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

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


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.

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.

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