish – a piscatorial phenomenon I’ve hoped to see ever since I was a kid reading William Beebe’s classic The Arcturus Adventure. What a tenuous existence for such a vulnerable and weak swimmer, hugging the Sargassum as it is dashed about in the waves. Even with its weed-like disguise and ability to blend in with the plants, it must lead a challenging life.

A unique member of the otherwise bottom-dwelling frogfishes, the Histrio histrio has smooth skin, and spends its life hitch-hiking along in the gulf-weed forest. Like other members of the family Antennariidae, it is an ambush predator, luring other creatures to their doom by angling with its fleshy fins.

The Sargassum fish (Histrio)

The Sargassum fish (Histrio)

Needlefish and Sargassum fish

Needlefish and Sargassum fish

Another highlight for me is the water striders we found in several samples. These “true bugs” (Hemiptera) are remarkable for several reasons. Most varieties of these “pond-skaters” (Or Jesus Bugs if you are from Texas) are found on calm freshwater lakes and streams, but a few members of this family (Gerridae) are the only true marine insects – representing a tentative Arthropod reinvasion of the sea after their splendid foray onto land hundreds of millions of years ago.

Two great finds: Sygnathus pelagicus– A Sargassum pipefish – a cousin of the sea horse. Halobates – the water strider. An example of the Pleuston community.

Two great finds:
Sygnathus pelagicus– A Sargassum pipefish – a cousin of the sea horse.
Halobates – the water strider. An example of the Pleuston community.

Using surface tension to their advantage, they “skate” along by flicking their middle and hind legs, and can even “communicate” with each other by vibrating the surface of the water with the hair-like setae on their feet. On lakes their prey is other insects like mosquito larvae, confined to the surface. How they manage to find food and communicate at the surface of the raging sea is a mystery, but whatever the means, they are adept at it, and we recovered them in half of the samples.

The ocean's insect: The  remarkable water stride

The ocean’s insect: The remarkable water stride

The scientists who provided the net are generally more interested in ichthyoplankton to monitor fish eggs and larvae to predict population trends, and monitor impacts like oil spills; so this is why samples are preserved to return to the lab in Miami.

Before packing up things after our marathon sampling spree I was able to examine our catch and observed a few things:
1. I am the “High-Hook” on the cruise – catching far more fishes (albeit tiny ones) than the rest of the crew with their fishing poles. (Needlefish, sargassum fish, pipe fish, filefish and several larval species)
2. Depending on the time of day the samples were taken, there is a marked difference in the quantity and composition of organisms that have separated from the Sargassum and settled in the sample jars – (Noticeably more at night than during daylight hours).
3. There appears to be a greater variety of sea grasses present (Turtle grass, etc.) on the eastern (Bahamas side) of the Straits. We observed one seabean – drift seeds and fruits (or disseminules) from terrestrial plants.
4. Plastic bits are present in all samples – particularly plastic ties (Table 1.)

Settled organisms in sample jars.

Settled organisms in sample jars.

Sargassum fauna: Portunid crab – with eggs on her belly.
(Portunus was a Roman god – Protector of harbors and gates,
who supposedly also invented navigation)

Belly view of a Caridean shrimp

Belly view of a Caridean shrimp

A tiny fish egg ready to hatch!

A tiny fish egg ready to hatch!

A larval fish begins its perilous journey in the Gulf Stream.

A larval fish begins its perilous journey in the Gulf Stream.

Site/Local time

Notable Contents*

Biomass Site Depth
8 Day 17:48 Weed, Grasses(3 spp) 3.0 mm 79˚12’ 485 m
7 Day 16:10 Grasses(4 spp) 2.0 mm 79˚17’ 616 m
6 Day 14:30 Grasses(2 spp) Fish eggs and larva Trace 79˚22’ 708 m
5 Day 12:45 Water striders, Grass (1 spp) Trace 79˚30’ 759 m
4 Day 10:13 Crustacean larva, shrimp (large), 7.0 mm 79˚36’ 646 m
3 Dawn 07:53 Crustacean larva, shrimp (large), water striders Trace 79˚41’ 543 m
2 Night 05:10 Crustacean larva, shrimp (small), Pipefish, water striders 7.0 mm 79˚46’ 388 m
1 Night 02:48 Crustacean larva, shrimp, needlefish, Sargassum fish, Herring(?), Portunid crabs, shrimp (large), Copepods 13 mm 79˚51’ 264 m
0 Night 00:37 Crustacean larva, shrimp, Copepods 25 mm 79˚56’ 148 m

*Plastic bits and Sargassum weed and its endemic epibionts are present in all samples.

Table 1.   Contents in sample jars.

There is a marked difference in the quantity and composition of organisms collected at night (Left).

There is a marked difference in the quantity and composition of organisms collected at night (Left).

There is a marked difference in the quantity and composition of organisms collected at night (Left) and during the day (Right).

There is a marked difference in the quantity and composition of organisms collected during the day (Right).

With sampling completed we steer north to ride the Gulf Stream towards the Brown’s home-port,  and turn away from the bright lights of Florida …

“Where the spent lights quiver and gleam;
Where the salt weed sways in the stream;
Where the sea-beasts rang’d all around
Feed in the ooze of their pasture ground:”

Matthew Arnold

"Red sky at morning...sailor take warning!"

“Red sky at morning…sailor take warning!”

Homeward bound:

A storm battering the Midwest will impede our progress back north to Charleston and threatens to bring us the only foul weather of the cruise. Note the location of the cold front over the Florida Straits.

“Now the great winds shoreward blow;
Now the salt tides seaward flow;
Now the wild white horses play,
Champ and chafe and toss the spray.”
Matthew Arnold

As the sailors say: "The sheep are grazing." A gale is brewing and kicking up whitecaps as we sail north to Charleston.

As the sailors say: “The sheep are grazing.”
A gale is brewing and kicking up whitecaps as we sail north to Charleston.