Longline Shark Survey – NOAA Teacher at Sea Blog

August 31, 2018August 31, 2018

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.

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.

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.

Male Great Hammerhead 10. 5 ft.

Great Hammerhead cephalofoil

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 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.

Nurse shark in cradle

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.

juvenile tiger shark

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.

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.

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.

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 on long line

Sandbar Shark in cradle

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.

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.

remora sucker pad

remora being weighed

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.

August 20, 2018August 21, 2018

Stephen Kade: What is Long Line Fishing? August 19, 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 35’ 34’’ N, 80 56’ 48’’ W, 20 miles off the coast of Jessup, Georgia

Date: August 2, 2018

Weather Data from Bridge: Wind speed 14 knots, Air Temp: 27c, Visibility 10 nautical miles, Wave height 2 ft.

Science and Technology Log

Longline fishing is a technique that consists of one main fishing line with many baited hooks that come of that line on shorter lines, (like branches off a tree) attached at various distances. Long lines are used in both coastal areas and the open ocean and are often placed to target specific species. If the long line is suspended in the top or mid depth water, it is called pelagic longline fishing. If it is on or near the ocean floor by weighting it down to the sea floor, it is called bottom longline fishing. A high-flyer buoy is placed at either end to mark the position of the line in the water so boats can see it while submerged, and so it can be found when it needs to be retrieved. Weights are placed on each end and the middle of the line to hold the line down to a specified depth.

Longline_KadeTAS2018 — Computer created infographic of long line fishing process by NOAA TAS 2018 Stephen Kade

On board NOAA Ship Oregon II, the mission is a red snapper/shark longline fishing survey in the Gulf of Mexico and the Western North Atlantic coast. I was on the first of four legs of the survey that left Pascagoula, Mississippi, rounded the bottom of Florida and stopped for 44 stations between West Palm Beach FL, up to Cape Hatteras, NC, and back down to Port Canaveral, FL. NOAA’s mission is to research current shark and snapper populations in specific areas as determined by NOAA shark scientists and related state Fishery Departments.

The Oregon II has a large spool of 3mm monofilament fishing line on deck. For our survey, we used a line that was one mile long, and had 100 baited hooks approximately 50 feet apart. The hooks are attached to the line by gangions. Gangions are 12 foot long monofilament lines with a hook on one end and a manual fastener at the other end that can be taken on and off each time the line is deployed. All 100 hooks on the gangions are baited with Atlantic mackerel.

numbering gangions — The team attaches the gangion numbers and hands over for deployment

To deploy the line into the water, it takes a team of 6 people. The first person strings the line from the spool and through various pulleys along the length of the ship moving toward the back of the boat before tying it to the high flyer buoy and returning to the spool control to deploy the mile long line into the water. A team of two works to attach a specific number tag onto each gangion, and then to retrieve the 12 foot long gangion from a barrel. The numbered, baited, gangions are handed one by one to the next team member who attaches the gangion of the main long line every 60 feet as the line descends into the water. This crewman also places three weights on the line to hold it onto the ocean floor, one at each end, and one in the middle. When all hooks are deployed, the line is cut from the spool and the high-flyer buoy is attached to mark the end of the line in the water.

deploying high-flyer — Deploying the high-flyer buoy after all 100 gangions and weights are attached.

The last member of the science team is at a computer station on deck and they are in charge of inputting data into the computer. Each time a buoy, weight, or gangion goes into the water, a specific button is pushed to mark the items place in the water. This is done so when a shark comes up on a numbered hook, NOAA scientists know exactly the latitude, longitude and depth of where that specific shark was caught. Scientists upload this important data immediately to NOAA servers for later use so they can assess average populations in specific areas, among many other data points.

The bait stays down on the ocean floor for about an hour before the boat returns to retrieve it. The retrieval process is similar to deploying the line except that it takes longer to bring it in, as there are now some fish and sharks attached to the hooks. If the hooks are empty, the number is taken off the line, and the gangion is placed back in the barrel until the next station. If there is a shark or fish on the line, it is pulled onto the deck and data is collected before the shark is safely placed back into the water. The first step is unhooking the fish, before it is measured. The shark is measured from the tip of the nose to various parts of the body to determine the size in those areas. The gender of the shark is also determined, as well as the maturity. Finally, the shark is weighed on a scale and most are tagged before being photographed and released. The process only takes about two minutes to safely ensure the shark survives. The data is recorded on a data log, and after the retrieval, the data is input into a database.

Removing Gangions — Gangions are taken off the long line, de-baited, de-numbered and put back in barrel.

Personal Log

Before coming on the Oregon II, I knew only about the fishing process on a larger scale from what I’d read about, or seen on television. I was slightly intimidated that without experience, I’d likely be slowing down the experienced team of professionals from their difficult job. As we headed out to sea, I found out it would take a few days before we reached our first station and that gave me time to get to know the crew, which was very valuable. There are two crews, each work 12 hours a day, so fishing was happening around the clock. I was able to listen to their advice and explanation of the techniques used in the long line process, and also some fantastic stories about their lives and families. Their patience with me and the other volunteers during those first few stations gave us time to get up to their speed, and from then out it was like clockwork. It was certainly hard to work outside all day, but the passion, skill, and humor of the crew made it quite fun work each day and night. It was impressive and amazing to see how this efficient process is used to help NOAA scientists and fishermen collect data from vast areas of the ocean for two weeks. I am proud to say I helped a great team to get information that can help us understand how to help populations of sharks and fish for long into the future.

Stephen removes shark — TAS 2018 Stephen Kade taking shark off gangion, ready to measure, weigh, and put back in ocean

September 15, 2016March 26, 2021

Barney Peterson: What Are We Catching? August 28, 2016

NOAA Teacher at Sea

Barney Peterson

Aboard NOAA Ship Oregon II

August 13 – 28, 2016

Mission: Long Line Survey

Geographic Area: Gulf of Mexico

Date: Sunday, August 28, 2016

Weather Data is not available for this post because I am writing from the Biloxi/Gulfport Airport.

WHAT ARE WE CATCHING?

This is a long-line survey. That means we go to an assigned GPS point, deploy hi-flyer buoys, add weights to hold the line down, add 100 baited hooks, leave it in place for an hour, and retrieve everything.

mackerel-bait-fish — Mackerel is used to bait the hooks.

As the equipment is pulled in we identify, measure and record everything we catch. Sometimes, like in the case of a really large, feisty shark that struggles enough to straighten or break a hook or the lines, we try to identify and record the one that got away. We tag each shark so that it can be identified if it is ever caught again. We tally each hook as it is deployed and retrieved, and the computer records a GPS position for each retrieval so scientists can form a picture of how the catch was distributed along the section we were fishing. The target catch for this particular survey was listed as sharks and red snapper. The reality is that we caught a much wider variety of marine life.

We list our catch in two categories: Bony fish, and Sharks. The major difference is in the skeletons. Bony fish have just that: a skeleton made of hard bone like a salmon or halibut. Sharks, on the other hand, have a cartilaginous skeleton, rigid fins, and 5 to 7 gill openings on each side. Sharks have multiple rows of sharp teeth arranged around both upper and lower jaws. Since they have no bones, those teeth are embedded in the gums and are easily dislodged. This is not a problem because they are easily replaced as well. There are other wonderful differences that separate sharks from bony fish.

Bony Fish we caught:

The most common of the bony fish that we caught were Red Groupers (Epinephelus morio), distinguished by of their brownish to red-orange color, large eyes and very large mouths. Their dorsal fins, especially, have pointed spikes.

chrissy-with-enormous-grouper — Chrissy holding an enormous grouper

We also caught Black Sea Bass (Centropristus striata) which resemble the groupers in that they also have large mouths and prominent eyes.

A third fish that resembles these two is the Speckled Hind (Epinephelus drummondhayi). It has a broad body, large mouth and undershot jaw giving the face a different look. Yes, we did catch several Red Snapper (Lutjanus campechanus), although not as many as I expected. Snappers are a brighter color than the Red Groupers, and have a more triangular shaped head, large mouth and prominent canine teeth.

The most exciting bony fish we caught was barracuda (Sphyraena barracuda). We caught several of these and each time I was impressed with their sleek shape and very sharp teeth!

Most of the bony fish we caught were in fairly deep water.

Eel

Flying Fish

Sharks:

We were fortunate to catch a variety of sharks ranging from fairly small to impressively big!

The most commonly caught were Sandbar Sharks (Carcharhinus plumbeus): large, dark-gray to brown on top and white on the bottom.

Unless you really know your sharks, it is difficult for the amateur to distinguish between some of the various types. Experts look at color, nose shape, fin shape and placement, and distinguishing characteristics like the hammer-shaped head of the Great Hammerhead (Sphyrna mokarran) and Scalloped Hammerhead (Sphyrna lewini) sharks that were caught on this trip.

The beautifully patterned coloring of the Tiger Shark (Galeocerdo cuvier) is fairly easy to recognize and so is the yellowish cast to the sides of the Lemon Shark (Negaprion brevirostris).

Tiger Shark

Lemon Shark

Other sharks we caught were Black-nose (Carcharhinus acrontus), Atlantic Sharp-nosed (Rhizoprionodon terraenovae), Nurse Shark (Ginglymostoma cirratum), Blacktip (Carcharhinus limbatus) and Bull Sharks (Carcharhinus leucus).

Atlantic Sharp-nosed

Nurse Shark

Bull Shark

Several of the sharks we caught were large, very close to 3 meters long, very heavy and very strong! Small sharks and bony fish were brought aboard on the hooks to be measured against a scaled board on the deck then weighed by holding them up on a spring scale before tagging and releasing them. Any shark larger than about 1.5 meters was usually heavy and strong enough that it was guided into a net cradle that was lifted by crane to deck level where it could be measured, weighed and tagged with the least possibility of harm to either the shark or the crew members. Large powerful sharks do not feel the force of gravity when in the water, but once out of it, the power of their weight works against them so getting them back into the water quickly is important. Large powerful sharks are also pretty upset about being caught and use their strength to thrash around trying to escape. The power in a swat from a shark tail or the abrasion from their rough skin can be painful and unpleasant for those handling them.

PERSONAL LOG

The Night Sky

I am standing alone on the well deck; my head is buzzing with the melodies of the Eagles and England Dan. A warm breeze brushes over me as I tune out the hum of the ship’s engines and focus on the rhythm of the bow waves rushing past below me. It is dark! Dark enough and clear enough that I can see stars above me from horizon to horizon: the soft cloudy glow of the Milky Way, the distinctive patterns of familiar favorites like the Big Dipper and the Little Dipper with its signature bright point, the North Star. Cassiopeia appears as a huge “W” and even the tiny cluster of the “Seven Sisters” is distinct in the black bowl of the night sky over the Gulf of Mexico. The longer I look the more stars I see.

This is one of the first really cloudless nights of this cruise so far. Mike Conway, a member of the deck crew came looking for me to be sure I didn’t miss out on an opportunity to witness this amazingly beautiful show. As I first exited the dry lab and stumbled toward the bow all I could pick out were three faint stars in the bowl of the Big Dipper. The longer I looked, the more my eyes grew accustomed to the dark, and the more spectacular the show became. Soon there were too many stars for me to pick out any but the most familiar constellations.

As a child I spent many summer nighttime hours on a blanket in our yard as my father patiently guided my eyes toward constellation after constellation, telling me the myths that explained each one. Many years have passed since then. I have gotten busy seeing other sights and hearing other stories. I had not thought about those long ago summer nights for many years. Tonight, looking up in wonder, I felt very close to Pop again and to those great times we shared.

August 7, 2015August 21, 2021

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.

Yesterday, during a brief period of downtime, I took the opportunity to go down to the engine room. Temperatures routinely exceed 103 ^oF, 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.

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.*

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. 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.*

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.

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.

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*

“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).

silky measure silky hold

August 5, 2015August 21, 2021

Kathleen Gibson, Hammerheads on the Line, August 4, 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: Aug 4, 2015

Coordinates:
LAT 3323.870N
LONG 07736.658 W

Great Hammerhead Photo Credit: Ian Davenport — Great Hammerhead (Photo Credit: Ian Davenport)

Weather Data from the Bridge:
Wind speed (knots): 28
Sea Temp (deg C): 29.2
Air Temp (deg C): 24.2

Early this morning the night shift caught and cradled a great hammerhead shark (Sphyrna mokarran). This is a first for this cruise leg. I’m sure that just saying “Hammerhead” conjures an image of a shark with an unusual head projection (cephalofoil), but did you know that there are at least 8 distinct Hammerhead species? Thus far in the cruise we have caught 4 scalloped hammerheads (Sphyrna lewini), one of which I was fortunate to tag.

Science and Technology Log

All eight species of hammerhead sharks have cephalofoils with differences noted in shape, size, and eye placement, to name a few. Research indicates that this structure acts as a hydrofoil or rudder, increasing the shark’s agility. In addition, the structure contains a high concentration of specialized electro sensory organs (Ampullae of Lorenzini) that help the shark detect electric signals of other organisms nearby. The eye placement at each end of the cephalofoil allows hammerhead sharks to have essentially a panoramic view with only a slight movement of their head – quite handy when hunting or avoiding other predators.

Comparison of Scalloped and Great Hammerhead Sharks
Image Credit: NOAA Fisheries Shark Species

Great hammerhead sharks are highly migratory. They are found worldwide in tropical latitudes, and at various depths. There are no geographically Distinct Population Segments (DPS) identified. The great hammerhead, as its name implies, is the largest of the group and average size estimates of mature individuals varies between 10-14 ft in length with a weight approximately 500 lb.; the largest recorded was 20 ft in length. The one we caught was ll ft. in length.

As with most shark species, the numbers declined rapidly between 1975 and 1995 due to the fin fishing industry and focused sport fishing often fueled by fear and misinformation. One has to wonder what the average length was before that time.

Scalloped Hammerhead sharks are the most common hammerhead species. Their habitat overlaps that of the great hammerhead, though they are more often found in slightly shallower waters. In contrast to the great hammerhead, scalloped hammerheads are only semi-migratory, and scientists have identified Distinct Population Segments around the world. This is important information when evaluating population size and determining which groups, if any, need regulatory protection.

Weighing a small Scalloped Hammerhead Photo Credit: Ken Wilkinson — *Weighing a small scalloped hammerhead*
Photo Credit: Ken Wilkinson

Scalloped Hammerhead on deck. Photo: Erica Nuss — *Scalloped hammerhead on deck*
Photo: Ian Davenport

The average life expectancy for both species is approximately 30 years. Males tend to become sexually mature before females, at smaller weights; females mature between 7-10 years (sources vary). In my last log I discussed shark reproduction – Oviparous vs. Viviparous. (egg laying vs. live birth). All hammerheads are viviparous placental sharks but reproductive patterns do differ. Great hammerheads bear young every two years, typically having 20-40 pups. A great hammerhead recently caught by a fisherman in Florida was found to be pregnant with 33 pups. Scalloped have slightly fewer pups in each brood, but can reproduce more frequently.

Career Spotlight – NOAA Corps

Setting and retrieving the Longline requires coordination between Deck Operations and the Bridge. Up until now I’ve highlighted those on deck. Let’s learn a bit about two NOAA officers on the Bridge.

The NOAA Corps is one of the 7 Uniformed Services of the United States and all members are officers. The Corps’ charge is to support the scientific mission of NOAA, operating and navigating NOAA ships and airplanes. Applicants for the Corps must have earned Bachelor’s degree and many have graduate degrees. A science degree is not required but a significant number of science units must have been completed. It’s not unusual for Corps recruits to have done post-baccalaureate studies to complete the required science coursework. New recruits go through Basic Officer’s Training at the Coast Guard Academy in New London, Connecticut.

Lt. Lecia Salerno – Executive Officer (XO) – NOAA

: Lt. Lecia Salerno at the helm or the Oregon II during Longline retrieval.

Lt. Salerno is a 10-year veteran of the NOAA Corps and has significant experience with ship operations. She was recently assigned to the Oregon II as the XO. This is Lecia’s first assignment as an XO and she reports directly to Captain Dave Nelson. In addition to her Bridge responsibilities, she manages personnel issues, ship accounts and expenditures. During these first few weeks on her new ship, Lt. Salerno is on watch for split shifts – day and night – and is quickly becoming familiar with the nuances of the Oregon II. This ship is the oldest (and much loved) ship in NOAA’s fleet, having been built in 1964, which can make it a challenge to pilot. It’s no small task to maneuver a 170-foot vessel up to a small highflyer and a float, and continue moving the ship along the Longline throughout retrieval.

Lecia has a strong academic background in science and in the liberal arts and initially considered joining another branch of the military after college. Her assignments with NOAA incorporate her varied interests and expertise, which she feels makes her job that much more rewarding.

Lt. Laura Dwyer on the Bridge of the Oregon II — Lt. Laura Dwyer on the Bridge of the *Oregon II*

Lt. Laura Dwyer- Junior Officer – NOAA Corps

Laura has always had a love for the ocean, but did not initially look in that direction for a career. She first earned a degree in International Business from James Madison University. Her interest in marine life took her back to the sea and she spent a number of years as a scuba diving instructor in the U.S. and Australia. Laura returned to the U.S. to take additional biology coursework. During that time she more fully investigated the NOAA Corps, applied and was accepted.

Laura has been on the Oregon II for 1.5 years and loves her work. When she is on shift she independently handles the ship during all operations and also acts as Navigator. What she loves about the Corps is that the work merges science and technology, and there are many opportunities for her to grow professionally. In December Laura will be assigned to a shore duty unit that is developing Unmanned Underwater Vehicles (UUV).

Personal Log

Measuring a Sharpnose Photo: Kristin Hannan — *Notice the white spots on the dorsal side of this atlantic sharpnose, characteristic of this species.*
Photo: Kristin Hannan

It’s amazing to think that just over a week ago I held my first live shark. We caught over 30 sharks at our first station and our inexperience showed. At first even the small ones looked like all teeth and tail, and those teeth are not only sharp but carry some pretty nasty bacteria. It took all of us (new volunteers) forever to get the hooks out quickly without causing significant trauma to the shark–or ourselves. A tail smack from this small-but-mighty tiger shark pictured below left me with a wedge-shaped bruise for a week!

Immature Male Tiger Shark. He's cute but he taught me a lesson with his tail. — *Immature Male Tiger Shark.*
*He’s cute but he taught me a lesson with his tail.*

Since then we have caught hundreds of sharks. We’ve caught so many Atlantic Sharpnose that on occasion it seems mundane. Then I catch myself and realize how amazing it is to be doing what I’m doing– holding a wild animal in my hands, freeing it from the circle hook (finally!), looking at the detailed pattern of its skin, and feeling it’s rough texture, measuring it and releasing it back into the sea.

Sandbar Shark on the Line — *A beautiful sandbar shark on the line.*

I’m pleased to be able to say that my day shift team has become much more confident and efficient. Our mid-day haul yesterday numbered over 40 sharks, including a few large sharks that were cradled, and it went really smoothly.

Weighing in. Hook out - No Problem! Photo: Jim Nienow — *An Atlantic Sharpnose weighing in at 2.1 kg.*
Photo: Kristin Hannan

Out it Comes - No Problem Photo: Ian Davenport — *Taking a closer look at an Atlantic Sharpnose shark.*
Photo: Ian Davenport

At this point I’ve had a chance to work at most of the volunteer stations including baiting hooks, throwing off the high-flyer marker, numbering, gangions, throwing bait, data entry, tagging shark, removing hooks, and measuring/ weighing. A highlight of last night was getting to throw out the hook to pull in the high-flyer marker at the start of retrieval. I’m not known for having the best throwing arm but it all worked out!

Ready to Throw Photo: Kristin Hannan — *Ready to Throw*
Photo: Kristin Hannan

Got it! Photo: Kristin Hannan — *Right on Target!*
Photo: Kristin Hannan

Question of the Day: What is this?

NOAA SHARK FACTS: Bite off More that you can chew

For more on hammerheads: click

For my incoming Marine Science students — Investigate two other hammerhead species. How are they distinguished from great hammerheads?