Tag: sand dollars

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Anne Mortimer: Fishing, July 7, 2011

NOAA Teacher at Sea
Anne Mortimer
Onboard NOAA Ship Oscar Dyson
July 4 — 22, 2011 

Mission: Pollock Survey
Geographical area of cruise: Gulf of Alaska
Date: July 7, 2011

Weather Data from the Bridge
Air temperature: 9.53 C, Foggy
Sea temperature: 8.19 C
Wind direction: 145
Wind Speed: 18.73 knots
Barometric pressure: 1013.22 mbar

Science and Technology Log

Last night, we attempted a bottom trawl for walleye pollock. The way scientists know that fish are present is by using acoustic sampling. The centerboard of the ship is set-up with sound emitting and recording devices. When a sound wave is emitted toward the bottom, it will eventually be returned when it hits a fish or the ocean bottom. This is called echo-sounding and has been used by sport & commercial fisherman and researchers for many decades. The sound waves are sent down in pulses every 1.35 seconds and each returned wave is recorded. Each data point shows up in one pixel of color that is dependent on the density of the object hit. So a tightly packed group of fish will show as a red or red & yellow blob on the screen. When scientists see this, they fish!

This echogram shows scientists where fish can be found.

The scientists use this acoustic technology to identify when to put the net in the water, so they can collect data from the fish that are caught. The researchers that I am working with are specifically looking at pollock, a mid-water fish. The entire catch will be weighed, and then each species will be weighed separately. The pollock will all be individually weighed, measured, sexed, and the otolith removed to determine the age of the fish. Similar to the rings on a tree, the otolith can show the age of a fish, as well as the species.

pollock otolith
A pollock otolith.
Pollock otolith in my hand

These scientists aren’t the only ones that rely on technology, the ships navigation systems is computerized and always monitored by the ship’s crew. For scientific survey’s like these, there are designated routes the ship must follow called transects.

globe chart
This chart shows the transects, or route, that the ship will follow.
This chart shows the route (white line) of the ship once fish were spotted. When scientists find a spot that they want to fish (green fish symbol), they call up to the bridge and the ship returns to that area. As the ship is returning, the deckhands are preparing the net and gear for a trawl.

Personal Log

I think that I must have good sea legs. So far, I haven’t felt sick at all, although it is very challenging to walk straight most times! I’ve enjoyed talking with lots of different folks working on the ship, of all ages and from all different places. Without all of the crew on board, the scientists couldn’t do their research. I’ve been working the night shift and although we’ve completed a bottom trawl and Methot trawl, we haven’t had a lot of fish to sort through. My biggest challenge is staying awake until 3 or 4 am!

Did you know?

That nautical charts show depths in fathoms.  A fathom is a unit of measurement that originated from the distance from tip to tip of a man’s outstretched arms. A fathom is 2 yards, or 6 feet.

Species list for today:

Humpback Whale

Northern Fulmar

Tufted Puffin

Stormy Petrel

petrel
Fish biologist Kresimir found this petrel in the fish lab; attracted to the lights it flew inside by accident. The petrel is in the group of birds called the tube-nosed sea birds. They have one or two "tubes" on their beak that helps them excrete the excess salt in their bodies that they accumulate from a life spent at sea.

In the Methot net:

Multiple crab species including tanner crabs

Multiple sea star species, including rose star

Sanddollars

Juvenile fish

Brittle stars

Sponge

Multiple shrimp species including candy striped shrimp

shrimp variety
These are some of the shrimp types that we found in our Methot net tow.
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Channa Comer: The End of the Journey, May 21, 2011

NOAA Teacher at Sea
Channa Comer
On Board Research Vessel Hugh R. Sharp
May 11 — 22, 2011


Mission: Sea Scallop Survey Leg 1
Geographical area of cruise: North Atlantic
Date: Saturday, May 21, 2011

Final Log
This will be my final log of the cruise. Unlike previous posts, it will not be separated into a science and a personal log. For my final post, I’ve integrated the two because what I’ve

The Last Tow
The Last Tow

gained from the trip is both scientific and personal. In addition to all that I’ve learned about what happens on a Sea Scallop Survey, the FSCS, scallops in general, and many of the other creatures that live on the North Atlantic Ocean floor, I will be taking home new questions to answer and new avenues to explore.

This was my first experience with marine biology and I couldn’t have had a better one. Rather than reading about the ocean in a textbook, I was able to experience it, in all its grandeur, wonder, beauty, diversity, and unpleasantness (sea sickness, green sand dollar slime, sea squirts, sea mouse). I also couldn’t have asked for better hosts that all the people at NOAA who helped to make this trip possible –everyone in the Teacher at Sea program who helped before the trip and everyone here on the boat.

With the many, many, many tows and baskets and baskets of sand dollars, I’ve developed a fascination with them and many questions to answer when I get home. While I’ve learned a bit about them here on the ship, there is still so much to learn about them. Why are they in such abundance in certain areas? How can you tell the difference between a male and a female? How exactly do they reproduce? What is there function in the deep sea food web? What is their life span? Why the green slime? If their anus and mouth is in the same place, how what mechanism exists to turn one function off when the other is active? If any of you know the answers to these questions, feel free to share.

I owe a special debt of gratitude to Vic, the chief scientist who was always willing to share whatever he knows (and he knows a lot), answer all of my many questions, always went out of his way that I had everything that I needed to fulfill my Teacher at Sea obligations, and made me feel like part of the “family.” I am also extremely thankful to all the other members of my watch (and Chief Jakub) for being such an amazing group to work with. We worked together for 12 hours each day for 11 days and NEVER HAD A FIGHT! Everyone always made a conscious effort to be kind, courteous and helpful. Definitely a great lesson to take back with me. One of the most special things about this experience has been the opportunity to get to know the people on board, to learn about their varied backgrounds and how they ended up where they are.
Through my participation in the Teacher at Sea program, I’ve also learned a greater appreciation for the food that I eat. There is so much that happens before food gets to my plate that I usually take for granted. In the case of scallops, the Sea Scallop Survey is just one part of a very complex picture that includes fishermen who make a living for themselves and provide jobs and opportunities for others, all of the organisms who share the ocean with scallops that are affected by scallop fishing, the ocean ecosystem, and the consumers who buy and eat scallops. In reflecting on this, I’m reminded of a series of articles that I read recently about integrating Native American science (viewing science from a holistic perspective with consideration of how our choices affect ecological balance) with western science. While our immediate needs and wants cannot be minimized, as a society, we could definitely benefit a broader, more long-term view of how our choices affect us over the long term, especially as we are faced with diminishing resources and an ever-expanding population.

Thanks to all of you who followed my adventure by reading the blog. And thank you for your comments, both on the blog and via email.

Until the next adventure…………