Welcome to STRES: Seasonal Trophic Roles for Euphausia superba


This webpage is dedicated to interactions between local school children and scientists 
exploring Antarctic krill and polar food web dynamics (May 12- June 12, 2013). 

Posts about our travels, scientific successes, and failures will be updated frequently. We will also answer questions directed to us from the classrooms at Wakefield Elementary, in South Kingstown, RI. 
     
     
      

Related links: 
Meet the STRES scientists    Photos                     Other cruise links

Wakefield Elementary Presentation                    



What is Euphausia superba?
A species of krill found in the Southern Ocean.
(krill: small crustaceans; like tiny shrimp)
                                        photo: Uwe Kils
Why study them?
Antarctic krill, Euphausia superba, makes up an estimated biomass of over 500,000,000 tons, roughly twice that of humans. Half of this is eaten by whales, seals, penguins, squid and fish each year, making them an important part of the Antarctic food web. We will go and study how krill behave during the late fall. We want to know how active they are, where they live, if they swarm together and what they have been eating.

                                                          
Take a look at where we are going                                                                











 




Questions from Wakefield Elementary     Students
New questions from Mrs. Masciarelli's 4th grade class
Have any animals chased the boat?  

They do not chase the boat but they are attracted to it and curious about it. Also, because we clear space in the ice, whales, seals, and penguins like to play in the open water around us. 

What is the largest krill you have found?    How big is an adult krill?
5.6 cm is the largest we have seen. An adult can be as big as 6 cm, so we found a pretty big one. On average they are 3-4 cm.

Have you seen any other boats?   
We have not seen any boats in the Southern Ocean. The last boat we saw was in the Straits of Magellan. 

How many people on the boat?   
There are 55 people on the boat. 27 of us are scientists, 10 science support people who help us with instruments and computers, and then 18 crew who drive the ship, run the ship, and cook and clean for everyone. Everyone is working  hard.

Is the clothing you brought adequate for keeping you warm?
Yes, the clothing has been keeping us warm and safe. For example, when we work on deck at water level, we must wear float coats that will help to keep us a float if we feel into the water and are bright orange so that someone could easily spot us. We also wear steel toed work rubber boats to protect our feet while we work with heavy instruments and keep us from slipping on wet decks. When we are not working, we have warm coats and boots that make it comfortable to stand outside and whale watch for quite a while. 

How many different kinds of whales have you seen?  

We have seen only humpback whales on this trip so far. There are lots of pictures posted of them.

Where else are krill found?
Krill are found in every ocean, although Euphasia superba is restricted to the Antarctic.


Is there an animal that feeds only on krill?

Probably not only on krill. However, humpback whales and  penguins get about 90% of their nutrition from krill. 
That would be like eating the same thing 9 days out of 10.

Do krill hatch from eggs?   
Yes. Krill lay their eggs in deep water and the eggs sink into deep water where they are less likely to be eaten by a fish. When they hatch, they start to swim up to where food is. 

Does a baby krill have a different name for example puppy and dog?
There are names for different life stages. The first stage after hatching from an egg is called a nauplii. Next they are called calyptopsis, this is when they develop tails. A young krill, that really looks like a krill, is called a furcillia.

New questions from Mrs. Congdon's 1st grade class

1 Have you seen any whales  -  Max.
Yes, we see humpback whales nearly every day. That is the only species we have seen though. It is not the right time of year for Orcas.
2 Have you seen any rookeries -  Sydney and Clea.
No. We have not been near enough to land yet and the penguins do not stay in their rookeries during the autumn so if we did, we might not see penguins there. We do see them by the ship quite often. They are super cute.
3When will you be going on land class? What will you do there? class
We are going on land tomorrow to tour the US Station where people go to do Antarctic science. Stay tuned, we will tell you more about our visit after we return. 
4 What information have you found/ learned so far about the krill Mrs Congdon?
Probably the most important thing that we have learned is that there are lots and lots of krill but there seems to be very little to eat in the water. We have some krill in tanks and we have been trying to feed them various things. Interestingly, the stuff they like the best is the sediment from the bottom of the bays where they live. We also know, from Chris' camera, that the krill spend a lot of time on the bottom. So, we think that when there is little sun and the plants do not grow that the krill may eat sediment off the bottom.  The sediment is nutritious because it contains the plant remains that sank down from the water. It is sort of like compost.


Questions from Mrs. Congdon's 1st Grade class

Q:  How cold has it been?  Class question
We have been really lucky because it has not been terribly cold. The air temperature has been around -4°C (25°F) for the past few days (see graph). In science we always use the Celsius temperature scale where fresh water freezes at 0° and boils at 100°C. Salt water freezes at a lower temperature and the water here is just above freezing at -1.5°C. Working with this very cold water is a bit difficult because when you take it out of the ocean it freezes in the very cold air.


Q:  What kind of seals and birds have you seen? Max Knight
Seals of the Antarctic Peninsula
written by Bethany Jenkins
I'm a scientist studying little plants in the ocean, but on this trip I've become fascinated with the seals.  They are playful and look a lot like cute puppies.  They are very graceful in the water and like to sunbathe on ice bergs.  Here is a description of the kinds of seals we see down here on the Antarctic peninsula.

Leopard seals:  These are muscular seals with a slightly boxy head.  Penguins are very afraid of them because these seals will eat them for lunch, or dinner or yes even for breakfast. The like to hang out by themselves

Crab eater seals:  these seals are skinnier than the other seals and have a coat that is uniformly tan and grey.  They are shy around people but like to hang out with other seal friends

Weddell seals: These seals are chubby and have light grey spots.  They like to sleep on their sides and they also prefer to spend time napping alone.

Antarctic Fur seals:  These are fuzzy seals that look like circus performing seals. They are the only seal down here with ears that are visible on the outside.  They often stand on their flippers and swim through the water like dolphins.
Weddell and Crabeater Seals

Weddell Seal

Fur Seal

Fur Seal

Crabeater Seal

Fur Seal

Leopard Seal

Weddell Seal 
Birds are the most common animal we are seeing. We have seen Snow petrels, Gulls, brown browed albatross, cape petrels, and more.

Q:  Have you seen any penquins? What kind? Clea Graham
We have seen Adelie penguins. We have seen them swimming in large groups and one night one popped out of the water onto an ice flow just behind the ship where we got a great view.

Q:  How strong has the wind been?  Sam Guckel
We are working in small bays where the winds tend to be lower. However, we did have a windy day with 20-30 knot (nautical miles/hour) winds (see graph). Saturday night, the katabatic winds began to blow. Katabatic winds are really cold strong winds that come from the center of the Antarctic Continent and blow down toward the coast. They blew >40 knots and can be higher than 70 knots. We moved away from the coast to try to get into open water where the winds were not likely to blow ice into the ship. Sunday, we went back into the bay to work and the water was clear. Kerry called it the Antarctic Zamboni (like at the ice rink) because it left us with a smooth pool of open water.


New questions from Mrs. Hagerty's Kindergarden class


Q: How many krill are in a swarm?  Abby
It is hard to know exactly how many krill will swarm together.  When they do, there can be 1000's or 10,000's in each cubic meter of sea water.  A cubic meter is like a square box of water that is 1 meter long on each side.  One meter is about 39 inches.  With our camera system we have probably seen a hundred krill in a cubic meter.  Krill swarms are small compared to how much ocean is around us, so finding one is hard.

Q: What is the temperature today in Antartica?  Elliot
Today it was a bit colder.  The high temperature was about 25 F.  Since we have been here it has been as warm at 40 F and as cold as 15 F.  We expect it to get colder over the next couple weeks.  Yesterday it rained for a while and melted a lot of the snow that is on the ship.

Q: Are all shrimp krill?  Hope
Shrimp and krill are different types of animals.  Krill are in a group called Euphausiids  (pronounced like you-foul-sids).  These animals have gills for breathing on the outside of their bodies behind their thorax.  Shrimp are grouped with crabs and lobsters and called Decapods.  Decapods have 10 appendages, likes legs or claws.  The appendages are also a bit more complex that you would find on a krill.  Decapods have gills inside their bodies.

Q: Have you seen any other animals?  Ben M.
Here is a short list of the animals we've seen so far.  Whales, penguins, fur seals, crab eater seals and leopard seals all seem to like the edges of the sea ice.  There are also many kinds of birds around.  The most common are the southern petrel, snow petrel and cape petrel.  We also see a few types of seagulls.

Q: How much daylight is there each day?  Luca
Right now the sun is coming up at 9:20 and setting around 2:50.  That is about 5 hours of useful daylight.  The days are also getting shorter, by about 6 minutes each day.  When we leave for home on June 8th, the sun will come up at 10:10 and set around 2:10.  It is also very cloudy and we have not seen the sun yet!





Q: 
What does Punta Arenas mean? the Graham Family, 6 May

    A: Punta Arenas translates to "Sandy Point" in English. 
    

Q: What are krill classified as?

   A: 
Krill are crustaceans, like shrimp and lobsters. They are also zooplankton. Zooplankton means floating animals.

Q: What is the lifespan of a krill?

   A: 
Antarctic krill live 5-7 years. So, you all would be a super old krill.

Q: Where do you put the cups when you lower them in the water? 

   A: 
We put the cups into a mesh bag and tie them to an instrument so that they “feel” the pressure as they are lowered through the water.

Q: Why do krill have so little blood?

   A:
We are not sure about this- what is this question based on? Most crustaceans have copper in their blood, so that it looks green instead of red like our iron rich blood but we are not sure if they have a little or a lot of blood.

Q: How many hours a day do the scientists work?

   
A: 
That depends on the day. For example, while we travel to where we think the krill are, we are working only for a few hours at a time, taking water and looking at what types of organisms are living there. We are also getting everything we need to take water and krill samples ready.







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