Stephen Kade: How Sharks Sense their Food & Environment, August 9, 2018

NOAA Teacher at Sea

Stephen Kade

Aboard NOAA Ship Oregon II

July 23 – August 10, 2018

 

Mission: Long Line Shark/ Red Snapper survey Leg 1

Geographic Area: 30 19’ 54’’ N, 81 39’ 20’’ W, 10 nautical miles NE of Jacksonville, Florida

Date: August 9, 2018

Weather Data from Bridge: Wind speed 11 knots, Air Temp: 30c, Visibility 10 nautical miles, Wave height 3 ft.

Science and Technology Log

Sharks have senses similar to humans that help them interact with their environment. They use them in a specific order and rely on each one to get them closer for navigational reasons, and to find any food sources in the area around them. The largest part of the shark’s brain is devoted to their strong sense of smell, so we’ll start there.

Smell– Sharks first rely on their strong sense of smell to detect potential food sources and other movement around them from a great distance. Odor travels into the nostrils on either side of the underside of the snout. As the water passes through the olfactory tissue inside the nostrils, the shark can sense or taste what the odor is, and depending which nostril it goes into, which direction it’s coming from. It is said that sharks can smell one drop of blood in a billion parts of water from up to several hundred meters away.

Ampullae of Lorenzini and nostrils

Ampullae of Lorenzini and nostrils of a sharpnose shark

Sharks can also sense electrical currents in animals from long distances in several ways. Sharks have many electro sensitive holes along the snout and jaw called the Ampullae of Lorenzini. These holes detect weak electrical fields generated by the muscles in all living things. They work to help sharks feel the slightest movement in the water and sand and direct them to it from hundreds of meters away. This system can also help them detect the magnetic field of the earth and sharks use it to navigate as well.

Ampullae of Lorenzini and nostrils

Ampullae of Lorenzini and nostrils of a sharpnose shark

Hearing– Sharks also heavily use their sense of smell to initially locate objects in the water. There are small interior holes behind their eyes that can sense vibrations up to 200 yards away. Sound waves travel much further in water than in the air allowing them to hear a great distance away in all directions. They also use their lateral lines, which are a fluid filled canal that runs down both sides of the body. It contains tiny pores with microscopic hairs inside that can detect changes in water pressure and the movement and direction of objects around them.

Sight– Once sharks get close enough to see an object, their eyes take over. Their eyes are placed on either side of their head to provide an excellent range of vision. They are adapted to low light environments, and are roughly ten times more sensitive to light than human eyes. Most sharks see in color and can dilate their pupils to adapt to hunting at different times of day. Some sharks have upper and lower eyelids that do not move. Some sharks have a third eyelid called a nictitating membrane, which is an eyelid that comes up from the bottom of the eye to protect it when the shark is feeding or in other dangerous situations. Other sharks without the membrane can roll their eyes back into their head to protect them from injury.

dilated pupil of sharpnose shark

dilated pupil of sharpnose shark

Touch– After using the previous senses, sometimes a shark will swim up and bump into an object to obtain some tactile information. They will then decide whether it is food to eat and attack, or possibly another shark of the opposite gender, so they can mate.

Taste– Sharks are most famous for their impressive teeth. Most people are not aware that sharks do not have bones, only cartilage (like our nose and ears) that make up their skeletal system, including their jaw that holds the teeth. The jaw is only connected to the skull by muscles and ligaments and it can project forward when opening to create a stronger bite force. Surface feeding sharks have sharp teeth to seize and hold prey, while bottom feeding sharks teeth are flatter to crush shellfish and other crustaceans. The teeth are embedded in the gums, not the jaw, and there are many rows of teeth behind the front teeth. It a tooth is damaged or lost, a new one comes from behind to replace it soon after. Some sharks can produce up to 30,000 teeth in their lifetime.

Personal Log

While I had a general knowledge of shark biology before coming on this trip, I’ve learned a great deal about sharks during my Teacher at Sea experience aboard the Oregon II. Seeing, observing, and holding sharks every day has given me first hand knowledge that has aided my understanding of these great creatures. The pictures you see of the sharks in this post were taken by me during our research at sea. I could now see evidence of all their features up close and I could ask questions to the fishermen and scientists onboard to add to the things I read from books. As an artist, I can now draw and paint these beautiful creatures more accurately based on my reference photos and first hand observations for the deck. It was amazing to see that sharks are many different colors and not just different shades of grey and white you see in most print photographs. I highly encourage everyone that has an interest in animals or specific areas of nature to get out there and observe the animals and places firsthand. I guarantee the experience will inspire you, and everyone you tell of the many great things to be found in the outdoors.

Animals Seen Today: Sandbar shark, Great Hammerhead shark, Sharp nose shark

Kathleen Gibson, Conservation: Progress and Sacrifice, August 6, 2015

 NOAA Teacher at Sea
Kathleen Gibson
Aboard NOAA Ship Oregon II
July 25 – August 8, 2015

Mission: Shark Longline Survey
Geographic Area of the Cruise: Atlantic Ocean off the Florida and Carolina Coast
Date: Evening, Aug 6,2015

Coordinates:
LAT   3035.997   N
LONG   8105.5449 W 

Weather Data from the Bridge:
Wind speed (knots): 6.8
Sea Temp (deg C): 28.3
Air Temp (deg C):  28.9

I’ve now had the chance to see at least 9 different shark species, ranging from 1 kg to over 250 kg and I’ve placed tags on 4 of the larger sharks that we have caught.  These numbered tags are inserted below the shark’s skin, in the region of the dorsal fin.  A small piece from one of the smaller fins is also clipped off for DNA studies and we make sure to  record the tag number. If a shark happens to be recaptured in the future, the information gathered will be valuable for population and migration studies. The video below shows the process.

Tagging a Nurse Shark Photo: Ken Wilkinson

Tagging a nurse shark.
Photo: Ken Wilkinson

 

After checking that the tag is secure, I gave the shark a pat.  I agree with Tim Martin’s description that it’s skin feels like a roughed-up basketball.

 

We’ve had a busy couple of days.   The ship is further south now, just off the coast of Florida, and today we worked three stations. The high daytime temperatures and humidity make it pretty sticky on deck but there are others on board working in tougher conditions.

Many thanks to Jack Standfast for the engine room tour.

Many thanks to Jack Standfast for the engine room tour.

Yesterday, during a brief period of downtime, I took the opportunity to go down to the engine room. Temperatures routinely exceed 103 o F, and noise levels require hearing protection.  My inner Industrial Hygienist (my former occupation) kicked in and I found it fascinating; there is a lot going on is a small space.  My environmental science students won’t be surprised at my excitement learning

Here it is... The RO unit!

Here it is… The RO unit!

about the desalination unit (reverse osmosis) for fresh water generation and energy conversions propelling the vessel.

I know, I know… but it was really interesting.

 

Science and Technology – Conservation

Sustainability,  no matter what your  discipline is, refers to the wise use of resources with an eye toward the future. In environmental science we specifically talk about actively protecting the natural world through conservation of both species and habitat.   Each year when I prepare my syllabus for my AP Environmental Science course, I include the secondary title “Working Toward Sustainability”.  I see this as a positive phrase that establishes the potential for renewal while noting the effort required to effect change.

Sustainability is the major focus of NOAA Fisheries (National Marine Fisheries Service) as it is “responsible for the stewardship of the nation’s ocean resources and their habitat.”  I’m sure that most readers have some familiarity with the term endangered species or even the Endangered Species Act, but the idea that  protection extends to habitats and essential resources may be new.

Getting the hook out of the big ones is equally challenging.

Getting the hook out of the big ones is equally challenging.

Regulation of  U.S. Fisheries

Marine fisheries in the United States are primarily governed by the Magnuson-Stevens Fishery Conservation and Management Act, initially passed in 1976. Significant reductions in key fish populations were observed at that time and the necessity for improved regulatory oversight was recognized.  This act relied heavily on scientific research and was intended to prevent overfishing, rebuild stocks, and increase the long-term biological and economic viability of marine fisheries. It was this regulation that extended U.S. waters out to 200 nautical miles from shore.  Previously, foreign fleets could fish as close as 12 nautical miles from U.S

Two sandbar sharks on the line.

Two spinner sharks on the line.

shores.

Under this fisheries act, Regional Fishery Management Councils develop Fishery Management Plans (FMP) for most species (those found in nearby regional waters) which outline sustainable and responsible practices such as harvest limits, seasonal parameters, size, and maturity parameters for different species. Regional councils rely heavily on research when drafting the FMP, so the work done by NOAA Fisheries scientists and other researchers around the country is critical to the process.  Drafting a Fishery Management Plan for highly migratory fish that do not remain in U.S. waters is challenging and enforcement even more so.  Recall from a previous blog that great hammerheads are an example of a highly migratory shark.

Threats to Shark Populations and Conservation Efforts

Shark populations around the globe suffered significantly between 1975 and 2000, and for many species (not all sharks and less in the USA) the decline continues. This decline is linked to a number of factors.  Improved technology and the development of factory fishing allows for increased harvest of target species and a subsequent increase in by-catch (capture of non-target fish). Efficient vessels and refined fishing techniques reduced fish stocks at all levels of the food web, predator and prey alike.

More significantly, the fin fishing industry specifically targets sharks and typical finning operations remove shark fins and throw the rest of the shark overboard.  These sharks are often still living and death results from predation or suffocation as they sink.  Shark fins are a desirable food product in Asian dishes such as shark fin soup, and are an ingredient in traditional medicines.  They bring a high price on the international market and sharks with big fins are particularly valuable.

A scalloped hammerhead in the cradle. This was the fist shark I tagged.

A scalloped hammerhead in the cradle. This was the fist shark I tagged.

Sandbar (Carcharhinus plumbeus) and great hammerheads (Sphyrna mokarran) and scalloped hammerheads (Sphyrna lewini) that we have seen have very large dorsal and pectoral fins, which are particularly desirable to fin fisherman.  There are many groups, international and domestic, working to reduce fin fishing, but the high price paid for fins makes enforcement difficult. The Shark Finning Prohibition Act implemented in 2000, in combination with the Shark Protection Act of 2010 sought to reduce this practice.  These acts amended Magnusen-Stevens (1976) to require that all sharks caught in U.S. waters have their fins intact when they reach the shore.  U.S. flagged vessels in international waters must also adhere to this ban, therefore no fins should be present on board that are not still naturally attached. The meat of many sharks is not desirable due to high ammonia levels, so the ban on fin removal has dramatically reduced the commercial shark fishing industry in the United States. (Read about some good news below in my interview with Trey Driggers )

The video below featuring the Northwest Atlantic Shark cooperative summarizes these threats to shark populations.

It must also be mentioned that in the 25 years after the release of the book and film “Jaws”, fear and misunderstanding fueled an increase in shark hunting for sport. The idea that sharks were focused human predators with vendettas led many to fear the ocean and ALL sharks. In his essay “Misunderstood Monsters,” author Peter Benchley laments the  limited research available about sharks 40 years ago,  even stating that he would not have been able to write the same book with what we now know.  He spoke publicly about the need for additional research and educational initiatives to spread knowledge about ocean ecology.

Close up of our first cradled sandbar shark.

Close up of our first cradled sandbar shark. This is one of my favorite pictures.

The United States is at the forefront of shark research, conservation and education and in the intervening years, with the help of NOAA Fisheries and many other scientists, we have learned much about shark ecology and marine ecosystems. It’s certain that marine food webs are complex, but that complexity is not always fully represented in general science textbooks. For example, texts often state that sharks are apex predators (top of the food chain).  This applies to many

This one is pretty big for an Atlantic sharpnose. Photo Credit: Kristin Hannan

This one is pretty big for an Atlantic sharpnose.
Photo Credit: Kristin Hannan

species including great white and tiger sharks, but it doesn’t represent all species.  In truth, many shark species are actually mesopredators (mid level), and are a food source for larger organisms.  Therefore conservation efforts need to extend through all levels of the food web.

The Atlantic sharpnose  (Rhizoprionodon terraenovae) and Silky Shark (Carcharhinus falciformis) are examples of mesopredators.  It was not uncommon for us to find the remains of and small Atlantic sharpnose on the hook with a large shark that it had attracted.

Sandbar shark with Atlantic sharpnose also on the line.

Sandbar shark with Atlantic sharpnose also on the line.

 

William  (Trey) Driggers – Field Research Scientist – Shark Unit Leader ( is there a III?)

Its a beautiful day on the aft deck. William" Trey" Driggers is the Lead Scientist of the Shark Unit. Photo: Ian Davenport

Its a beautiful day on the aft deck. William” Trey” Driggers is the Lead Scientist of the Shark Unit.
Photo: Ian Davenport

Trey is a graduate of Clemson University and earned his Ph.D at the University of South Carolina.  He’s been with NOAA for over 10 years and is the Lead Scientist of the Shark Unit, headquartered in Pascagoula, MS. His responsibilities include establishing and modifying experimental protocols and general oversight of the annual Shark/Red Snapper Longline Survey. Trey has authored numerous scientific articles related to his work with sharks and is considered an expert in his field.  He is a field biologist by training and makes it a point to participate in at least one leg of the this survey each year.

Sandbar shark ( Carcharhinus plumbeus)

Sandbar shark (Carcharhinus plumbeus)

I asked Trey if analysis of the data from the annual surveys has revealed any significant trends among individual shark populations. He immediately cited the increased number of sandbar sharks and tied that to the closure of the fin fisheries. Approximately 20 years ago, the Sandbar shark population off of the Carolina and Florida coasts was declining. Trey spoke with an experienced fisherman who recalled times past when Sandbar sharks were abundant. At the time Trey was somewhat skeptical of the accuracy of the recollection — there was no data to support the claim.  Today the population of Sandbar sharks is robust by comparison to 1995 levels, and the fin removal legislation is likely a major factor.  Having the numbers to support this statement illustrates the value of a longitudinal study.

Trey notes that it’s important for the public to know of the positive trends like increases in Sandbar shark populations and to acknowledge that this increase has come at a cost.  The reduction and/or closure of fisheries have had radiating effects on individuals, families and communities.  Fishing is often a family legacy, passed down through the generations, and in most fishing communities there is not an easy replacement. In reporting rebounding populations we acknowledge the sacrifices made by these individuals and communities.

Personal Log- Last posting from sea. 

Thirty minutes before leaving Pascagoula we were informed that the V-Sat was not working and that we would likely have no internet for the duration of the cruise.

Pascagoula at night.

Pascagoula at night.

We had a few minutes to send word to our families and in my case, TAS followers. I think most of us were confident a fix would happen at some point, but we’re still here in the cone of silence. It’s been challenging for all on board and makes us all aware of how dependent we are on technology  for communication and support.  I’ve gotten a few texts, which has been a pleasant surprise. One tantalizing text on the first day said “off  to the hospital  (to give birth)”, and then no follow-up text for weeks.  That was quite a wait!  I can imagine how it was aboard ship in times past when such news was delayed by months—or longer.  I was looking forward to sharing photos along the way, so be prepared for lot of images all at once when we get to shore!  As for my students, while it would have been nice to share with you in real time, there is plenty to learn and plenty of time when we finally meet.

Captain Dave Nelson

Captain Dave Nelson

I’d like to thank Dave Nelson, the Captain of the Oregon II, who greeted me each day saying  “How’s it going Teach?” and for always making me feel welcome. Thank you also to all of those working in the Teacher at Sea Program office for making this experience possible.  Being a part of the Shark Longline Survey makes me feel like I won the TAS lottery.  I’m sure every TAS feels the same way about their experience.

Special thanks to Kristin Hannan, Field Party Chief Extraordinaire, for answering my endless questions (I really am a lifelong learner…), encouraging me to take on new challenges, and for her boundless energy which was infectious. Sharks are SOOO cool.

Here’s a final shout out to the day shift–12 pm-12 am–including the scientists, the Corps, deck crew and engineers for making a great experience for me.  Ian and Jim – It was great sitting out back talking. I learned so much from the two of you and I admire your work.

Ian Davenport, Jim Nienow and me relaxing on the aft deck between stations. Photo: Trey Driggers

Ian Davenport, Jim Nienow, and me relaxing on the aft deck between stations. Photo: Trey Driggers

And, to all on board the Oregon II, I admire your commitment to this important work and am humbled by the personal sacrifices you make to get it done.

Day shift operating like clockwork Photo Credit: Ian Davenport

Day shift operating like clockwork.
Photo Credit: Ian Davenport

Awesome day shift ops. Photo Credit: Ian Davenport

Awesome day shift ops. Getting it done!
Photo Credit: Ian Davenport

This has been one of the hardest and most worthwhile experiences I’ve ever had. It was exhilarating and exhausting, usually at the same time.  I often encourage my students to take on challenges and to look for unique opportunities, especially as they prepare for college.  In applying to the TAS program I took my own advice and, with the support of my family and friends, took a risk.  I couldn’t have done it without you all.  This experience has given me a heightened respect for the leaps my students have made over the years and a renewed commitment to encouraging them to do so.  Who knows, they may end up tagging sharks someday. Safe Sailing Everyone.

Sunset over over the Atlantic Ocean. August 5, 2015

Sunset over over the Atlantic Ocean. August 5, 2015

“Teach”

Learn more about what’s going on with Great White sharks by listening to the following NOAA podcast:
Hooked On Sharks

A few more photos…

The ones that got away...

The ones that got away…  It took something mighty big to bend the outer hooks.

 It took teamwork to get a hold of this silky shark (Carcharhinus falciformis).

silkyondecksilky measuresilky hold

 

Kathleen Gibson, Time to Fish! July 29, 2015

High flyer away! Photo Credit : Kristin Hannan

High flyer away!
Photo Credit : Kristin Hannan

NOAA Teacher at Sea
Kathleen Gibson
Aboard NOAA Ship Oregon II
July 25-August 8, 2015

Mission: Shark Longline Survey
Geographic Area of the Cruise: Atlantic Ocean off the Florida and Carolina Coast
Date: July 29, 2015
Coordinates:
LAT 2933.3326N
LONG 8029.065W

Weather Data from the Bridge:
Wind speed (knots): 9.2
Sea Temp (deg C): 29.6
Air Temp (deg C):  28.7

Yesterday was the first full day of sampling.  We were off the coast of Miami, FL and it was relatively shallow.  I’m not sure how many sharks I expected to see on my first day, but certainly not the 80 + that we did catch!

Science and Technology Log –  A, B, C’s of Fishing for Sharks

Kristin Hannan preselected our stations following a random stratified approach. Sampling stations have A, B, or C designations, depending on the depth (A is more shallow than B or C). The night crew went on duty at midnight and completed one station yesterday morning.  We completed three stations during our shift yesterday and three more today.

The bridge lets us know when we’re 30 minutes from our  station, and we begin preparations. We bait the hooks with mackerel 20 minutes ahead of time.

When we get to the station, the longline is fed out from the stern of the ship and extends one mile.  A

Throwing Bait - I'm passing baited gangions to Tim Martin to attach to the Longline. Moments after this photo my TAS hat took flight and joined the sharks of the Atlantic.

Throwing Bait –
I’m passing baited gangions to Tim Martin to attach to the Longline. Moments after this photo my TAS hat took flight and joined the sharks of the Atlantic.

marker, called a high flyer, is attached to the beginning of the line. One hundred baited gangions are attached to the line at intervals after which another high-flyer marks the end of the line. The ship then returns to the starting point, the line is hauled in and the fun begins. If there is a shark on the line, the deck crew fisherman calls out “Shark On!”  That’s the signal for someone from the science group to step up and take the shark, remove the hook and collect data.

The following data collected is collected for all sharks:

  • Species
  • Precaudal Length: Nose to base of tail
  • Fork Length: Nose to fork of tail
  • Natural Length: Nose to tail
  • Total Length: Nose to end of tail when extended manually
  • Weight (Kg)
  • Sex Determination

Tag numbers and tissue sample collection is also noted if applicable.

Early morning haul back by the night shift. Video taken from the highest point on the ship. 

Most of the sharks caught were small enough to bring up and hand to the science team.  We use a wooden measuring board to determine lengths. Those that were a bit larger were brought up on deck by the fishermen and they required multiple handlers to collect data.

Very large sharks had to be measured with the help of a cradle and hoist.  The cradle is lowered to water level and large sharks are coaxed onto the cradle using the hook and line they are still attached to.  A hoist brings them to deck height for assessment.  Deck Operations Crew manages all shark retrieval and determines when is safe for us to proceed.

Atlantic Sharpnose

Atlantic Sharpnose Photo Credit: Kristin Hannan

Me holding a mature male Atlantic Sharpnose Photo Credit: Kristin Hannan

Most of the sharks that we’ve caught have been Atlantic Sharpnose.  This shark is relatively small (adults average 0.85 M) and are found in shallow Atlantic coastal waters from New Brunswick down into the Gulf of Mexico, and even off the coast of Brazil.  They are known by at least 8 common names in different regions.  My Biology students would recognize this as a good example of why it’s important to use agreed-upon scientific names for scientific research.  The scientific name for this species is Rhizoprionodon terraenova.  It has a long snout (longer than the width of the head) and most adults have a few white spots on a gray body.

Sharpnose mature relatively quickly and can begin producing offspring within two years; also, they can have up to 5-7 pups at once. These are major factors contributing to the abundance of this species.  In comparison, larger sharks may take up to 15 years to reach maturity and typically have fewer offspring in each brood.  

Our catch also included one Blacknose (Carcharhinus acronotus) and multiple Scalloped Hammerhead (Sphyrna lewini), Nurse (Ginglymostoma cirratum) and Spinner sharks (Carcharhinus brevipinna).

Larger specimens were brought to deck height using a cradle, for weight, size, and sex determination, and were lowered back into the water after being measured and tagged.

Nurse Shark in cradle

Nurse Shark in cradle (Photo Credit: Ian Davenport)

A Sandbar shark in the cradle. I'm in the yellow helmet tagging the shark.

A Sandbar shark in the cradle. I’m in the yellow helmet tagging the shark. ( Photo Credit: Erica Nu

 

Hook removal required bolt cutters after I tagged this Sandbar Shark.

Hook removal required bolt cutters after tagging  this Sandbar Shark.

 

Career Spotlight

If your interests tend toward science mixed with heavy machinery, skilled fishing, robotics or electronics, perhaps one of the following careers is for you.

Tim Martin: Chief Boatswain

Tim Martin Chief Boatswain

Tim Martin Chief Boatswain

As the Chief Boatswain, Tim Martin is responsible of all activities that happen on deck and he maintains constant communication with the bridge during all operations.  Tim came to NOAA fisheries with a wealth of experience gained while serving in the U.S. Navy and later as a commercial fisherman in the Pacific Northwest.  He was initially classified as a “Skilled Fisherman” with NOAA and has worked his way up to Chief Boatswain.

He and his group set and retrieve the longline. They also run all of the heavy deck equipment, such as the cranes that are used to position the shark cradle for large sharks and the CTD (water Sampling device).  The Chief Boatswain is also responsible for training new crewmembers and maintaining ship supplies.  In addition, Tim has earned Dive Master Certification through the NOAA Diving School, considered to be the best civilian diving school in the US.

 

 

Tim Martin and deck Crew cradling a Tiger shark. Note the wooden dowel at center used to attach tags. ( Photo Credit: Erica Nuss)

Tim Martin and deck crew cradling a Tiger shark. Note the wooden dowel at center used to attach tags. (Photo Credit: Erica Nuss)

When asked what keeps him going, Tim is very clear that he believes the work that NOAA Fisheries does is very important, and he is proud to be able to use his expertise to support NOAA’s efforts.  This satisfaction somewhat tempers the challenges of the job which include being at sea for at least 6 months of the year, and constantly being in a training flux. Tim feels a strong bond with his crew and there is a clear sense of mutual trust and respect among them. 

Ken Wilkinson: Electronic Technician (Supreme), NOAA Fisheries Engineering Unit

Ken has been with the Engineering Unit of NOAA Fisheries for 26 years.  The mission of his Unit is to

Ken using his skills to filet a Red Snapper

Ken using his skills to filet a Red Snapper

support NOAA Fishery research by developing innovative technology. Ken always wanted to work on the water and he initially studied Marine Biology in college, but he migrated toward electronics.  His work allows him to combine two great interests.  His work takes him to sea 50-80 days each year.

A major focus of the electronics unit is to support the Reef Fish program.  Trawling nets and longline apparatus will damage reef systems.  In order to assess reef fish populations in a non-invasive way, Ken and his group work a number of Remotely Operated Vehicles that capture still and moving images that can be used later to determine abundance and species diversity.   Ken’s unit has also developed a device called an Autonomous Underwater Vehicle (AUV). This programmable instrument scans the sea floor using lasers and  data collected is used to develop more accurate sea floor maps.

Bathymetric map of the Longline sampling area- NOAA

Bathymetric map of the Longline sampling area- NOAA

 

New device: Kennenator 5000 Dual Laser

Ken Wilkinson and his Kennenator 5000.

Ken Wilkinson and his Kennenator 5000.

Ken is on board the Oregon II testing his new device that can be used to assess the size of large sharks without bringing them to deck height. Ken’s device has two lasers set at a fixed distance from one another.  The beams are directed toward the shark while it remains at the surface of the water. Various measurements can be extrapolated from the laser measurement. Large sharks caught on the longline survey are typically brought to the surface in the cradle for assessment.  Cradle use is preferred as it allows tagging and tissue sample collection and sex determination. However, there are situations when this is not possible such as when poor weather conditions develop which limit sling operations, and some small vessels are not equipped with sling equipment.

Personal Log

The Challenge

The Challenge

The fast pace of the haul back at early stations was jarring.  I stepped up when “Shark On” was called and a writhing Sharpnose was thrust into my hands.  The first task is to get the hook out of the shark’smouth and this is no small feat.  The circle hook is designed is to reduce the chance that the shark will swallow the hook or get hurt by it, but getting these hooks out of the mouth without hurting the shark requires technique.  There will be plenty of opportunities to get the hang of in the next week.

A highlight of this first day was getting up close to a 2 meter long Scalloped Hammerhead brought to the surface in the cradle.  I was able to feel its head, observe its eyes, and place an identification tag near its dorsal fin before it was lowered back into the water.

Smaller Scalloped Hammerhead on deck. It took two of us to hold this one in place fore measuring and tagging.

Smaller Scalloped Hammerhead on deck. It took two of us to hold this one in place fore measuring and tagging. (Photo Credit: Ian Davenport)

 

Julie Karre: A Weekend with the Wind and Wild Sharks, August 2-4, 2013

NOAA Teacher at Sea
Julie Karre
Aboard NOAA Ship Oregon II
July 26 – August 8, 2013

Mission: Shark and Red snapper Longline Survey
Geographical Area of Cruise: Atlantic Ocean off the Coast of Florida
Date: Friday, August 2 – Sunday, August 4, 2013

Weather Data from the Bridge
Friday – SW WINDS 10 TO 15 KNOTS
SEAS 3 TO 5 FEET
SCATTERED SHOWERS AND THUNDERSTORMS

Saturday – SW WINDS AROUND 15 KNOTS
ISOLATED SHOWERS AND THUNDERSTORMS MAINLY AFTER MIDNIGHT
SEAS AROUND 4 FEET

Sunday – W WIND 5 TO 7 KNOTS BECOMING VARIABLE AND LESS THAN 5 KNOTS
A CHANCE OF SHOWERS AND THUNDERSTORMS MAINLY AFTER 10PM
SEAS AROUND 3 FEET

Science and Technology Log
In this log we’ll take a closer look at the sharks we’ve brought on board:

Atlantic Sharpnose Shark:

Volunteer Arjen Krigsman works on a Sharpnose on his birthday!

Volunteer Arjen Krijgsman works on a Sharpnose on his birthday!

The Atlantic Sharpnose has been the most abundant shark on our survey and will continue to be abundant for the rest of the cruise, even in the Gulf of Mexico. It is in fact one of the species that is on the Least Concern list in terms of its vulnerability. It is often a victim of by-catch and makes up 1/3 of the commercial landings of sharks in the United States. But being capable of producing offspring in abundance, the Sharpnose remains a steady species with moderate population growths. As indicated by its name the Atlantic Sharpnose is found all along the U.S. Atlantic coast and even as far as New Brunswick, Canada. When the Oregon II makes its way back into the Gulf of Mexico, it will likely continue to make an appearance on deck.

Blacknose Shark

Blacknose Shark Photo Credit: Claudia Friess from her 2009 Longline cruise on the Oregon II. Unfortunately, when we caught the Blacknose it was too dark to get a good picture.

Blacknose Shark
Photo Credit: Claudia Friess from her 2009 Longline cruise on the Oregon II.  When we caught a Blacknose on this cruise it was too dark to get a good picture.

The Blacknose Shark shares a similar body with the Sharpnose, but is marked by a (drumroll please) black mark on its nose. Unfortunately, the Blacknose doesn’t share its abundance with the Sharpnose. The Blacknose is listed as Near Threatened due to its high mortality rates in shrimp trawl nets. The Blacknose is suffering a decline in its population. The Oregon II has only seen 5-6 Blacknose during this leg of the survey.

Nurse Shark

Nurse Shark Photo Credit: Claudia Friess from her 2009 Oregon II cruise. Unfortunately, it was too dark to get quality photos from our Nurse Shark.

Nurse Shark
Photo Credit: Claudia Friess from her 2009 Oregon II cruise. Again, it was too dark to get quality photos of our Nurse Shark.

The Nurse Shark, the first big shark we cradled, is characterized by sedentary and relatively docile behavior. They are still relatively mysterious in their migratory behavior and the gene flow between populations. Recently, it has been shown in population decline in certain areas perhaps due to its vulnerability to catch, but also perhaps because of habitat alteration.

Scalloped Hammerhead

Measuring a Scalloped Hammerhead.

Measuring a Scalloped Hammerhead.

The Scalloped Hammerhead has been my favorite so far. A friend of mine characterized it as the hipster of the shark world. There is something truly magnificent about those wide-set eyes. Unfortunately, the Scalloped Hammerhead is Endangered. The Scalloped Hammerhead can be found in coastal temperate waters all around the world. In each of these regions, it is threatened by capture, mostly as by-catch in fishing gear, gillnets, and longlines. Hammerhead shark fins are also more valuable than other species because of their high fin count. The species is in decline.

Bull Shark

Bull Shark! 232 pounds!

Bull Shark! 232 pounds!

The Bull Shark is a unique shark species because it can survive in freshwater for extended periods of time. This ability has caused it to be categorized as Near Threatened because it often gets caught in fisheries, but it is not a target species the way others are. Here’s what Kristin Hannan had to say: “Bull sharks’ ability to tolerate greater salinity extremes means that it is likely to be in more productive areas like at the input of rivers.  The rivers which dump high levels of nutrients into the system spur on production, high nutrients means more phytoplankton, more phytoplankton means more small critters eating and so on up.  These areas also mean hot spots for fishing activities as productivity means more fish, more fish means more predators, more interaction with gear, more possibilities for shark mortality.”

Sandbar Shark

A Sandbar Shark coming up on the cradle.

A Sandbar Shark coming up on the cradle.

The Sandbar Shark, which we caught in abundance one night, is a widespread species in warm temperate waters. Studies have found that it is a long-lived species, but it does not reproduce quickly so it has become Vulnerable due to overfishing. The species is currently in decline. The Sandbar is considered valuable because of their fins, which are large.

Tiger Shark 

A medium sized Tiger Shark was brought on deck to be measured and tagged. Kristin Hannan stands waiting for it to stop moving.

A medium sized Tiger Shark was brought on deck to be measured and tagged. Kristin Hannan stands waiting for it to stop moving.

The Tiger Shark is commonly found world wide in tropical and warm coastal waters. Aside from the Sandbar, it is the largest shark we have caught the most of. Fortunately, it is considered a fast-growing species with the ability to reproduce abundantly. It is not considered at a high risk for extinction, but the desire for fins makes the risk of further population decline a distinct possibility.

Night Shark

This Night Shark was the only of its kind we brought up so far.

This Night Shark was the only one of its kind we’ve brought up so far.

We have only caught 1 Night Shark during our survey. It is a Vulnerable species. It is prized mostly for its fins and meats and is caught in abundance off the coast of Brazil. Studies have shown that most of the Night Sharks landed were below 50% maturity, which is 8 years for males and 10 years for females. In the United States, the Night Shark is listed as a prohibited species.

When talking to Kristin about these sharks, she shared this about their reproduction, “All sharks are considered K-selected species like humans; we are late to mature, grow slowly and reproduce relatively few young comparatively to say a bony fish that might produce thousands of babies in its lifetime (s-selected).  So when we talk about a tiger [shark] vs. a sandbar [shark] being more or less productive, it is definitely in relation to each other and not all fish. A tiger [shark] does produce more young than some other species but way less than the red grouper he goes after for dinner.  This is why all sharks are so sensitive to fishing pressures; they have a considerably longer bounce back time.”

Personal Log
It’s hard to believe that over a week has passed, but given how much we have seen and done, it makes sense.

As I get more and more comfortable handling sharks and working on the boat, I have noticed a few things. My sister-in-law Elizabeth noticed a few years ago that my family has a love for responding to each other (and often friends and acquaintances) with movie quotes. The most commonly quoted movies in our family include The Big Lebowski, The Princess Bride, Blues Brothers, To Kill A Mockingbird, and many more. I am no exception to this family trend.

So while we’re all eagerly awaiting the call that a shark is on the hook, it occurred to me that this movie-quoting affliction had not escaped this trip. When a fish or shark is caught on one of our hooks, the fishermen call out “Fish on” to notify those of us handling to come over and retrieve the animal. I realized that this was no common call in my head, though. Each time I hear the “Fish on” I hear it more in the call of “Game Ooon” from Wayne’s World. I suppose that’s a hazard of anyone growing up in the 90s. What proves I am truly a Karre though is that when I’m talking to the shark I’m handling, asking and sometimes begging it to be still so I can remove the hook quickly and reduce its harm and pain, in my head the shark is responding “Oh I’m cooperating with you” in the voice of William H. Macy from the movie Fargo.

"Fish ooonnn" - A Sharpnose comes up to join us.

“Fish ooonnn” – A Sharpnose comes up to join us.

"Oh I'm cooperating with you" says the Sharpnose that has just come aboard the Oregon II.

“Oh I’m cooperating with you” says the Sharpnose that has just come aboard the Oregon II.

Did You Know?
There are over 6000 known coral species around the world. We have brought up several pieces of coral on our clips. Kevin found a bright red piece of coral, which prompted a lesson for us about how many red corals release an irritant that will make our skin burn and sting. Fortunately, that’s not what Kevin brought up!

The sun is setting on my trip and all I can say is that it has been extraordinary.

The sun is setting on my trip and all I can say is that it has been extraordinary.

Kaitlin Baird: Some Essential Tools! September 14, 2012

NOAA Teacher at Sea
Kaitlin Baird
Aboard NOAA Ship Henry B. Bigelow
September 4 – 20, 2012

Mission: Autumn Bottom Trawl Survey with NOAA’s North East Fisheries  Science Center
Geographical Area: Off the Coast of Cape Hatteras, North Carolina
Date: September 14th
.

Location Data:
Latitude: 35′ 10.67
Longitude:  75’33.60     

Weather Data:
Air Temperature: 23.40 (approx.74 °F)
Wind Speed: 2.17 kts
Wind Direction:  Southwest
Surface Water Temperature:2 7.61 °C (approx. 82°F)
Weather conditions: Sunny and fair

Science and Technology Log

One of the things I was curious about was the deployment of these large instruments and the technology that supports it. One of the keys to the deployment of things like the BONGO nets, Continuous Depth Recorders (CTD’s) and the trawl net itself are winches. A winch spools the wire cable that is hooked to all of the instruments and allows them to move up, down and out into the water column. With some of the instruments, like the BONGO’S and CTD casts, a retractable A-Frame is used to lower the cable from the winch. You can see the A-Frame on the right and the winch on the left in the photo below. This winch in particular controls the deployment of the net and connects to two winches on the stern that roll out the net to open up the mouth. The wire is constantly monitored from the bridge on the screen below and is automatically adjusted to maintain equal tension on both sides.

Winch for fishing nets, Tension monitor on winches from the bridge and A-frame

Winch for fishing nets, Tension screen for winches from the bridge and retractable A-frame

Once the net is run out with the aid of the winches, it is constantly monitored for its shape during the tow with a number of different censors attached to the net. There is an autotrawl system that sets the depth of the trawl and the tension of the wires. A Global Positioning System (GPS) plots the position of the net for each trawl so that it can be associated with all organisms caught in the tow. At the end of the tow the winches reel back the cable and a crane brings the net with the catch over to the “checker” where the net is unloaded!

Monitoring the position and shape of the trawl in the water

Monitoring the position and shape of the trawl in the water

Personal Log:

The fun part begins when the net opens and all the animals enter the checker. When all of the catch goes into the checker the scientists take a look at the catch, and remove anything too large to go up the conveyor belt. If a fish dominates the catch it will “run”. This means, as it goes down the conveyor belt it won’t be taken off and it will be weighed by the basketful and then a subsample will be taken for further analysis.

The fish are all divided up by species and electronically coded in the FSCS system to be measured. After they are measured, the system will prompt for further analysis for that particular species. If extra sampling of the fish is required,  it is labeled with a printed sticker for the species with a unique barcode that can be scanned to retrieve its record in the database.

tag for the organisms to designate its ID and what is to be done with it

Tag for the organisms to designate its ID and what is to be done with it

I thought I’d share some photos with you of some of the unique things we have seen so far fishing today. We are off the coast of Carolina and finishing up our Southern stations today into early morning!

Fish caught off of North Carolina

Fish caught off of North Carolina

Catch of the day! Thanks for reading!

Shark caught off of Carolina coast

Atlantic Sharpnose Shark caught off of Carolina coast

Andrea Schmuttermair: Tows Away! June 26, 2012

NOAA Teacher at Sea
Andrea Schmuttermair
Aboard NOAA Ship Oregon II
June 22 – July 3

Mission: Groundfish Survey
Geographical area of cruise: Gulf of Mexico
Date: June 26, 2012 

Ship  Data from the Bridge:
Latitude:  2805.26N
Longitude: 9234.19W
Speed:  10mph
Wind Speed:  5.86 knots
Wind Direction:   E/SE
Surface Water Salinity:  35.867 PPT
Air Temperature:  28.8 C
Relative Humidity: 86%
Barometric Pressure:  1010.51 mb
Water Depth:  96.5 m

Science and Technology Log


Sunrise

Sunrise on the Oregon II

Opisthonema oglinum, Lagadon rhomboides, Chloroscombus chrysurus…..yes, I have officially started dreaming about taxonomic names of our fish. It’s day 4 and I now have a much better grasp at identifying the variety of critters we pull up in our trawls. I am always excited to be out on deck when they bring up the trawl to see what interesting critters we catch. Surprises are great!

Do you want to know where the Oregon II is headed?

Check out Ship Tracker at http://shiptracker.noaa.gov/

If you click on the link above, you can see the path that our ship is taking to hit all of our stations for the survey. We often have station after station to hit- meaning as soon as we are done sorting and measuring, we have to bring in the next catch. Because some stations are only 3-5 miles apart, we sometimes have to do “double dips”, where we put in the trawl for 30 minutes, pull it up, and put it right back in again.

It’s been interesting to note the variety of our catches. Croakers, bumperfish, and shrimp have been in high abundance the last 2 days as we were in shallower water. Before that we had a couple of catches that had a high abundance of pinfish. When we take our subsample, we typically enter data for up to 20 of that particular species. We take length measurements on each fish, and on every fifth fish. We will also weigh and sex it (if sexing is possible).

Shrimp in the Gulf

A comparison of the various sizes of shrimp we pull up from our trawls.

Shrimp waiting to be measures

A relatively small catch in comparison to the 200+ we’ve been pulling up recently.

When we were in shallower waters, we had a significant increase in the number of shrimp we brought up. Tuesday morning was the first catch that did not have well over 200 shrimp (this is because we’ve been moving into deeper waters).  For the 3 commercial shrimp, white (farfantepenaeus setiferus), pink (farfantepenaeus duorarum), and brown (farfantepenaeus aztecus), we take 200 samples, as opposed to our high-quantity fish, where we will only take 20 samples. For each of the commercial shrimp we catch, we measure, weigh and sex each shrimp. I’ve gotten very good at identifying the sex of shrimp- some of the fish are much more difficult to tell. The information we get from this survey will determine the amount of shrimp that boats can take during the shrimping season in Louisiana and Mississippi. During the first leg of the groundfish survey, the data collected determined the amount of shrimp that could be caught in Texas. The groundfish survey is crucial for the shrimping industry and for ensuring that shrimp are not overfished.

Students- think of the food chain. What would happen if we overfished and took out too many shrimp? (Hint: Think of predators and prey.)

Sunrise

The trawl net at sunrise

We’ve now started doing 2 different tows  in addition to our trawls. Some of the stations are trawl stations, whereas others are plankton stations.

The trawl on deck

Alex, Alonzo and Reggie unloading the trawl net.

At a trawl station, we lower the trawl from the stern down to the ocean floor. The trawl net is meant for catching larger critters that live at the bottom of the ocean. There is a chain, also known as a “tickler”, which moves lightly across the ocean floor to lure fish to leave their hiding spots and swim into our net. The trawl is down for 30 minutes, after which it is brought back on deck to weigh the total catch, and then brought back into the wet lab for sorting.

Another important mission of the groundfish survey is to collect plankton samples. To do this, we use a Neuston tow and a bongo tow.

neuston tow

The Neuston tow about to pick up a lot of Sargassum- oh no!

The Neuston tow has a large, rectangular frame with a fine mesh net attached to it. At the end of the net is a large cylindrical bucket, called a codend, with a mesh screen meant for catching the organisms. In comparison to the trawl net, which has openings of 41.4mm , the Neuston’s mesh is only 0.947mm. This means the mesh is significantly finer, meant for catching some of the smaller critters and plankton that would otherwise escape the trawl net. The Neuston tow is put on the surface of the water and towed for 10 minutes. Half the tow is in the water while half is out. We end up picking up a lot of Sargassum, or, seaweed, that is found floating at the water’s surface. When we gather a lot of Sargassum, we have to sift through it and spray it to get out any of the organisms that like to hide in their protective paradise.

Bongo tow

The bongo tow on deck waiting to be sent down to about 3m from the ocean floor.

After we’ve completed the Neuston tow, we do the bongo tow.  The bongo’s mesh is even finer than the Neuston tow’s mesh at only 0.333mm. The bongo has 2 parts- a left and a right bongo (and yes they do look a little like bongo drums- hence their name). The top part of the bongo is a large cylinder with an open bottom and top. The net is attached to this cylinder, and again at the bottom of each side is cylindrical tube  called codends meant to catch the plankton. The bongo tow is meant to take a sample from the entire water column. This means that instead of riding on the surface of the water, it gets sent down to about 3 meters from the ocean floor (there is a sensor at the top that is 2m from the bottom of the net)  and brought back up immediately.

Sifting through the sieve

The remnants from our Neuston tow. This is the sieve we use to weed out what we want and don’t want.

bongo leftover

Here are our 2 samples from the bongo tow. The left one is preserved in ethanol and the right is preserved in formaldehyde (10% formalin and sea water)

Neuston tow samples

Here is a sample from the Neuston tow. Carefully camouflaged are thousands of crab megalops, aka juvenille crabs.

For both tows, it is important to rinse the nets to get any lasting organisms we might not see with our own eyes into our sample. Once we’ve done this, we bring the tubes back into the wet lab where we continue to rinse them through a sieve so that only certain items are leftover. In the Neuston, we often find small fish (usually less than 3mm), baby shrimp, crabs and Jessica’s favorite, the Sargassum fish. Most recently a few flying fish got caught in our Neuston tow. Prior to pulling it up, I was enjoying watching them flit across the water- they were about all we could see in the water in the middle of the night. After being rinsed thoroughly through the sieve, we preserve them by placing the sample in a glass jar with either ethanol or formaldehyde solutions. They are preserved in ethanol for DNA work and in formaldehyde for long-term preservation. These samples are then saved to send to a lab in Poland, which is the sorting center for the SEAMAP samples.

Flying fish

Flying fish we pulled up in our Neuston tow at nighttime.

Personal Log

My stateroom

My sleeping quarters (top bunk), also known as a stateroom. My roommate is Kristin, one of the scientists on board.

Well, I think I am finally getting used to the schedule of working the night shift. I am thankful that my bunk is on the bottom floor of the ship- which means it is completely dark- so that I can sleep during the daytime. Yesterday was probably one of the least busy days we’ve had so far, and because we were in deeper waters, our trawls were much smaller. This means I had a little more time to work on my blogs, which at times can be hard to fit in. It amazes me that we have internet access on the ship, and it’s not even as slow as I expected. It goes down from time to time, especially when the waters are rough. We’ve been fortunate to have pretty calm waters, aside from the first day.

You may have heard about Hurricane Debby on the news as it prepared to hit the Gulf. On Sunday, we were heavily debating heading back to Galveston to “bunker down” and ride out the storm. However, the storm that was forming seemed to dissipate and head in a different direction, thank goodness.  I was not thrilled about the possibility of heading back to port!

We had our first drills the day after we set sail. The drills- fire and abandon ship are distinguished by different types of bells, similar to using Morse code. The abandon ship drill was fun. We got to put on our survival suit, which is like a big orange Gumby suit. It not only protects you in cold water, but also makes you highly visible. I remember reading some of the former TAS blogs, and this picture was always in. Of course, I’ve got to add mine as well.

Survival Suit

Here I am in my survival suit. Judd also decided to be in the picture. 🙂

I’ve been having fun exploring different areas of the ship, even though there is only so far you can go on the ship. Yesterday, I went up to the bridge, which is the front of the ship where the captain or the NOAA Corps officers steer the ship from. You can think of it like a control center of an airplane. There are navigation charts (both computerized and paper) and radars that help guide the ship so it knows what obstacles are out there. There is a great view from the bridge that you don’t get anywhere else on the ship. It’s also fun to watch the folks down on deck when they are deploying the CTD or either of the 2 tows.

We’ve caught such an abundance of critters, I thought I’d share some of my favorite catches thus far:

cownose ray

Here I am holding a cownose ray (Rhinoptera bonasus)- my favorite catch yet. He weighed about 25lbs! This one was the highlight of my day as rays are some of my favorite ocean critters!

Atlantic sharpnose shark

One of the 4 Atlantic sharpnose sharks (Rhizoprionodon terraenovae) we’ve caught so far.

Sharksucker
A sharksucker (Echeneis naucrates)- these guys hang onto sharks to catch a ride- he’s still alive so is able to hang onto my arm!

Critter Query Time!

Critter Query #1: What is a fathom (in your own words please)?

Critter Query #2: What are the differences between skates and rays?

Jennifer Goldner: Sharks 101, August 18, 2011

NOAA Teacher at Sea
Jennifer Goldner
Aboard NOAA Ship Oregon II
(NOAA Ship Tracker)
August 11 — August 24, 2011

Mission: Shark Longline Survey
Geographical Area: Southern Atlantic/Gulf of Mexico
Date: August 18, 2011

Weather Data from the Bridge
Latitude: 26.05 N
Longitude: 84.05 W
Wind Speed: 5.20 kts
Surface Water Temperature: 30.30 C
Air Temperature: 31.20 C
Relative Humidity: 67.00%

Science and Technology Log

Living in the landlocked state of Oklahoma, I am unfamiliar with sharks.  Thus today, with the help of the scientists, I’m going to give some basics of sharks that I have learned this week.  Class title:  Shark 101.  Welcome to class!

Let me start by telling you the various sharks and amount of each we have caught this week in the Gulf of Mexico. We have caught 7 nurse sharks, 2 bull sharks, 4 sandbar sharks, 73 Atlantic sharpnose sharks, 15 blacknose sharks,  5 blacktip sharks, 5 smooth dogfish, 2 silky sharks, and 4 tiger sharks.  For those of you that took the poll, as you can see the correct answer for the type of shark we have caught the most of is the Atlantic sharpnose shark.   The sharks ranged in size from about 2 kilograms (Atlantic sharpnose shark) to 100 kilograms (tiger shark). Keep in mind a kilogram is 2.24 pounds. 

In addition to the sharks caught we have also caught yellowedge, red, and snowy grouper, blueline tilefish, spinycheek scorpionfish, sea stars, and a barracuda.

From the last post you now know that we soak 100 hooks at a time. Throughout the survey we have had as little as no sharks on the line in one location and up to 25 on the line in other locations.

Me holding a spinycheek scorpion fish

Me holding a spinycheek scorpionfish

Blueline tile fish

Blueline tilefish

Drew, Scientist, holding a barracuda

Drew, Scientist, holding a barracuda

yellowedge grouper

Yellowedge grouper

When a shark is brought on board, it is measured for total length, as well as fork length (where the caudal fin separates into the upper and lower lobes).  The sex of the shark is also recorded.  A male shark has claspers, whereas a female shark does not.  The shark’s weight is recorded.  Then the shark is tagged. Lastly, the shark is injected with OTC (Oxytetracycline) which can then be used to validate the shark’s age.  It should be noted that for larger sharks these measurements are done in the cradle.  For perspective, I had Mike, fisherman, lay in the cradle to show the size of it. Also on this trip, some of the scientists tried out a new laser device.  It shoots a 10 cm beam on the shark.  This is then used as a guide to let them know the total length.  Thus, the shark can actually be measured in the water by using this technique.

Do you see the 2 laser dots on the shark?  This 10 cm increment helps scientists estimate the length of the shark.

Mike, Fisherman, in the shark cradle- It is approximately 8 feet long.

Mike, Fisherman, in the shark cradle — It is approximately 8 feet long.

Shark diagram

Shark diagram

Mark Grace, Chief Scientist, weighs a shark

Mark Grace, Chief Scientist, weighs a shark

Male shark on the left (with claspers), female shark on the right (no claspers)

Male shark on the left (with claspers), female shark on the right (no claspers)

Mark Grace, Chief Scientist, and Adam, Scientist, measure a nurse shark in the cradle

Mark Grace, Chief Scientist, and Adam, Scientist, measure a nurse shark in the cradle

Mark Grace, Chief Scientist, assists me tagging an Atlantic sharpnose shark

Mark Grace, Chief Scientist, assists me tagging an Atlantic sharpnose shark

Tim, Lead Fisherman, holds the bull shark while I tag it!

Tim, Lead Fisherman, holds the bull shark while I tag it!

Giving antibiotics to an Atlantic sharpnose shark

Injecting OTC into an Atlantic sharpnose shark

Here are some things I learned about each of the sharks we caught.

1.  Nurse shark:   The dorsal fins are equal size.  They suck their food in and crush it.  Nurse sharks are very feisty.  See the attached video of Tim, Lead Fisherman and Trey, Scientist, holding a nurse shark while measurements are being taken.

The skin of nurse sharks is rough to touch.  Incidentally, all  types of  sharks’ skin is covered in dermal denticles (modified scales) which is what gives them that rough sandpaper type feeling.  If you rub your hand across the shark one way it will feel smooth, but the opposite way will feel coarse.

Dermal denticles, courtesy of Google images

Dermal denticles, courtesy of Google images

Cliff, Fisherman, getting a nurse shark set to measure

Cliff, Fisherman, getting a nurse shark set to measure

2.  Bull shark– These are one of the most aggressive sharks.  They have a high tolerance for low salinity.

Bianca, Scientist, taking a blood sample from a bull shark

Bianca, Scientist, taking a blood sample from a bull shark

bull shark

Bull shark

sandbar shark

Sandbar shark

3. Sandbar shark– These sharks are the most sought after species in the shark industry due to the large dorsal and pectoral fins.  The fins have large ceratotrichia that are among the most favored in the shark fin market.

4.  Atlantic sharpnose shark– The main identifying characteristic of this shark is white spots.

Atlantic sharpnose shark

Atlantic sharpnose shark

5.  Blacknose shark– Like the name portrays, this shark has black on its nose.  These sharks are called “baby lemons” in commercial fish industry because they can have a yellow hue to them.

blacknose shark

Blacknose shark

Me holding a blacknose shark

Me holding a blacknose shark

6.  Blacktip shark- An interesting fact about this shark is that even though it is named “blacktip,” it does not have a black tip on the anal finThe spinner shark, however, does have a black tip on its anal fin.

Jeff and Cliff getting a blacktip shark on board

Jeff and Cliff getting a blacktip shark on board

Tagging a blacktip shark

Tagging a blacktip shark

7. Smooth dogfish– Their teeth are flat because their diet consists of crustaceans, such as crabs and shrimp.

Travis, Scientist, weighing a smooth dogfish

Travis, Scientist, weighing a smooth dogfish

8. Tiger shark– Their teeth work like a can opener.  They are known for their stripes.

A large tiger shark got tangled in our line.  Notice the 2-3 foot sharpnose shark. The tiger shark is about 5 times larger!

A large tiger shark got tangled in our line. Notice the 2-3 foot sharpnose shark at the left. The tiger shark is about 5 times larger!

Me with a tiger shark

Me with a tiger shark

Daniel, Scientist, holding a tiger shark

Daniel, Scientist, holding a tiger shark

9.  Silky shark- Their skin is very smooth like silk.

Daniel, Scientist, holding a silky shark

Daniel, Scientist, holding a silky shark

Another thing I got to see was shark pups because one of the scientists on board, Bianca Prohaska, is studying the reproductive physiology of sharks, skates, and rays.  According to Bianca, there are 3 general modes of reproduction:

1.  oviparous–  Lays egg cases with a yolk (not live birth).  This includes some sharks and all skates.

2.  aplacental viviparous – Develops internally with only the yolk.  This includes rays and some sharks.  Rays also have a milky substance in addition to the yolk.  Some sharks are also oophagous, such as the salmon shark which is when the female provides unfertilized eggs to her growing pups for extra nutrition.  Other sharks, such as the sand tiger, have interuterine cannibalism (the pups eat each other until only 1 is left).

3. placental viviparous– Develop internally initially with a small amount of yolk, then get a placental attachment.  This includes some sharks.

Yet another thing that scientists look at is the content of the shark’s stomach. They do this to study the diet of the sharks.

Skate egg case, Courtesy of Google images

Example of oviparous- Skate egg case, Courtesy of Google images

Placental viviparous

Example of placental viviparous

Dogfish embryo, courtesy of Google images

Example of aplacental viviparous- Dogfish embryo, courtesy of Google images

Contents from the stomach of a smooth dogfish (flounder and squid)

Contents from the stomach of a smooth dogfish (flounder and squid)

Personal Log

Anyone who knows me realizes that I appreciate good food when I eat it.  Okay, on NOAA Ship Oregon II, I have not found just good food, I have found GREAT cuisine!   I am quite sure I have gained a few pounds, courtesy of our wonderful chefs, Walter and Paul.  They have spoiled us all week with shrimp, steak, prime rib, grilled chicken, homemade cinnamon rolls, turkey, dressing, mashed potatoes, and gravy, and the list goes on!   Just talking about it makes me hungry!

Walter is a Chef de Cuisine.  I want to share with you two of the wonderful things, and there are many more, he has prepared for us this week.  The first is called ceviche.  On our shift we caught some grouper.  Walter used these fish to make this wonderful dish.

Grouper used to make ceviche

Grouper used to make ceviche

In addition to the grouper, the ingredients he used were lemon juice, vinegar, onions, jalapeno, kosher salt, and pepper.  He mixed all the ingredients together.  The citric acid cooks the raw fish.  It has to be fresh fish in order to make it.  Instead of lemon juice, apple juice or orange juice can be substituted.  All I know is that since I arrived on NOAA Ship Oregon II, I heard from the entire crew about how great Walter’s ceviche was and it did not disappoint!

Walter, Chef de Cuisine, with his award winning ceviche

Walter, Chef de Cuisine, with his award winning ceviche

Walter's maccaroons

Walter’s macaroons

Another thing Walter is famous for on board NOAA Ship Oregon II are his macaroons.  These are NOT like ANY macaroons you have ever tasted.  These truly melt in your mouth.  Amazingly, he only has 4 ingredients in them: egg whites, powdered sugar, almond paste, and coconut flakes.  They are divine!!

On another note, I would like to give a shout out to my 5th grade students in Jay Upper Elementary School!  (I actually have not had the chance to meet them yet because I am here as a NOAA Teacher at Sea.  I would like to thank my former student, Samantha Morrison, who is substituting for me.  She is doing an outstanding job!!)

Dolphin swimming alongside the ship

Dolphin swimming alongside the ship

Jay 5th Grade:  I cannot wait to meet you!  Thank you for your questions!  We will have lots of discussions when I return about life at sea.  Several of you asked if I have been seasick.  Fortunately, I have not.  Also, you asked if I got to scuba dive.  Only the dive crew can scuba dive.  We are not allowed to have a swim call (go swimming) either.  As you can see, there is plenty to do on board!  Also, you may have noticed that I tried to include some pictures of me tagging some sharks.  Lastly, this dolphin picture was requested by you, too.  Dolphins LOVE to play in the ship’s wake so we see them every day.

Enjoy the view!

I LOVE the scenery out here!  I thought I’d share some of it with you today.

I thought these clouds looked like dragons. What do they look like to you?

I thought these clouds looked like dragons. What do they look like to you?

The vertical development of clouds out here is amazing!

The vertical development of clouds out here is amazing!

Starboard side at sunset

Starboard side at sunset

Sunset from the stern

Sunset from the stern

Sunset in the Gulf of Mexico aboard NOAA Ship Oregon II

Sunset in the Gulf of Mexico aboard NOAA Ship Oregon II

Sunset, port side

Sunset, port side