Denise Harrington: What Fish Do I Eat? October 3, 2016

Posted on October 12, 2016 by deniseharrington

NOAA Teacher at Sea

Denise Harrington

Aboard NOAA Ship Oregon II

September 16-30, 2016

Mission: Longline Survey

Geographic Area: Gulf of Mexico

Date: Monday, October 3, 2016

I asked Kevin Rademacher, Research Fisheries Biologist at the Pascagoula, Mississippi Lab, what fish I could eat and still support sustainable fisheries. He answered with a question, “Have you read the book Four Fish?” When I finished reading the book by Paul Greenberg, I spoke to Kevin again. “What do you think now?” He asked.

I said “There is something about wild fish that makes me want to catch and eat them, but I worry about whether we are eating wild fish out of existence.”

Yellowedge grouper (Epinephelus itajara). Photo: Matt Ellis/NOAA Fisheries

“Have you talked with Adam? He’s the numbers guy,” Kevin said. It seems like the good teachers are always sending students away in search of their own answers.

Adam Pollack is a contract Fisheries Biologist with Riverside Technology, Inc., and works on the night crew. We sometimes cross paths at midnight or noon. Catching him wouldn’t be easy.

Here, Adam measures a shark too large to bring on deck. Photo: NOAA Fisheries

During one of these transition times, we had a moment to talk. I asked Adam about his earliest fish memory. He smiled. “At about five, I went fishing with my dad. We had a house in the mountains surrounded by a bunch of lakes.” Adam and his dad would sit by the lake with their lines in the water “watching the bobber disappear.” He smiles again. These little largemouth bass changed his life.

Adam takes a selfie with a red drum (Sciaenops ocellatus).

At first, he was set on becoming a professional bass fisherman but made a practical switch to marine biology. He took all the science electives and the hardest math classes he could. He went on to Southampton College on Long Island, New York, where he got lots of hands-on experiences beginning in his freshman year. He believes a good education should include lots of opportunities, as early as possible, for interactive learning in a real world environment.

Once he graduated, Adam got his dream job: working in the Gulf of Mexico during the field season and then crunching numbers the rest of the year. He takes the data scientists collect to the SouthEast Data, Assessment, and Review (SEDAR). SEDAR is a cooperative process through which scientists, fishermen, and policy makers look at the life history, abundance trends, and other data to determine how many fish we can catch sustainably.

Adam, and many others, also look at how catastrophic events like Hurricane Katrina and the Deepwater Horizon oil spill affect marine species in the Gulf of Mexico. After Hurricane Katrina, he said, shrimping efforts died down by about 40%. The effects of the oil spill are still a little murky. Many of the biologists on board initially predicted dire and immediate effects. Yet unlike the spill in Alaska, the warm Gulf of Mexico water is host to bacteria, plants, and other living things that might be eating up the oil. Many questions, such as whether these living things will mitigate the effects of a spill, are still being asked. “Deepwater Horizon is always on our minds,” Adam says. There are also naturally occurring events like harmful algal blooms and long term issues like climate change that affect fish populations.

Oil rigs dot the horizon as Tim Martin, Chief Boatswain, gets ready to retrieve the longline. Photo: Matt Ellis/NOAA Fisheries

Here, Paul Felts, Fisheries Biologist, weighs a yellowedge grouper (Hyporthodus flavolimbatus). Photo Matt Ellis/NOAA Fisheries

“Can you tell me about snapper?” I asked Adam. Red snapper (Lutjanus campechanus), assessed every other year, is a hot button topic for commercial and recreational fishermen alike in the Gulf. The species was in decline. Recreational fishermen went from a 180 day season to catch fish to an 8 day season and from 10 to 2 fish a day per person. Commercial fishermen weren’t happy either: they could only take 49% of the year’s quota for red snapper, while the recreational fishermen get to catch 51% of the quota. Fairness is not just a second grade concern, it is a major sticking point in regulating fisheries world wide.

Snapper is as tasty as it is beautiful. Photo: Matt Ellis/NOAA Fisheries

Red snapper is a vulnerable species. Snapper settle to the bottom of the water column from larvae. They are at high risk of mortality from ages 0-5, the same time when they are close to human activity such as oil rigs, shrimping grounds and easy to access fishing areas. Those who manage the fisheries are trying to get the snapper through that vulnerable stage. Like money in the bank accruing interest, a 10 year old snapper can produce more eggs than a five year old. Before we take snapper from the sea, we must make sure a healthy older population remains to reproduce.

TAS Denise Harrington holds up two red snapper. Photo: Matt Ellis/NOAA Fisheries.

Once an assessment is complete, scientists determine a maximum sustainable yield: how many fish can be taken from the population and still keep enough around to make more fish for the future. Take a look at a shark assessment and a snapper assessment. Looking at these long and complicated assessments, I am glad we have people like Adam who is willing to patiently work with the numbers.

Gathering the best data and making it available to people who collaborate to make informed decisions is an important part of Adam’s job. We all want fish and NOAA fisheries biologists are doing their best to make that happen for us, and for generations to come.

Personal Log

My time aboard the Oregon II has come to an end. Bundled up in my winter clothes, I look out over a rainy Oregon landscape filled with fishermen hoping to catch a fall Chinook salmon. Two places with different weather and many different fish species. Yet many of our challenges are the same.

Back at school, students and teachers welcome me enthusiastically. Instead of measuring desks and books as part of our Engage NY curriculum, we measured sharks and their jaws. Many of these students have never been out of Oregon, many have not been to the beach, even though it is only 4 miles away. With NOAA, South Prairie Elementary students were able to learn about faraway places and careers that inspire them.

Soon these seven year old children will be in charge. I am thankful to the NOAA crews and the Teacher at Sea program staff, as they’ve prepared generations of students of all ages to collaborate and creatively face the task that lies ahead.

Denise Harrington: First Day Jitters, September 21, 2016

Posted on September 25, 2016 by deniseharrington

NOAA Teacher at Sea

Denise Harrington

Aboard NOAA Ship Oregon II

September 16-30, 2016

Mission: Longline Survey

Geographic Area: Gulf of Mexico

Date: Wednesday, September 21, 2016

My first day on the longline cruise seems so long ago with three days of work under my belt. The night before my first shift, just like when school starts, I couldn’t sleep. Trying to prepare was futile. I was lost, lost in the wet lab, lost in my stateroom, lost in the mess. I needed to get some gloves on and get to work, learning the best way I know how: by doing.

At noon, I stepped out the fantail, life vest, gloves, hard hat, and sunscreen on, nervous, but ready to work. The Gulf of Mexico horizon was dotted with oil rigs, like a prairie full of farmhouses. Heat waves rose from the black deck.

Dr. Trey Driggers baits the hooks.

TAS Denise Harrington baits hooks.

Fifteen minutes before arriving at our first station, our science team, Field Party Chief Dr. Trey Driggers, Field Biologist Paul Felts, Research Biologist Kevin Rademacher, NOAA Science Writer Matt Ellis, and I began to prepare for our first station by baiting the hooks with mackerel (Scomber scombrus). I learned quickly that boots and grubby clothes are ideal for this task.

Once all the hooks were baited, Chief Boatswain Tim Martin and Paul release a high flyer, a large pole with a buoy at the bottom and a reflective metal flag on top.

The buoy, connected to the boat by the longline, bobbed off toward the horizon.

Tim attached the first of three weights to anchor the line to the sea floor.

As the longline stretched across the sea, Kevin attached a numbered tag to the baited hook held by Paul.

Paul passed the baited, tagged hook to Tim, who attached 100 hooks, evenly spaced, to the one mile longline.

On another station, Paul attached numbers to the gangion (clip, short line, and baited hook) held by Trey. Each station we change roles, which I appreciate.

Setting the longline is rather predictable, so with Rush and Van Halen salting the air, we talked about our kids, dogs, riots in the news, and science, of course. The tags will help us track the fish we catch. After a fish is released or processed, the data is entered in the computer and shared with the scientific community. Maybe one of these tagged fish will end up in one of the many scientific papers Trey publishes on sharks each year.

The line soaked for an hour waiting for snapper, tilefish, eels, sharks, and other fish to bite. While the line soaked, Mike Conway, skilled fisherman, and I lowered the CTD, a piece of equipment that measures conductivity (salinity), temperature, and depth, into the water. Once the biologists know how salty, cold, and deep the water is, they can make better predictions about the species of fish we will find.

Denise and Mike lower the CTD.

Styrofoam cup comparison

We attached a bag holding a few Styrofoam cups to see how the weight of the water above it would affect the cup. Just imagine the adaptations creatures of the deep must have developed to respond to this pressure!

The ship circled back to hook #1 to give each hook equal time in the water. After an hour, we all walked up to the well deck, toward the bow or front of the ship. We pulled in the first highflyer and weight. We pulled in the hooks, some with bait, and some without. After 50 hooks, the middle weight came up. We still didn’t have a fish. I began to wonder if we’d catch anything at all. No data is still data, I thought. “Fish on eighty three!” I heard someone yell. I wake from my reverie, and get my gloves on.

It was a blacknose shark (Carcharhinus acronotus), “pound for pound, the meanest shark in the water,” says Trey. He would know, he’s the shark expert. It came up fighting, but was no match for Kevin who carefully managed to get length, weight, and sex data before releasing it back into sea.

Kevin measures the shark’s length in millimeters, Paul takes records the data, and Matt takes photos.

Then Kevin weighs it in kilograms.

With one shark to process, the three scientists were able to analyze the sexual maturity of the male blacknose together. I learned that an adult male shark’s claspers are hard and rotate 180˚, allowing them to penetrate a female shark. An immature shark’s claspers are soft and do not rotate. For each male shark, we need to collect this data about its sex stage.

Here, you can see Trey rotating the clasper 180 degrees.

Later, Paul talked about moments like these, where the field biologists work side by side with research biologists from all different units in the lab. Some research biologists, he notes, never get into the field. But Kevin, Trey, and others like them have a much more well-rounded understanding of the data collected and how it is done because of the time they spend in the field.

Fortunately, the transition from inexperienced to novice was gradual. The second line was just as easy as the first, we only brought in two fish, one shark and one red snapper (Lutjanus campechanus).

Dissection Photos: Matt Ellis/NOAA Fisheries

For the red snapper, we removed the otoliths, which people often call ear bones, to determine age, and gonads to determine reproductive status. I say “we” but really the scientists accomplished this difficult feat. I just learned how to process the samples they collected and record the data as they dissected the fish.

We set the longline a third time. The highflyer bobbed toward the orange sun, low on the horizon. The ship turned around, and after an hour of soaking, we went to the well deck toward the front of the ship to pull in the longline. The sky was dark, the stars spread out above us.

“One!” “Three!” “Seven!” “Nine!” The numbers of tags with fish on the line were being called out faster than we could manage. It seemed like every other hook had a shark on it. Two hours later we had collected twenty-eight Atlantic sharpnose (Rhizoprionodon terraenovae) sharks and had one snapper to process. Too busy working to take pictures, I have nothing to document my transition from inexperienced to novice except this data sheet. Guess who took all this data? Me!

Personal Log

NOAA Ship Oregon II is small, every bunk is filled. I share a stateroom with the second in command, Executive Officer (XO) Lecia Salerno, and am thankful she is such a flexible roommate, making a place for me where space is hard to come by.

Last night, as I lay in my bunk above XO Salerno and her office, I felt like Garth on Wayne’s World, the thought that “I’m not worthy” entering my head. All members of the crew are talented, experienced, and hard-working, from the bridge, to the galley, to the engine room, and out on the deck where we work. I’ve made a few mistakes. I took the nasty thought and threw it overboard, like the slimy king snake eels (Ophichthus rex) we pull from the deep.

King Snake Eel (Ophichthus rex)

In the morning I grabbed a cup of coffee, facing the risk of being the least experienced, slowest crew member to learn, with curiosity and perseverance. First day jitters gone, I’m learning by doing.

Denise Harrington: Joining the Longline Crew, September 17, 2016

Posted on September 19, 2016 by deniseharrington

NOAA Teacher at Sea

Denise Harrington

Aboard NOAA Ship Oregon II

September 16-30, 2016

Mission: Longline Survey

Geographic Area: Gulf of Mexico

Date: Saturday, September 17, 2016

Location: 29^o 2.113’ N 93^o 24.5’ W

Weather from the Bridge: 28.9^oC (dry bulb), Wind 6 knots @ 250^o, overcast, 2-3′ SE swell.

Science Log

The muggy afternoon air did not dampen my excitement as we left Galveston, Texas, aboard the National Oceanic and Atmospheric Administration (NOAA) Ship Oregon II. I am a NOAA Teacher at Sea, participating in a longline survey in the Gulf of Mexico, surveying sharks and bony fish.

Fellow volunteers Leah Rucker and Evan Pettis and I bid farewell to Galveston. Evidence of human influence, such as development, oil rigs, barges, and ships, is not hard to spot. Photo: Matt Ellis, NOAA

When I tell people about the Teacher at Sea program, they assume I teach high school or college, not second grade in rural Tillamook, Oregon. Yet spend a few moments with any seven or eight year old and you will find they demonstrate significant potential as scientists through their questions, observations, and predictions. Listen to them in action, documented by Oregon Public Broadcasting, at their annual Day at the Bay field trip.

Just as with language acquisition, exposing the young mind to the process of scientific inquiry ensures we will have a greater pool of scientists to manage our natural resources as we age. By inviting elementary teachers to participate in the Teacher at Sea program, NOAA makes it clear that the earlier we get kids out in the field, the better.

Each year, my students develop a science or engineering project based upon their interests. Here, South Prairie Elementary students survey invertebrates along a line transect as part of a watershed program with partners at Sam Case Elementary School in Newport, Oregon.

The NOAA Teacher at Sea program will connect my students with scientists Dr. Trey Driggers, Paul Felts, Dr. Eric Hoffmayer, Adam Pollock, Kevin Rademacher, and Chrissy Stepongzi, as they catch sharks, snapper, and other fish that inhabit the Gulf of Mexico. The data they collect is part of the Red Snapper/Shark Bottom Longline Survey that began in 1995. The survey, broken into four legs or parts each year, provides life cycle and population information about many marine species over a greater geographic distance and longer period of time than any other study of its kind.

Leg IV is the last leg of the survey. After a long season of data collection, scientists, sailors, and fishermen will be able to return to their families.

My twelve hour shift begins tomorrow, September 17, at noon, and will continue each day from noon until midnight until the most eastern station near Panama City, Florida, is surveyed. Imagine working 12 hour shifts, daily, for two weeks straight! The crew is working through the day and night, sleeping when they can, so shutting the heavy metal doors gently and refraining from talking in the passageways is essential. I got lucky on the day shift: my hours are closer to those of a teacher and the transition back to the classroom will be smoother than if I were on the night shift.

Approximately 200 stations, or geographic points, are surveyed in four legs. Assume we divide the stations equally among the legs, and the first three legs met their goal. Leg IV is twelve days in duration. How many stations do we need to survey each day (on average) to complete the data collection process? This math problem might be a bit challenging for my second graders, but it is on my mind.

Mulling over the enormity of our task, Skilled Fisherman Chuck Godwin and I discuss which 49 year old fisherman will end up with more wrinkles at the end of the survey. Currently, I am in the lead, but I bet he’s hiding some behind those shades. Photo: Mike Conway

I wonder what kind of sharks we will catch. Looking back at the results of the 2015 cruise report, I learned that there was one big winner. More than half of the sharks caught were Atlantic sharpnose (Rhizoprionodon terraenovae) sharks. Other significant populations of sharks were the blacktip (Carcharhinus limbatus) shark, the sandbar (Carcharhinus plumbeus) shark, and the blacknose (Carcharhinus acronotus) shark.

: sandbar shark (Carcharhinus plumbeus)

: Atlantic sharpnose shark ( Rhizoprionodon terraenovae)

: blacknose shark (Carcharhinus acronotus)

My fellow Teacher at Sea, Barney Peterson, participated in Leg II of the 2016 survey, and by reading her blog I learned that the shark they caught the most was the sandbar shark.

In this sample data sheet from the end of Leg III, all but one of the sharks caught were the blacknose sharks. Notice the condition of two of the fish caught: “heads only.” Imagine what happened to them!

Personal Log

My first memory of a shark was when my brother, an avid lifetime fisherman, took several buses across the San Francisco Bay area to go fishing. That afternoon, he came home on the bus with a huge shark he’d caught. I was mesmerized. We were poor at the time and food was hard to come by, but mom or dad insisted sharks were not edible, and Greg was told to bury the shark in the yard. Our dog, Pumpkin, would not comply, and dug that shark up for days after, the overpowering smell reminding us of our poor choice. I don’t have many regrets, but looking back on that day, I wish we had done something differently with the shark.

Since then, I’ve learned that shark is a popular source of protein in the diets of people around the world, and is growing in popularity in the United States. In our survey area, Fisheries Biologist Eric Hoffmayer tells me that blacktip and sandbar sharks are the two most commercially important species. Our survey is a multispecies survey, with benefits beyond these two species and far beyond our imagination. As demand increases, so too does the need for careful management to keep fisheries sustainable. I am honored to be part of a crew working to ensure that we understand, value, and respect our one world ocean and the animals that inhabit it.

Jeff Miller: Sharks and Dead Zones, September 12, 2015

Posted on September 13, 2015 by jefdl26501

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 12, 2015

Data from the Bridge
Ship Speed: 9.2 knots
Wind Speed: 8.8 knots
Air Temp: 27,7°C
Sea Temp: 30.2°C
Seas: 1-2 meters
Sea Depth: 457 meters

GPS Coordinates
Lat: 27 47.142 N
Long: 094 04.264 W

Science and Technology Log
On September 8 – 9, we surveyed a number of stations along the Texas and Louisiana coasts that were in shallow water between 10-30 meters (approximately 30-100 feet). Interestingly, the number of sharks we caught at each station varied dramatically. For example, we pulled up 65 sharks at station 136 and 53 sharks at station 137, whereas we caught only 5 sharks at station 138 and 2 sharks at station 139. What could account for this large variance in the number of sharks caught at these locations?

Weighing a bonnethead shark caught off the coast of Texas.

One key factor that is likely influencing shark distribution is the amount of dissolved oxygen in the water. Oxygen is required by living organisms to produce the energy needed to fuel all their activities. In water, dissolved oxygen levels above 5 mg/liter are needed for most marine organisms to thrive. Water with less than 2 mg/liter of dissolved oxygen is termed hypoxic, meaning dissolved oxygen is below levels needed by most organisms to thrive and survive. Water with less than 0.2 mg/liter of dissolved oxygen is termed anoxic (no oxygen) and results in “dead zones” where little, if any, marine life can survive.

As part of several missions, including the ground fish and longline shark surveys, NOAA ships sample the levels of dissolved oxygen at survey stations in coastal waters of the Gulf of Mexico. Measurements of dissolved oxygen, salinity, and temperature are collected by a device called the CTD. At each survey station, the CTD is deployed and it collects real-time measurements as it descends to the bottom and returns to the surface.

Standing with the CTD, which is used to measure dissolved oxygen, salinity, and temperature.

Data collected by the CTD is used to produce maps showing the relative levels of dissolved oxygen in coastal regions of the Gulf of Mexico. For more environmental data go to the NOAA National Centers for Environmental Information.

Map showing dissolved oxygen levels in the coastal areas of the Gulf of Mexico. Red marks anoxic/hypoxic areas with low dissolved oxygen levels. Source: NOAA National Centers for Environmental Information.

Environmental surveys demonstrate that large anoxic/hypoxic zones often exist along the Louisiana/Texas continental shelf. Because low dissolved oxygen levels are harmful to marine organisms, the anoxic/hypoxic zones in the northern Gulf of Mexico could greatly impact commercially and ecologically important marine species. Overwhelming scientific evidence indicates that excess organic matter, especially nitrogen, from the Mississippi River drainage basin drives the development of anoxic/hypoxic waters. Although natural sources contribute to the runoff, inputs from agricultural runoff, the burning of fossil fuels, and waste water treatment discharges have increased inputs to many times natural levels.

Map showing sources of nitrogen runoff in the Mississippi River drainage basin. Source NOAA National Centers for Coastal Ocean Science.

Nitrogen runoff from the Mississippi River feeds large phytoplankton algae blooms at the surface. Over time, excess algae and other organic materials sink to the bottom. On the bottom, decomposition of this organic material by bacteria and other organisms consumes oxygen and leads to formation of anoxic/hypoxic zones. These anoxic/hypoxic zones persist because waters of the northern Gulf of Mexico become stratified, which means the water is separated into horizontal layers with cold and/or saltier water at the bottom and warmer and/or fresher water at the surface. This layering separates bottom waters from the atmosphere and prevents re-supply of oxygen from the surface.

Since levels of dissolved oxygen can greatly influence the distribution of marine life, we reasoned that the high variation in the number of sharks caught along the Louisiana/Texas coast could be the result of differences in dissolved oxygen. To test this idea, we analyzed environmental data and shark numbers at survey stations along the Louisiana/Texas coast. The graphs below show raw data collected by the CTD at stations 137 and 138.

Dissolved oxygen levels at station 137 (green line; raw data). At the surface: dissolved oxygen = 5.0 mg/liter. At the bottom: dissolved oxygen = 1.5 mg/liter. Notice the stratification of the water at a depth of 7-8 meters.

Dissolved oxygen levels at station 138 (green line; raw data). At the surface: dissolved oxygen = 5.5 mg/liter. At the bottom: dissolved oxygen = 0 mg/liter. Notice the stratification of the water at a depth of 7-8 meters.

Putting together shark survey numbers with environmental data from the CTD we found that we caught very high numbers of sharks in hypoxic water and we caught very few sharks in anoxic water. Similar results were observed at station 136 (hypoxic waters; 65 sharks caught) and station 139 (anoxic waters; 2 sharks caught).

Relationship between dissolved oxygen levels and numbers of sharks caught at stations 137 and 138.

What can explain this data? One possible answer is that sharks will be found where there is food for them to eat. Thus, many sharks may be moving in and out of hypoxic waters to catch prey that may be stressed or less active due to low oxygen levels. In other words, sharks may be taking advantage of low oxygen conditions that make fish easier to catch. In contrast, anoxic waters cannot support marine life so there will be very little food for sharks to eat and, therefore, few sharks will be present. While this idea provides an explanation for our observations, more research, like the work being done aboard the NOAA Ship Oregon II, is needed to understand the distribution and movement of sharks in the Gulf of Mexico.

Personal Log
My time aboard the Oregon II is drawing to a close as we move into the last weekend of the cruise. We have now turned away from the Louisiana coast into deeper waters as we travel west to Galveston, Texas. The weather has changed as well. It has been sunny and hot for much of our trip, but clouds, rain, and wind have moved in. Despite this change in weather, we continue to set longlines at survey stations along our route to Galveston. The rain makes our job more challenging but our catch has been relatively light since we moved away from the coast into deeper waters. Hopefully our fishing luck will change as we move closer to Galveston. I would like to wrestle a few more sharks before my time on the Oregon II comes to an end.

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

Posted on September 10, 2015 by jefdl26501

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.

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.

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.

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.

Collecting measurements from a large 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.

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.

Jeff Miller: Fishing for Sharks and Fishes, September 6, 2015

Posted on September 7, 2015 by jefdl26501

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 6, 2015

Data from the Bridge
Ship Speed: 9.7 knots
Wind Speed: 5.6 knots
Air Temp: 30.9°C
Sea Temp: 31.1°C
Seas: <1 meter
Sea Depth: 52 meters

GPS Coordinates
Lat: N 28 06.236
Long: W 095 15.023

Science and Technology Log
Our first couple days of fishing have been a great learning experience for me despite the fact that the fish count has been relatively low (the last three sets we averaged less than 5 fish per 100 hooks). There are a number of jobs to do at each survey station and I will rotate through each of them during my cruise. These jobs include baiting the hooks, numbering and setting the hooks on the main line, hauling in the hooks, measuring and weighing the sharks/fish, and processing the shark/fish for biological samples.

Each gangion (the baited hook and its associate line) is tagged with a number before being attached to the main line.

A number clip is attached to each gangion (baited hook and its associated line) to catalog each fish that is caught.

After the line is deployed for one hour, we haul in the catch. As the gangions come in, one of us will collect empty hooks and place them back in the barrel to be ready for the next station. Other members of the team will process the fish we catch. The number of fish caught at each station can vary widely. Our team (the daytime team) had two stations in a row where we caught fewer than five fish while the night team caught 57 fish at a single station.

Empty hooks are collected, left over bait is removed, and the gangion is placed back in the bucket to be ready for the next station.

So far we have caught a variety of fishes including golden tilefish, red snapper, sharpnose sharks, blacknose sharks, a scalloped hammerhead, black tip sharks, a spinner shark, and smooth dogfish. The first set of hooks we deployed was at a deep water station (sea depth was approx. 300 meters or 985 feet) and we hooked 11 golden tilefish, including one that weighed 13 kg (28.6 pounds).

On our first set of hooks in deep water, we caught a number of golden tilefish including this fish that weighed nearly 30 pounds.

We collect a number of samples from fishes such as red snapper and golden tilefish. First we collect otoliths, which are hard calcified structures of the inner ear that are located just behind the brain. Scientists can read the rings of the otolith to determine the approximate age and growth rate of the fish.

Otoliths can be read like tree rings to approximate the age and growth rate of bony fishes. Photo credit: NOAA Marine Fisheries.

The answer to the poll is at the end of this post.

You can try to age fish like NOAA scientists do by using the Age Reading Demonstration created by the NOAA Alaska Fisheries Science Center. Click here to visit the site.

When sharks are caught, we collect information about their size, gender, and sexual maturity. You may be wondering, “how can you determine the sex of a shark?” It ends up that the answer is actually quite simple. Male sharks have two claspers along the inner margin of the pelvic fins that are used to insert sperm into the cloaca of a female. Female sharks lack claspers.

Male and female sharks can be distinguished by the presence of claspers on male sharks.

Personal Log
After arriving at our first survey station on Thursday afternoon (Sep. 3), everyone on the ship is in full work mode. We work around the clock in two groups: one team, which I belong to, works from noon to midnight, and the other team works from midnight to noon. The crew and science teams work very well together – everyone has a specific job as we set out hooks, haul the catch, and process the fishes. It’s a well oiled machine and I am grateful to the crew and my fellow science team members for helping me learn and take an active role the process. I am not here as a passive observer. I am truly part of the scientific team.

I have also learned a lot about the fishes we are catching. For example, I have learned how to handle them on deck, how to process them for samples, and how to filet them for dinner. I never fished much my life, so pretty much everything I am doing is new to me.

I have also adjusted well to life on the ship. Before the cruise, I was concerned that I may get seasick since I am prone to motion sickness. However, so far I have felt great even though we have been in relatively choppy seas (averaging about 1-2 meters or 3 to 6 feet) and the ship rocks constantly. I have been using a scopolamine patch, an anticholinergic drug that decreases nausea and dizziness, and this likely is playing a role. Whether it’s just me or the medicine, I feel good, I’m sleeping well, and I am eating well. The cooks are great and the food has been outstanding. All in all, I am having an amazing experience.

Poll answer: This fish is approximately nine years old (as determined by members of my science team aboard the Oregon II).

Jeff Miller: Cruising to the Survey Stations, September 2, 2015

Posted on September 3, 2015 by jefdl26501

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 2, 2015

Data from the Bridge
Ship Speed: 11.6 knots
Wind Speed: 7 knots
Air Temp: 24.7°C
Sea Temp: 29.6°C
Seas: 3-4 ft.
Sea Depth: 589 meters

GPS Coordinates
Lat: 28 01.364 N
Long: 091 29.104 W

Map showing our current location and the site of our first survey station

Science and Technology Log
After a one day delay in port at Pascagoula, MS we are currently motoring southwest towards our first survey station in the Gulf of Mexico near Brownsville, TX. Our survey area will include random stations roughly between Brownsville and Galveston, TX.

Survey stations are randomly selected from a predetermined grid of sites. Possible stations fall into three categories: (A) stations in depths 9-55 meters (5-30 fathoms), (B) stations in depths between 55-183 meters (30-100 fathoms), and (C) stations in depths between 183-366 meters (100-200 fathoms). On the current shark longline surveys, 50% of the sites we survey will be category A sites, 40% will be category B sites, and 10% will be category C sites. Environmental data is also collected at each station including water temperature, salinity, and dissolved oxygen.

Several questions you may have are why do a shark survey, how do you catch the sharks, and what do you do with the sharks once they are caught? These are great questions and below I will describe the materials and methods we will use to catch and analyze sharks aboard the Oregon II.

Why does NOAA perform shark surveys?
Shark surveys are done to gather information about shark populations in the Gulf of Mexico and to collect morphological measurements (length, weight) and biological samples for research.

How are shark surveys performed?
At each collection station, a one mile line of 100 hooks baited with Atlantic Mackerel is used to catch sharks. The line is first attached to a radar reflective highflyer (a type of buoy that can be detected by the ship’s radar). A weight is then attached to the line to make it sink to the bottom. After the weight is added, about 50 gangions with baited hooks are attached to the line. At the half mile point of the line, another weight is attached then the second 50 hooks. After the last hook, a third weight is added then the second highflyer. The line is left in the water for one hour (time between last highflyer deployed and first highflyer retrieved) and then is pulled back on to the boat to assess what has been caught. Small sharks and fishes are brought on deck while larger sharks are lifted into a cradle for processing.

Sampling gear used includes two highflyers, weights, and 100 hooks

Longline hooks used for the shark survey

Longline hooks used in the shark survey

Shark cradle used to collect information about large sharks

What data is collected from the sharks?
Researchers collect a variety of samples and information from the caught sharks. First, the survey provides a snapshot of the different shark species and their relative abundance in the Gulf of Mexico. Second, researchers collect data from individual sharks including length, weight and whether the shark is reproductively mature. Some sharks are tagged to gather data about their migration patterns. Each tag has an identification number for the shark and contact information to report information about where the same shark was re-caught. Third, biological samples are collected from sharks for more detailed analyses. Tissues collected include fin clips (for DNA and molecular studies), muscle tissue (for toxicology studies), blood (for hormonal studies), reproductive organs (including embryos if present), and vertebrae (for age and growth studies).

Personal Log
One of the desired traits for participants in the Teacher at Sea program is flexibility – cruising schedules and even ports can change. I have now experienced this first-hand as we were delayed in port in Pascagoula, MS for an extra day. Though waiting an extra day really isn’t a big deal, it is hard to wait since myself and the rest of the scientific crew are all anxious to begin the shark survey. Since we also have two days of cruising to reach our first survey site, this means we all have to find ways to pass the time. I have used some of my time trying to learn about the operation of the ship as well as the methods we will be using to perform the longline survey. I also watched a couple movies with other members of the science team. The ship has an amazing library of DVDs.

Getting ready to leave Pascagoula aboard the NOAA Ship Oregon II

Safety is very important aboard the Oregon II so today we performed several drills including an abandon ship drill. This drill requires you to wear a survival suit. Getting mine on was a tight squeeze but I got the suit on in the required time.

In my safety suit during an abandon ship drill

Did You Know?
The NOAA Commissioned Officer Corps is one of the seven uniformed services of the United States. Can you name the other six uniformed services? Think about this and check the answer at the bottom of this post.

NOAA Corps Officers perform many duties that include commanding NOAA’s research and survey vessels, flying NOAA’s hurricane and environmental monitoring planes, and managing scientific and engineering work needed to make wise decisions about our natural resources and environment.

Answer: The seven uniformed services of the United States are: (1) Army, (2) Navy, (3) Air Force, (4) Marine Corps, (5) Coast Guard, (6) NOAA Commissioned Officer Corps, and (7) Public Health Service Commissioned Corps.

NOAA Teacher at Sea Blog

Tag Archives: longline survey

Denise Harrington: What Fish Do I Eat? October 3, 2016

Personal Log

Denise Harrington: First Day Jitters, September 21, 2016

Denise Harrington: Joining the Longline Crew, September 17, 2016

Jeff Miller: Sharks and Dead Zones, September 12, 2015

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

Jeff Miller: Fishing for Sharks and Fishes, September 6, 2015

Jeff Miller: Cruising to the Survey Stations, September 2, 2015