Dredging in the Gulf of Mexico

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Dredging in the Gulf of Mexico
Aboard the 116 Research Vessel Pelican
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Some details about the Gulf of Mexico dredging
trip.

• Bill Cargile leased the vessel for 6 days to find
  live cones to photograph and use for scientific
  purposes.
• I was an invited guest and my job was to find
  cones for Bill, as was JSC member Billy Aley.
  Other guests were Dr. Emilio Garcia, Tina Petway,
  Dr. Darryl Felder, and a few other scientific
  colleagues of Emilio.
• With the emptying of the first dredge I noticed
  how vivid the shell colors were, especially the
  red, orange and yellows. All the photos that you
  will see are the natural colors, of the common to
  rare shells found. They were photographed in a
  small aquarium or shallow dish. With each dredge
  I would collect some of the bottom material for
  background for the live animals.
• Bill was only interested in the cones, and I was
  allowed to keep any of the other shells I found
  in the dredge material.
• On board is a wet lab with running salt water,
  and a dry lab that we used to photograph and work
  with the shells. A computer screen on the wall of
  each lab gave a constant readout of latitude,
  longitude, and depth, plus showed the vessels
  position on the chart.
• Crew members were great from Captain to deck
  hands all were friendly and most helpful.
• Last but not least, the meals were fantastic. The
  cook even made all the wonderful breads served.
  Typical was crab legs, steaks, shrimp, 3 salads,
  3 starches, 3 veggies, French bread, two
  different desserts.and that was ONE meal.

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The Pelican evolved from a research vessel
concept developed by a group of scientists from
universities throughout the Gulf coast. She has
four laboratories and is capable of taking 16
scientists to sea for periods up to three weeks
at a time. R/V Pelican is based at LUMCON's
DeFelice Marine Center in Cocodrie, LA.
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CraneUsed primarilyfor loading vessel at dock
and handling deck loads at sea. Occasionally in
deploying instrumentsoverboard.
Some of the equipment used to dredge for shells.
A-Frame The A-frame is primarily used in
conjunction with the trawl winch for mooring
deployment and retrieval, net trawls, coring
devices,etc. The A-frame is equipped with lights,
various cleats and pad eyes, and other smaller
blocks.
Trawl Winch This winch is usually used in
conjunction with the stern mounted A-frame. Local
controls are primarily used for trawling, coring,
and mooring deployment
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This photo is from NOAA, with their permission.
It shows a calcareous reef with marine life.
These pinnacles rise abruptly from the deep, soft
muddy sediment. Shown is West Bank, Flower
Gardens Sanctuary at 30 meters.
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The dredge is pulled across the bottom over
calcareous banks, collecting rubble, gravel and
sand for about 15 minutes. The trawling winch and
the A Frame is then used to bring the dredge up
to the deck, where it is placed on the sorting
table.
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Then the winch lifts the dredge and the two
crewmen assist in dumping the contents onto the
table. Once the dredge is stored, we are allowed
to sort through the material. About 6-7 people
can comfortably work at the table.
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Very first shell found,Scaphella dubia
(Broderip, 1827) Dredged from 65 meters.
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Turbo castanea Gmelin, 1791Shells differ from
our local (NE FL) offshore specimens by having
bright red coloration and large spines. Often a
shallow water species. Common shell collected in
63-65 meters.
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Olivella watermani McGinty, 1940 From Sacket
Bank (first dredge), 65 meters.
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Morum dennisoni (Reeve,1842) Dredged from 78
meters.
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Full animal view.
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Trachycardium magnum (Linnaeus, 1758)
Reddish-yellow externally, with white interior. A
common shallow water species, this specimen came
from 66 meters.
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Chicoreus consuela (A.H. Verrill, 1950) dredged
from 64-68 meters
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Same species, another specimen with different
coloration.
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Cymatium rehderi A. H. Verrill, 1950. First known
specimen from GOM.
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Close-up of Cymatium rehderi Dredged from 68
meters of water.
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Antillophos chazaliei (Dautzenberg, 1900) dredged
from 65-80 meters, mud and gravel bottom,
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Antillophos virginiae Schwengel, 1942from mud
99-110 meters.
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20 mm. Euvola chazaliei Dautzenberg, 1900, from
63 meters, new record from NW GOM.
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Glycymeris decussata (Linnaeus, 1758) dredged
from 46-52 meters. Decussate pattern is caused by
the periostracum.
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Colubraria testacea (Mørch, 1852) Shelly Dwarf
Triton
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Here is the 12 X 11 foot benthic skimmer being
deployed. It was designed and built in 2006 by
Dr. Felder.
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My collection from one haul with the benthic
skimmer.
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Sconsia striata (Lamarck, 1816) Dredged from
100-104 meters.
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Close-up of Sconsia striata
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Fusinus excavatus (G.B. Sowerby II, 1880)
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Amusium papyraceum (Gabb, 1873) Paper Scallop.
Common in the dredge from 48-90 meters.
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Close-up view of eyes, tentacles, mantle and
gills of A. papyraceum.
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Amygdalum politum (A.E. Verrill and S.
Smith,1880) collected by the benthic skimmer from
400-460 meters. Shells are still attached in
their mud/fibrous matrix. The recess is like a
pouch. Size of shell approx. 30mm.
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Some of the live conesnails found for Bill from
mud dredged at 105 meters with the benthic
skimmer.
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Conus clarki Rehder Abbott, 1951.Dredged with
Benthic skimmer from 103-105 meters.
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Distorsio clathrata (Lamarck, 1816). Dredged
from mud in 103-105 meters.
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Look at the periostracum on this specimen.
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Hindsiclava macilenta (Dall, 1889). Dredged from
127 meters using the benthic skimmer.
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Tenagodus modestus (Dall, 1881).These snails are
sponge commensals and have detached whorls
throughout, characterized by laterally slitted
lines with small holes. Early whorls smooth and
white they live with apertures facing outside
the sponge allowing for respiratory and
gill-filter-feeding activities.
T. modestus lives embedded inside Demospongiae
hosts as seen in the photo to the left. The grey
material is sponge. Somewhat common down to 400
fathoms, grows to 5-6 inches in length. Dredged
from 67-71 meters.
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Conus erminieus Born, 1778 Turtle ConeOne
species of cone collected for Bill.
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Close-up of C. ermineus. This species has also
been collected in 110-120 feet of water offshore
of NE FL and North Carolina.
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Bill Cargile removing the toxin sac from cone.
The toxin is sent to a scientist for studies,
and the body goes to two different sources for
DNA, one in Germany and the Florida Museum of
Natural History, Gainesville.
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More of the same with a different conesnail.
The process for extracting the toxin on the
vessel was as follows Liquid nitrogen (available
on boat) was poured into a styrofoam cup. It was
then drizzled over the conesnail. The animal was
frozen instantly. (Why drizzle the liquid? On the
first try a half-cup was poured over the
conesnail, and it broke the shell.) After about
30-60 min. defrosting time, with use of a teasing
needle the animal is extracted intact. Scalpel is
used to find the toxin gland. The rest you see in
photo.
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Two Spiny paper Cockles of the genus Papyridea.
Upper left and lower left photos are the same
specimen. Same w/ shells on right. They do have
some distinct differences. Shell on right is more
inflated, length is 35mm by 30mm Wide. Shell on
left is 35mm by 25mm. Both from approx. 65-76
meters.
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Callista eucymata (Dall, 1890)Glory-of-the-Seas
VenusFrom 65-68 meters on rocky, sandy bottom.
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Astraea phoebia Roding, 1798 Long-spined Star
ShellI have found this species as far north as
Frying Pan Shoal, NC
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Previous photo and photo at left shows how
heavily encrusted these shells can be. The shell
below still needs cleaning but will be a
beautiful red. Size 45mm.
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Just a sample of some of the smaller shells that
I still need to identify (plus grunge), if I ever
find the time to work on them.
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Cypraeacassis testiculus(Linnaeus,
1758)Reticulated Cowrie-helmetDredged from
67-70 meters on rocks and sand.
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Haliotis pourtalesi Dall, 1878Pourtales
AbaloneDredged from 78 to 91 meters. All H.
pourtalesi were dead specimens.
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Cerithium litteratum (Born,1778) Stocky
CerithFrom 65 meters of water. Next photo is a
close-up of the unusual- looking animal.
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(No Transcript)
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Spathochlamys benedicti (A. E. Verrill and
Bush, 1897) 8mm shell.
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In this shot you can see the eyes of this 6mm
shell.
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15mm Coralliophila aberrans (C. B. Adams, 1850)
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Fingernail-sized juvenile Ctenoides mitis
(Lamarck, 1807) from 46-52 meters, sand and rocks.
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14mm juvenileCharonia tritonis variegata
(Lamarck, 1816) Dredged from sand, coral rubble
in 46-52 meters.
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Natica marochiensis Stimpson, 1851 from 64-68
meters.
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This beautiful yellow 3 inch seahorse came up in
the dredge, and he was rushed to my aquarium.
After he got rid of a couple of air bubbles, we
put him into the water, and I like to think he
made it back to the bottom.
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This small 30mm deep water octopus was also
released after being photographed. Notice the
very large eyes. Possibly a juvenile.
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Bursa ranelloides (Reeve, 1844) 67-70 meters.
This form far more typical of the Western
Pacific.
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Bursa ranelloides
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Bursa rhodostoma thomae (dOrbigny, 1847)
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Bursa checking out the Morum that just crawled
over his back.
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This beautiful miter is being called Mitra sp.
aff. antillensis Dall, 1889until identification
is certain. Approx. 25 mm in size.
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Mitra straminea A. Adams, 1853Gulf Stream
MiterDredged from 78 meters on gravel, sand
bottom.Notice the similarity of body features in
this species and the previous species.
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I collected two of these 12-15mm chitons which I
gave to Dr. Garcia so he could collaborate with
Bill Lyons on identification.
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Erosaria acicularis Gmelin, 1791Atlantic Yellow
Cowrie
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Yoldia solenoides Dall, 1881 From the benthic
dredge, 63 meters.
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Vexillum cubanum (Aguayo and Rehder, 1936)
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Spondylus americanus Hermann, 1781 from 68
meters. Donated to Tina Petway for the Houston
Museum of Natural Science.
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Americardia media(Linnaeus, 1758)27mmDredged
from 63-65 meters.
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For the ending photo - another great image by
NOAAs photographers.