SGU finally arriving at the scene for our first week of field work!

10 days ago our research ship Ocean Surveyor left our previous project on a bank in the middle of the Baltic sea where we have been surveying geology and habitats since early summer. After a three-day transit we arrived to the northern most outpost of the Swedish marine waters, Haparanda in the Bothnian Bay. This journey also marked the transition of working on projects related to the national marine spatial planning in the open ocean where much of our mapping have taken place the last few years, to a regional/local and coastal project in an Archipelago Sea with its own set of challenges. It’s so fun to finally be here!

S/V Ocean Surveyor and our smaller launch “Ugglan” at Seskarö. Ugglan is equipped with similar survey equipment’s and sampling capacity as the mother ship but tailored for shallow waters and a small crew of 2-3 people.

We have set up our first basecamp on Seskarö where a currently abandoned sawmill provide a sheltered harbor. Our first impression of Seskarö was welcoming locals (of which two paddled sea kayaks through our catamaran hull one evening:) and a beautiful island. The water also surprised us with good visibility and pleasant swimming in 23 degrees warm water as we took a first dip in the sea.

island with one tree
At the moment the land is still rising in this area of Sweden. The lone tree tells the tale on our way to our survey! The low laying islands are beautiful to watch in the rugged landscape.

The unusual warm summer even up in the north have made many of us think more about how climate change will affect us in the future. As the northern outpost of the Swedish marine waters this region could be under even more pressure then other areas. This, along with the always important mission to understand our oceans better for more informed decision making, and to raise awareness and curiosity of the marine environment, make me feel that it is more relevant then ever that we are here and that a interdisciplinary mapping project like SEAmBOTH exists. If we are to have some idea of what the future brings and how we can adapt to those challenges, I believe it to be critical to have basic understanding and good maps of the present situation.

I who writes this short blog, Gustav Kågesten, are working with mapping marine habitats and understanding human impacts on marine ecosystems for the Geological Survey of Sweden. I’m also currently starting up our part of the SEAmBOTH project”

the blog writer in Ugglan
Gustav Kågesten (right) and Olof Larsson (left) surveying in the shallow waters outside Haparanda/Torneå with the small research vessel Ugglan.

So, what are we doing here and what have we done so far?

We work on mapping the Swedish side of the SEAmBOTH area with full coverage depth and geology data (3 – 70 meters depth, shallower areas will be mapped with laser from an airplane at a later time) as well as taking samples and videos/photos of the seabed. We also collect some oceanographic data as part of the survey. With help from the experts at SLU Aqua, we will also take samples of the animals living in the sediments (infauna). By combining the collected information in models, we can make maps of both geology and common organisms living on the seafloor in the area. To our help we use multibeam sonars, sediment profilers and boomers (looking deeper down into the seabed), ctd probes (salinity, temperate, depth), oxygen and current meters (the sensors sit on our UV-cameras together with a ctd), samplers and underwater cameras. Once we have got further along with this work we will post another blog and show you more results of what is down there 😊!

I think the rest of the story from our first week is better told in the images below.

Now pray for good weather so we get as much area surveyd as possible until the 4th of October when we leave the area.

Time to go out for another day of surveying!

seamboth_pilotproject area_swe
A first draft of our adapted survey plan (black lines), which also includes a small overlap into Finland to ensure seamless maps between our two countries – the oceans know no borders as we all know, but sometimes forget. Surveying in coastal areas with complex and partly unknown topography is very challenging for survey planning. We think we have gotten off with a good start though! Some areas are deep enough for S/V Ocean Surveyor, and the shallower areas Ugglan will take care of. Not all areas will be surveyed as time is limited. Which areas we will coved depends both on priorities (see numbers in the image and the red lines) prevailing winds and overall weather conditions during the next six week. We hope the fall storms will wait a bit longer since the outer areas are very exposed.
Anna Surveying seambotth on OS
Anna Svensson, SGU, multitasking by keeping an eye on two different sonar systems, talking to the bridge of the next planned line, as well as routinely measuring oceanographic conditions (using a moving vessel profiler) that we use to calculate the speed of sound. She also makes sure our high precision positioning systems are up and running. Enough to keep you busy!
Ctd profile collected during survey from Ocean Surveyor, you can see how the salinity varies between 2 and 0, where the freshwater lens is likely caused mainly by the Torne river. You also see that the water above 5-10 meter are very warm.
sediment profile
Sediment profiles penetrating the sediments and showing us the geology underneath the seabed.
multibeam survey
One of the first multibeam sonar images of the more exposed deeper parts of the area revealed what we think are hard clay reefs, but we have yet to find out for sure when we go to sample these locations! We also hope to get an idea of what processes could have formed those features.
Infauna training and our samplers
Infauna sampling training with SLU Aqua specialist Erik Karlsson. He has now got the geologists at SGU up to speed with how to catch little animals and put them in jars of alcohol for further analysis in the lab. It is a well known fact that sediment properties strongly affect the infauna community. But the more detailed knowledge how sediment and infauna are distributed in space and time is less known. Likely parts of the seabed in the SEAmBOTH project are of extra value for infauna (and thereby larger animals living on them) and we hope to understand this relationship better.
We expected our second camera and sampling observation site to be quite empty of life since it was a flat 36 meters deep postglacial clay area. Instead we found a ripping current and an abundant shrimp community, likely hiding at the seafloor to avoid predators at day (so they can go up and grab a snack at night time in the surface waters when the coast is clear). You never know for sure what you will find until you go and look yourself 😊
Looking at sediment profiles we can get information from the past, and perhaps a glimpse into the future. The image shows our first sample in the survey area using a Van Veen grab sampler at 19 meters depth. The red and black layers show that organic content and oxygen levels have varied with the seasons.
OS and Ugglan on the way home
S/V Ocean Surveyor and Ugglan on their way home after a long day at sea outside Haparanda. We start at 8 am and finish our day at 9 pm, as long as the light is still on our side.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s