Stephen Kade: Shark On! August 29, 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: Southeastern U.S. coast

Date: August 29, 2018

 

Scientific Journal

Shark On!” was the shout from the first person that sees a shark hooked to the long line that was being hauled up from the floor of the ocean. I heard this phrase often during the first leg of the long line Red Snapper/ shark survey on the NOAA ship Oregon II. We began fishing in the Northwest Atlantic Ocean, off the coast of West Palm Beach, Florida. We traveled north to Cape Hatteras, North Carolina, and back south to Port Canaveral over 12 days this summer.

hauling in the long line

Oregon II scientific crew, Chief Boatswain, and skilled fishermen hauling in the long line.

During our long line deployments each day, we were able to catch, measure, tag and photograph many sharks, before returning them to the ocean quickly and safely. During these surveys, we caught the species of sharks listed below, in addition to other interesting fish from the ocean.  This blog has scientific information about each shark, and photographs taken by myself and other scientists on board the Oregon II. The following information on sharks, in addition to scientific data about hundreds of other marine wildlife can be found online at the NOAA Fisheries site: http://fisheries.noaa.gov.

Great Hammerhead Shark-  Sphyrna mokarran  Hammerhead sharks are recognized by their long, strange hammer-like heads which are called cephalofoils. Great hammerheads are the largest species of hammerheads, and can grow to a length of 20 feet. The great hammerhead can be distinguished from other hammerheads as they have a much taller dorsal fin than other hammerheads.

Great hammerhead

Great Hammerhead in cradle for data collection and return to sea.

When moving through the ocean, they swing their broad heads from side to side and this motion provides them a much wider field of vision than other sharks. It provides them an all around view of their environment as their eyes are far apart at either end of the long hammers. They have only two small blind spots, in front of the snout, and behind the cephalofoil. Their wide heads also have many tiny pores, called ampullae of Lorenzini. They can sense tiny electric currents generated by fish or other prey in distress from far distances.

 

The great hammerhead are found in tropical and temperate waters worldwide, and inhabiting coastal areas in and around the continental shelf. They usually are solitary swimmers, and they eat prey ranging from crustaceans and squid, to a variety of bony fish, smaller sharks and stingrays. The great hammerhead can bear litters of up to 55 pups every two years.

Nurse Shark- Ginglymostoma cirratum Nurse sharks are bottom dwellers. They spend their life in shallow water, near the sandy bottom, and their orangish- pinkish color and rough skin helps them camouflage them. At night they come out to hunt. Nurse sharks have short, serrated teeth that can eat through crustaceans such as crabs, urchins, shrimp, and lobsters. They also eat fish, squid, and stingrays. They have two feelers, or barbels, which hang from either side of their mouth. They use their barbels to search for prey in the sand. Their average adult size is 7.5- 9 feet in length and they weigh between 160-230 lbs. Adult females reach a larger size than the males at 7- 8.5 feet long and can weigh from 200-267 lbs.

Nurse Shark

Nurse Shark- Ginglymostoma cirratum

Nurse sharks are common in the coastal tropical waters of the Atlantic and also in the eastern Pacific Ocean. This species is locally very common in shallow waters throughout the Caribbean, south Florida to the Florida Keys. Large juveniles and adults are usually found around deeper reefs and rocky areas at depths of 10-250 feet during the daytime and migrate into shallower waters of less than 70 feet deep after dark.

 

Juveniles up to 6 feet are generally found around shallow coral reefs, grass flats or mangrove islands in shallow water. They often lie in groups of forty on the ocean floor or under rock ledges. Nurse sharks show a preference for a certain resting site, and will repeatedly go back to to the same caves for shelter or rest after leaving the area to feed.

Tiger Shark- Galeocerdo cuvier  Adult Tiger sharks average between 10 -14 feet in length and weigh up to 1,400 lbs. The largest sharks can grow to 20 feet and weigh nearly 2,000 lbs. They mature between 5 and 10 years, and their life span is 30 years or more. Tiger sharks are named for the brown stripes and patches they have on their sides when they are young. As they get older, they stripes eventually fade away.

 

They will eat almost anything they come across, and have been referred to as the “garbage cans of the sea”. Their habitat ranges from shallow coastal waters when they are young, to deep waters over 1,500 feet deep. They swim in shallow waters to hunt lobster, squid, fish, sea turtles, birds, and smaller sharks.

tiger shark

10.5 foot Tiger shark caught and returned by NOAA ship Oregon II. photo by Will Tilley

They migrate with the seasons to follow prey and to give birth to young. They swim in cool waters in the summer, and in fall and winter they migrate to warm tropical waters. Their young grow in eggs inside the mother’s body and after 13 months the sharks hatch. The mother gives birth to a litter of 10 – 80 pups. Their current status is currently Near Threatened.

 

Stephen Kade

TAS 2018 Stephen Kade returning sharpnose shark to ocean.

Sharpnose Shark- Rhizoprionodon terraenovae Atlantic sharpnose sharks are small for sharks and have a streamlined body, and get their name from their long, pointy snout. They are several different shades of gray and have a white underside.  Atlantic sharpnose sharks can grow to up to 32 inches in length. Atlantic sharpnose sharks have been observed to live up to 18 years. Females mature at around 2 years old in the Atlantic when they reach approximately 24 inches in length. Atlantic sharpnose sharks are commonly found in the western Atlantic from New Brunswick, Canada, right through the Gulf of Mexico. They are commonly caught in U.S. coastal waters from Virginia around to Texas.

Sharpnose shark

Sharpnose shark

Atlantic sharpnose sharks eat small fish, including menhaden, eels, silversides, wrasses, jacks, toadfish, and filefish. The lower and upper jaws of an Atlantic sharpnose shark have 24 or 25 rows of triangular teeth. Atlantic sharpnose sharks mate annually between mid-May and mid-July in inshore waters, and after mating, they migrate offshore to deeper waters.  They also eat worms, shrimp, crabs, and mollusks.

 

Sandbar Shark- Carcharhinus plumbeus.  The most distinctive feature of this stocky, grey shark is its huge pectoral fins, and long dorsal fin that increases its stability while swimming. Females can grow between 6 – 8.5 feet, and males grow up to 6ft. Its body color can vary from a blue to a light brown grey with a pale white underside. The sandbar shark lives in coastal waters, living in water that is 20 to 200 feet deep. Rarely is its large dorsal fin seen above the water’s surface, as the sandbars prefer to remain near the bottom. It commonly lives in harbors, lagoons, muddy and sandy bays, and river mouths, but never moves into freshwater. The sandbar shark lives in warm and tropical waters in various parts of the world including in the Western Atlantic, from Massachusetts down to southern Brazil.

Sandbar shark

Sandbar shark tagged, measured, weighed and ready to go back after photo.

The sandbar shark spends the majority of its time near the ocean floor, where it looks continuously for prey, such as small fish, mollusks, and various crustaceans. Their main diet consists largely of fish. Sandbar sharks give birth to between 1 and 14 pups in each litter. The size of the litter depends on the size of the mother, with large females giving birth to larger litters. Pregnancy is estimated to last between 8- 12 months. Females move near shore to shallow nursery areas to give birth. The females leave coastal areas after giving birth, while the young remain in the nursery grounds until winter, when they move into warmer and deeper water.

 

 

Fun Fact- Remoras, or shark suckers, live in tropical oceans around the world. They have a rigid oval- shaped sucker pad on top of their head that it uses to attach itself to sharks and rays. It is symbiotic relationship where both animals gain something from their temporary union. Remoras mouths are at the top front of the body so while attached to a shark’s body, they do their host a favor by nibbling off skin parasites. They can also eat scraps of leftover food the shark leaves behind while they also enjoy a free ride. The shark gains a day at the spa for a body scrub, and can rid itself of parasites in a way it couldn’t have before!

Personal Journal

It was certainly an unforgettable experience being able to work with the scientific and fishing team for this shark survey. The opportunity to see and handle these sharks up close for two weeks has informed me of so many interesting things about these wonderful and vital members of the ocean.  I can now take this information and share it first hand with students in my classroom, and members of my community. I also want to work to bring a positive awareness to these vital members of the ocean food web so they can thrive well into the future. As an artist, this trip has been invaluable for me, as now I’ve seen the how colorful and varied sharks are and other various anatomy details you just can’t see in books or television. This new awareness will help to make my future paintings more accurate than before.

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

Denise Harrington: A Shark A Day, September 29, 2016

NOAA Teacher at Sea

Denise Harrington

Aboard NOAA Ship Oregon II

September 16-30, 2016

Mission: Longline Survey

Geographic Area: Gulf of Mexico

Date: Thursday, September 29, 2016

Science Log

The cruise is coming to a close. Looking back at my three experiences with NOAA, hydrography (mapping the ocean), fisheries lab work, or shark and snapper surveys,  I couldn’t decide which was my favorite.  Like the facets of a diamond, each experience gave me another perspective on our one world ocean.

Just like different geographic locations and work, each shark species give me a lens through which I can appreciate the mysteries of the ocean.  Every day, I held, measured, kissed, or released a different species of shark. In the Gulf of Mexico, there are 44 shark species frequently caught.  Fortunately, I saw quite a few, and will share some, in the order in which I met them.

Our first night fishing, we caught many Atlantic sharpnose sharks (Rhizoprionodon terraenovae).  They are named for their long flat snout and sharp nose. It seemed whenever we caught one, a bunch more followed. They were abundant and kept us busy.

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Paul Felts, Fisheries Biologist, records measurements while Kevin Rademacher, Fisheries Biologist, wrestles and measures the shark. Matt Ellis, NOAA Science Writer, took amazing pictures throughout the cruise.

Day two, we caught a deep water Cuban dogfish (Squalus cubensis).  

 

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The Cuban dogfish’s huge iridescent eyes were entrancing.

On September 2o, we almost caught a bull shark (Carcharhinus leucas).  We brought the cradle down, but the shark thrashed its way off, refusing to be studied. The bull shark, along with the tiger shark, are “one of the top three sharks implicated in unprovoked fatal attacks around the world.”

Within a couple days of catching the Cuban dogfish, we caught another shark with iridescent eyes. It turns out this similar looking shark was not a Cuban dogfish, but a rare roughskin spiny dogfish (Cirrhigaleus asper).  

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Dr. Trey Driggers, Field Party Chief, and prolific shark researcher, surprised us all when he reported this was the first roughskin spiny dogfish he had ever caught!

The beautifully mottled, sleek, immature tiger shark (Galeocerdo cuvier) caught on September 23 had remarkable skin patterns that apparently fade as the shark ages. Adult sharks can get as large as 18 feet and 2,000 pounds.  Along with the bull shark, it is one of the top three species implicated in unprovoked, fatal attacks worldwide.

September 24 we caught a fascinating scalloped hammerhead (Sphyrna lewini).  The flat extended head of this hammerhead is wavy, giving it the “scalloped” part of its name.  Its populations in the Gulf have drastically decreased since 1981, making it a species of concern.

 

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Here, Kevin measures one of several scalloped hammerhead sharks we caught on Leg IV of the survey.

We also caught a silky shark (Carcharhinus falciformis). Like other Carcharhinus sharks, the silky shark has a sharp “Carchar,” nose “hinus” (Greek derivation), but also has a silky appearance due to its closely spaced dermal denticles.

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I instantly felt the silky was the most beautiful shark I’d seen. Photo: Matt Ellis/NOAA Fisheries

 

We  saw two of the three smoothhound species present in the Gulf.  On September 25, we caught a Gulf smoothhound, (Mustelus sinusmexicanus), a species named less than 20 years ago. Much is left to learn about the ecology and biology of this recently discovered shark.

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Getting ready to weigh the gulf smoothhound, Kevin Rademacher, Fisheries Biologist, stops for a photo.                                                      Photo: Matt Ellis/NOAA Fisheries

Then, I watched the night crew catch, measure and tag a dusky shark (Carcharhinus obscurus).

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Photo: NOAA Fisheries

On September 26, we caught a sandbar shark (Carcharhinus plumbeus).  Despite its size,  the sandbar shark poses little threat to man.

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The sandbar shark’s large fin to body ratio and size make them a prime target for commercial fisheries. Photo: Matt Ellis/NOAA Fisheries

Due to over-fishing, sandbar shark populations are said to have dropped by as much as 2/3 between the 1970’s and the 1990’s. They are now making a comeback, whether it be from fishing regulations, or the decreased populations of larger sharks feeding on juvenile sandbar sharks.

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This sandbar shark attacked a blacknose shark that had taken our bait. Photo: Matt Ellis/NOAA Fisheries

We tagged many sharks during my two weeks on the Oregon II.  If you never catch one of those sharks again, the tag doesn’t mean anything.  But this week, we also caught a previously tagged sandbar shark!  Recapturing a wild marine animal is phenomenal.  You can learn about its migration patterns, statistically estimate population sizes, and learn much more. The many years of NOAA’s work with this species in particular demonstrates that thoughtful, long term management of a species works.

 

On September 27, we almost caught a nurse shark (Ginglymostoma cirratum). The barbels coming from its mouth reminded me of a catfish or exotic man with a mustache.

Today, September 29, was our last day of fishing, a bittersweet day for me.  That nurse shark that got away, or more likely, another one like it, came up in our cradle.

Every day we caught sharks, including a few other species not mentioned here.  Only once our line came back without a fish.  The diverse characteristics and adaptations that allow each of these species to survive in a challenging marine environment inspire biologists as they try to categorize and understand the species they research.   While catching so many different species of sharks gives me hope, many members of the crew reminisce about times gone by when fish were more abundant than they are now.

Personal Log

I am the kind of person who always struggles to return from an adventure.  I have learned so much, I don’t want to leave.  Yet I know my class at South Prairie is waiting patiently for my return. I hope to share these many marine species  with my class so that we all may view every moment with curiosity and amazement.

 

 

 

 

Jeff Miller: Wrestling Sharks for Science, September 9, 2015

NOAA Teacher at Sea
Jeff Miller
Aboard NOAA Ship Oregon II
August 31 – September 14, 2015

Mission: Shark Longline Survey
Geographical Area: Gulf of Mexico
Date: September 9, 2015

Data from the Bridge
Ship Speed: 9.4 knots
Wind Speed: 6.75 knots
Air Temp: 29.4°C
Sea Temp: 30.4°C
Seas: <1 meter
Sea Depth: 13 meters

GPS Coordinates
Lat:  N 29 25.103
Long:  W 092.36.483

Science and Technology Log
The major goal of our mission is to survey shark populations in the western Gulf of Mexico and collect measurements and biological samples.  The sharks are also tagged so if they are re-caught scientists can learn about their growth and movements.

Sharks are members of the class of fishes called Chondrichthyes,which are cartilaginous fishes meaning they have an internal skeleton made of cartilage.  Within the class Chondricthyes, sharks belong to the subclass Elasmobranchii together with their closest relatives the skates and rays.  There are about 450 species of living sharks that inhabit oceans around the world.

Sharks, or better put their ancient relatives, have inhabited the oceans for approximately 450 million years and have evolved a number of unique characteristics that help them survive and thrive in virtually all parts of the world.  The most recognizable feature of sharks is their shape.  A shark’s body shape and fin placement allow water to flow over the shark reducing drag and making swimming easier.  In addition, the shark’s cartilaginous skeleton reduces weight while providing strength and flexibility, which also increases energy efficiency.

Blacktip shark

Measuring a blacktip shark on deck. The blacktip shark shows the typical body shape and fin placement of sharks. These physical characteristics decrease drag and help sharks move more efficiently through water.

When I held a shark for the first time, the feature I noticed most is the incredible muscle mass and strength of the shark.  The body of a typical shark is composed of over 60% muscle (the average human has about 35-40% muscle mass).  Most sharks need to keep swimming to breathe and, therefore, typically move steadily and slowly through the water.  This slow, steady movement is powered by red muscle, which makes up about 10% of a sharks muscle and requires high amounts of oxygen to produce fuel for muscle contraction.  The other 90% of a sharks muscle is called white muscle and is used for powerful bursts of speed when eluding predators (other sharks) or capturing prey.

Since sharks are so strong and potentially dangerous, one lesson that I learned quickly was how to properly handle a shark on deck.  Smaller sharks can typically be handled by one person.  To hold a small shark, you grab the shark just behind the chondrocranium (the stiff cartilage that makes up the “skull” of the shark) and above the gill slits.  This is a relatively soft area that can be squeezed firmly with your hand to hold the shark.  If the shark is a bit feisty, a second hand can be used to hold the tail.

Holding a sharpnose shark

Smaller sharks, like this sharpnose shark, can be held by firmly grabbing the shark just behind the head.

Larger and/or more aggressive sharks typically require two sets of hands to hold safely.  When two people are needed to hold a shark, it is very important that both people grab the shark at the same time.  One person holds the head while the other holds the tail.  When trying to hold a larger, more powerful shark, you do not want to grab the tail first.  Sharks are very flexible and can bend their heads back towards their tail, which can pose a safety risk for the handler.  While holding a shark sounds simple, subduing a large shark and getting it to cooperate while taking measurements takes a lot of focus, strength, and teamwork.

Holding a blacktip shark

Teamwork is required to handle larger sharks like this blacktip shark, which was caught because it preyed on a small sharpnose shark that was already on the hook.

 

Measuring a blacktip shark

Collecting measurements from a large blacktip shark.

 

Holding a blacktip shark

Holding a blacktip shark before determining its weight.

When a shark is too big to bring on deck safely, the shark is placed into a cradle and hoisted from the water so it can be measured and tagged.  We have used the cradle on a number of sharks including a 7.5 foot tiger shark and a 6 foot scalloped hammerhead shark.  When processing sharks, we try to work quickly and efficiently to measure and tag the sharks to minimize stress on the animals and time out of the water.  Once our data collection is complete, the sharks are returned to the water.

Tiger shark in the cradle

Large sharks, like this tiger shark, are hoisted up on a cradle in order to be measured and tagged.

Personal Log
We are now in full work mode on the ship.  My daily routine consists of waking up around 7:30 and grabbing breakfast.  After breakfast I like to go check in on the night team to see what they caught and determine when they will do their next haul (i.e. pull in their catch).  This usually gives me a couple hours of free time before my shift begins at noon.  I like to use my time in the morning to work on my log and go through pictures from the previous day.  I eat lunch around 11:30 so I am ready to start work at noon.  My shift, which runs from noon to midnight, typically includes surveying three or four different stations.  At each station, we set our baited hooks for one hour, haul the catch, and process the sharks and fishes.  We process the sharks immediately and then release them, whereas we keep the fish to collect biological samples (otoliths and gonads).  Once we finish processing the catch, we have free time until the ship reaches the next survey station.  The stations can be anywhere from 6 or 7 miles apart to over 40 miles apart.  Therefore, our downtime throughout the day can vary widely from 30 minutes to several hours (the ship usually travels at about 10 knots; 1 knot = 1.15 mph).  At midnight, we switch roles with the night team.  Working with fish in temperatures reaching  the low 90°s will make you dirty.  Therefore, I typically head to the shower to clean up before going to bed.  I am usually in bed by 12:30 and will be back up early in the morning to do it all over again.  It is a busy schedule, but the work is interesting, exciting, and fun.  I feel very lucky to be out here because not many people get the opportunity to wrestle sharks.  This is one experience I will always remember.

Julie Karre: Let’s Haul it Back Now, Ya’ll! July 30, 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 Range of Cruise: Atlantic
Date: Tuesday, July 30, 2013 

Weather Data from the Bridge
SW WINDS 5 TO 10 KNOTS BECOMING SE IN THE AFTERNOON
SEAS 2 TO 3 FEET WITH A DOMINANT PERIOD 14 SECONDS
SLIGHT CHANGE OF SHOWERS AND THUNDERSTORMS

Science and Technology Log

Preparing for a haul back. Everyone wears a PFD (personal flotation device) during a haul and a helmet if the cradle is used.

Preparing for a haul back. Everyone wears a PFD (personal flotation device) during a haul and a helmet if the cradle is used.

What an incredibly fast-paced morning/end of shift for the night shift! As the day shift was getting up and wandering out to check in, the night shift was putting out their first set of the cruise. Day shift, which I’m on, put out two sets the afternoon/night before. Night shift had to skip two last night because of the current. But this haul back made up for it. The crew processed 64 sharks – Sharpnose and Blacknose – at a swift, demanding pace. It was a learning experience to see them handle it so calmly, never missing a beat.

Night shift volunteers Page Vick and Claudia Friess work together to remove a hook.

Night shift volunteers Page Vick and Claudia Friess work together to remove a hook while Ian Davenport records the data.

Night Shift Watch Leader and NOAA scientist Lisa Jones takes a Sharpnose Shark from a fisherman.

Night Shift Watch Leader and NOAA scientist Lisa Jones takes a Sharpnose Shark from a fisherman and removes its hook.

A weighed, measured, sexed shark is released to the ocean.

A weighed, measured, sexed shark is released to the ocean.

At noon it was our turn and by 2pm we were putting out the first of three hauls we would do that day. That first haul brought up 56 sharks in just over an hour’s time. I was recording the data as measurements were taken. We brought up Sharpnose Sharks and Blacknose Sharks. It has been such an eye-opening experience bringing up sharks these last two days because it is so easy to imagine sharks as being enormous and ferocious, which of course some are, but we are bringing up sharks that, for the most part, can be held up with one hand and weigh less than 4.5kg. I think it is important to remember that the images of The Great White and Bull Sharks are not necessarily representative of all sharks. That doesn’t mean that these smaller sharks are not dangerous, it just means they’re not enormous and overwhelming.

Volunteers Holly Perryman and Kevin Travis handle sharks as I record the data.

Volunteers Holly Perryman and Kevin Travis handle sharks as I record the data. Photo Credit: Claudia Friess

We had just enough time to rebait the hooks and hang out for a few minutes before we set out another set 9 miles later. That haul back was light, but did come with a Scalloped Hammerhead. When we get these large sharks (Nurse, Tiger, Hammerhead, Sandbar), it requires a large cradle attached to a crane. The cradle is lowered into the water and the shark is led on with the line attached to the hook. This requires a lot of precise coordination. The person operating the crane cannot see the shark and is then dependent on those at the opening to be clear and loud with directions. Two people hold ropes that stabilize the cradle. They have to stay in sync so that the moving shark doesn’t throw itself over a side, while another person is trying to control the shark with the line attached to the hook. It’s really incredible to watch this team of skilled fishermen and scientists work so quickly with such a large animal. Each large animal is measured, weighed, tagged, and a small tissue sample is taken. Then the cradle is lowered and it swims gracefully away.

It's Hammer time! This Scalloped Hammerhead was very exciting. Photo Credit: Claudia Friess

It’s Hammer time! This Scalloped Hammerhead was very exciting. Photo Credit: Claudia Friess

It's Hammer time! This Scalloped Hammerhead was very exciting. Photo Credit: Claudia Friess

It’s Hammer time! Chief Boatswain Tim Martin keeps a firm grip on the head of the shark. Photo Credit: Claudia Friess

A quick dinner later and then we set out what ended up being our last set around 9:30 pm. At 10:50 pm we began our haul back, which was light on Sharpnose and Blacknose. We got a few and they were small, but the real treat was hauling up 4 Sandbars. Of the 4, we brought up 2 because the other 2 got away. The Sandbar is a really beautiful shark. It has a high first dorsal fin and is one of the largest coastal sharks in the world. According to Chief Scientist Kristin Hannan, the Sandbar’s large fin makes it more desirable by fishermen harvesting fins. Having seen these large, but gorgeous, animals and how gracefully they swim makes me sad that they would be desirable for such an unsustainable practice. Fortunately, in 2008 the National Marine Fisheries Service banned all commercial landings of Sandbar Sharks. The Sandbar is currently listed as a vulnerable species due to overfishing.

Kristin Hannan measuring a Sandbar Shark in the cradle.

Kristin Hannan measuring a Sandbar Shark in the cradle.

This haul back gave me a unique perspective. In previous hauls I’d been over where the fish are measured, weighed, and data recorded. But this time I was racking hooks as they came back, which means that I was just below the window where NOAA Corps Officer ENS Rachel Pryor was driving the ship. This is ENS Pryor’s first longline survey and she said it’s the survey that has the deck and bridge the most connected. Because we’re pulling up animals from a bottom longline, the control of the ship is crucial. The driver must control the ship on station making sure it doesn’t drift over the longline and in those instances of bringing up big sharks on the cradle, he or she keeps us on the station so there isn’t too much tension on the line. Whether it’s ENS Pryor, another NOAA Corps officer, or the Captain, Master Dave Nelson, he or she is just as essential to the survey as the people handling the sharks. Truly a team effort.

The set ended right at a shift change and we were lucky to make that switch on a light haul. Most of the hooks came up empty, including emptying of our bait, so something down there enjoyed an easy free meal.

I took the opportunity to watch the stars for a while before heading to bed. I was not disappointed.

Personal Log

During those first three days of no fishing, much reading was done. I finished a book on Sunday and am waiting to start my other book since I only brought two, but others on the ship have been reading a lot during breaks. At least two people have read the entire Hunger Games Trilogy while on board. It should come as no surprise to my students that this makes me VERY happy. The seventh and eighth graders of Armistead Gardens will be returning to school in August for a Hunger Games semester. The eighth graders read the first book before we left school last year, so we are set to keep reading. The seventh graders begin the Games when we meet in August.

Ladies and Gentlemen, let the 19th Longline Games begin!

Ladies and Gentlemen, let the 19th Annual Longline Games begin! Volunteers Claudia Friess and Mike Hendon devouring the Hunger Games trilogy. Both have started and finished the series since we departed Pascagoula.

BOOK REPORT:

I finished the debut novel by Carrie Mesrobian, which is scheduled to be released this fall. I began reading on Thursday the 25th when I moved onto the ship, but I had to slow myself down because I only have one other book. So I paced it enough to give me a few more days of pleasure. And what a pleasure it is to read such a raw and real book. I read a lot of young adult fiction, mostly for pleasure and sometimes to know what my students are in. I love what young adult literature offers readers in terms of dealing with certain experiences. I have not read many young adult novels written from the male perspective, though. I know there are many, but I have not done a very good job of getting into them. I loved reading Evan. His self-loathing was so real that I was immediately on his side. I thought the sensitive subject matter was handled realistically and appropriately. Well done. Can’t wait to read it again.

An exquisite sunset at the end of a beautiful day.

An exquisite sunset at the end of a beautiful day.

Did You Know?

I learned this from a science teacher at Armistead Gardens Elem/Middle school – there are FOUR meteor showers peaking last night and tonight – Piscis, Austrinids, Aquariids, and Capricornids. Maybe some of my “shooting stars” were from these meteor showers. Thanks Ms. Palmisano for sharing your knowledge!

This is the 19th year of doing the Shark and Red Snapper Longline Survey. That’s a lot of data!

Animals Seen

Sharpnose, Rhizoprionodon terraenovae
blacknose, Carcharhinus acronotus
Sea Nettle, Chrysaora quinquecirrha
Sandbar, Carcharhinus plumbeus
Scalloped hammerhead, Sphyrna lewini

Seastar

Volunteer Kevin Travis with a starfish that came up on a clip. Photo Credit: Claudia Friess

Volunteer Kevin Travis with a starfish that came up on a clip. Photo Credit: Claudia Friess

Steven Frantz: Sharks at Sea, August 3, 2012

NOAA Teacher at Sea
Steven Frantz
Onboard NOAA Ship Oregon II
July 27 – August 8, 2012

Mission: Longline Shark Survey
Geographic area of cruise: Gulf of Mexico and Atlantic off the coast of Florida
Date: August 3, 2012

Weather Data From the Bridge:
Air Temperature (degrees C): 28.79
Wind Speed (knots): 14.14
Wind Direction (degree): 199.05
Relative Humidity (percent): 070
Barometric Pressure (millibars): 1017.95
Water Depth (meters): 58.0
Salinity (PSU): 35.635

Location Data:
Latitude: 3409.72N
Longitude: 17611.11W

SHARKS AT SEA

Our 300th mission aboard the Oregon II is a Longline Shark Survey.  Stratified randomly selected sites have been generated using Arc GIS Software. This eliminates potential bias in sampling and each area has an equal opportunity to be sampled. Two depth strata zones (A: 5-30 fathoms, B: 30-100 fathoms) have been factored for the Atlantic. In order to avoid all sampling sites randomly bunched all together, the area has been divided into 60 nautical mile geographic zones from southern Florida to North Carolina. 60% of our effort (ex. time at sea) is put toward “A” stations and 40% of our effort is put toward “B” stations. This method of picking stations is called proportional allocation.

We are here to find sharks. This is important because so very little is known about them, or many of the other animals living in an extreme environment (extreme for people to live in).

One if the first sharks we caught was a blacknose shark, Carcharhinus acronotus. It is relatively small, a uniform gray color, and has a black tip on its nose.

Black-Nose Shark

Here I am holding Black-Nose Shark

The most common shark found so far has been the sharpnose shark, Rhizoprionodon terraenovae. Both sharpnose and blacknose sharks are considered to be small coastal sharks by the National Marine Fisheries Service. While similar in size to the black nose shark, the sharpnose shark is spotted. When brought on board, their size is nothing compared to their strength. I guess you have to act tough when you’re little!

Sharpnose being Weighed

Sharpnose being Weighed

Tough though they may be, we caught several sharp-nose sharks that have become bait themselves! I wonder what (kind of shark?) it was that ate the back half of this sharp-nose?

Shark as "Bait"

Shark as “Bait”

One of the many data we are collecting is the sex of the sharks. Pictured below are a male (top), then female (bottom). The male shark has claspers, which are used for internal fertilization. Claspers are also used to determine a male’s age depending on how calcified they are.  This is the standard way to determine sex on all the sharks we have caught thus far.

Male Sharpnose Shark

Male Sharpnose Shark

Female Sharpnose Shark

Female Sharpnose Shark

Another piece of data collected is a clip of flesh from a fin. This is a non-lethal way for scientists to obtain DNA for genetics studies and possibly for use in population structure for identification purposes.

Fin Clipping

Fin Clipping

As we saw above, some sharks don’t make it on board alive. While this is uncommon, the opportunity does present itself for more invasive study not done on living animals. Sharpnose sharks give birth to live young (viviparous). Pictured below are young sharks taken from a female. It is interesting to note that whether the shark is male or female can be determined at this early stage. Remember, not all sharks reproduce this way.

Baby Sharpnose

Baby Sharpnose

Sandbar sharks, Carcharhinus plumbeus, have been the next most common sharks caught. These are quite a bit larger than sharp-nose sharks, averaging 150 centimeters long and 35 kilograms in mass.

Sandbar Shark

Sandbar Shark

We must be safe when collecting data. Shark’s skin is like sandpaper, so if the teeth or tail doesn’t get you, you can also be given a pretty red rash by the scrapping of their skin against your skin.

Measuring a Sandbar Shark

Measuring a Sandbar Shark

Tagged Sandbar Shark

Tagged Sandbar Shark

Sandbar sharks were popular with the shark fin soup industry because they have a very large dorsal fin compared to their body size. Sharks were caught, their fin was cut off, and then the still-living shark was released back into the ocean to die. This practice has been outlawed in U.S. waters.

Sandbar Shark & Me

Sandbar Shark & Me

Watch the video below as a sandbar shark is caught and brought to the Oregon II.

The prettiest shark (at least to me) I’ve seen so far is the tiger shark, Galeocerdo cuvier. They can get very large. Three meters long or more! The ones we’ve found have been smaller. The one I’m holding is very young. The umbilical scar was still visible! Tiger shark teeth are different from most sharks in that a tiger shark’s teeth are made to slice their prey, like the shells of sea turtles.

Tiger Teeth

Tiger Teeth

Tiger Shark & Me

Tiger Shark & Me

Sharks don’t have eyelids, like we have eyelids, to protect their eyes. They have what is called a nictitating membrane to protect their eyes. Here is a picture of the nictitating membrane partially covering a sharpnose shark’s eye.

Nictitating Membrane

Nictitating Membrane

The most unusual shark we’ve caught has been the scalloped hammerhead shark, Sphyrna lewini. Once on board the Oregon II they seemed to be docile (for a shark), however, their eyes on the far ends of their head were always looking, watching what was going on.

Why is their head shaped like it is? Even scientists don’t know for sure. Some think it acts as a hydrofoil to help it move through the water. Other scientists think (because of its large size) it helps detect electrical impulses in the water (like a sixth sense). Do you have any ideas why their head is shaped the way it is?

Scalloped Hammerhead Shark

Scalloped Hammerhead Shark

Scalloped Hamerhead Shark

Scalloped Hammerhead Shark

Scalloped Hamerhead Shark

Scalloped Hammerhead Shark

I have been working the day shift: from noon to midnight. The other crew is the night shift. In addition to what we have seen so far, the night shift has also seen a great hammerhead, Sphyrna mokarran and a silky shark, Carcharhinus falciformes.

We still have five days of fishing left. What will we catch next? I’ll let you know!