Tag: midwater trawl

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Scott Davenport: Heading to Sea, May 21, 2012

NOAA Teacher at Sea
Scott Davenport
Aboard NOAA Ship Bell M. Shimida
May 21-May 27, 2012

Mission: Rockfish Survey
Geographical area of cruise: Eastern Pacific, off the California coast and next to the Mexican Border
Date: May 21, 2012

Personal Log

Hi, my name is Scott Davenport and I am excited to be a part of NOAA’s Teacher at Sea Program.  It is going to be great. I teach at Paul T. Albert Memorial School located in scenic Tununak, Alaska.  It is a Yup’ik village on the Bering Sea. Most families practice subsistence living. My subject is junior high generalist, meaning I teach everything. Last year, I had a great group of seventh and eighth graders. It was my first year in Alaska and as a full-time teacher. Everyone learned a lot.

Tununak Seventh and Eighth Graders. Can you tell it is the last day of school?

Teacher at Sea intrigued me because it opens wide array of possibilities. A consistent issue at our school is what comes next? Graduation is a celebration, but it also brings apprehension and uneasiness. There are not a wide range of jobs in the village. It is normally limited to fishing, teaching, being a cashier, store stocker, or bush pilot. A NOAA boat offers a wider range of careers.  My experience on the ship will help my students make connections to new possibilities. The long cruises followed by long breaks  fit with subsistence living. They can have the time to go on a two week moose hunt and not miss work. Being located on the sea, most of my students  are acclimated to spending time on the water. My experience will  open eyes.

While on board the Bell M. Shimada, we have seven objectives. Objective #1: Sample the epi-pelagic micronekton. That means–thanks to Cynthia explaining it to me–we are going to see what is living in the upper water column. The specific fish we are looking for are the  juvenile rockfish. We will also survey Pacific whiting, juvenile lingcod, northern anchovy, Pacific sardine, market squid and krill. Objective #2: Characterize prevailing ocean conditions and examine prominent hydrographic features. Objective #3: Map the distribution and abundance of krill. Objective #4: Observe seabird and marine mammal distribution and abundance. Objective #5: Collect Humboldt squid. Objective #6: Conduct deep midwater trawls to examine mesopelagic specimen. Finally Objective #7: Examine feeding habits of jellyfish. My personal objective is to not vomit at sea.

The three things I am looking forward to most are meeting new people, witnessing scientific research, and learning new, unexpected items. My three biggest concerns are falling overboard at night into a never-ending dark abyss, the food, and making sure I contribute to the work/use my time wisely.  I am also excited to have a break from snow.

In the fall, the stairs went down.
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Tanya Scott, June 20, 2010

NOAA Teacher at Sea
Tanya Scott
Onboard NOAA Ship Miller Freeman
June 16 – 21, 2010

Mission:  Ecology of Juvenile Fishes  
Geographical Area: Central Oregon/Washington Coast
Current Location:  35 miles offshore, steaming to Seattle, WA
Date:  Sunday, June 20, 2010

Today is my last full day aboard the Miller Freeman.  It is currently 4:00 pm and I have just woken up!  I find that being on a ship rocks me to sleep.  Or, could it be that I was up until 6:00 am this morning?  Either way, I am fully rested and ready to rinse and store all of the scientific equipment in preparation for our departure tomorrow morning.  We are currently steaming towards Seattle, Washington where we will depart the ship.

Our work on Saturday turned out to be very interesting.  While pulling the midwater trawl, a small pod of Pacific Whitesided dolphin became interested in our tow.  They swam very close to the net for a time and had everyone worried that they may become entangled.  Luckily, they lost interest and swam away.  If they had become entangled in the net there are many protocols that would have been implemented.  The marine mammal stranding unit in Washington would have been called, a representative would have been sent to meet the ship, and many photographs taken as documentation.  It is always a concern that marine mammals may become entangled in nets but fortunately, this time was not one of those cases.

Krill brought in from the midwater trawl.

The catches from our midwater trawl brought up the familiar species of krill, purple lanternfish, rockfish, and hake.  Since the depth of this trawl does not target adult fish, we have been dealing almost exclusively with juvenile and larvae fish.  Our last haul produced more larvae rockfish than usual, which is good for the scientists conducting this survey.  They are, however, trying to determine where the largest concentrations of juvenile rockfish are during the season.  Rockfish are an important species in the Pacific Northwest.  It would be easy for you to think of how important flounder are in our area.  Rockfish are harvested for sale in fish markets and therefore are threatened by over harvesting.  It is important to monitor their movement and habitat in order to determine when and where Pacific Hake regulations should be put in place.  Another commercially important species is the Pacific Hake.  This fish is deboned and sold as fish sticks in the grocery store.  I’m sure that most of you have eaten a Pacific Hake and didn’t even know.  These fish are commonly caught by fisherman and, just as the rockfish, their populations are threatened by over harvesting.  When Pacific Hake are caught in the midwater trawl, their length is measured, recorded, and the fish are returned to the ocean.  All of the data collected by the scientist involved in this study will help to ensure the survival of these commercially viable species.  More importantly, keeping their populations stable will mean that the food web remains intact.  Just as we have discussed in class many times, everything on earth has its place.  Something else always depends on it for food, shelter, survival, and well being.

Pacific Hake

Since today is the last full day on board we will be preparing the equipment for transport back to Newport, Oregon.  It is important that everything is rinsed with freshwater to prevent corrosion.  After being rinsed and dried, we will package everything in boxes.  Our bunks will be stripped, our lockers emptied, and staterooms cleaned.  Although my time on board is coming to an end, I know that I will have many memories and experiences to share with you when I return.

Pacific Hake larvae

Tanya Scott

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Tanya Scott, June 18, 2010

NOAA Teacher at Sea
Tanya Scott
Onboard NOAA Ship Miller Freeman
June 16 – 21, 2010

Mission:  Ecology of Juvenile Fishes  
Geographical Area: Central Oregon/Washington Coast
Date:  Friday, June 18, 2010
 
Science and Technology Log
Before telling you about my experiences in the last day or so, I’d like to give a little more information about the experiments being conducted by Oregon State University (OSU).  The title of this study is:  The Stock Assessment Improvement Program (SAIP) Ecology of Juvenile Fishes off Oregon/Washington.  The primary purpose of this study is to assess the ecology and population of juvenile fishes between Willapa Bay, WA and Heceta Head, OR as part of a NOAA Fisheries Stock Assessment.  Scientists are trying to gain a better understanding of the direct and indirect linkages between oceanographic conditions and fish survival in the marine environment.  This is becoming more important as the need to manage fish stocks increases.  Scientists collect data concerning biotic and abiotic conditions and assess the relationship between these factors and fish populations.

As many of you already know, there is a very similar need in NC for such studies.  If you recall, our scallop season was closed for two years and only opened briefly last year for harvest.  Such closures and limitations are put on species such as scallop in order to give populations time to recover from over harvesting.  Similar problems are also encountered on the west coast with many species that fisherman harvest for sale to the public.  One important thing to remember is that the food you order in a restaurant had to be harvested from someone, somewhere.  Another good example is shrimp, which many of you love to eat!  Fisherman harvest shrimp to sell in markets which in turn, are sold to restaurants and grocery stores.  If fisherman take shrimp without regard for their population then problems eventually arise.  It is the goal of scientists to monitor issues such as population and species health before they become a problem.  Monitoring is the goal of the SAIP project being conducted by OSU and NOAA.

One of the challenges of this trip has been adjusting to the work/sleep schedule.  Most of the samples collected by OSU scientists are done during the night.  There are 4 stations a night that must be sampled and there is about an hour of transit time between each station.  After catching up on a bit of sleep yesterday, I awoke around 2 am this morning to assist with the last two stations.

When a station is reached, three instruments are deployed and data is recorded.  Below is a description of each:

1.  CTD:  I discussed this in the previous log.  This instrument is used to collect data including salinity, temperature, density, turbidity, dissolved oxygen, and florescence.  It is important to know what abiotic factors affect the population of juvenile fish.  Bknowing what factors affect their movement, scientists are better able to determine where and wpopulations can be found.  For example, the average water temperature is 12.9 Celsius where our samples are taken.

2.  Bongo Tow:  This interesting piece of equipment is deployed when the ship slows to about 1-2 knots.  We usually travel at a speed of about 12 knots on average.  When the Bongo goes over, everyone knows because we all slow down!  The Bongo Tow consists of two nets that are lowered into the water at a depth of 100 meters.  The Bongo Tow collects a small sample of the water column at this depth and is then brought back to the surface.  My job has been to rinse the Bongo tow once it is onboard, collect any organisms that were caught in the nets, and preserve them.  These samples are then taken back to the OSU lab where scientists examine the contents under a microscope.  They are looking for tiny organisms called zooplankton and phytoplankton.  These organisms are an important food source for juvenile fish and scientists want to know what food is available where fish are found.  In addition to zoo and phytoplankton we have captured krill and Dungeness crab larvae.

Here I am before deploying the CTD. We are required to wear a life jacket, hard hat, and foul weather gear when working.

3.  Midwater trawl:  This is the most exciting part of each station rotation.  This net is towed from the aft (back) of the ship for 15 minutes at a depth of around 30 meters.  The purpose of this trawl is to capture juvenile fish to be counted and measured.  Once onboard, scientist work to separate all species found in the net.  Below is a list of the species caught this morning as we sorted:

I am holding a juvenile squid that I’ve sorted from the trawl.

Flatfish larvae (very similar to our flounder), Pacific Hake, Squid, Rockfish larvae, Whitebait Smelt, Juvenile King-of-the-Salmon, Popeye blacksmelt, Slender barracudina, and blue lanternfish.

Today, we are steaming ahead to our first station about 11 miles off the coast of southern Washington.  We will begin sampling tonight at 7:00 pm once we reach the station and continue to sample the remaining 3 stations.  The work is usually completed around 5:00 am so I am off to catch up on sleep again as I will be up into the wee hours of the morning!  One thing that I do enjoy about being up at these odd hours is watching the sunrise on the open ocean.  What a beautiful way to greet each day!
Until tomorrow…
Tanya Scott