Bonus Projects

Baltic Diversity Notes - BONUS BIO-C3

Bringing you updates on Baltic Sea biodiversity from the BIO-C3 project and thoughts on life as a young researcher
18.03.2016 00:17

3 changes under the surface that we can feel in everyday life

Anna Törnroos

As our project, the BIO-C3 ( is all about finding out what has happened and what is going to happen to the diversity of the Baltic Sea marine life, I thought I’d share my top three human-induced changes to our sea that affect your everyday life. 

It is a fact that also under the glittering Baltic Sea surface, the environments in which animals and plants live have changed profoundly during the last decades. These changes are all related to our way of living and are in turn affecting the way we use and profit from the sea.


Here are my three picks of key human pressures in the Baltic Sea and some examples of how we are affected:


1.     Nutrient loading 

Also called “eutrophication” is an effect of us allowing too much nitrogen and phosphorous into the sea, primarily because of our way of growing crops, farming animals as well as harvesting forest and treating our wastewater. This makes the sea “bloom” with toxic and annual algae that, when dying and breaking down, leave the sea bottom and animals without air. This in turn leave the animals and fish higher up in the food chain searching for food and better living conditions.

How are you affected?  Ever experienced a closed beach or seen the water turn into pea soup in the summer? Or wondered why the birds on the beach and fish in the bay are different than you remembered from childhood? Perhaps you have seen the black and white mould like substance (the bacteria breaking down the excess plant or animal material) on the bottom when you have been swimming?


2.     (Over)Fishing 

During the last century we have increased and changed our way of getting food from the sea, from local small scale coastal fishing to large scale vacuum cleaning of the offshore water column. Unfortunately often throwing unwanted fish over board and using the fish for other than direct human consumption. Fishing too much and for only a handful of species affects the balance between animals in the sea and ultimately what we can harvest from the sea.

How are you affected?  Only finding Norwegian lax and not local fish, or any fish living in the Baltic Sea, in the shop anymore? Ever read about the struggle of the local, national fishermen in the news?


3.    Climate change 

We all know that the globe is warming, and for the Baltic Sea this have particularly meant an increase in storms, water temperature as well as the way the water moves in and out of the Baltic Sea, affecting in turn how saline the water is and which animals that can cope with the changes. 

How are you affected? Enjoying an earlier and warmer spring, summer or autumn season? Seeing the effects of ever increasing number of storms or higher water levels in coastal cities or on coastal constructions? Or perhaps experiencing a shortage of drinking water in the summer or muddy sediment filled swimming waters? Ever reflecting on why a species, for example jellyfish, bird or plant, that you’ve spotted once or twice before now seem to thrive in your bay a little bit too well?

Storms and increased water levels are an effect of climate change - perhaps have you also been affected?

Have you also experienced the effects and do you have other examples?

I think and hope that many, if not all three pressures were somewhat familiar to you? If this is the case, then policy makers and we the scientists have managed to communicate the problems. 

Now there are of course also other threats such as chemicals, marine litter, increased marine traffic that should be mentioned, as they are also interacting with the pressures above and affecting our lives. And to make it even more complicated, these pressures interact and are difficult to disentangle.


But what about the solutions? Well, that is of course a key question! To get there, however, we need to figure out what we really want from our sea? How much interference by marine traffic, toxic algal blooms and marine litter do you want when you are sunbathing on the beach during the record warm summer days, dreaming about that tasty Baltic Sea fish you used to eat as a child? We do want our 20th century life style, but what can we tolerate and how much do we want to be affected?


I leave you with those thoughts on Baltic Sea pressures and changes until next time, but please feel free to let me know what you’ve experienced!

- Anna

Return to headlines | 2 Comments | Comment

21.03.2016 13:35
Eutrophication is turning the sandy beach of my childhood into a foul-smelling bed of rotten algae!
23.03.2016 14:48
Interesting to read! Although I have to say I am a bit worried now... What would be your suggestions for me as a citizen? To put more pressure on politicians clearly, but what else can I do? Buy ecological food products only? Avoid buying any fish from the Baltic Sea?