David Knight: Work Out and Work Up: Part I, July 17, 2018

NOAA Teacher at Sea

David Knight

Aboard NOAA Ship Pisces

July 10-23, 2018

 

Mission: Southeast Fishery-Independent Survey

Geographic Area: Southeastern U.S. coast

Date: July 17, 2018

Weather Data from the Bridge:

Latitude: 30° 30.2 N
Longitude:
80° 15.6 W
Sea wave height:
1-2 ft
Wind speed:
15 kts
Wind direction:
187°
Visibility:
10 nm
Air temperature:
30.1 °C
Barometric pressure:
1014.7 mB
Sky:
Broken Clouds

Science and Technology Log

Warning!!! Great Science Ahead…


Part I.

Waiting to see

Waiting to see what the traps have brought up this time… (photo by David Knight)

As fish traps begin to be brought up by the deck crew, scientist wait to see what may be in the trap. I’ve actually found that I am looking over the deck in anticipation of new fish that may have been caught, or to see how many fish will need to be “worked up.” Once the fish have been removed from the trap and emptied into a large bin, they are then sorted by species into 17-gallon bins to determine the total weight of all fish.  Moving 17 gallons worth of fish up to the lab bench to the scale can be quite a “work out.” There have been a couple of hauls that have captured so many fish of a particular species that more than one bin has to be used. After the fish have been weighed, the total length of each fish is determined to get a length frequency of the entire catch.  For species like Tomtate (Haemulon aurolineatum), every fish is measured and then returned to the ocean. For some species, a pre-determined percentage are kept for a more detailed work up that may include the extraction of otoliths, removal of gonads, or a collection of stomach contents. The data collected from each fish will then be used by scientists in a number of different agencies and in different states to better understand the growth and reproduction of the particular species. All of this data is then used to create management plans for economically and ecologically important fish as well as to gain a better understanding of its life history.

Work Up

Length.

Measuring fish

Measuring the length of each, individual fish. (photo taken by Nate Bacheler)

One may assume that a very long fish is also very old, but that is not necessarily the case. The length of a fish is not a good way to determine the age of a fish because factors such as temperature and food availability may alter the growth rate. Many fish grow very rapidly early on, but then slow their growth, so it is possible that a fish that is twelve years old is the same size as a fish that is three years old. Because many fish demonstrate logistic growth rates in terms of length, it is important to use additional pieces of data to determine their age.

Otolith.

In the head of ray-finned fish, one can find small, bone-like structures called otoliths. These structures have a variety of sensory functions that include detection of sound vibrations in water, movement, and its orientation in the water. As fish age, calcium carbonate will be added to the otolith, forming ring-like structures that can be used to determine the age of a fish, much like a tree will add new tissue each season forming tree rings.  Otoliths are the best way to determine the actual age of a fish.

IMG_6677

Otoliths. [left to right: Black Sea Bass, Red Snapper, Jackknife fish] (photo by David Knight

For the fish that we were sampling, we remove the sagittal otoliths which are located beside the brain just about level with the eyes. To extract them, a cut is made on the dorsal side of the fish with a sharp knife to gain access to the skull case.  To extract otoliths from some very “hard-headed” fish, a saw is used, while others take little effort. After a few hours of otolith extraction, I feel as though I am getting the hang of it, although I am nowhere near as fast as the biologist on board! I’ve been collecting otoliths from Black Sea Bass (Centropristis striata) and Vermillion Snapper (Rhomboplites aurorubens) to bring home with me to create a lab for my class and to post on the NOAA Teacher-at-Sea website.

Extracting otolith

Looking for a perfect extraction of otolith from Vermilion Snapper. (photo taken by Nate Bacheler)

Be sure to check back for Part II. Gonads, Diet and DNA


Personal Log

The motion of the ship has not been a problem so far and I stopped taking any motion sickness pills after the first day. As I have been removing otoliths from fish, I cannot help but think about the similarities in how both fish and humans perceive their spatial environment and maintain balance. In our vestibular system, we too have otoliths that help to sense acceleration in a vertical and horizontal direction. Of course my thoughts then go to a dark place…what if someone were removing my otoliths to determine my age?

 

Did You Know?

The longest known life span in vertebrates is found in the Greenland Shark (Somniosus microcephalus). It is estimated that the Greenland shark grows less than 1 cm per year. Since sharks do not have otoliths, scientist have to analyze proteins found in the lens of their eye.  In 2016, scientist from the University of Copenhagen collected a 5 m shark that was estimated to be about 392 years old, but may be anywhere from 272 to 512 years old.

Reference: Eye lens radiocarbon reveals centuries of longevity in the Greenland shark (Somniosus microcephalus). Science  12 Aug 2016: Vol. 353, Issue 6300, pp. 702-704

Carmen Andrews: A Fishing Expedition in the Atlantic, Continued, July 13, 2012

NOAA Teacher at Sea
Carmen Andrews
Aboard R/V Savannah
July 7 – 18, 2012

Mission: SEFIS Reef Fish Survey
Location: Atlantic Ocean, off the coast of Daytona Beach, Florida
Date: July 13, 2012

Latitude:      29 ° 19.10   N
Longitude:   80
° 24.31’  W       

Weather Data:
Air Temperature: 28.3° C (82.94°F)
Wind Speed: 12 knots
Wind Direction: from Southeast
Surface Water Temperature: 27.48 °C (81.46°F)

Weather conditions: Sunny and Fair

Science and Technology Log

Catching bottom fish at the reef

As the fish trap lies at the bottom of the ocean at the reef site, fish can enter and exit freely through the opening.

Red snapper swimming near a fish trap

Red snapper swimming near a sunken fish trap

 

At the end of approximately 90 minutes, the R/V Savannah returns to the drop site and begins the process of raising the trap with whatever fish remain inside. The six traps are pulled up in the order in which they were dropped.

Scientists and crew waiting to arrive at a trap location

Scientists and crew waiting to arrive at a trap location

The crew member on watch in the wheelhouse will maneuver the boat toward the paired poly ball buoys at a speed of about 5 knots. The boat draws alongside each pair on the starboard side.

R/V Savannah approaching poly ball buoys on the starboard side

R/V Savannah approaching poly ball buoys on the starboard side

One of the scientists throws a grappling hook toward the line that links the  poly balls.

Throwing the grappling hook to secure buoys

Throwing the grappling hook to secure buoys

The line is hauled in and passed to a waiting scientists, who pull the poly balls on deck. There is substantial hazard associated with this step. Undersea currents can be very powerful near the bottom where traps are set. As scientists are pulling in the cable by hand, unexpected current force can yank the trap cable, rope and buoys out of their hands and off the deck in an instant. If personnel on deck aren’t mindful and quick to react, the speeding rope can cause serious rope burn injury.

Nate is pulling poly balls and rigging onto the deck, as Adam P. gets ready to take the line

Nate is pulling poly balls and rigging onto the deck, as Adam P. gets ready to take the line

The cable connecting the fish trap and the poly balls is pulled in and threaded through the pulley system of a pot hauler. The pot hauler is an automated lifting tool that is operated by the second crew member on watch. At this time the first crew member on watch has left the wheel house and is piloting the boat from a small cab on deck above the pot hauler, so he can monitor the action below.

Pot hauler hoisting the fish trap to the boat

Pot hauler hoisting the fish trap to the boat

The pot hauler makes a distinctive clicking sound as it draws the trap toward the surface at an angle. It can take one to five minutes to raise the trap to the deck, depending on the depth of the water.

Tight cable raising submerged fish trap

Tight cable raising submerged fish trap

As the fish trap becomes visible, shimmering rapidly changing shapes can be seen as  fishes’ bodies catch and reflect sunlight.

Fish trap breaking the surface of the water

Fish trap breaking the surface of the water

The trap clears the water and gets pulled aboard.

Grabbing the fish trap

Grabbing the fish trap and pulling it aboard

Very quickly, and with two scientists holding each side, the trap is upended onto its nose and suspended above the deck. A third scientist opens the trap door at the bottom and the fish are shaken into a plastic bin.

Orienting the fish traps to ready them for dumping into bins

Orienting a fish trap to ready it for dumping the catch into a bin

Freshly caught red snapper and black sea bass

Freshly caught red snapper and black sea bass

 

Ice pellets are shoveled onto the fish and a cover is snapped on the bin. If the catch is small, fish may be placed in a bucket or tub and cover with ice.

Fish are covered in ice before the bin cover is snapped on

Fish are covered in ice before the bin cover is snapped on

A numbered tag is removed from the trap and tied onto the bin to identify specimens from each catch. The containers holding the day’s catch are set aside for later processing.

Every so often, unexpected sea life is brought up in the traps. The catch has included sea stars, sea urchins, several kinds of tropical fish and many moray eels.

Moray eel slithering on the deck.

Moray eel slithering on the deck. A moray’s bite can be very severe.

Video cameras are also removed from the top of the trap. Their data cards will be downloaded. Fish behavior and surrounding habitat videos will be analyzed, along with anatomical specimens and size data taken from the fish themselves in the wet lab.

Personal Log

Every day brings more wildlife encounters and sightings. I am dazzled by the many fascinating organisms I’ve been able to see up close. Sometimes I am quick enough to grab my camera and put the animal into my view finder, focusing clearly enough to catch a great image. Here are a few of those images (including some new friends from the cruise):

Adam P. holding a barracuda

Adam P. holding a barracuda

Daniel with a wahoo

Daniel with a wahoo

Trolling with a hooked dolphinfish

Trolling with a hooked dolphinfish

Sea stars

Sea stars

A sheerwater -- bird found in open water

A sheerwater — bird found in open water

Sheerwaters dive beneathe the surface to catch fish.

Sheerwaters dive beneath the surface of the water to catch fish. This bird is consuming a fish with its wings open to balance itself on the water.

Other times I have to capture a memory. Last night I tried reef fishing. I have no experience fishing. At all. Adam P. handed me his own rod and reel. The hook was baited and the line was already lowered to the bottom, down at around 40 meters (more than 120 feet).

Shortly after I took it, the tip of the rod began to bend downward and pull. I asked Adam if that meant something had been hooked.  He said, “Go ahead. Reel it in.” That’s when I discovered that even recreational fishing is tough work – particularly this unfamiliar technique of holding the rod with the right hand and reeling in with the left. Neophyte to fishing is me.

When the fish got to the surface, Adam took the big, beautiful black sea bass off the hook for me. On the deck it splayed out the spines of its dorsal, caudal and pectoral fins defensively. I was concerned because the fish’s air bladder was hanging out of its mouth from its rapid ascent to the surface. Adam punctured the air bladder to deflate it. He threw the fish back into the sea at my request, and assured me that the fish will go on with its life.  I’m optimistic it will.

Carmen Andrews: News from Somewhere in the Atlantic Ocean off the Coast of Georgia, July 9, 2012

NOAA Teacher at Sea
Carmen Andrews
Aboard R/V Savannah
July 7 – July 18, 2012

Mission: SEFIS Reef Fish Survey
Geographical Location: Atlantic Ocean, off the coasts of Georgia and Florida
Date: July 9, 2012

Location Data:
Latitude: 30 ° 54.55’   N
Longitude: 80 ° 37.36’  W       

Weather Data:
Air Temperature: 28.5°C (approx. 84°F)
Wind Speed: 6 knots
Wind Direction: from SW
Surface Water Temperature: 28.16 °C (approx. 83°F)
Weather conditions: Sunny and fair

Science and Technology Log

Purpose of the research cruise and background information

The Research Vessel, or R/V Savannah is currently sampling several species of fish that live in the bottom or benthic habitats off the coasts of Georgia and Florida.

Reef fish study area

The coastal zone of Georgia and Florida and the Atlantic Ocean area where the R/V Savannah is currently surveying reef fish

These important reef habitats are a series of rocky areas that are referred to as hard bottom or “live” bottom areas by marine scientists. The reef area includes ledges or cliff-like formations that occur near the continental shelf of the southeast coast. They are called ‘reefs’ because of their topography – not because they are formed by large coral colonies, as in warmer waters. These zones can be envisioned as strings of rocky undersea islands that lie between softer areas of silt and sand. They are highly productive areas that are rich in marine organism diversity. Several species of snapper, grouper, sea bass, porgy, as well as moray eels, and other fish inhabit this hard benthic habitat.

Reef fish

Hard bottom of reef habitat, showing benthic fish — black sea bass is on left and gray trigger fish is on right side of image.

It is also home to many invertebrate species of coral, bryozoans, echinoderms, arthropods and mollusks.

Bottom organisms pulled up with fish traps

Bottom-dwelling organisms, pulled up with fish traps deployed in the reef zone.

The rock material, or substrate of the sea bottom, is thought to be limestone — similar to that found in most of Florida. There are places where ancient rivers once flowed to a more distant ocean shoreline than now. Scientists think that these are remnants of old coastlines that are now submerged beneath the Atlantic Ocean. Researchers still have much to discover about this little known ocean region that lies so close to where so many people live and work.

The biological research of this voyage focuses primarily on two kinds of popular fish – snappers and groupers. These are generic terms for a number of species that are sought by commercial and sports fishing interests. The two varieties of fish are so popular with consumers who purchase them in supermarkets, fish markets and restaurants, that their populations may be in decline.

Red snapper close up

Red snapper in its reef habitat

At this time, all red snapper fishing is banned in the southeast Atlantic fishery because the fish populations, also known as stocks, are so low.

How the fish are collected for study

The fish are caught in wire chevron traps. Six baited traps are dropped, one by one from the stern of the R/V Savannah. The traps are laid in water depths ranging from 40 to 250 feet in designated reef areas. Each trap is equipped with a high definition underwater video camera to monitor and record the comings and goings of fish around and within the traps, as well as a second camera that records the adjacent habitat.

Chevron fish trap

Fish swimming in and out of a chevron fish trap

I will provide the details of the fish trapping and data capture methods in a future blog.

Who is doing the research?

When not at sea, the R/V Savannah is docked at the Skidaway Institute of Oceanography (SKIO)on Skidaway Island, south of Savannah, Georgia. The institute is part of the University of Georgia. The SKIO complex is also the headquarters of the Gray’s Reef National Marine Sanctuary. The facility there has a small aquarium and the regional NOAA office.

The fisheries research being done on this cruise is a cooperative effort between federal and state agencies. The reef fish survey is one of several that are done annually as part of SEFIS, the Southeast Fisheries Independent Survey. The people who work to conduct this survey are located in Beaufort, North Carolina. SEFIS is part of NOAA.

The other members of the research team are from MARMAP, the Marine Research Monitoring Assessment and Prediction agency, which is part of the South Carolina Department of Natural Resources . This team is from Charleston, South Carolina.

Carmen, suited up to retrieve fish from traps

Mrs. Andrews, on deck near the stern of the R/V Savannah, getting ready to unload fish traps

NOAA also allows “civilians” like me — one of the Teachers at Sea– as well as university undergraduate and graduate students to actively participate in this research.

Walter Charuba: Trap Deployment, July 21st, 2011

NOAA Teacher at Sea
Walter Charuba
Aboard R/V Savannah
July 18 — 29, 2011

Mission: Reef Fish Survey
Geographical Area: Southeast Atlantic Ocean
Date: July 21, 2011

Science and Technology Log

Dear Blog Aficionados,

Cumulonimbus clouds on the horizon

Cumulonimbus clouds on the horizon

Today I saw two different types of sea turtles, a bunch of jelly fishes, dolphins, and the people on the boat. It has been a beautiful day and I am trying to rest up because it is going to be a long day and night of setting up traps and categorizing fish. The weather here is hot and somewhat clear. I believe there is a high pressure system over us at this time. However, when you look over the coast of Florida there are these extremely large rain clouds, which are cumulonimbus clouds, rising into the sky.  The sky is clear all around the boat and suddenly there is this large mass of clouds. Last night was very memorable when a lightning storm intermittently made this region glow. I stood at the bow, stern, port side, or starboard side in wonder of this spectacle. (Hopefully I will learn locations by the end of the trip.)

The last time I wrote about myself I was a bit nauseated, which does not do much for the self-esteem. My name is Walter Charuba and I have been teaching for a number of years. (This is code for not wanting to give you a specific number.) I am lucky to work for Grosse Pointe Schools at a great school called Brownell Middle School. I am also lucky to live in Grosse Pointe Farms and I actually live about a half a block from my school. This makes my carbon footprint sort of a toe print.

I have won numerous teaching awards such as Best Dressed Teacher, Youngest Looking Teacher (I hand out treats for this one.) and Teacher Who Lives Closest to School. After filling out the forms and passing the physical, and these examples from my wonderful resume, I was lucky enough to be chosen for the NOAA Teacher at Sea Program. Seriously, I do feel very fortunate to be part of this program and learning from these scientists.

You now may be wondering what exactly am I doing on this wonderful boat called the Savannah?  (If you are not wondering about it, could you change your focus, because this concerns my next paragraph!)  I am assisting in a very large fisheries survey by setting up fish traps, deploying of fish traps, and collecting data about the fish. When laid flat, the fish traps are six by five feet across and two feet deep. In these traps we place 24 menhaden bait fish, which are a close relative to the herring, if that means anything to you.

Then 5 to 6 traps are dropped off the back of the boat with special cameras to record activity around the trap. These cameras take about ninety minutes of footage. The traps also have two buoys connected to them to assist in collection. The areas where the traps are dropped are designated by the Chief Scientist, Warren Mitchell. Using sonar, Warren has to consider depth, currents, distance, topography, and a time schedule. Not an easy decision.

Setting the fish traps with bait

Setting the fish traps with bait

Science Watch Chiefs, Sarah Goldman and David Berrane, have to make certain the drop offs go smoothly. They have to make certain there are enough bait in the traps, and if all materials are ready for a perfect drop. Trap and data collection are another major responsibility of the chief scientists, and this will be the topic of the next blog.

Thanks for reading,

Walt (Mr. Charuba to my students.)

We caught a shark

We caught a shark