Algae species of the month – February

For February, our Algae species of the Month will be two closely related species of brown algae, both of which belong to the family Scytosiphonaceae.
The first species is Petalonia fascia, also known by the common names Sea Petals or Broad Leaf Weed. It is a marine species that is not able to live in low brackish salinity, so it does not occur inside the Baltic Sea. It is, however, common along the coast of the North Sea and along the Swedish west coast. I found these specimens all dried up on one of the plastic containers that were sent ashore by the storm Urd, on a beach near the Tjärnö Marine biological station at Stromstad. So, in order to investigate what alga species it was that had settled on the container , I carefully removed the thin brown-green flat membranes that were attached to the plastic with only a tiny attachment-disc. The name Petalonia fascia reveals a lot about how the algae looks. Petal means leaf and fascia means ribbon in Italian.

The other marine species is Scytosiphon lomentaria,  known as Leather Tube or Chipolata Weed, and is just as Petalonia fascia a species that you can find during the cold season. It can form a belt just below the surface in the outer archipelago on the Swedish west coast in early spring and early summer. It is becoming more rare in the southern Baltic Sea and northwards from the Danish sound up to the Southern Quark, where the salinity is too low for it to survive. The ribbon-like thalli are yellow-brown and can be up to 25 cm long and 1-2 cm wide. They are hollow and have repeated “laced” narrow parts, making them look like a string of sausages, which gave the species its Swedish name, Sausagestring (Korvsnöre).  Scytos  means skin in Greek,  siphon  means pipes or tubes and  lomentaria  means lacing in Latin. So with a little knowledge of the ancient classical languages , the Latin name will provide you with information on how the algae looks.

3scytosiphon-ma%cc%8alning-l-kautsky

Both species have a complex life cycle. It is only the major strands of Scytosiphon lomentaria or leaf-shaped pieces of Petalonia fascia that are visible to the naked eye and are found in early spring to early summer. These are the sexual stage of the algae lifecycle, called gametophyte. They grow from a small, millimeter-sized disc with which the algae is attached to the substrate. These small discs are all that is left for the rest of the year, and they form the second stage of the lifecycle, known as the sporophyte.

4stenyta-med-sma%cc%8a-fla%cc%88ckar-skorpor-av-alger

It is not possible to tell if the small brown spots or membranes you can see on a rock are sporophytes, which will grow in the spring so that the stone is covered by long sausage strings. Just wait and see. Maybe it’s some completely different species that emerges from all the microscopic stages that overwinter on the rocks and shells in anticipation of the return of light and warmth.  And for the ice to melt. However, it is amazing how much  freezing and dehydration the species living in the littoral zone can withstand.

5stenar-och-skal

To determine what species I found dried-up on the red plastic container from Ireland was easy. I just had to put the dry seaweed in a little water on a plate so it was possible to take a photo. You have to take what you can find in order to get a good background. Once re-hydrated, then it was easy to recognize that it was Petalonia fascia, because this is a species I have found before on the Swedish west coast. Also, I found some blue mussel and small saddle oyster-shells  which made for a nice image.

6tallrik-med-arter

On a plate is where both Petalonia fascia and the closely related species Scytosiphon lomentaria really belong! Were you to visit Japan or other countries where it is common to eat different algae, you will find them dried and for sale under many different names; Kayamo-nori, Hime-kayamo, Ito-kayamo, Mugiwara-nori, Sugara, Yore- kayamo. I am not sure, but maybe they can be purchased at stores specializing in Asian products in Sweden too. Both species are known for their content of antioxidants. Otherwise, you can find your own little “Kayamo-nori” in the spring. It’s fine to eat just as it is. Just make sure they are picked far from discharges of polluted waters and not inside the marina.

Alga species of the month – January

This year we will introduce a new alga every month. Everything from the large brown algae such as the bladderwrack, ( Fucus vesiculosus ) and narrow wrack ( Fucus radicans ) who have been the theme in our research for many years (and will continue to emerge during the studies this year), to small microscopic algae that may not be so famous. We want to show you how exciting alga are and what good they do by producing oxygen and also which products we get from different alga species and what they can do.
The alga of January: Haematococcus pluvialis

Blogregnsalg.png

In the small rock pools in the archipelago is often found a microscopic unicellular green alga. This alga, Haematococcus pluvialis , is called blood rain alga in Swedish and it is widely spread across Europe, Africa and North America. The latin name comes from the Greek word haema and Staphylococcus , which means blood and seed. pluvialis come from Latin and means rain.
They belong to the group of green algae and swim around by two thin flagella in the front side of the cell. In these small waterbodies of the rockpools, the environmental conditions vary quite a lot and blood rain algae can adapt and survive such different conditions as strong sunlight, drying out and freezing in winter, by forming special immobile resting spores with thick cell walls. The resting spores are filled with starch, fat, and astaxanthin, a red pigment. The spores become a sticky mass, forming a thin red film that sticks to the rock surface. When living conditions become better, for example, after a rain, the spores can transform and return to moving green algae.

vilsporer.png

Astaxanthin is a substance that protects the cell from degradation by free radicals, which attack the cell during different types of stress, e.g. when the cell is exposed to strong UV radiation. Blood rain alga is cultivated because of its high content of astaxanthin, which can protect the human body’s cells against free radicals and boost the immune system. Today we find astaxanthin in a number of products out on the market, including feed in salmon farming. The substance is for example vital to the salmon’s maturation and spawning and also helps protect against various diseases. Wild salmon ingest astaxanthin through their natural food, small crustaceans who have eaten algae.

Happy New 2017, and a movie.

We wish all our readers a very happy new 2017. During 2016, we had no less than 2434 visitors.

2017 will be a year full of activity in our seaweed resarch on bladderwrack (Fucus vesiculosus) in the Baltic Sea. We hope to share lots of our exciting experiments and resluts with both old and new readers.

As winter seems to finally have decided to arrive in full here in Sweden, we treat you to a film showing the marine life at the Swedish west coast. Diver Edvin Thörnholm filmed all this material during one year in the Gullmar Fjord. The movie consists of material from 150 dives, showing the marine life at different depths and types of substrate in the fjord.

With this movie, Edvin wants to share the beauty of the underwater world and show how it varies with both season and time of day. The speaker voice is in Swedish, but if you see something and wish to know what it is, just mail us and state at what time in the film the organism is shown, and we’ll get back to you with a name in Latin and English. Enjoy!

The Gullmar fjord is the only threshold fjord in Sweden and by many regarded as the best dive site for marine biology. The local divecenter in the town Lysekil, DiveTeam, has many skilled marine biologists in their staff for those who whish for a guided “veggie-dive”.

 

A wee in the Baltic Sea?

For two weeks, the bachelor course “Environment of the Baltic Sea” from Stockholm University have been stationed at the Askö Laboratory for field studies. The course includes many relevant methods for new biologists. Among other things, the students have been fishing with survey gillnets, dug the mud of soft bottoms, and done meticulous inventories of vegetation and animal community in three shallow bays.

IMG_8099

Enthusiastic students snorkle out to make an inventory of the flora in a Baltic Sea shallow bay.

Part of the course also focuses on how humans affect the Baltic Sea ecosystem. For an easy way to show how urine in the sea affects the growth of phytoplankton, i.e. eutrophication, the students were instructed to set up 4 pieces of plastic tanks of 1 m3 (1000 liters) and fill with seawater. One tank was used as control and nothing else was added to it. In the other three 3dl, 6 dl and 12 dl of urine was added in order to study the phytoplankton response to different nutrient levels.

IMG_8102

0,3 permille urine and a week of sun clearly demonstrates how the phytoplankton thrive in response to nutrients.

This year I also put a piece of the filamentous alga Cladophora glomerata in the tanks. This algae grows just below the surface and thrives in nutrient-rich waters. When grown in high nutrients, it gets a darker green color. This is clearly seen in the most eutrophic tank with 1.2 liter of urine per 1,000 liters of water.

IMG_8101

The control treatment has no added urine, and the Cladophora glomerata has a light green colour.

IMG_8103

In the tank with the highest concentration (1,2 dl), the Cladophora glomerata has grown well and is dark green. The water is full of phytoplankton and does not exactly make one keen to take a bath.

Vegetation is beneficial for fish recruitment

Fish in the hand of humans – a Baltic Seminar. At the Baltic seminar last week two interesting presentations were given, one about the linkage between benthic vegetation cover and fish recruitment and production and the other one the strong impact by large fishing companies.First, Johan Eklöf, Department of Ecology, Environment and Plant Sciences, Stockholm University, presented the impact of cascading effects and the close interaction between rooted aquatic plants and seaweeds and fish recruitment of for instance pike and perch in shallow Baltic Sea bays. Shown both in more and more scientific studies and experiments.

1Large fish -plant benefits

In the first figure the positive effect of large fish is shown on the filamentous algae and how rooted aquatic plants benefit the recruitment of fish .e.g perch in shallow parts of the archipelago.

2PLants juvenlie pike

Fig. 2 shows that there seems to be a threshold of 20 % cover that is optimal for recruitment.This was followed by a presentation by Henrik Österblom, from Stockholm resilience centre about the large impact of big companies managing the fish stocks, both, on a global scale and in the Baltic Sea.

3fishmarket

The seminar ended with a panel discussion addressing the question if the fish stocks are in the hand of humans and if we will be able to find ways of sustainable use of and management of fish stocks.

4panel Balticseminar

Can the knowledge of the strong link between vegetation and fish recruitment be transferred to better management of shallow bays and coastal areas? Sofia Wikström and Gustaf Almqvist at the Baltic Sea centre, Stockholm University added to the discussion about the need of further improving our understanding of these complex ecosystems for a long-term sustainable management of fish species like pike and perch.

Fucus radicans takes to the Royal Dramatic Theatre stage

To celebrate the 70th birthday of His Majesty King Carl XVI Gustaf, a unique show “An evening about the Baltic Sea- Hopes and threats” was given in his honour at the Royal Dramatic Theatre on the 25th of April. On stage was more than 10 scientists together with leading dignitaries from several authorities and politicians who gave lively narratives of what is happening in the Baltic Sea. Everything from the slow geological changes over the years to the formation of new species all the way to the political situation today.
1Dramaten

A truly dramatic moment was when Ett mycket dramatiskt ögonblick var när professor emeritus Ragnar Elmgren from Stockholm University spoke of what species can be found in the Baltic Sea today. Suddenly, a large Ascophyllum nodosum falls down from above, landing just behind him!

Professor Elmgren cooly states that this species has not managed to migrate into the Baltic Sea due to the low salinity. The common seaweed species that most people reckognise, the bladderwrack, is an important foundation species for life in the Baltic Sea. Many species find shelter or food in the bladderwrack.
This is the moment when Fucus radicans enters the stage, from the pocket of Ragnar. Fucus radicans has formed an own species from Fucus vesiculosus in less than a couple of thousand years. It is the only known endemic species in the Baltic Sea, which means it is not found anywhere else i the world seas.

Seaweed smells of the sea and is also edible. Someone who has tried Fucus radicans canapées (se tidigare inlägg) is the Swedish king, on a visit to the Askö Laboratory.

It is relatively easy to separate Fucus radicans and Fucus vesiculosus when they grow together in sympatry. Fucus radicans appropriate common name is narrow wrack. The thallus is much narrower that that of Fucus vesiculosus and Fucus radicans lacks the bladders that have given Fucus vesiculosus its name.
4Smal o blåstång

Between the presentation on stage, we the audience were entertained with beautiful music from the orchestra and songs. Amonst them an interpretation of ”Rönnerdal han dansar över Sjösala äng” (Rönnerdal is dancing over Sjösala meadow)by Evert Taubes, where the background was a lovely seagrass meadow.

5sjögräsäng

The show ended with all participants on stage and His Majesty the King expressed his thanks for a rewarding evening, emphasizing his own keen interest in environmental questions in general and those of the Baltic Sea in particular.

6Kungen tackar

Artificial algalbelt created by ferry traffic

h3>In the non-tidal Baltic Sea, the daily wash from the regular ferry traffic along the archipelago shores creates an algal zonation similar to a tidal shore. The regular wash of the rocky shores bordering the ferry route results in marked green algal zone. In the springtime it is composed of e.g. Spirogyra species and in the summer by Cladophora glomerata and Enteromorpha/Ulva species. Just below the green algal belt a zone of Fucus vesiculosus is found. The swell created by the ferry traffic is enough to keep the thalli wet and not drying out. The daily wash from the ferry traffic also affects the communities in rock pools. If you want to know more about these changes have a look at the article by Östman and Rönnberg Effects of ships’ waves on rock-pools in the Åland …

algzonering ovan ytanSvallvågor

3Spirogyra i luppen

A stone with Spirogyra spp. collected from the Askö laboratory a week before.

This algal belt could be observed from the ferry last week when I was travelling from Mariehamn, Åland to Stockholm,Sweden. The other less positive effects from the traffic is the strong erosion of sandy coastal parts where threes are falling down and the shores are disappearing, leaving larger stones and boulders along the shore.

erosionsstrand