Jeff Peterson: The Work in the Eastern Gulf, July 19, 2018

NOAA Teacher at Sea

Jeff Peterson

Aboard NOAA Ship Oregon II

July 9 – 20, 2018

 

Mission: Summer Groundfish Survey

Geographic Area of Cruise: Gulf of Mexico

Date: July 19, 2018

 

Weather Data from the Bridge

Date: 2018/07/19

Time: 16:34:47

Latitude: 29 57.6 N

Longitude: 087 02.60 W

Speed over ground: 7.3 knots

Barometric pressure: 1014.49

Relative humidity: 84%

Air temperature: 26.8 C

Sea wave height: 1 m

 

Science and Technology Log

We arrived off the coast of Florida on the evening of Sunday, July 15, and sampled stations in the eastern Gulf until the afternoon of Thursday, July 19. We used the same fishing method during this part of the cruise (bottom trawling), but added a step in the process, deploying side scan sonar in advance of every trawl. This measure was taken both to protect sea life on the ocean floor (sponges and corals) and to avoid damaging equipment. The sea bottom in this part of the Gulf—east of the DeSoto Canyon—is harder (less muddy) and, in addition to coral and sponge, supports a number of species markedly different than those seen in the western Gulf.

 

Side Scan Sonar

In contrast to single-beam sonar, which bounces a single focused beam of sound off the bottom to measure depth, side scan sonar casts a broader, fan-like signal, creating nuanced readings of the contour of the ocean floor and yielding photo-like images.

Towed Side Scan

How side scan sonar works: The harder the object, the stronger the image returned. See: https://oceanservice.noaa.gov/education/seafloor-mapping/how_sidescansonar.html#

 

Side scan sonar device

Side scan sonar device in its cradle.

 

 

Rigged and ready for deployment.

Rigged and ready for deployment. Signals from the sonar are conducted up the cable and picked up by the electrically powered lead on the block.

 

on its way in

Side scan sonar on its way in astern.

 

descending

Side scan sonar just beneath the surface & descending.

 

When we arrive a station in this part of the Gulf, we begin by traversing, covering the usual distance (1.5 miles), but then turn around, deploy the side scan sonar, and retrace our course. Once we’ve returned to our starting point, we recover the sonar, turn around again, and—provided the path on the sea bottom looks clear—resume our course through the station, this time lowering the trawl. If the side scan reveals obstructions, it’s a no-go and the station is “ditched.”

 

Coming about

Coming about before deploying the side scan sonar.

 

 

And Now for Something Completely Different . . . Fish of the Eastern Gulf

Panama City, Florida

Off Panama City, Florida – Tuesday morning, July 17, 2018

We spent the first half of this leg of the survey in the western Gulf of Mexico, going as far west as the Texas-Louisiana border. The second half we’re spending in the eastern Gulf, going as far east as Panama City. From here we’ll work our way westward, back to our homeport in Pascagoula.

Thanks to different submarine terrain in the northeastern Gulf—not to mention the upwelling of nutrients from the DeSoto Canyon—it’s a different marine biological world off the coast of Florida.

Here’s a closer look at the submarine canyon that, roughly speaking, forms a dividing line between characteristic species of the western Gulf and those of the eastern Gulf:

Bathymetric map of the Gulf of Mexico

Bathymetric map of the Gulf of Mexico, with proposed dive sites for Operation Deep-Scope 2005 indicated by red arrows and yellow numbers. Site #1 is on the southwest Florida Shelf in the Gulf of Mexico, where deep-water Lophilia coral lithoherms are found. #2 is DeSoto Canyon, a deep erosional valley where upwelling of deep nutrient rich water means greater animal abundances. #3 is Viosca Knoll, the shallowest site, where spectacular stands of Lophelia provide abundant habitat for other species. See: https://oceanexplorer.noaa.gov/explorations/05deepscope/background/geology/media/map.html

 

And here’s a selection of the weird and wonderful creatures we sampled in the eastern Gulf. As this basket suggests, they’re a more brightly colored, vibrant bunch:

Basket of catch

A basket of fish. Upper right: Lane Snapper, Lutjanus synagris. On the left: Sand Perch, Diplectrum formosum. The plentiful scallops? Argopecten gibbus.

 

 

Sand Perch, Diplectrum formosum

Sand Perch, Diplectrum formosum

Razorfish, Xyrichtys novacula

Razorfish, Xyrichtys novacula

A basket of Xyrichtys novacula

A basket of Xyrichtys novacula

 

Angelfish, Holacanthus bermudensis

Angelfish, Holacanthus bermudensis

Angelfish closeup

Holacanthus bermudensis details: tail fins (front specimen), pectoral fin & gill (behind)

 

Jackknife Fish, Equetus lanceolatus

Jackknife Fish, Equetus lanceolatus

Lined Seahorse, Hippocampus erectus

Lined Seahorse, Hippocampus erectus

 

 

Argopecten gibbus

Argopecten gibbus (all 2,827 of them)

Pink Shrimp, Farfantepenaeus duorarum.

Pink Shrimp, Farfantepenaeus duorarum. Note the signature “pink” spot by my thumb.

 

Calamus

Calamus

 

Lionfish, Pterois volitans

Invasive scourge of the Gulf: Lionfish, Pterois volitans

Lionfish, Pterois volitans

Lionfish, Pterois volitans

 

Burrfish, Chilomycterus schoepfii

Burrfish, Chilomycterus schoepfii

 

 

Scorpionfish (aka Barbfish), Scorpaena brasiliensis

Scorpionfish (aka Barbfish), Scorpaena brasiliensis

 

Southern Stargazer, Astroscopus y-graecum (juvenile)

Southern Stargazer, Astroscopus y-graecum (juvenile)

 

Ocellated Moray Eels, Gymnothorax saxicola

Ocellated Moray Eels, Gymnothorax saxicola

 

Trumpetfish, Aulostomus maculatus

Trumpetfish, Aulostomus maculatus

 

 

Video credit: Will Tilley

 

debris

Mysterious debris: A bottom-dwelling payphone?

 

Personal Log

Our move into the eastern Gulf marks the midpoint of the cruise, and we’ll be back to Pascagoula in a few short days. The seas haven’t been as serenely flat as they were in the eastern Gulf, nor has the sky (or sea) been its stereotypically Floridian blue, but I’ve found life aboard ship just as pleasurable and stimulating.

storm

A squall on Monday morning, July 16, 2018. Off the stern there to starboard, Blackfin Tuna were jumping.

 

In my final blog post, I’ll have more to say about all the great folks I’ve met aboard NOAA Ship Oregon II—from its Deck Department members and Engineers, to its Stewards and NOAA Corps officers and inimitable Captain—but here want to reiterate just how thoughtful and generous everybody’s been. The “O2” is a class act—a community of professionals who know what they’re about and love what they do—and I couldn’t be more grateful to have visited their world for a while and shared their good company.

Busy as we’ve been, I haven’t had much time for sketching during this part of the cruise, and, as the selection of photos above suggests, I’ve concentrated more on taking pictures than making them. Still, I’ve begun a small sketch of the ship that I hope to complete before we reach Pascagoula. It’s based on a photograph that hangs in the galley, and that I’m going to attempt to reproduce actual size (3 3/8” x 7”) . Here’s where things stand early on in the process:

IMG_8230 2.jpg

Work in progress: sketch of NOAA Ship Oregon II

 

Did You Know?

Any of the western Gulf fish in the basket from my last blog post? Here it is again:

Basket of Fish from Western Gulf

Basket of Fish from Western Gulf

And here is a visual key to the four species I was fishing for, each figuring prominently in my blog post for July 15:

Basket of fish revision

Basket of Fish from Western Gulf: now color-coded

1: Red Snapper, Lutjanus campechanus

2: Longspined Porgy, Stenotomus caprinus

3: Gulf Butterfish, Peprilus burti

4: Brown Shrimp, Farfantepenaeus aztecus

A few Stenotomus caprinus and Peprilus burti have been left unhighlighted. Can you find them?

Christopher Faist: Limited Visibility, July, 21 2011

NOAA Teacher at Sea
Chris Faist
Aboard NOAA Ship Henry B. Bigelow
July 20 — August 1, 2011

Mission: Cetacean and Seabird Abundance Survey
Geographical Area: North Atlantic
Date: July 21, 2011

Weather Data
Air Temp:  21 ºC
Water Temp: 19 ºC
Wind Speed: 19 knots
Water Depth: 163 meters

Science and Technology Log
The purpose of cruise is to accurately count marine mammals and seabirds in the North Atlantic.  There are two separate groups of scientists: the marine mammal team and the seabird team.

Chris Faist using the "Big Eyes"

Chris Faist using the "Big Eyes"

Mammals
The first order of business on a trip to count marine mammals is to ensure that all observers (including myself) are familiar with the types of cetaceans (dolphins and whales) that may be seen during the survey.  Last night all of the marine mammal observers gathered in the conference room to review photographs and field guides depicting each of the species that might be seen on the trip.  Using high-resolution photographs, we reviewed length, coloration, body shape and behaviors that distinguish each dolphin and whale to the most specific level of classification, Genus and species.

To make sure that all (or as close to all as possible) animals in the study area are counted, observers will be using high power binoculars, or “Big Eyes”, to extend their ability to see and identify animals even at great distances (about 7 miles from the ship).

Observation Station

Observation Station

Two teams of four, highly experienced observers will work simultaneously during the survey time.  From two different locations on the ship, the flying bridge (top deck) and the roll tank deck (about 15 feet below the flying bridge) each team of observers will rotate stations every 30 minutes.  One observer will start on the port (left) “Big Eyes” to observe animals on that side.  The second observer will be at the computer to record what is seen and search for animals close to the boat without using binoculars.  The 3rd observer will start on the starboard (right) “Big Eyes”, while the 4th person is on break.

It is believed that this method, of two teams of 4 observers each, will allow observers to count all of the animals in the survey area.  After the cruise is over the scientists will use math equations to get estimates of animals within the North Atlantic.

Pencil Close Up

Pencil Close Up

Birds
Since the weather was windy today, the mammal team did not work but there is a team of seabird observers on-board as well.  Mike and Marie are here to count all of the seabirds that occur in the survey area.  They are able to spot seabirds in rougher conditions (higher wind speeds) allowing them to collect data during most daylight hours.  Today, Mike was showing me how to accurately judge the distance between the boat and birds.  While technology may help others Mike likes to use an old fashion “pencil method”.  If you look carefully at the picture you will see marks on the pencil.  When he holds the pencil at arm’s length and puts the top of the pencil at the horizon, each of the marks indicate a different distance.  The top mark is 300m from the ship, middle is 200m and the bottom mark indicates 100m.  This gives Mike and Marie a quick guide to accurately judge distance to record their seabird observations.

Personal Log

Due to foggy and windy conditions the marine mammal observers are waiting for better conditions to start surveying.  While this is bad for the scientists, it is great for me.  I have had some time to learn to navigate the ship, nap, get my “sea legs” and interview many of the scientists and crew.

What I am finding is a highly trained, experienced group of individuals that love the ocean.  Each person brings a unique set of talents and background forming a complete team with the same goal, accurately counting the numbers of protected species in the North Atlantic.  I am very excited to be a part of such a great team.

Mary Anne Pella-Donnelly, September 19, 2008

NOAA Teacher at Sea
Mary Anne Pella-Donnelly
Onboard NOAA Ship David Jordan Starr
September 8-22, 2008

Mission: Leatherback Use of Temperate Habitats (LUTH) Survey
Geographical Area: Pacific Ocean –San Francisco to San Diego
Date: September 19, 2008

Weather Data from the Bridge 
Latitude: 3624.8888 N Longitude: 12243.8013 W
Wind Direction: 261 (compass reading) SW
Wind Speed: 8.0 knots
Surface Temperature: 16.385

Figure indicating migration of different genetic stocks of Pacific leatherback turtles.

Figure indicating migration of different genetic stocks of Pacific leatherback turtles.

Science and Technology Log 

Turtle Genetics 
Peter Dutton is the turtle specialist on board, having studied sea turtles for 30 years.  His research has taken him all over the tropical Pacific to collect samples, study behaviors and learn more about Dermochelys coriacea, the leatherback turtle. Mitochondrial DNA (is clonal=only one copy) is only inherited maternally (from the mother), so represents mother’s genetic information (DNA), while nuclear DNA has two copies, one inherited from the mother and the other from the father .By looking at the genetic fingerprint encoded in nuclear DNA it is possible to compare hatchling “DNA fingerprints”, with their mother’s and figure out what the father’s genetic contribution was. This paternity (father’s identifying DNA) analysis has produced some intriguing results.

Peter Dutton looking for turtles with the ‘big eyes’.

Peter Dutton looking for turtles with the ‘big eyes’.

An analysis of chick embryos or hatchling DNA indicates all eggs were fertilized throughout the season from the same dad. It is thought that the female must store sperm in her reproductive system. Successively, throughout the nesting season, a female will lay several clutches, one clutch at a time.  Females come in to the beach for a brief period (leatherbacks – approx 1.5 hrs) every 9-10 days to lay eggs for the 3 or 4 month nesting season (they lay up to 12). Sometimes it is the same beach; sometimes it is a beach nearby. Research done on other sea turtles is showing some species have actually produced offspring with other species of sea turtle. One example is of a hawksbill turtle with a loggerhead turtle in Brazil. In this case, the phenotype appeared to indicate one species, while the DNA analysis indicates the animal was a hybrid, with a copy of DNA from each of the two different species. At some point geneticists may need to re-define what constitutes a “species”.

The last few eggs most of the leatherback turtles lay are infertile, yolkless eggs.  No one is certain about the function of these eggs, although several theories have been suggested. Many unknowns exist about these turtles. Scientists have not yet found a means to determine the age of individual sea turtles, so no one knows how long-lived they are. The early genetic research on leatherbacks showed some information that surprised the scientists.  It had been thought that all leatherbacks foraging off the northwestern coast of USA originated in the eastern tropical Pacific, from nesting beaches in Mexico.  Careful DNA analysis, however, found that animals at California foraging grounds are part of the western Pacific genetic stock recently identified by Dutton and colleagues. Both Peter and Scott have emphasized that there is still much to learn, and they have just begun, however, much has also been learned during the past six years, including the origin of leatherbacks that utilize California waters.

Personal Log 

Yesterday the sun came out and it was a glorious evening.  A group of us watched the sunset from the flying bridge, and then later watched the moon rise.  It was spectacular, and with the ‘big eyes’, it was possible to see many of the moon’s craters.  The stars were also magnificent!  Today has been cloudy with a layer of fog eventually drenching the boat.  This weather has made yesterdays blue skies all the sweeter.

Words of the Day 

Mitochondrial DNA: DNA found within the mitochondria – originates from the mother; Clonal: identical to the original; Clutch: a single batch of eggs, laid together; Hybrid: one gene from one species and the second gene from a second species; Species: an organism that can mate with another of its own kind and produce fertile offspring.

Animals Seen Today 

Common dolphin Delphinus delphis, Fin whale Balaenoptera physalus, Black-footed Albatross Phoebastria nigripes, Moon jellies Aurelia labiata, Sea nettle jellies Chrysaora fuscescens, and Common dolphins Delphinus delphis.

Questions of the Day 

  1. Geneticists are beginning to obtain new tools to figure out how similar animals are related to each other. What are some questions you have related to leatherback turtle genetics?
  2. Scott’s turtle map shows that leatherbacks nesting in the Western Pacific migrate across the Pacific to the coast of North America, while leatherbacks that nest in Costa Rica only migrate to waters off the South American coast.  Why might some populations stay in the same region, while others cross the Pacific Ocean?
Sunset over the port side

Sunset over the port side