Eelgrass meadows are underwater, natural grass fields, and just like coral reefs, they play a vital role as sanctuaries for marine life, protecting coastal areas from erosion and very importantly, their roots deposit large amount of CO2. Studies have shown, that as much as 35 times more CO2 is stored per square meter, compared to the rainforest. They take up CO2 via photosynthesis and releases oxygen, much of which they use to sustain themselves and grow, but this oxygen factory is also what sustains the oxygen level, we have in our atmosphere. So, say ‘hi’ to the coolest little grass in the World and let me introduce you to the problems eelgrass is facing and how we can help it make a come-back – thus helping ourselves.
Eelgrasses need sunlight to perform their photosynthesis, but they may not become too hot. How deep they can live, depends on the sun’s ability to reach them. And this is one reason, why eelgrass no longer spread sufficiently, since in many regions, chemical changes in the water have caused other species to overdevelop, which shades for the sunlight, so it doesn’t reach the eelgrass. I am talking about algae, that is thriving, multiplying, and blooming extensively because of the added nitrates, that is running into the water.
It can be hard to see the algae shade, but you can recognise an area, that is suffering from an overproduction of algae by how the eelgrass is covered in what looks like fur. It consists of epiphytes, that are covering the leaves. Once is has gotten to that point, the eelgrass is suffocating and will not be able to perform its photosynthesis. But not only the plants are suffering. Not too long ago, I found a pibefish that has also been covered in epiphytes, giving it a very hard time to manoeuvre. From the visual inspection it looked like the algae had found a way to fasten onto the reproductive organs, which raises the question if the fish will be able to reproduce.
The image clearly shows how eelgrass get covered in a ‘fur’ of epiphytes.
This pibefish has also been inhabited by epiphytes.
In many developed, coastal area, the presence of nitrates and thereby algae, are a result of unfiltered sewage water from households and industries as well as run-off from agricultural fields, where fertilizers are used. The algae shade is not the only problem. Upon the algae bloom, they die and fall to the bottom, where bacteria will eat them, but in that process, that bacteria use oxygen, which adds to the already weakened oxygen level around the eelgrass meadows. Basically, we have caused a massive imbalance to an ocean culture, where counter factors have previously been able to coexist, but we have now given the algae the upper hand. The situation is comparable to the culture, we have in our bellies. We have a lot of bacteria in our digestive organs, which can perfectly exist there and to some extend are also necessary, but if they get too many or in other ways come out of balance, we get ill.
The problem that eelgrass is facing, worries many and marine biologist from SDU Science (The Scientific Department of the Southern University in Denmark) have been studying and testing methods to repopulate sandy patches, where the eelgrass has had a set-back and is not able to spread again on its own due to the changed balance in the marine environment.
Some areas are not fitted for restoration, because the oxygen deprivation on the seabed has been so harsh, that only a muddy bottom remains, where new eelgrass roots would not be able to fasten. But luckily there are still available patches, where eelgrass can be planted.
A handful of eelgrass is harvested off a still healthy, thriving area. Preferably in the middle of a patch. That allows, for the hole that is left to recover fast – a bit like a wound in our skin. The harvested eelgrass is brought to land and separated into single shoots, that are then tied onto stainless steel nails. The nails add some leverage to the roots and tests have shown, that no harm is caused to the underwater composition. The seabed naturally contains and stores high levels of metal anyways.
Once the shoots have been prepared on land, divers and freedivers goes out to plant the shoots. Close enough for them to multiply, but also with some distance, so those shoots, that came from a dense patch, will now form a much larger patch. It is basically a scaling process. But as easy and simple as all of this sounds, it requires time and precision. Not only does it take about 3 people on land tying shoots to supply one diver in the water, everything is also accounted for, so that it is possible to monitor the progress to create proof of concept. Mechanical and automized methods have been thought about and tested, but not proved as efficient as the hard, manual labour. Personally, I think it is beautiful, that this exact method is what works, since the industrialisation and aims to mass produce in agriculture, for instance using fertilizer, is what got us here. There is no short cut, there is only the way of nature.
Now, that the method has been shown to be effective, the scientists from SDU and the supporting municipality of Vejle, Denmark (Vejle Kommune) wanted to get more people involved, not only for the sake of the debate and to create focus, but also to get all hands on deck in the work. So, through Os Om Havet, an NGO who has specialized in hosting ocean aware event for citizens, they have been able to get a lot more volunteers involved.
Mads from Vejle Kommune introduces the project to the Os Om Havet voluonteers.
Rune from SDU Science shows how shoots are being prepared.
A close-up of an eelgrass shoot ready to be planted again.
The events take place during the Danish Summer, where weather conditions for the work is more pleasant. Everybody can help, because as explained earlier, it takes 3 people to prepare shoots to supply one diver for the planting. If you are a certified diver (scuba or freediver), you can also participate in the water. Planting the shoots must be done quite precisely to ensure a good chance for the shoot’s survival. They are planted in a circular pattern with 25 shoots of which an average of 20 will make it and spread into a dense patch from out the pattern. This takes about 2-3 years. So, while, it might be labour hard and time consuming, once the grass has gotten a chance to spread, it will reward us quite quickly.
With more eelgrass covering the bare sandstrechtes, we provide for sanctuaries for juvenile fish life and already while, the planting is undergoing, the divers will witness how little fish move in. It is quite stunning. Wildlife is craving for natural structures, which is why projects like these, and also artificial stone reefs and other reef restorations projects has their entitlement.
On the larger scale, we must also demand change for what caused the degradation. We must limit how much nitrates we allow to enter the water, so that the algae population gets back to a normal balance. Industrial agriculture takes up too much land. Alone in Denmark, 80% of the fields are used to growing crops to feed the meat production, meaning we have acres and acres of fields with food, that we then feed to what is then later to become food as well. It is like doing everything double, cause for a massive nitrate pollution through fertilizer as well as contributing to a meat production that is highly unethical and responsble for large CO2 emissions to the atmosphere. If everyone aimed for a more plantbased diet, we could limit the square meters on which we grow crops as well as limiting the amount of animals, that need to suffer on our behalf. The push must come from the political side, but you as a citizen can make your own choice, every time you go shopping as well as spreading awareness to friends and family. There is another way to feed us all and still reduce our nitrate and CO2 emissions. And if at the same time, we repair a bit of the damage, we have done by restoring eelgrass, we are speeding up the process a lot.
If you are interested in participating in Os Om Havet’s eelgrass restoration, make sure to follow them on Facebook or Instagram, to know when the next event will happen. Events will be posted on Facebook with links to register. Registration is necessary, but you are always more than welcome to contact them or myself if you have further questions.
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