Brad Rhew: Getting Fishy With It, July 29, 2017

NOAA Teacher at Sea

Brad Rhew

Aboard NOAA Ship Bell M. Shimada

July 23 – August 7, 2017

 

Mission: Hake Survey

Geographic Area of Cruise: Northwest coast

Date: July 28, 2017

 

Weather Data from the Bridge

Latitude 4359.5N
Longitude 12412.6 W
Temperatue: 54 degrees
Sunny
No precipitation
Winds at 23.5 knots
Waves at 2-4 feet

 

Science and Technology Log

We are officially off! It has already been an amazing experience over the last couple of days.

One of the goals of this project is to collect data that will be used to inform the Pacific hake stock assessment. This falls in line with the Pacific Whiting Treaty that the US-Canadian governments enacted to jointly manage the hake stock. NOAA and Department of Fisheries and Oceans-Canada (DFO) jointly survey and provide the hake biomass to the stock assessment scientists. (Refer to the link in my last blog about additional information on this treaty.) Major goals of the survey are to determine the biomass, distribution, and biological composition of Pacific hake using data from an integrated acoustic and trawl survey. Additionally, we are collecting a suite of ecological and physical oceanographic data in order to better understand the California Current Large Marine Ecosystem (CCLME).

There is a very detailed process the scientists go through to collect samples and data on the hake caught and selected for sampling. They want to learn as much as possible about these fish to help with the ongoing research projects.

Here is a quick guide and understanding of how sampling works and what data is collected:

  1. Determine the length and sex of the fish.
    1. To determine the length, the fish is placed on a magnetic sensor measuring board. The magnet is placed at the fork of the tail fin; the length is recorded into the data table. (See figure A.)
      TAS Rhew Blog 2 photo A

      Figure A. Determining the length of the fish.

       

    2. To determine the sex, the fish is sliced open on the side. Scientist look to see if ovaries (for females) or testes (for males) are present. They also can determine the maturity of the fish by looking at the development of the reproductive organs. (See figure B.)

      TAS Rhew Blog 2 photo B

      Figure B. Determining the sex of the fish.

  2. Determine the mass.
    1. The Hake are placed on a digital scale and then massed. The data also gets entered into the database. (See figure C.)

      TAS Rhew Blog 2 photo C

      Figure C. Massing the fish on a digital scale.

  3. Removing of the otoliths (ear bones).
    1. Hake have two otoliths. How this is done is the scientist first cuts a slight incision on top of the fish’s head. (See figure D.)

      TAS Rhew Blog 2 photo D

      Figure D. Making an incision on the fish’s head to remove otoliths.

    2. The head is then carefully cracked open to expose the bones. (See figure E.)
    3. The bones are removed with forceps and then placed in a vial. The vial is then barcode scanned into the database. The otoliths will then be sent to the lab for testing. Scientists can run test on the otoliths to determine the age of the selected fish. (See figures F and G.)
  4. Removing a fin clip.
    1. Fin clips are removed from the Hake for DNA sampling to be completed back on shore in the lab. This gives researchers even more information about the selected fish.
    2. The fin clip is removed using scissors and forceps. (see figure H.)

      TAS Rhew Blog 2 photo H

      Figure H. Removing a fin clip.

    3. The clip is then placed on a numbered sheet. (see figure I.)

      TAS Rhew Blog 2 photo I

      Figure I. Placing the fin clip on a numbered sheet.

    4. The number is also entered into the database with all the other information collected on that particular fish.
  5. All the information is collected in one database so it can be assessed by scientists for future research. (see figure J.)

    TAS Rhew Blog 2 photo J

    Figure J. All information is stored in a database.

 

Personal Log

Even though this survey is just beginning this has been such an amazing experience already. I have learned a great deal about oceanography and marine research. I cannot wait to use my experiences back in my classroom to expose my students to careers and opportunities they could be a part of in their future.

Another great aspect of being a Teacher at Sea is the relationships I’m building with other scientists and the crew. It is amazing to hear how everyone became a part of this cruise and how passionate they are about their profession and the world around them.

 

Did You Know?

This is Leg 3 of 5 of this Summer Hake Survey. Two more legs will be completed this year to collect even more data on the fish population.

 

Fascinating Catch of the Day!

When we fish for Hake it is very common to collect some other organisms as well. Today’s fun catch was Pyrosomes or Sea Tongues!

These free-floating colonial tunicates are found in the upper part of the open ocean. Pyrosomes rely on the currents to move them around the ocean. They are typically cone shaped and are actually made up of hundreds of organisms known as zooids. The Zooids form a gelatinous tunic that links them together creating the cone shape. They are also bioluminescent and give off a glow in the ocean.

TAS Rhew Blog 2 photo collage

Fun with pyrosomes!

Check it Out!

If you want to learn more about what is happening on the Bell M. Shimada, check out The Main Deck blog for the ship:

https://www.nwfsc.noaa.gov/news/blogs/display_blogentry.cfm?blogid=7

Karen Grady: Sometimes You Find A Little Something Extra, April 16, 2017

NOAA Teacher at Sea

Karen Grady

Aboard NOAA Ship Oregon II

April 5 – April 20, 2017

Mission: Experimental Longline Survey

Geographic Area of Cruise: Gulf of Mexico

Date: April 16, 2017

 Weather Data

Latitude 2848.37 N
Longitude 09247.66 W
76 degrees
Sunny
No precipitation
Winds at 11 KTS
Waves at 2-4 FT

Science and Technology Log

Sometimes when a shark or fish is brought on board it has a “hitchhiker’ attached. We caught a blacknose shark that had a common remora, often referred to as a sucker fish, or shark sucker, attached to it. Scientist Kevin Rademacher placed this sharksucker (Echeneis naucrates) on my arm. I couldn’t really feel it but he was stuck there until I peeled him off. It was like peeling a piece of tape off. You can see from the photo how he is designed to attach to host species. Their head is actually a modified dorsal fin that has an oval shaped sucking disk with slat-like structures that open and close to create suction and take a firm hold against the skin of its host animal such as a shark, turtle, whale, or ray. By sliding backward, the remora can increase its suction, or it can release itself by swimming forward. They can be small like the one attached to my arm or they can grow to over two feet in length. The remora can move around on the host, removing parasites while at the same time gaining protection provided by the host. This relationship is often looked at as one of commensalism where both the host and the remora benefit.

Photos of the remora that was attached to a black-nosed shark.

When one hears that this is an experimental long-line survey of sharks and reef fish, all you think of is catching these creatures and collecting data. However, scientists are collecting data about the environment as well. It is very useful to obtain information about the water where they catch large numbers of a species and areas where they may not catch anything. One way they can do this is by using a Conductivity Temperature Depth Profiler (CTD).

The CTD gives scientists a profile of the water column where we just put out our line. The CTD has sensors that collects information on oxygen levels, temperature, water clarity, chlorophyll concentration, and salinity. The CTD is placed in the water and allowed to sit for three minutes to let the oxygen sensors soak and adjust from being on the deck and lowered into the water. The crew lowers it to a depth that is decided based upon the depth to the ocean floor. They like to take it as close to the bottom as possible in order for the information they gather to be as complete as possible. It is allowed to settle, run its scans and then is brought back up to the surface and the sensors are flushed with fresh water. The data is automatically loaded into the database. This information is collected at each station. It takes a joint effort of the deck, science and bridge crews to place the CTD in the water. Walkie talkies are utilized for communicating between all the crew involved in the operation.

Personal Log

Being at sea with Easter approaching had its moments when I thought of family and friends. We have our Easter traditions and I would be missing them this year. The Easter Bunny (Field Party Chief, Kristin Hannan) decided we needed an early visit this year. I think she was right. The surprise and the treats perked all the science staff up.

TAS Karen Grady 4-16-17 Easter basket

FPC Kristin Hannan asks me often if I have any questions about what they are doing or anything in general. I will be honest… I have gotten so caught up in what we are doing, trying to do my best at whatever job I am working on, and being in awe that I am actually out here that I forget to ask questions about the details. I love the anticipation of what might be on the next hook, I am mesmerized by the sleek lines of the sharks when we have them on board.

TAS Karen Grady 4-16-17 shark liver

Shark liver

When we had one come onboard that was dead due to low oxygen levels in the water where we caught it, we did a dissection on the deck while we waited to put out another line. The animal science nerd in me came to life!   I had no idea the liver was the largest organ inside a shark. Think about it …these creatures have no body fat and they store their energy in the liver. Then we looked at the intestines. There is not a lot of room in there so the shark we looked at the intestines are rolled up like you would roll a piece of paper. This gives them maximum absorption area but takes up a limited space.

 

 

 

One thing I think of as we are catching these species is that very few people stop and think about the actual research scientists do to help understand what is needed to maintain healthy populations. It is necessary to do these surveys, catch the species, tag some, draw blood, take fin clips, keep whole specimens, and dissect some. On our cruise we were lucky enough to ultrasound a few pregnant sharks and see the pups inside.

TAS Karen Grady 4-16-17 shark ultrasound

Baby sharks visible on ultrasound

Now stop and think about all those things I just listed that we do at times. When a hook comes up and there is a fish or shark on it is handed off to one of the science crew.  It is noted in the computer that there was a something caught. The science crew member will take measurements and weight of the fish or shark. If it is a shark, the sex will be noted and some species may be tagged, have a fin clip taken and blood drawn. While all of these activities are taking place, the next hooks keep being brought up. The deck can get pretty crazy if there are several hooks in a row with something on them. The data collector has to keep tag numbers, species, measurements, samples and weights all written in the correct spot while having two or three people calling them out for different fish and or sharks. I had experience working cattle which would mean filling syringes, writing down tag numbers, filling taggers, etc. But this is even crazier than that could get at times. And everything stops if someone calls “hardhats” because that means we have one big enough for the cradle. Working back writing down data or taking measurements you can’t see what is on the next line so you sneak up for a peak when they say it’s a big one then you get out of the way.   One of the best experiences so far was almost getting a big tiger shark in the cradle. I was lucky enough to get a video of her, so stay tuned! Unfortunately, when the big shark brushed against the cradle she snapped the line and was gone with a huge spray of water.

This second leg of the experimental long-line survey is winding down. There have been long days but they are filled with laughter, giggles, anticipation, excitement, teachable moments (I can finally get the circle hooks out by myself…sometimes) , and the dreaded words “snapper.” I mean nothing against the Red Snapper, they are a bright colorful and tasty fish, but when you are hoping for a shark to be on the hook…. let’s just say the sets where we get 12 snapper and two sharks are not our favorites.

Photos: “Shark!” or “Fish on!” means a busy deck.

TAS Karen Grady 4-16-17 hammerhead cradle

Scalloped hammerhead shark

When the guys at the rail grab the hard hats it means it is time for the cradle and we get to see things like this gorgeous scalloped hammerhead. Things move very quickly when one is in the cradle. Safety for those on deck comes first and everyone is focused on getting measurements, fin clip and a tag on the shark and getting it safely back in the water as quickly as possible.

TAS Karen Grady 4-16-17 baby tiger shark

Baby tiger shark

Baby tiger shark in the cradle. They warned me that they were cute and they were so right. Yes, a shark can be “cute” when your referring to baby tiger sharks and baby hammerheads!

Did You Know

Sharks store energy in their liver. It is the largest organ in their body. The heart on the other hand is extremely small in comparison to the size of the shark.

TAS Karen Grady 4-16-17 hammerhead dissection

Dissected scalloped hammerhead with liver visible

Look at the liver of this scalloped hammerhead. It is amazing how big it is in relation to the body of the shark. This is just one way these amazing creatures are designed to be efficient and survive in their underwater world.

Sharks have a nictitating membrane that they can close over their eye for protection. When a shark is brought on deck you can touch near the eye and the membrane will automatically move to close.

TAS Karen Grady 4-16-17 nictitating membrane

Nictitating membrane partially closed on the eye of a scalloped hammerhead

Denise Harrington: Spotlight on a Blacktip Shark, September 24, 2016

NOAA Teacher at Sea

Denise Harrington

Aboard NOAA Ship Oregon II

September 16-30, 2016

Mission: Longline Survey

Geographic Area: Gulf of Mexico

Date: Saturday, September 24, 2016

Yesterday, I was in the crew lounge, working on my next blog, when Eric Hoffmayer, Research Fishery Biologist, called me out to the fantail to see a large deceased female blacktip shark (Carcharhinus limbatus) brought in that morning.

countershade-2

(deceased) female blacktip shark

The contrast between the gray and white skin caught my eye. The countershading, a dark grey color on top, had a light bronze hue that sparkled in the light. A white band starting at its pectoral fins widened until it merged with the belly at the anal fin.

If there is a mortality, the science team uses the opportunity to dissect the fish, collecting additional information otherwise unavailable.  When we catch a shark, we release it as quickly as possible. The urgency of getting shark back in the water keeps me from carefully studying its detailed characteristics.

While I understand the loss of this particular shark touches many of us on board, understanding the species better through the loss is a practical, necessary approach to  managing the marine environment.  Without an in depth understanding of sharks, their populations, life cycle, and reproduction, there is no way we can sustainably manage fish populations.  Some may find dissection unappealing, and for those folks you may want to skip this blog, but not without first thanking the biologists who do this work compassionately. They keep our fisheries sustainable.

I rubbed my hand from the head to the tail.  It was smooth. Rubbing from the tail to the head felt just the opposite, rough like sandpaper.  Tiny dermal denticles allow sharks to move quickly through the water, an adaptation so amazing, it was put to use by designers of swimsuits in the Olympics and engineers of Navy ships.

Eric, Adam, and Chrissy, placed the shark on the table.  Eric cut the shark and pulled out a long sack that looked like empty sausage casing. At the end of the casing was a tiny shark pup. Trey joined the crew as they took data on each of the six pups.  The shark was pregnant.

The golden colored egg casing is still about six times the size of the pup, giving it plenty of room to grow.

The golden colored egg envelope is still about six times the size of the pup, giving it plenty of room to grow.

 

Here, Trey stretches out the casing demonstrating the significant amount of room left for the pup to grow,

Here, Fisheries Biologist Eric Hoffmayer stretches out the egg envelope demonstrating the significant amount of room left for the pup to grow. In the background you can see the egg envelop of another pup stretching across the table.

From the number of pups in a brood, to the possibility of immaculate shark conception, the reproduction of blacktip sharks is of interest to fishery biologists.  Without knowing all about shark reproduction, how many, and where sharks reproduce, we cannot sustainably manage this species, or fisheries in general.

Trey takes me through each stage of reproduction. The blacktip shark is viviparous, like humans. They are born alive, “vivi,” and develop within the mother getting nutrients through a placenta.

life-cycle-diagram

 

Egg

The shark life cycle begins in the female shark’s ovary with an egg.   Trey hands me an ovary that holds the eggs.  It is a large sack of many small red pinpoint size spheres with about 6 larger marble like balls from the high in the body cavity. These eggs wait to mature until the conditions are ideal for reproduction. At that time, the follicle ruptures, and the egg comes out.

Shark eggs are fertilized inside the female’s body.  The male fills his siphon sacs with seawater, and then flexes his abdomen to shoot the seawater and semen into the female shark through his clasper.

p1090186

Now I understand why we spin the clasper of a male shark to determine its maturity.  I was able to rotate this male Gulf smoothhound shark (Mustellus sinusmexicanus) clasper 180 degrees and reported it as an adult male.

Embryo/Pup

The male blacktip shark is often ready to mate in April to May but the females are often not ready to reproduce until June or July.  With many sharks, blacktip sharks included, the sperm can remain inside the female until she is ready to reproduce.  When that moment arrives, the egg slips through the ostium, down the anterior oviduct, and into the oviducal gland where it is fertilized by the sperm. For the blacktip shark, usually 4-6 eggs will be fertilized and develop into shark pups.  Females usually reproduce every other year.

 

large-yolk-little-shark

Note that different sharks have different modes of reproduction.  For example, Cuban dogfish (Squalus cubensis) reproduce through aplacental viviparity or ovoviviparity. The tiny pups you see here nourish themselves with the yolk “ovo” and have no placental connection to their mother.  They are born live “vivi,” and able to feed and protect themselves. Some sharks are oviparous, which means they lay eggs  that hatch later.

Initially,  the blacktip shark embryo uses the nutrients from a yolk sac for about 10-11 weeks. For the remaining time inside the mother, the pup increasingly gets nutrients from the mother through a placenta.  They are viviparous and remain inside the mother for approximately 10 months until they can survive on their own.  I held a pup, still connected to its mother by the umbilical cord. The similarities between human reproduction and blacktip shark reproduction surprised me so much I began to question the classification of viviparous sharks as fish.

 

holding-pup

I held a pup, still connected to its mother by the umbilical cord.

Immature Shark/Juvenile

For approximately two months after it is born, the immature shark has an umbilicus (like a bellybutton) that is still open.  During this phase of the life cycle it is called a neonate, or newborn.  It is otherwise just like a miniature adult blacktip shark.  It can hunt and hide from predators (including its mother).

immature-blacktip

Here, Eric and Evan Pettis, Texas Parks and Wildlife Fisheries Biologist, tag, measure, and release an immature blacktip shark.

 Mature Shark/Adult

Individual sharks even within a species mature at different rates, just like humans.  Generally, a male blacktip shark matures between 4-5 years of age, and females between 7-8 years.

p1080498

This 1385 mm male mature blacktip shark was brought in our second day of the survey.

How does the shark’s life cycle affect fisheries?

Evolutionarily speaking, placental viviparity gave the blacktip shark and others like it an advantage; the shark is born able to survive independently.  But this adaptation has also has a downside:  the females only produce a small brood, unlike other fish that use broadcast fertilization.

During gestation, the female shark we caught most likely migrated to our current location just off the coast of the Mississippi from deeper waters.  Called the Fertile Fisheries Crescent, the Mississippi Sound is one the most productive seafood areas in the nation.  Another risk to this species is pollution and over-fishing in the fragile estuarine habitat, the juvenile shark’s nursery.

There is demand for the high quality blacktip shark meat, the fins, and even the carcasses for fishmeal. The work NOAA Fisheries does to collect information about shark populations over time and over a wide geographic area not only helps keep blacktip shark populations sustainable, it also gives us valuable information about the ocean’s health in general.

 

Personal Log

Today I reached the half way point in my time on the longline crew.  I finally feel like I am getting into the groove, finding my way around the ship, and meeting people beyond my fishing buddies.  Valerie  McCaskill, Chief Steward, and her cousin, Ava Speights cook amazing seafood, grilled veggies, and au gratin everything. Ava showed me a great piece of exercise equipment, Jacob’s Ladder, to allow me to enjoy the great food guilt free.

Each station, each day, a new adventure.

Obed Fulcar, July 28, 2010

NOAA Teacher at Sea Obed Fulcar
NOAA Ship Oscar Dyson
July 27, 2010 – August 8, 2010

Mission:Summer Pollock survey III
Geograpical Area:Bering Sea, Alaska
Date: August 7, 2010

Weather from the Bridge:

Time:04:42 am
Latitude:61.04 North
Longitude:178.06 West
Wind Speed:10.74 knots
Wind Direction:50 degrees North
Sea Temperature:8.99 C (48.02 F)
Air Temperature:8.2 C (46.76 F)
Barometric Pressure: 1010.1 millibars
Cloudy Skies

SCIENCE AND TECHNOLOGY LOG:

Me with a pollock

Me with a pollock

Friday, July 23: The Walleye Pollock survey has been conducted since 1979, every summer by MACE (Midwater Assessment and Conservation Engineering) part of the Alaska Fisheries Science center (AFSC). The sea was quite calm compared to the last days, giving us a break from sea sickness. The other day I missed the trawl, but I will not today. As soon as we saw the fish in the Acoustic sonar screens I knew it was trawling time, so I ran up to the bridge to witness the whole thing. The started deploying an Aleutian Wind Trawler or AWT net that was attached to a giant winch with huge ropes and chains. The long net had a front orange section with smaller openings compared to the back. I was invited to come to deck by deckhand Buddy Gould. He is a veteran New england fisherman from Rhode Island, now living in Florida.

Buddy Gould

Buddy Gould

I asked permission from Commanding Officer CO Mike Hashlyck , and went on deck wearing a PFD, and a hard hat. After trawling the net behind the ship for what felt like an eternity, it was finally hauled back, the catch of Pollock was then spilled into a box leading to the wet labfor slicing and dicing. I went inside an put on rain boots, a plastic jacket and a jumpsuit, plus elbow high plastic glove and got down to slice and measure Pollock. While sorting out the fish we found a Pacific Flounder and a Rock sole fish, both flat bottom fish. For the next several days while conducting the survey, I kept dissecting the content of the stomachs of everal fish to find out what they have been eating. I learned that the main diet of Pollock was made up of animal plankton called Euphasiids, also known as krill. 

Krill

Krill

These small organisms are arthropods or segmented invertebr ates (without internal skeleton), and just like shrimps, and crabs, their bodies are covered by an exoskeletonor shell, with paired antennae, pincers, and legs. They were present in the stomach of all the specimens in a pink color mass. There was one large maturity level 4/5 Pollock that when I opened its stomach, a large Northen Pacific shrimp came out of it. Then in later catches I observed that all the stomachs were very dark-blue looking. When I opened the stomach of one fish there was a dark purple mass of another arthropod called Pelagic amphipods, or sea fleas. Amphipods swim drifting in the water column and are larger than euphasiids or krill, wich instead formed massive swarms swimming at great depths by day but heading to suface by night. I was able to witness this pattern when once the echogram from the acoustic radar showed a swarm of krill drifting from the surface to the bottom as the sun was rising.

Pelagic amphipods

Pelagic amphipods

Animal Species observed:

Arrowtooth Flounder (Atheresthes stomias), Northern Rock Sole fish (Lepidopsetta polyxystra), Northern Pacifi Shrimp

VOCABULARY: Amphipods, Arthropods, Ecograms, Euphasiids, Exoskeleton, Invertebrates, Krill

PERSONAL LOG:

I realized that this tiny organism (the krill) is crucial for the survival not only of many animals in the ocean, but ultimately of us humans. We have historically harvested the rich waters of the Bering Sea for food, and most recently as a source of cheap protein to feed cattle and even pets. Disasters such as the recent massive oil spill from the tracgic explosion of the Deep Horizon oil platform, own by giant multinational BP, and the Exxon Valdez oil spill in Alaska during the 80’s are examples of how fragile the marine ecosystem is. But the number one threat to ocean fisheries is actually overfishing exploitation of the ocean resources. I heard stories about the foreign fleets that come to Russian waters and overfish with impunity, while at the same time processing, canning, and packing all their catch aboard their ships, taking it all back to their countries, without sharing any jobs opportunities with the local communities. Historically local fishing fleets have fished sustainably, bringing back to local ports the catch, allowing canneries, and fish markets to also benefit from it. We have to spread the word about this injustice and begin to question our own habits, to see what can we change in our consumption that will have a positive impact in this urgent matter.

“Echando la Red en Alta Mar” El mareo de ayer no me permitio participar en la pesca del Pollock, pero no hoy! Tan pronto me entere, subi al puente para observar lo todo. Mi buen amigo del personal de cubierta, Buddy Gould pescador de Rhode Island radicado en la Florida, me invito a bajar a cubierta. Despues de ahbe asegurado permiso del Oficial Comandante Mike Holshyck, baje a la cubierta con chaleco flotador y casco de seguridad a cuestas. La anaranjada Red de Arrastre fue lanzada al mar por unos gigantescos rollos de cables y cadenas pesadas. Luego de lo que parecio una eternidad, la red fue traida a bordo y la pesca fue depositada en una rampa en la cubierta por una grua pesada. Yo fui adentro rapidamente y me vesti con guantes, poncho, pantalones, y botas de plastico y me puse las manos a la obra: a picar los pescados! Durante el proceso note que los estomagos de los pescados cambiaron de color rosado a color purpura. El contenido de los estomagos incluia un plankton-animal llamado Euphasiid o Krill, un artropodo (invertebrados parecidos al camaron y el cangrejo), asi como otro llamadoAmphipods, los cuales constituyen la dieta primaria de especies de peces como el Pollock, y el Salmon, asi como de las ballenas jorobadas. El krill no solo es primordial para estas especies marinas sino para la raza humana, que depende de las reservas alimenticias del Estrecho de Bering como gran fuente de proteina. Es lamentable que este fragil recurso natural no sea celosamente cuidado, cuando vemos como el desastre del derrame de la Plataforma Petrolera Deep Horizon en el Golfo de Mexico, y en los 80’s del Exxon Valdez en Alaska, puede facilmente hacer desaparecer la pesqueria. Pero el enemigo numero uno de este recurso natural es realmente la pesca desmedida por parte de flotas pequeras extranjeras que viene a las aguas del Estrecho de Bering, pescando indiscriminadamente. Estos barcos no solo pescan, si no que procesan y empaquetan todo a bordo sin dejar si quiera oportunidad a las comunidades locales de participar del beneficio sostenido. Tenemos que hacer eco de esta injusticia y autoanalizar nuestros habitos a fin de ver que podemos cambiar para poder hacer un impacto positivo.

Obed Fulcar, July 26, 2010

NOAA Teacher at Sea Obed Fulcar
NOAA Ship Oscar Dyson
July 27, 2010 – August 8, 2010

Mission:Summer Pollock survey III
Geograpical Area:Bering Sea, Alaska
Date:July 26, 2010

Weather from the Bridge: 

Time: 04:18 am
Latitude:60.02 N
Longitude:176.59 W
Wind Speed:15.2 knots
Wind Direction:180 degrees South
Sea Temperature:9.2 C (48.56 F)
Air Temperature:8.2 C (46.76 F)
Barometric Pressure: 1009.7 mb
Cloudy Skies

SCIENCE & TECHNOLOGY LOG:
The purpose of this mission aboard the Oscar Dyson is for a team of scientists to conduct a survey of the Bering Sea Walleye Pollock population, in oder to help the government establish sustainable commercial fishing quotas that will allow to manage a healthy population of this abundant, but yet fragile species. In order to carry the Pollock survey it is necessary to perform a combined Acoustic -Trawl Survey where acoustic data is collected along a line transect and then a Trawl (net) is used to catch a sample quantity of the fish observed in the acoustic data.

Acoustics Lab

Acoustics Lab

In the Acoustic Lab there are a number of video monitors displaying several screens. Taina Honkalehto, the Chief Scientist of the Oscar Dyson explained to us how the acoustic sonar operates. First the acoustic survey relies on Sonar technology where it sends an acoustic “ping” powerful enough to detect fish at any depths. It travel back and forth between the bottom and the surface of the ocean, and its signature then registered on a video screen, allowing us to “see” where the fish are and the precise location. One screen shows an actual graph, or “echogram”, displaying several layers at different depths in colors ranging from gray, blue, green, yellow, orange to red. The dark red color represented the ocean floor, and the green/blue dots represented the fish. The darker the color, the more dense were the objects. Another sceen showed the location of the ship on a Nautical Topographic Map, including a red line showing transects (line routes) followed by the ship., as well as icons showing the points where the fish has been detected along the way. Tainathen uses this constant information to decide how to instruct the bridge into when where to position the ship in order to launch thetrawl net.

transect lines

Transect Lines

The trawl net used is known as an Aleutian Wing Trawl (AWT). It is equipped with specialized sensors that show in the video monitor where the fish are in relation to the net. Once the trawl is finished the net is then hauled back and the contents spread on deck for sorting out and identification. Target species such as the Walleye Pollock will be separated to be measured and weight then released overboard. Some of the catch will be kept for dissection to determine the sex, and to determine the age by studying the Ear bone or Otholith,that registers the gowth of the fish by marking each year with a dark ring, just like the growth rings on a tree. The otolith, stomach contents, and sample fish are carefully placed in vials, mesh and ziploc bags to be sent to NOAA’s Alaska Fisheries Science Center in Seattle for laboratory analysis. all this information will tell us how healthy is the Pollock population o the Bering sea, and help determine commercial fishing quotas for next year’s fishing season.

Video Monitor

Video Monitor

PERSONAL LOG:

I could not help to think about the amount of technology involved in the Pollock survey. I am pretty sure that Mr.Sanchez, my school technology teacher would be excited to see all the servers, CPUs, monitors, and all the coputer harware and gear used around here onboard the Oscar Dyson. I believe that the middle school students of the Maria Teresa Mirabal school MS319 will be right at home, since they are accustomed to used technology as part their everyday school work. From getting their password to log on into the school website network, using Netbooks for interactive podcast lessons, to taking online reading comprehension quizzes, these are part of a technology rich learning environment. Technology literacy is basic for a 21st Century education. But technology alone is not enough if we don’t tech the kids how to apply it in the real world. One example of the importance of using mathematical skills in the real world is best demonstrated in the Acoustic survey when calculating the estimated size of the fish that appears as dots on the Acoustic radar screen. The sonar software allows to isolate the fish by scanning a selected area of the monitor display and calculating the average decibel (sound unit) value per dot representing a fish. Knowing this value we can replace it in a given formula and easily calculate the approximate size of the fish in order to start trawling.

VOCABULARY:
Aleutian (Alaska native group), Dissection, Decibel, Nautical Topographic Map (underwater map of the ocean floor), Otolith, Transect

Tecnologia en Alta Mar” El proposito de la Mision abordo del Oscar Dyson es la de tomar un muestreo del Pollock o Bacalao para poder determinar que tan robusta esta su poblacion, a fin de poder determinar las cuotas apropiadas a ser dictadas a las flotas de pesca comercial. Para poder hacer este muestreo es necesario el uso de tecnologia de Sonar Acustico en combinacion con el uso de la Red de Arrastre.Todo comienza en el Laboratorio Acustico donde un numero de pantallas de monitor muestran diferentes imagenes. Taina Honkalehto, la Cientifico en Jefe del Oscar Dyson, nos explico que la tecnologia de sonar consiste en enviar un “ping” acustico que es lo suficiente poderoso para viajar de la superficie al fondo del mar de ida y vuelta, penetrando las capas mas profundas. La onda acustica que es reflejada es pues registrada en las pantallas permitiendonos ver una imagen de la ubicacion de los peces, y la precisa profundidad. Una pantalla nos muestra una grafica en tiempo real con lineas de diferentes colores que van del gris, azul, verde, amarillo, hasta el rojo que representa el fondo del mar. Otra pantalla nos muestra un Mapa Topografico Nautico que incluye una linea roja mostrando la linea de transeccion o el curso que sigue la nave. Con toda esta informacion Taina puede instruir al puente sobre que ruta de navegacion debe tomar la nave a fin de hacer la pesca. La red de Arrastre Aleutina, empleada en el muestreo, esta equipada con sensores especiales que indican en la pantalla la ubicacion de los peces en todo tempo. Realmente tienen la pesca totalmente calculada a lo mas minimo! Tan pronto se termina la pesca, el contenido de la red es pues depositado en la cubierta donde los peces seran separados para ser medidos y disecados a fin de averiguar el sexo y la edad. Muestras del contenido del estomago, y especimenes seran recogidos a fin de enviarlos a los laboratorios de NOAA en Seattle para determinar si la poblacion estara optima para la peca de la proxima estacion.