Natalie Macke, August 23, 2010

NOAA Teacher at Sea: Natalie Macke
NOAA Ship: Oscar Dyson

Mission: BASIS Survey
Geographical area of cruise: Bering Sea
Date: 9/2/2010

The result of each of our trawls thus far on the Oscar Dyson is a sample set of  jellyfish.  There’s at least one man on board who enjoys to see that sort of catch in the net.  (As opposed to our Chief Boatswain, Patrick…) Over this past weekend, the enthusiasm our lead scientist (Ed Farley, Salmon guy)showed for his ability to catch and recover these invertebrates, soared to a new all time high and a record for the Dyson crew.  (Once again, to the dismay of the well-respected fishermen working here on the Dyson  ..  not quite the story they want to bring home.)  On Sunday, our transects had us closer to the western coast of Alaska than our previous sample points.  Our Acoustician, Sandy Parker-Stetter, saw it all coming..  I think she probably said something like..  “Ed, we’re in the jellies…”.  The length of the trawl times can be modified, but how many jellies could there be anyway..  Well, that was quickly answered Sunday morning with a catch of 7,500 lbs of jellyfish (oh.. and a p. cod, salmon and pollock here or there to be fair)

So one way to become familiar with the Mellanaster Chrysora is to be knee high deep in them.  From each of our station trawls, Bruce sorts the jellyfish by type and then collects counts, relative size and mass data from up to fifty jellyfish samples of each species type (Fifty..  remember this number…).  The video below is a view of our catch coming down the belt to be sorted by the scientists.  If you listen to the audio you’ll hear Bruce reminding all of us what he needs for his sample set…

As our cruise progressed over the weekend the question of why and how we study jellyfish became my focus.  So I sat down with Bruce and he filled me in on what is known and a lot of what is unknown about these invertebrates.

Bruce has been a part of the BASIS cruises for the past 7-8 years.  In terms of changes in jellyfish he simply stated that people are seeming to notice them more, so potentially there may be an increase in their biomass.  This is what he and the scientists are trying to determine.  Just recently, the research community has shown an interest in learning more about their impact in various ecosystems.  The reality with research in this part of the world is that if it doesn’t impact the industries, then money for learning more about them can be sparse.

There are basically four types of jellyfish that are common to the Bering Sea;

• Chrysora Mellanaster
• Cyanea Capillate (Lion’s mane)
• Phacellaphora Kamchatka (Fried egg Jelly)
• Aurelia Labiata (Moon Jelly)

This time of year, the jellyfish are in their second (and last) phase.  The opaque regions you see in the center of their bodies are the gonads, the sexual organs of the invertebrate.  Once the jellyfish spawn, (shed their gametes) they die sometime in October in the Bering Sea.  This massive biomass then sinks to the bottom of the ocean where very highly popularized detritivores now have a new food source..  Yes..  it’s crab-feeding time.  Well, that is atleast what the scientists suspect.  It is actually quite difficult to have proof of what is eating the jellyfish since they are >99% water.  Once consumed, the jellies break-down almost instantly.  So an inspection of stomach contents for evidence of feeding on jellyfish is near impossible.  But I think back as to how I acted at the Grand Aleutian with the “all you can eat” King Crab buffet..  and I think the likely-hood of the crabs eating jellyfish during their annual fall buffet is quite probable.

So this brings me back to the enthusiasm of our Chief Scientist, Ed Farley.  Apparently, Bruce had shared the jellyfish / King Crab hypothesis with him…  because, that evening’s trawl (10:00 PM with an amazing sunset for a backdrop)brought us our 10 ton catch of jellies.  Tasking the winch, breaking the net..  I won’t really say how the fishermen reacted.  But the scientists were thrilled.  They had lots to sort through.  Sandy, the acoustician just shook her head.

So the BASIS Cruise 2010 will now go down in infamy for the largest jelly-catch ever.  But on calm seas and a beautiful evening, sorting through jellyfish seems like the perfect thing to do.

Personal Log:  

I have certainly learned the importance of wearing the correct fishing gear on board the Dyson.  Every time I think I’m just stepping into the fish sorting room for a look, I wind up with that gelatinous goo all over.  I guess my new found fondness for jellyfish has created a type of attraction not clearly explained by laws of physics.  So, I will in the future save on trips to the laundry by making a more conscience effort to wear the “Bering Orange Rubber Suit”.  (Mine name for it..  not theirs)

For those who have been concerned..  I did indeed find the gym and have been using the elliptical everyday.  Unfortunately, all this had done is provide me the mental freedom to enjoy more than my “Daily Recommended Serving” for Oreo Cookies.  Honestly, I’ve usually exceeded that amount by 9AM.

Lastly, I have taken a number of photographs here on the Oscar Dyson which are worth sharing.  So I will make a page devoted to images I have caught which I’ll update during the rest of our cruise..  Look for the link on the right hand column entitled, “Day on the Dyson”.

I have to say, our team is quite a handsome bunch!!