Karah Nazor: Sorting Protocol and the Ubiquitous Tunicates of the Central CA Coast: Salps and Pyrosomes, May 30, 2019

NOAA Teacher at Sea

Karah Nazor

Aboard NOAA Ship Reuben Lasker

May 29 – June 7, 2019


Mission: Rockfish Recruitment & Ecosystem Assessment

Geographic Area: Central California Coast

Date: May 30, 2019

Last night I fell asleep, twice, at the lab bench in between trawls, since I am still adjusting to being on the night shift.  We worked from 9:00 P.M. to 6:30 A.M. After the shift I had a nice hot shower and slept a solid 9 hours from 7:00 AM to 4:00 PM.  Hopefully, I will be less drowsy tonight!

Upon waking, I went to the galley and grabbed some Raisin Bran and coffee and took it up to the flying bridge to hang out with Ornithologist Brian Hoover.  Our current location is in the middle of the Channel Islands, an area I know something about because my friend Evan Morrison, mentioned in my first blog, helps with the Channel Islands Swimming Association, and I would like to swim between these islands one day.  Lauren Valentino, Flora Cordoleani, Ily Iglesias and I congregated on the flying bridge and decided we should exercise. We joined Flora in her squat challenge (80 squats on this particular day), followed by 5 minutes of planking and a bit of erging.  Half of female members of the fish sorting team are avid rock climbers. They did lots of pull-ups using the rock ring climbing training holds that are installed there.

It felt nice and warm when the ship stopped for deployment of the Conductivity, Temperature and Depth (CTD) Rosette, and it got chilly again as the wind picked up when the ship started moving again. We saw a few whale spouts in the distance and at 5:30 P.M. we went down to the galley for a delicious meal of steak and mashed potatoes.  I am beginning to really appreciate how nice this whole experience has been in terms of amenities. The NOAA Reuben Lasker first set launch in 2014 and is a state of the art fisheries vessel with a sophisticated acoustics lab, fish lab, dynamic positioning system, CTD, etc., but is ALSO equipped with creature comforts including a movie lounge, an ice cream cooler loaded with ice cream sandwiches, snickers, fruit pops, you name it, and my personal favorite – a coffee bar where all coffee is freshly ground, an espresso machine, and all varieties of milk and creamers, including Reese’s cup whipped cream. The mattress in my stateroom bunk is quite comfortable and the shower gets hot within seconds! I doubt it can get much better than this for a research experience at sea?

Game Plan and Trawling Line: Point Sal line with five 15 minute hauls.

I am familiar with the sorting protocol now. The catch is dropped from the net into the bucket by members of the deck crew and survey tech, with the oversight of Keith Sakuma, Chief Scientist and NOAA Operations Officer Keith Hanson.  The bucket is immediately placed in the fish lab and this is when the fish sorting team starts our work.

Cobb Trawl net
Dropping the catch from the Cobb Trawl net into the bucket.
fish on a sorting tray
A volume of fish just placed on a sorting tray. This catch has a lot of anchovies, krill, and California smoothtongues.
Separating the krill
Separating the krill from the myctophids, Northern anchovies, and California smoothtongues.
Sorting fish group photo
Team Red Hats sorting fish. NOAA’s Keith Hanson in the rear left side.


SORTING AND COUNTING METHOD

We start by carefully picking through a 2000 mL or 5000 mL volume of the harvest, depending on Keith Sakuma’s initial assessment of the species density and volume in the bucket.  The first volume of catch to be sorted is evenly dispersed onto four white sorting trays arrayed on the main lab bench. Once you have a pile of the catch on your tray, you start to separate them into piles of different types of organisms, such as Northern anchovies, ctenophores, krill, salps, pyrosomes, Californian smoothtongues, squid, rockfish, myctophids, and young of year (YOY) fish.  I prefer to use my hands for sorting while others use forceps. Once sorted, we count the number of individuals for each species. If we have difficulty identifying an animal that we have not yet seen, we ask Keith Sakuma or a more experienced team member to help with identification. YOY fish, some in larval form, are particularly difficult for me.

Once sorted and counted, we verbally call out the common name and number of organisms to Keith Sakuma who manually records the data in a 3-ring binder for the lab hard-copy.   For smaller organisms, such as krill or salps, or in hauls with a high number of any particular species, it would be quite tedious to pick out and count each individual in the total haul.  This is why we start with a small subsample volume or 0.5, 2 or 5L, count the individuals in that small volume, establish the ratio for the number of individuals in that volume, and then extrapolate and calculate by the total volume of the haul.  For example, if we counted 97 pyrosomes in the initial 5L sort, and we collected a total of 1000L, then we can say that there are 19,400 pyrosomes in the haul.

Chief Scientist Keith Sakuma
Chief Scientist Keith Sakuma recording the data from a haul during sorting.

Once 20 individuals of each species have been called out, we no longer have to count that species since the ratio for this catch has already been established and to expedite sorting the rest of the volume.  Following sorting, the length of the twenty representatives of each species is measured using electronic calipers and the values populate on an Excel spreadsheet. After measuring, specimens requested by various research institutes including Scripps Institution of Oceanography, Moss Landing, and Monterey Bay Aquarium Research Institute (MBARI) are collected, labelled and frozen.

Flora Cordoleani
Flora Cordoleani keeping track of which specimens are to be preserved for various research groups.
Keith Sakuma bagging specimens to send to collaborators.

Creature(s) feature: Salps and Pyrosomes. 

Salps What are these strange gelatinous organisms in our catch that look like little puddles of clear jelly with a red, green, yellow, and brown digestive organ in the center?  They are goopy, small and slippery making them difficult to pick up by hand. They float on the sea surface and are ubiquitous in our hauls BUT NOBODY KNOWS ABOUT THEM.

These creatures are called salps and belong to the subphylum Tunicata. Tunicates have a notochord in their early stage of life which makes them members of the phylum Chordata, to which humans also belong. Having a transparent body is a way escape being preyed upon.

A group of salps. This species is dime to quarter sized and this number of salps occupies a volume of ~10-15 ml once placed in a beaker.
Salp digestive organs.

Salps are planktonic tunicates  That can be found as individual salps or in long chains called blastozooids.   The salps shown in the photo below were individuals and were notable in most of our hauls. Individual salps in this pile are dime to quarter sized and occupy a volume of ~10-15 ml. We measured the volume of salps in every haul.

While on the topic of salps, I will tell you about a cool 1 inch long salp parasite I found on my sorting tray (see image below). Keith Sakuma explained that it was a deep sea amphipod called Phronima which is a parasitoid that takes up residence inside of a salp’s body, eats the salp’s organs, and then lays its eggs inside of the salp. The King-of-the-salmon, Trachipterus altivelis, (which we are also catching) uses its protrusible jaw to get inside of the salp just to eat this amphipod!

Phronima amphipod
Phronima amphipod – lives and reproduced in salp after eating the salp’s organs. King-of-the-salmon fish use their protrusible jaws to eat the amphipod.
King-of-the-salmon
King-of-the-salmon, Trachipterus altivelis
King-of-the-salmon jaw protruded
King-of-the-salmon, Trachipterus altivelis, who preys upon phronima living inside of salp, with jaw protruded.
A large haul full of salps.

Another type of salp we keep catching is Thetys vagina, a large solitary species of nektonic salp that feeds on plankton, such as diatoms, and is an important carbon sink in the ocean. Thetys has an external surface, or test, that is covered with bumps and ridges, as seen in the photo below.

Thetys vagina, the twin-sailed salp.
Thetys vagina, the twin-sailed salp.
internal filtering organ
The internal filtering organ of Thetys vagina.
Kristin Saksa examining a larger Thetys
Kristin Saksa examining a larger Thetys vagina, or the twin-sailed salp. The dark colored tentacles are downward facing. This is the siphon where water enters the sac-filled body.

Pyrosomes Pyrosoma atlanticum are another type of planktonic tunicate which are very numerous in most of our hauls. Pyrosomes look like bumpy pink hollow tubes with openings on both ends. They are rigid in structure and easy to pick up by hand, whereas salps are goopy and difficult to pick up by hand.  We have collected some pyrosomes that are 13 inches long, while most are in the 4-6 inch range. The small pyrosomes look like clear Tic Tacs, but they do not taste as such.

Pyrosoma atlanticum
Pyrosoma atlanticum, with an ~6 inch specimen on the left and small pyrosomes on the right.

How can pyrosomes be so ubiquitous just 20 miles or so off of the Central California Coast, but I have never seen one that has floated up on the beach or while swimming?

Pyrosoma atlanticum are also planktonic tunicates, but are colonial organisms made up of many zooids held together by a gelatinous structure called the tunic. One end of the tube is wide open and filters the water for zooplankton and phytoplankton, while the other end is tighter and resembles a diaphragm or sphincter. The pyrosomes we harvested appeared in diverse array of pinks and purples.  Pyrosomes are believed to harbor intracellular bioluminescent bacteria. Pyrosomes are drifting organisms that swim by beating cilia lining the branchial basket to propel the animals through the water and create a current for filter feeding. 

Pyrosome rainbow
Pyrosoma atlanticum assorted by color.
Kristin Saksa
Moss Landing Graduate Student Kristin Saksa excited about the large haul of Pyrosoma atlanticum.
high-five
Pyrosoma atlanticum high-five.

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.)

Scott Dickison, September 30-October 11, 2006

NOAA Teacher at Sea
Scott Dickinson
Onboard Research Vessel Shearwater
September 30 – October 11, 2006

Mission: Quantitative Finfish Abundance
Geographical Area: Channel Islands Marine Protected Areas
Date: September 30 – October 11, 2006

Santa Barbara, seen from the ship

Santa Barbara, seen from the ship

Prologue 

The cruise that I participated on was a multi-part project that spanned several weeks. I came on board for the final, and most interesting part of the project. Those parts you can read about in my log entries, however some background and technical information may be useful to better understand the operation.

The cruise took place onboard the NOAA R/V Shearwater. The project was called a Quantitative Finfish Abundance and Exploration of the Channel Islands Marine Protected Areas. A cooperative Remotely Operated Vehicle (ROV) study with the California Department of Fish and Game, Marine Applied Research and Exploration, and the Channel Islands National Marine Sanctuary.

When I arrived, the bulk of the work had been completed and it was time for the experimental portions of the project to take place. These experiments were designed to ensure the reliability, precision, and accuracy of the quantitative data collected by ROV survey. The basic operations involved live boating the ROV along predetermined track lines. That is, the RV Shearwater would proceed along a predetermined line on the surface that the ROV was also independently operating on at the ocean floor. The ROV had a range of 50 meters from the stern of the RV Shearwater. The ROV pilot had on-screen-display (OSD) from the video cameras mounted on the ROV, as well as an OSD that displayed the ROV position relative to the mother ship. This display is generated with the use of a sonar beacon mounted on the ROV and a sonar receiver lowered over the side of the mother ship.

On to the logs…

Deploying the ROV

Deploying the ROV

Saturday 9/30

Arrive at the R/V Shearwater. Got the lay of the land.

Sunday 10/1

Head out of the Santa Barbara Harbor in transit to Santa Cruz Island to pick up the research crew. With the team of scientists on board, we head out for our destination of East Point on Santa Rosa Island for the first deployment of the ROV.

The weather turned on us, with the winds blowing and the rain pounding. The seas got rough and the going was slow. This being the first day out, the sea legs had yet to be adjusted. This was the cause for a quick retreat to the head…

Finally made it to our testing location. Weather was dismal as the ROV was launched. Today’s mission was to “paint” fish with lasers mounted along side the ROV camera.  This was a very interesting procedure designed to measure fish length. Essentially capturing a fish on video and “painting” it with two laser dots at the known distance of 11 cm. Total fish length can then be calculated either by determining fish camera fish length and laser dot space, or by using the screen width and the fish length in comparison.

This day I became umbilical tender and hydraulic operator for launching and retrieving the ROV. I also observed the underwater video and fish painting process. This was a very interesting day becoming part of the crew and assisting in the work. Due to a couple of technical issues, we returned to Santa Barbara for the night.

Watching and operating the launch

Watching and operating the launch

Monday 10/2 

While crewmembers were working on correcting the technical issues, I assisted others with setting up lines for the next set of experiments. This required setting up vinyl covered steel cables at a length of 110 meters and marking them with colored flags every 10 meters that would be easy to view through the ROV cameras. These cables were also set up with loops on each end for linking together, or for securing weights. The cables were then spooled for ease of deployment and stowed for later use.

The technical issues as well were repaired and again we set out to sea. This day’s destination was Anacapa Island. With some sonar scanning, a sight was selected for the next sets of experiments, to determine accuracy of transect distance precision across the spatial dimension.

For this experiment, the 110 meter cables were laid across the bottom with high relief profiles.  This distance of cable would provide a length of 100 meters to run with the ROV. Divers also swam the line and took depth readings along the cable. The cable ran up and down over rocks and various substrates that are considered fish habitat. The concept being that there were more lineal feet of fish habitat in this relief than straight line distance.  The ROV recorded this distance, but this was a means to determine if those recordings were an accurate measurement.

The sight we were working was spectacular. We were on the southern tip of Anacapa Island. The shoreline of the island was shear rocky cliffs. The cliffs are a major nesting and roosting sight for the endangered California Brown Pelicans, they were everywhere both on the cliffs and circling in the sky. The area was also populated with sea lions. They were very amusing swimming around the boat and with their barks echoing off the cliffs of the island.  After the work here was done, we headed north for a protected cove to drop anchor for the night.

Brown pelican nesting area on the high cliffs

Brown pelican nesting area on the high cliffs

Tuesday 10/3

This day we headed back toward Anacapa to continue the track line experiments. Another shallow depth sight was selected toward the North end of the island. The same procedures were used here laying out the cable lengths that were then checked by divers and then run with the ROV.

The water was thick with small baitfish that was being fed on by schools of Bonita. This was a sight to see, and was particularly amusing to see the pelicans dive-bombing into the water also feeding on the baitfish.  This went on for most of the day.  Operations went well today and when complete the gear was collected and stowed. We headed off to another protected cove for the nights anchorage.

Wednesday 10/4 

We continued the track line experiments today. Work was going well so we started preparations for the next upcoming experiment. The preparations consisted of setting up fish models of various sizes and securing weights to then to enable deployment of them floating various heights off the bottom.  The fish models were constructed of a flat piece of neoprene with color copied pictures of the local significant fish species laminated and attached to the sides.

The sight of the day was a pod of dolphins leaping out of the water and splashing around in some sort of frenzy. We assumed the must have been feeding, but were not really close enough to tell exactly what was going on. Today’s tasks went well and I went out on the Avon to retrieve the cables and the divers. With all back onboard, we headed off to the nights anchorage.

On the zodiak

On the zodiac

Thursday 10/5 

Today we set out for a deep water site to continue the track line experiment. The previous sites had been in the 10 to 20 meter depth zones. Today we would run the track line experiment in a 50 meter depth zone.  This posed a different set of circumstances.  The tracking cable was spooled into a basket for deployment. It was then deployed skillfully and precisely by the well experienced deck officer. With the cable in place, the ROV was launched to run the line. This depth was to deep to send divers down, so the ROV did all the work.  Tracking went well and the ROV was brought back on board.

Recovery of the gear was a bit more difficult.  We had to haul back the cable and weights with a power winch as opposed to winding it back by hand in shallow water. After we got about half of the length back, it got jammed and snapped so fast my head spun. At least the experiment was completed.

After gathering and comparing the ROV data with the diver collected data it was apparent that the ROV collected nearly identical data to the diver collected data. This experiment seemed to be a success. ROV use and procedures seemed to be a reliable means to determine transect distance across the spatial dimension by my observations. Naturally the collected data would be reviewed later by the scientists on board to accurately determine the results.

Full moon rising

Full moon rising

During the day we continued to prepare the fish models for deployment tonight. With the track line experiments complete, we headed for a location suitable for the fish model experiment. This experiment was conducted in the evening to simulate the light conditions in the typical habitat depth of 50 meters.  The point of the experiment was to determine the accuracy of fish length as determined by ROV survey. The ROV survey used both paired lasers and distance sonar to determine fish length. When these procedures are utilized on fish models of known length, the scientists could determine if the process could be accurate when video capturing wild fish in the test zone.

As we arrived at the experiment location, the sun was setting and a most beautiful full moon was rising over a distant horizon. Divers were used to strategically deploy the models to simulate populations of wild fish.  The ROV was deployed and ran the line of fish models while video capturing the images. Tonight I had an opportunity to pilot the ROV. I thoroughly enjoyed this opportunity and spent some time observing some flat fish scurrying about the bottom as I waited for the divers to collect the fish models. Soon all was complete, the divers came back on board, and we recovered the ROV safely.  We remained at this location for the night, it was quite beautiful.

Friday 10/6…the final day.  

Today was a public relations day. We returned to Anacapa and met up with the California Dept. of Fish and Game boat, the R/V Garibaldi. They had brought some local writers and reporters out to cover the project. We still went on with the normal operations of surveying fish populations. It was another great day on board the NOAA  R/V Shearwater as a participant in the Teacher at Sea Program! Back to Santa Barbara we cruised.

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