Nature-based Solutions
The Integrated Mangrove Fish Farming System (IMFFS)

March 2022

We trudged through the abandoned coastal land to a colourful tent, where our most recent partners awaited us. The 10 families from the Yenadi tribe had recently moved into this coastal desert region. They lived in temporary housing near the mangroves, caught rodents in the adjacent coastal agricultural fields for income, and seasonally migrated as manual labourers. They were partnering with us to implement a new approach to land restoration.

 

This was 8 years ago, when I worked with IUCN India as a Grants Manager for the Asia-regional Mangroves for the Future (MFF) initiative.

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The saline and dehydrated soils increasingly plaguing our coastlines © Nisha DSouza

The Approach

In the Krishna delta (Machilipatnam district, Andhra Pradesh), kilometres of saline-affected and abandoned land stand testament to the unsustainable shrimp farms that spread across this coastline in the 1970s. For our partners, Praja Pragathi Seva Sangham (PPSS) and the  M.S. Swaminathan Research Foundation (MSSRF) this land presented  an opportunity to incentivise the restoration and conservation of mangroves through an Integrated Mangrove Fish Farming System (IMFFS).

 

IMFFS takes its cues from a defining characteristic of mangrove forests - their complexity. With their layered and diverse vegetation growth, extensively intertwining root system spread below and above the soil, and web of creeks and larger waterways, mangrove forests are wonderfully intricate in function and form. This is what supports their resilience to climatic shocks and stressors.

 

The IMFFS ponds mimic mangrove forest structures in many ways. The ponds are constructed using sluice gates that enable tidal flushing, making them an extension of the natural waterways coursing through adjacent forests. Blending an over-story of diverse mangrove trees, and an understory of mangrove associated, salt-tolerant plants along the bunds of the ponds, IMFFS maximises vertical spaces. Multi-trophic systems are developed within the ponds, often with crabs occupying either the bottom of the ponds or the spaces within and on the mangrove roots, fish within the water column and closer to the surface, and shellfish growing along the sides. The tides bring in other organisms which are not necessarily farmed, but which contribute to a healthy pond habitat. The farms are energy efficient (as they do not require oxygenation or change of water, both of which occur naturally with the tides).

 

By mimicking the natural forests, IMFFSs offer similar services, and can:

 

  • Prevent erosion and flooding of lands adjacent to the ponds (through increased soil absorptive capacities)

  • Restore degraded land and soils (or repurpose saline lands)

  • Absorb and store carbon

  • Provide climate-adaptive livelihoods (as the ponds change from mostly brackish to freshwater in the monsoons, freshwater species to be grown)

  • Contribute to strengthened food security

  • Allow biodiversity to recover from reduced fishing pressure in adjacent areas

 

The diversity of plants grown, and organisms farmed, varies by region, culture, and market demand. However, the IMFFS is implemented following a basic tenant: net zero (or net positive) impact on the surrounding environment. To realise this, only native species are grown, and stringent monitoring systems must be put into place to measure and anticipate risks, impacts, and changes.

The progression of mangrove growth around the ponds. As can be seen, the bunds are positioned such as to resemble mitochondria © MSSRF/IUCN

A Work in Progress

All of this isn’t to say that there aren’t challenges.

 

  • IMFFS is not easily replicable because of coastal land being unavailable or unsuitable for mangrove growth.

  • Land ownership and access determine who benefits, sometimes to the exclusion of others within the community.

  • IMFFS needs to be small-scale to be sustainable and is therefore not easily scalable.

  • Supplementary artificial feed for the ponds is largely composed of fish bycatch from other areas; the demand for this ultimately shifts fishing pressure to another part of our coastline.

  • Market forces dictate what species are grown; sometimes this means that farmers choose to farm introduced and invasive species with a higher market demand.

  • Maintenance of broken or degrading bunds, sedimentation in the ponds and associated activities can be expensive for financially-challenged farmers. 

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Various fish species are being cultured in the ponds in the Sundarbans © Nisha DSouza

A Reason for Optimism

In early 2022, I received news that the families we had worked with were able to sustain themselves on their ponds, and earn some income through the sale of their farmed fish in local markets, particularly during the first set of COVID lockdowns. This is what gives me hope and a reason for conservation optimism.

 

There is immense potential in mindfully executed nature-based solutions. They can potentially create millions of new jobs and trillions of dollars in additional revenue or cost savings within a next few years. This suggests that as economies around the world continue to grow, the stock of their natural resources will determine their economic and social prosperity in the future. There is no better time than now to invest in nature-based solutions and our futures.

by Nisha DSouza