Monday, August 11, 2014

Team In-Seine

I apologize for the long wait! Barrow is not known for its fast or reliable internet, and unfortunately I haven't been able to get online for well over a week now... but I have lots of pictures!
I have tried to tell my friends from Florida how bad the mosquitoes are on the North Slope of Alaska but pictures always fail to show how bad. This picture only shows a couple dozen sitting on Sam’s head, what is not shown is the swarm of hundreds that are buzzing around our heads at any given time.
On our way out to our furthest site “Monument” we came across a couple washed up dead gray whales. At first, these washed up animals can be rather alarming as they are quite common. If we found washed up marine mammals this often in Florida, that alarmed feeling would be justified, but here the water is so cold that decay occurs very slowly and the same animal may wash up on several beaches before it fully decays; this creates the illusion that there are far more dead whales out there than there really are.

In both cases, these whales were clearly attacked by Orcas, one of the Gray Whales very few predators. These scars that were all over the body are often mistaken for polar bear scratches, but they are actually killer whale teeth marks. Inside of these wounds you’ll notice hundreds of crustaceans, commonly known as whale lice, these critters are parasitic and feed on the skin of the whale.

NOAA ecotoxicologist, Sarah Allen, came to join us to collect baseline hydrocarbon data. Here she is setting up her passive samplers in the water column. This data will be invaluable in proving injury to nearshore ecosystems in the event of an oil spill.

While deploying one of Sarah’s passive samplers two local children were curious what we were doing and asked if they could help. We were more than happy to get Sadie and Jenny to learn a little bit about our methods and the extra sets of hands were appreciated.

A bag full of Arctic Sculpin (Myoxocephalus scorpioides). These are the sculpin that I will use for the isotope incorporation experiment at Florida International University. I have enough now, and will be preparing to ship them back to Florida alive in the next few days.

This week we had a mysterious appearance of millions of black pteropods. These creatures are commonly called the angels of the ocean as they have wing-like structures that they use to fly around the oceans. Most people don’t realize that these are actually a type of snail, and the wing is a modified foot. This picture shows the team digging through the countless pteropods trying to find the fish hidden underneath.

In order to better understand foodweb dynamics in our sampling sites, I am collecting plankton using a 0.5m diameter 500 micron net towed behind a boat, as well as stacked sieves to collect the smaller plankters. After I filter the water, I flush the particles off of the sieve mesh and collect the runoff. This concentrated mixture of plankton is then run through a Fluid Imaging FlowCAM, an instrument that takes a magnified picture of every particle that passes through it. This allows us to quantify the types of plankton that are available for fish to eat.

One of the great things about the design of our RV Nanuk is that all of the electronics are raises high off the water. Even if a large wave hits it, the pontoons can become completely submerged by the wave and it will not affect the electronics that are high and dry.

We have been struggling to catch Arctic Cod in our seines, trawls, and other sampling methods, but luckily for all the predators out there, we know they are there. This was the stomach contents of a Dolly Varden Char caught in a local’s gillnet. I counted 11 Arctic Cod that had not been digested and the remains of many more. Other than Arctic Cod, this gut was also filled with predatory hyperiid amphipods. This information will be invaluable when I try to piece together the food web.

This is our “from land” surveying convoy, geared up and ready to survey. The red ATV is loaded with our seine net on the back, an outboard motor and a data sonde on the front. The middle ATV tows a trailer filled with coolers full of gear, a plankton net, emergency gear, and a 8ft zodiac strapped on top of it. And the ATV on the right is towing another trailer carrying the USV Nanuk that is used for acoustic surveys. Further more, the lead and tailing drivers both carry a shotgun loaded with sabot slugs just in case we have to defend ourselves against polar bears. This is not a likely occurrence, but its best to be prepared.

Our team posing in front of the “Hollywood” sampling site. This site was names because of the houses seen in the background that were featured in the movie “Nanook of the North”.

This is by far the most awkward catch we have seen. A very large hermit crab that has tried to shove itself into the tiniest shell. This goes to show how little choice there is for these creatures in Barrow, there are not many snails to steal shells from. One thing that is really cool is that its exoskeleton had a copper colored iridescence that can be seen on the chelipeds (claws) in this picture.

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