When one thinks of deforestation, their mind usually conjures up images of large scale logging, wildfires or clearing land for plantations. However, deforestation is not simply a land-based issue. Marine vegetation, such as kelp and seaweed forests, are also under threat from climate change and human activity.
A Portugal-based NGO, SeaForester, aims to draw more attention to these so-called ‘forgotten forests’ as well develop innovative methods to re-grow lost underwater vegetation.
Of course, seeding new forests underwater has many more significant challenges than planting seeds on land. With this in mind, it is important for SeaForester for their methods to be cheap, scalable and easily replicable across the globe. As a result, they have developed their ‘Blue Front Yard’ approach which aims to reconceptualise how we think about our coastal areas – aligning them with land-based parks, forests and greenspaces.
SeaForester’s core solution involves using small stones which have been imbued with seaweed spores. These stones are then tended in specially-designed nurseries before being scattered from boats out into coastal areas. Once settled on the seafloor, the seaweed should take root and reforest underwater habitats.
One huge bonus of this approach is the ease in which seareforestation can be accomplished. No specialised equipment is required, no divers or underwater infrastructure. Instead, the stones can merely be dropped from normal watercraft. The basic raw materials behind the approach are also cheap and readily available.
Sea forests play a key role not only in the health of underwater environments, but also in regards to climate change. Seaweed can sequester up to five times more carbon than tropical rainforest and, thanks to their rapid photosynthesis, they can grow much quicker. It can also help reduce ocean acidification, combat eutrophication through nutrient filtration and provide oxygen. Additionally, kelp and seaweed forests provide important habitats for fish and other marine life, providing food, hiding places and nurseries. All this help promotes biodiversity, and is also incredibly important for coastal economies.
However, kelp forests are under severe threat and globally kelp forests have reduced by half in the last fifty years. Some areas have been particularly affected. Northern California and Tasmania have seen a 95 percent decrease, and Norway and 80 percent decrease. Warming oceans are largely to blame, as they allow disease to spread but also reduces the number of predators which keep grazing animals at manageable levels. On the Califronian coast, for example, a decline in sunflower starfish has caused the purple sea urchin population to explode, resulting in overgrazing.
In other places, such as off the coast of Vancouver, kelp forests have actually increased. This is due to the activities of urchin eating sea otters who have been feasting on the increased urchin population.
The importance of seaweed as a consumer product – it is used in everything from food production, to cosmetics to biofuels and fertiliser – has seen the increase in artificial seaweed farms, including some designed specifically to combat climate change. A recent report suggested that seaweed farms could be critical for filtering out nutrients and agricultural run-off which results in huge algae blooms – depriving areas of oxygen.
Currently, SeaForester is carrying out a number of research and seaforestation projects along the Portuguese coast, but also in Norway and Australia. It was recently selected as a finalist in the 2022 Earthshot Prize – a leading environmental prize established by the UK’s Prince William in 2020.