Blue carbon ecosystems, simply put, are ecosystems that store carbon, and provide many co-benefits for the wider environment.
Mangroves, seagrasses and salt marshes along the world’s coasts capture carbon and store it underground, acting as “carbon sinks”. Although these environments are smaller in size compared to the planet’s forests, they are able to capture and store carbon at a much faster rate. Not only are these coastal systems directly beneficial for reducing carbon in our atmosphere, but they also have many other positive benefits. They function as breeding and nursing grounds for many species as well as being important in the daily lives of local people [1]. Mangroves also act as physical barriers to defend against tsunamis and hurricanes [1].
It is clear that these ecosystems play an important role in protecting our planet and wildlife from the worst impacts of the climate crisis; yet despite their value, mangroves are one of the most threatened habitats in the world [2].
What's happening to these environments
As with most natural habitats, humans continue to degrade and destroy mangroves and coastal ecosystems. Since 1980, 20% of the world’s mangroves have been lost to logging, agriculture, and urban expansion [3]. Perhaps the greatest threat to mangroves and coastal environments is shrimp farming. Hundreds of thousands of acres of wetlands have been cleared for artificial shrimp ponds. The water diversions required for these shrimp farms drastically alter the flow of water that maintains the health of surrounding environments, including mangroves [2]. Not only this, but the amount of chemical waste from these farms contaminates surrounding waters and damages local habitats and species.
Mangroves are also destroyed to make way for rice paddies and palm oil plantations, resulting in further contamination and a change in the natural flow of water [2]. As mangroves have adapted to tidal fluctuations, changes to their habitats mean they can no longer survive.
Coastal development and urban expansion are also responsible for the loss of our vital coastal environments. Ports and marinas are among some of the many developments that negatively impact the surrounding ecosystems. Streams and wetlands are filled with concrete, causing chemical runoff and thus polluting mangroves and other habitats. In addition, more people means more noise, traffic, and garbage, which take a toll on animals and plants [2].
Moving forward
Thankfully, despite the years of warnings from scientists, the wider public is realising the importance of these habitats. In the UK, news stations have begun broadcasting the importance of mangroves on their broadcasts and websites. Celebrities have also started to use their influence to educate the public about mangroves. Zach Efron’s Down to Earth: Down Under highlighted the importance and impacts of mangroves and their surrounding coastal reefs. This airtime is incredibly positive. Education can only help individuals like us be fully aware of how our lifestyles indirectly help damage some of the most important habitats in our world.
Mangrove replanting schemes in various countries are beginning to successfully restore some of the coastal habitats. However, we need to take a stance of protecting, not just restoring what we have left. We as a population need to work with communities to transform our relationship with nature from exploitation to one of respect and harmony [2]. We must take responsibility and act immediately.
References
[1] Dahdouh-Guebas F, Jayatissa LP, Di Nitto D, Bosire JO, Lo Seen D, Koedam N. How effective were mangroves as a defence against the recent tsunami? Current Biology. 2005;15(12).
[2] Mangrove threats and solutions: AMNH [Internet]. American Museum of Natural History. [cited 2022Nov25]. Available from: https://www.amnh.org/explore/videos/biodiversity/mangroves-the-roots-of-the-sea/mangrove-threats-and-solutions#:~:text=By%20far%20the%20greatest%20threat,are%20densely%20stocked%20with%20shrimp.
[3] Trent S. Mangroves matter for people and planet [Internet]. Environmental Justice Foundation. [cited 2022Nov25]. Available from: https://ejfoundation.org/news-media/mangroves-matter-for-people-and-planet#:~:text=Logging%2C%20climate%20breakdown%2C%20agriculture%20and,world's%20mangroves%20have%20been%20lost.