Tag Archives: restoration

How aquaculture can restore mangroves

Mangrove forests are one of the world’s most productive ecosystems. They are huge biodiversity hotspots, providing habitats for various species and supporting coastal communities by protecting them from storm surges, erosion and tropical storms. They are also a vast carbon sink that can store up to five times more carbon per acre compared to rainforests. 

However, mangroves have been declining significantly over the years. By the end of the 1990s, global mangrove cover was estimated to have decreased by 35%. This was followed by a further 2.1% (3,363km2) decline between 2000 and 2016. The cause is primarily due to human activity, such as forest clearing and exploitation for timber production and raw materials, rapid coastal population growth, urban expansion and conversion to agriculture and aquaculture. In fact, growing aquaculture development has resulted in swaths of mangroves being converted into shrimp ponds to meet the rising global demand for farmed shrimp. 

Shrimp farms have long been accused of widespread mangrove destruction, but is this claim a fair one? This month, I took a deep dive into shrimp farming and mangrove deforestation and discovered some good news — that transformation is possible. Many countries, NGOs and private firms are actively looking for better ways to farm shrimp while safeguarding and replanting mangroves. I discovered a range of initiatives to establish tools and frameworks for environmentally responsible shrimp production and the farming of other species. The aim of these initiatives is to plant and restore mangroves through responsible farming, allowing mangrove ecosystems to flourish and provide a host of benefits.


Ecuador and Indonesia are two countries that have experienced rapid mangrove loss over the years. According to the National Coordinating Corporation for the Defence of the Mangrove Ecosystem of Ecuador, more than 70% of mangroves have been destroyed to make way for shrimp ponds. Meanwhile in Indonesia, 800,000 ha have been converted mainly into shrimp ponds over the past 30 years. 

However, shrimp farming in both countries plays a prominent role in global shrimp production and exports. It is also key to supporting small farmers, and this is where Conservation International comes in. This US NPO has developed an approach to farming shrimp that can help boost yields while restoring mangroves. The approach is to take half of a shrimp farm and restore it as a mangrove forest, while helping farmers increase their output on the rest. With pilot programmes in Ecuador and Indonesia, financing and technical expertise are provided to help farmers produce more shrimp, increase profits and restore mangroves. A loan fund is also being set up so that farmers can transition to more efficient production systems, while AI-based tools help to identify optimal sites for mangrove restoration.

Shrimp farming in Indonesia, while economically significant, faces several issues and challenges that have emerged as a result of its rapid development. These include disease outbreaks, massive shrimp mortality and economic losses, and water quality degradation due to the accumulation of organic matter and other pollutants in pond water and surrounding areas. In light of this, researchers are studying a mangrove-friendly shrimp farming model called silvo-fishery, which brings shrimp farming and mangrove restoration together in a low-intensity manner. The idea is to reduce environmental impacts, preserve biodiversity, and enhance carbon sequestration. According to Esti Handayani Hardi, professor at the Faculty of Fisheries and Marine Sciences at Mulawarman University, the practice promotes a more responsible and productive system by enhancing the natural ecosystem and improving livelihoods. She says that it offers a “win-win scenario” for more effective and sustainable mangrove rehabilitation and shrimp farming.

India, too, has been accused of mangrove destruction through its expansion of shrimp farming, especially along the east coast. But the country is dedicating extensive research, money and time into finding better ways to farm shrimp while increasing mangrove replanting efforts. The Swaminathan Foundation is a research institution in Chennai with a focus on sustainable rural development. Since 1993, it’s been working in Tamil Nadu, Andhra Pradesh, and Odisha on the east coast, where the majority of India’s shrimp farms are concentrated, and where shrimp farms and mangroves have long competed for scarce land along coastal creeks and riversides. Meanwhile, under a new initiative in the Sundarbans called Sustainable Aquaculture in Mangrove Ecosystem (SAIME), farmers are rearing black tiger shrimp. The aim of the project is to establish a model to demonstrate biodiversity-friendly aquaculture that will build a resilient ecosystem, and identify the extent to which blue carbon emissions associated with brackish water aquaculture could be reduced by integrating mangroves into shrimp farms. 


It was also encouraging to hear that other types of aquaculture are doing their part, too. Back in May, I chatted to Megan Sorby, Co-Founder and CEO of Pine Island Redfish, a redfish farm in Florida that’s created a sustainable, circular food system with fish waste. The farm’s recirculating aquaculture system (RAS) produces redfish and repurposes fish waste to cultivate red mangroves and nutrient-rich plants, such as sea purslane and barilla. After discovering that the nutrient profile of the waste from their farm is ideal for growing mangroves, Sorby and her team joined forces with an environmental apparel company to do their part. They collect mangrove seeds, which are nurtured in Pine Island Redfish’s nursery spaces, and transplant them along the west coast of Florida. 

“We can monitor and manage the waste nutrients that go into the mangroves very effectively, in other words fine-tune the waste to ensure that the mangroves grow in the most efficient way,” Sorby told me. “It’s very powerful to be able to say that we are using waste from farming redfish to grow plants that act as a nursery for juvenile redfish in the wild.” 

These initiatives prove that systemic transformation is possible, and it’s great to see positive trends that could act as examples for other species and regions that are facing similar challenges. Through efforts to protect ecosystems like mangroves, people in coastal regions can safeguard their natural resources and livelihoods, while such efforts also contribute to other areas like emissions reductions and blue carbon. Supporting these types of initiative is imperative for creating long-term, responsible solutions that contribute to even better farming and environmental conservation. 





Looking Back on Ocean

Since its release in May 2025, Sir David Attenborough’s new documentary, Ocean, has been generating discussions on a host of issues related to the plight of our seas. After watching it myself, I can see why it’s provoked such a significant response. It’s a celebration of marine life and a stark reminder of the threats facing the ocean today.

The aims of Ocean are clear – to protect the seas and send a message of hope. The documentary does an impressive job of demonstrating how almost every marine ecosystem is capable of regenerating in months or years. The messaging on the ocean’s resilience, capability for abundance and capacity to bounce back is encouraging. Ocean is also beautifully shot, with incredible scenes of kelp forests, coral reefs and brutal images of bycatch. Like many of Attenborough’s documentaries, I really enjoyed this footage, which captures the beauty and rich diversity of the seas so well while describing the far-reaching effects of losing both and the importance of taking steps to move in the right direction. Attenborough also says that knowledge is important for change. Ocean offers viewers a lot of important information that gives them plenty to think about and discuss.

One issue that the documentary hones in on is the destruction caused by bottom trawling. Footage of the practice and its effects are shocking. There is also a focus on scallop dredging and bycatch-heavy hauls where the bycatch is simply discarded. It’s a dark visual representation of commercial fishing, and the message behind it is powerful. As discussions over the documentary continue, there will undoubtedly be significant impacts on consumer trust towards seafood and public perceptions of commercial fishing.

There is no doubt that this kind of destruction needs to be highlighted, and Ocean raises key questions about how certain fishing methods are carried out and where they occur. However, the portrayal of bottom trawling and scallop dredging could benefit from additional context, and it was a shame that no fishermen or fisheries scientists were featured. Ocean makes many important points about the need to protect the sea and its fish stocks, and the debate around marine protection is essential. However, there was no mention of the people who work on fishing vessels every day or an introduction to the latest research by fisheries scientists. There was also no mention of the many important advances in sustainable fisheries management and fishing practices that are happening today. Through my work, I have come across an array of efforts from seasonal closures, gear modifications, gear that is designed to reduce seabed contact or minimise bycatch, monitoring systems on board vessels, and the use of AI to ensure that the ocean and its inhabitants are free from dangerous items like ghost gear. These are all evidence of a strong commitment to try and improve sustainability and establish well-managed fisheries. 

The UK public body Seafish says that in the UK, bottom trawling is managed as part of a broader fisheries management framework to ensure that impacts on fish stocks and marine ecosystems are avoided, mitigated or remedied. Seafish offers information on temporary, seasonal or permanent closures of fishing areas if there are concerns over marine conservation, and highlights the role of trawl fisheries in supporting coastal communities and fishing on grounds that have been fished for generations. Earlier this month, the UK also outlined plans to ban bottom trawling in more Marine Protected Areas (MPAs) to protect habitats and support important marine species such as lobster, clams and langoustine. Meanwhile,  The International Council for the Exploration of the Sea (ICES) also monitors bottom trawling worldwide and publishes independent assessments of the impact on seabed habitats. 

The UK is also aware of the issues surrounding scallop dredging and is working towards better management in this fishery. Two years ago, consultations were held on a king scallop fisheries management plan in England and Wales. Stakeholders discussed the introduction of dredge restrictions to protect scallop stocks, reduce any impact on the seabed and other marine species, and ensure the scallop industry’s future economic security. There was also a desire for king scallop stocks to be better understood, to identify interactions with the wider marine environment.

Professor Ray Hilborn, a marine biologist and fisheries scientist at the University of Washington, shared his opinion on Ocean in his latest newsletter, which I read after viewing the documentary. He pointed out that although unregulated fishing is a threat to marine ecosystems, so too are climate change, pollutants, plastics and terrestrial runoff of nutrients. He also explained that bottom trawling occurs only in a small portion of the global ocean, almost exclusively confined to continental shelves, and in countries with the largest amount of continental shelf — Russia, Canada, the USA, Australia and the Antarctic – the proportion of area trawled is very small. Most bottom trawling also occurs over more resilient environments such as sand, mud and gravel, he said, rather than more sensitive areas such as deep-sea coral or sponge beds. In fact, research shows that benthic communities in more resilient environments recover quickly, especially when trawling is well-managed. 

Hilborn concluded by stating that fishing of all forms, including trawling, can be done sustainably, ensuring food production for future generations. 

The UK and US are just two tiny examples of awareness towards the negative impacts of bottom trawling and scallop dredging. There are many more examples and viewpoints, and other nations are pursuing their own measures and working towards global agreements on marine conservation. This is more important than ever in light of this year’s UN Ocean Conference.

It’s worth highlighting that Ocean doesn’t say that commercial fishing as a whole is bad. The documentary is beautiful but devastating, and a reminder to all of us in the seafood sector, whether it’s fisheries or aquaculture, to think further about how we can take even more effective steps than the ones we are taking now. It’s exciting to see, once again, the attention given to critical issues that the ocean is facing. But at the same time, it’s important to remember that scientists, the fishing industry and more have been working hard for many years to improve fisheries and build something more sustainable. Like SeaspiracyOcean is a great opportunity for healthy, open discussions on fisheries, regulation and environmental protection, where all stakeholders can come together in a collaborative way.