Dive transect on the Swedish west coast

During the summer, the BalticSeaWeed blog did al ot of fieldwork, both at Askö on the east coast and Tjärnö on the west coast.

Among other things, we performed an inventory of algae populations along two transects (laid out measuring tape) outside Tjärnö on the salty west coast.

The scuba diver swims from the beach with a tape measure that has been attached at the waterline down to the depth where no more algae grow. Depending on water clarity, this may vary from a few meters to more than 20 meters depth.

Once the algae end, the diver takes out her slate (the single most important tool for any marine biologist) and begins by noting the depth and how much of the tape measure that’s been rolled out. Subsequently, the diver notes down all the algal species she sees and appreciates how much of them there are, on a 7-point scale (1, 5, 10, 25, 50, 75 and 100%).

When the diver has recorded all of this about the starting point, she swims slowly along the transect (tape measure) and continues to note the depth, length and species when it becomes a visible difference in the species that dominates, in order to produce a map of different “algal belts”.

Each “belt” is also sampled, using frames and bags. The diver uses a fixed size frame, which can be loose or attached to a bag, of a size usually 20×20 or 50×50 cm, depending on how many species and how much algae it is.

The diver puts the frame on the bottom, picks the largest algae by hand and puts them into the bag and then use a scraper to get off all the algae that grows within the frame and whisk them into the bag. It’s harder than it looks to work under water when everything is floating around.

For you to get an idea of how it works, Joakim Hansen, who helped out as dive buddy this summer, shared what he was filming with the BalticSeaWeed blog. Here’s how it looks when you scrape a frame.

Why, then have we done this, except that it’s very nice to go for a dive?

On these two sites, these inventories have been conducted for several years. In ecology, it is very important to have measurements that extend over a long period of time in order to see if there is a genuine change in the environment, or if it is just normal variations between years.

So during the cold, dark months, we will pick up our bags with frozen algae out of the freezer (there were over 30 of them), thaw them, sort them into piles according to species, dry and weigh and record in the protocols, thus getting the number of grams dry weight of each species that grew in each frame. By comparing our data with previous protocols, we can then see if it has become more or less of any species, and if any new species have appeared or if any have disappeared over the years.

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Autumn preparations at Askö Laboratory

Last Monday it was time to put the seaweed out in the sea for overwintering. After some different trials of overwintering indoors in the Experiment Hall at the Askö Laboratory, with extra lights and air pumps, we have found that it is still difficult to get good enough water circulation and movement for the seaweed to be happy. It becomes brittle and falls apart come spring. But tying plants on to net cages and placing them on the sea floor at some meters depth works just fine!
The weather was amazing. Calm and brilliant sun. But the water level was too high, so now they are places too shallow to remain in the bay all winter. We will have to come back later and move them to a deeper waters. That will be a dry suit -job.

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In this year’s seaweed plantation is material from Gotland that we have collected in order to try and solve the question of if there is a third ecotype of bladderwrack. We know from before that in the Baltic Sea we find both summer reproducing (end of May-June) and autumn reproducing (end July-October) bladderwrack. But now it seems that we have found a third type, that reproduces more or less constantly throughout the entire season (May-October).

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The Sea Environment Seminar of 2013, was held at Vår Gård located in Saltsjöbaden outside Stockholm. In the morning Lena went for a walk alongthe beach and found plenty of free-floating bladderwrack balls, both in the wrack wall on the beach and also floating in the shallow water, rolling around.

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According to litterature, these do not reproduce sexually, and we have never seen any reproductive tips on this form of bladderwrack. Naturally, she collected several wrackballs. Since Lena had forgotten to bring a plastic bag (wich is something a true marine biologist always should keep on her/him), she had to go back to the hotel reception and ask for one. Imagine their surprised looks. The day after, Lena went out to ASkö and tied the wrackballs to little ceramic tiles. What we are looking for is if these freee floating forms will become sexual in spring if they have a fixed up and down. Now they are placed in the sea for the winter, and all we can do is wait for the return of sunlight and warmth in spring, when we can dive down and check if there are any reproductive tips on them.

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Seaweed project within BalticSea 2020

Anyone who is interested in the Baltic Sea might have heard of Baltic Sea 2020 Foundation.
Baltic Sea 2020 is a foundation founded by Bjorn Carlson through a donation of 500 million SEK (55 million EUR). The Baltic Sea 2020 Foundation’s assets shouldfund projects that are action-oriented, innovative and helps to improve the knowledge of the Baltic Sea continuously until 2020. The BalticSea 2020 Foundation began its work in 2006 and has to date initiated more than 70 projects, of which 25 are ongoing.

One of these projects is about trying to re-establish bladderwrack inside Björnöfjärden, a bay outside Stockholm. Björnöfjärden is heavily eutrophicated and the water is quite turbid with particles that prevents the light from penetrating. It quickly becomes dark below the surface, so that only a few stands of seaweed survive here. Observant locals have informed us that there was plenty of seaweed in the Björnöfjärd in the past, however.

So, seaweed enthusiasts to the rescue!

Susanne Qvarfordt is ready to establish bladderwrack.

Susanne Qvarfordt is ready to establish bladderwrack.

Susanne Qvarfordt from the environment surveillance company Sveriges Vattenekologer has initiated a project that will examine what factors might prevent the seaweed population from re-establishing in Björnöfjärden.
In addition, she asked the BalticSeaWeed blog to help with our expertise!

So, during the first days of June, we collected fertile tips of bladderwrack. These were sexed (we cut the receptacles and see if they are male or female), so that we would get an appropriate ratio of males and females at each site.

Sexing seaweed is best done with a scalpell and a magnifying glass.

Sexing seaweed is best done with a scalpell and a magnifying glass.

The bladderwrack were made into small beautiful fertile bouquets which were then attached to a grid. These will be placed in the water, floating over a number of concrete plates, and hopefully make new small seaweed babies that can attach itself to the plates.

All is ready for a baby boom!

All is ready for a baby boom!

So, now we have placed three grids in Björnöfjärden and three in nearby Fjällsviks Bay, to see if any of the other actions carried out in Björnöfjärden will affect the seaweeds ability to reproduce.
So, keep your fingers crossed that no one gets caught with their anchor or fish tackle in our beautiful grids, and hope for calm weather at Midsummer full moon so that there will be many wee ones.

Placing a seaweed grid with buoys.

Placing a seaweed grid with buoys.

Around Gotland

Yessiree! It’s time to jump into the water again!

After a long winter with lots of ice, and a well deserved trip to warmer water, it was time for yours truly to submerge oneself into the cool waters of the Baltic Sea.

Field season 2013 opened on Wednesday 22 May at the scenic island of Gotland, jewel of the Baltic Sea.

For the faithful reader, it comes as no surprise that it was time for the inventory of summer reproducing bladderwrack around this beautiful island, as part of the investigation we made along the mainland coast and Gotland last year (see previous post on Tångbloggen 2012 – A seaweed odyssey).

Gotland is well known by many botanists for its amazing flora, and the orchids certainly fought for space with primroses and lily of the valley along the road as we drove north from Visby up towards our first stop just south of Lickershamn.

Orchis mascula- Early purple orchid

Orchis mascula- Early purple orchid

Unfortunately, I think most people fail to see how beautiful Gotland is below the surface. The clear water and the dense seaweed forests are magically beautiful and are conveniently found at knee-depth in the water. If you do not like to get wet, you can easily experience life below the surface with a pair of high rubber boots or waders and water binoculars.

Our second stop was out on the island Fårö, at Lauter huvud. At the moment it’s a rather low water level in the Baltic Sea. It is caused by the weather and is not unusual this time of year. But it gets a little tricky to swim when you are constantly running aground. It was easier to walk among the rauks and occasionally stick my head under the surface in order to verify single specimens of Fucus. Quite possibly the occasional tourist who stayed at the car park was wondering what we were doing. One is not exactly discreet in a bright red dry suit. Hope I did not destroy too many photographs by emerging between rauks like a jack-in-the-box.

Having swum a little off the cliff edge, where it goes from 0.5 meters deep to 15 meters, we went to today’s third and last site at Östergarn.

Here the waves rolled in with a quiet rhythm, and if I had not been busy counting, I would certainly have fallen asleep, it was so very peaceful. The sun had come out and warmed my back as I floated about. I saw plaice, viviparous eelpout (Zooarces viviparus), stickleback, and Lesser pipefish (Syngnathus rostellatus).

Plattfisken vilar bland tången.

The plaice is resting among the seaweed.

The night was spent at the nice hostel in Hemsedal, which had very comfortable beds.

Thursday morning began with a trip down to the southernmost tip of Gotland, the Hoburg. Here we encountered more nature lovers in the form of a flock of birdwatchers. The species often nests at the southern tips of both Oland and Gotland and is easily recognized by the telescope that is often worn over the shoulder.

I even saw Red-Backed Shrike (Lanius collurio), Northern Wheatear (Oenanthe oenanthe) and a yellow bird that I didn’t recognize.

The sea was calm and the swans that landed some distance away did not attack the red ball splashing around, muttering through a tube (snorkel). It was nice to see that htere were many small juvenile seaweed individuals there. Reproduction last year was apparently very successful. Always a good sign.

Our last stop for a dip was just south of Klintehamn. On the way there we visited the nice naturum center in Vamlingbo for a short break. With coffee in the body, we parked at what must be Gotland’s busiest road, and changed into work clothes.

“When you take off your pants, five cars and a bus will always appear” – Old jungle proverb

It was the only site with lots of bladders on the wrack! One might think that bladderwrack always have bladders, but no! If the site is exposed to strong wave action, no bladders are formed. This is to minimize wave grip, so that the wrack does not get torn off by the waves.

Blåsor på blåstången - inte en självklarhet.

Bladders on the bladderwrack – not always to be expected.

It was plenty of gammarids, prawns and isopods here, and I hope I got a picture of the Lesser Pipefish hiding amongst the seaweed. It was obvious that there is a lot of nutrients coming out into the water as runnof from land. The seaweed had much filamentous algae growing on them. Swimming across it reminded me of a shaggy rug.

After again having fulfilled the jungle proverb (Why?!?) we headed towards Visby and enrolled into the prison. If we get out tomorrow remains to be seen.

World Water Day dip

On Thursday 21st, we sneak started the International World Water Day with a dive outside the water museum Aquaria located on Djurgården, in central Stockholm.

The sun was shining from a clear blue sky and the water was almost three degrees Celsius. Ideal for a dive.

The audience was a primary school class of around thirty VERY interested young children. In order for them to experience what I do, I had kitted up my full-face mask with both a wireless talk communication (Buddy Phone) up to the surface, and an underwater filmcamera, connected by hose to a large TV-screen. The camera was kindly lent to us by SVENTAB. Thank you!

Aquaria

P4 Radio Stockholm was on location and broadcasted live from shore (in Swedish).

A lot of people seemed to think it was madness getting into the water at this time of year. But with a good dry suit (I dive with Ursuit Red-Q and SiTech ring system for dry gloves) and a full face mask, I don’t get as much as a drop of water on me. I was probably the warmest one of all that day. Underneath my drysuit, I wear a thin wool underwear and then a Fourth Element fleec underwear over. Very toasty!

Lena Kautsky managed the surface end of the Buddy Phone and passed on questions from the children. She also told them about how seaweed function like forrests of the sea.

During the dive, I found a lot of beer cans an bottles, seaweed and a treasure chest full of candy!!

Dykare

Seaweed on the rocks

It is SUCH an advantage to have access to an ice breaking ship when one works with seaweed.
Mid-March is unfortunately not always full of sun, birdsong and warm spring temperatures.
On March 18th, we wrwe out at the Askö laboratory to do a reading of some experiments that have been out in the sea over winter.

Havet the door

With a lilttle help from the ice breaking R/V AURELIA and skipper Eddie, I could reach one of the sites, located just south of the boathouse.

The seaweed has not suffered from the cold winter, but was in good shape. When I lifted the “weedbeds” up onto the ice, lots and lots of animals swam out. Small crustaceans, gastropods and caddis worms a plenty, all of them have spent the winter in the seaweed.

Tång o is

Allthough the visibility in the water is very good this time of year, and the temperature is, well, shall we say refreshing, I can’t help but longing for summer. It is quite a struggle to move large sheets of ice when one is i the water…

Amongst Treasure and Wrecks

Are you interested in the history of sunken ships? Do you dream of finding chests of treasure in the sea? Or are you interested in finding out what jobs includes working under preassure (2-5 bar)?

On May 4th, the exhibition Among treasures and wrecks opens at The Museum of Work in Norrköping, Sweden.

Here, you can take part of experiences and everyday-life from seven divers with different connections to diving; a rescue diver, a freediver, a sport diver, a marine biologist, a marine archeologist, a construction diver and an underwater photographer.

The exhibition is open until September 15th.

The BalticSeaWeed blog is, of course, represented!

Fenor