Lessons From the Restoration of a Mangrove System in Point Lisas, Trinidad and Tobago

The Commonwealth Blue Charter is highlighting case studies from the Commonwealth and beyond, as part of a series to spotlight best practice successes and experiences. To share your own case study, please contact us

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“Once you recreate the natural hydrological environment and there is a source of seedlings, natural mangrove regeneration will occur.” Dr Rahanna Juman, Director (Acting), Institute of Marine Affairs, Trinidad and Tobago

Summary

Significant impacts on the mangroves in Trinidad and Tobago date back to the 1780s, when the St Ann’s River was diverted and wetlands were reclaimed to expand the city of Port of Spain. Development of roads, housing, industries and other infrastructure along the coast has contributed to the decline of the mangrove forest. For instance, in 1979, approximately 500 ha of forest from Couva to north of Claxton Bay were reclaimed for the construction of the Point Lisas Industrial Park and DeepWater Port.

Since 2001, Trinidad and Tobago has had in place a National Policy and Programmes on Wetland Conservation. This includes the concept of “no net loss” of wetlands, their values and their functions on publicly owned lands and waters, and requires mitigation action where mangroves have been removed or adversely affected as a result of development works.

This case study shares the experience of a restoration project in the vicinity of Point Lisas Industrial Park, initiated in 1999. A historic case study is useful to show how a situation has played out – giving the benefit of hindsight to draw lessons. This example shows that the key success factor for this mangrove restoration project was not the planting but rather the restoration of the hydrology in the area to create the right conditions for natural colonisation and recovery.

The issue

Point Lisas, on the west coast of Trinidad, was developed in the late 1970s as a deep-water port and industrial park. The west coast is where the majority of mangrove forests are to be found; it is also where more than 70 per cent of the population reside and has experienced the most intense development.

In the late 1990s, the ammonia industry had cleared a 1200 m2 area of fringing mangrove forest to enable the placement of a pipeline to carry waste-water into the Gulf of Paria.

It was expected that the mangrove forest would regenerate naturally as seedlings were available from the adjoining wetlands.

After 18 months, however, the mangrove showed no sign of regeneration.

Given the national policy for no-net loss of mangrove ecosystems, action was taken to investigate the reasons for the lack of regeneration and to attempt restoration.

The response

In 1999, a replanting project was undertaken to recover the mangroves at Point Lisas cleared during the construction of the pipeline.

During the laying of the pipeline, marl used to the cover the pipeline was unevenly placed, altering the topography of the area and restricting tidal flow. To restore the natural topography, profiles were taken in the cleared area, and were compared with the adjoining mangrove forest. From these profiles, the amount of material to be excavated to restore the topography and to re-establish the tidal hydrology was determined.

Before replanting, the topography was restored by removing the overburden to re-establish the tidal flushing; this allows the area to be flooded by the high tide.

Following these works, and once it was established that the area was being flooded by the tide, 261 seedlings of three species of mangrove were planted – 170 red (Rhizophora mangle), 76 black (Avicennia germinans) and 15 white (Laguncularia mangle).

The long-term monitoring of this project has enabled observation of the site’s response over time.

Partnerships and support

The Institute of Marine Affairs, a government-funded research institute, was commissioned in 1999 by the ammonia plant that had laid the pipeline to restore the cleared mangrove area. The project was conducted jointly as a public-private partnership, with funding provided by the private company. Monitoring of this mangrove forest west of the plant still continues up to today.

Results, accomplishments and outcomes

After 10 months, the number of seedlings recorded had increased to 354 – 82 per cent of which were natural colonisers. Only 24 per cent of the transplants were recorded.

Most of the seedlings observed were black and white mangroves and they were natural colonisers (169 natural black mangrove and 120 natural white mangrove). The red mangroves, which were more abundant closer to the Couva river mouth did not establish in this area. The black and white mangroves dominated this area of swamp. This restored area had healthy seedlings and saplings and was washed regularly by high tides.

By 2003, the tree density was 30 trees per 0.01 ha, with tree height between 6 and 8 m. Shortly after 2003, the area suffered mangrove die back disease, but by 2006 there had been another period of regrowth, with the tree density returning to 13 trees per 0.01 ha and an average height of almost 10 m. There have been subsequent periods of die back and regrowth in the restoration area as a result of disease and infestation. However, there has not been any further replanting since 1999 and so the system appears quite resilient.

The restoration project in 1999 was considered a success; however, the planting of mangrove seedlings proved not necessary once the physical characteristics of the site had been restored. Without reconstruction of the gradient and tidal hydrology, the replanting would have failed to re-establish mangroves in this area.

Challenges

The main challenge was to determine why natural regeneration had not occurred as had been expected, given the plentiful supply of seedlings in the adjoining wetland areas.

The approach taken to conduct scientific surveys to determine what may have changed in the physical environment proved successful. This supports the need for evidence (scientific)-based decision-making.

Sources

Juman, R.A. (2013) ‘Restoration of a Mangrove System in Point Lisas, Trinidad and Tobago’. Presented to the 1st Mangrove Forum, Guyana.

Juman, R.A. and Hassanali, K. (2013) ‘Mangrove Conservation in Trinidad and Tobago, West Indies’, Chapter 2 in G. Gleason and T.R. Victor (eds) Mangrove Ecosystems. Nova Science Publications accessed via https://www.ima.gov.tt/wp-content/uploads/2018/04/ Mangrove-Conservation-in-TT.pdf

Juman, R.A. and Ramsewak, D. (2013) ‘Status of Mangrove Forests in Trinidad and Tobago, West Indies’. Caribbean Journal of Science, June.

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Post-COVID recovery should lock in ocean sustainability, says Commonwealth Secretary-General

The Commonwealth Secretary-General is urging governments to ensure their countries’ post-COVID economic recoveries are environmentally sustainable and safe for the ocean.

Forty-seven of the Commonwealth’s 54 member countries have a coastline while 25 are either small island developing states or ‘big ocean states’ relying heavily on the ocean for food and income.

Sustainable blue and green economies

On World Oceans Day (8 June), Secretary-General Patricia Scotland calls on countries to reform development strategies in a way that supports vibrant and sustainable blue and green economies.

She said: “The ocean is the life blood of so many Commonwealth countries and our environment should be the cornerstone as we put plans in place to recover our economies. The Commonwealth covers more than a third of coastal oceans in the world, contributing to a global ocean-based economy valued at US$3 to 6 trillion per year.

“COVID-19 impact has radically altered some of our key economic sectors and transformed the way we live, communicate and do business. While the fallout from the pandemic has had a huge impact on our blue economies, it also presents a crucial opportunity to strategise on how to accelerate the transition towards more sustainable economic practices built on climate resilience and ocean sustainability.

“The Commonwealth Blue Charter is one of the most effective platforms for global ocean action in the international landscape today. I commend the work of our member countries through the action groups and welcome the support we have received from national, regional and global partners, enabling us to mobilise together for ocean health.”

Blue Charter action groups

The Blue Charter is the Commonwealth’s commitment to work together to protect the ocean and meet global ocean commitments. Ten action groups, led by 13 champion countries, are driving the flagship initiative. More than 40 countries have signed up to one or more of these action groups, and counting.

Commonwealth Blue Charter action groups include:

  • Sustainable Aquaculture (led by Cyprus)
  • Sustainable Blue Economy (Kenya)
  • Coral Reef Protection and Restoration (Australia, Belize, Mauritius)
  • Mangrove Ecosystems and Livelihoods (Sri Lanka)
  • Ocean Acidification (New Zealand)
  • Ocean and Climate Change (Fiji)
  • Ocean Observations (Canada)
  • Commonwealth Clean Ocean Alliance (marine plastic pollution – United Kingdom, Vanuatu)
  • Marine Protected Areas (Seychelles)
  • Sustainable Coastal Fisheries (Kiribati)

Members of the private sector, academia and civil society – including Vulcan Inc, Bloomberg Philanthropies, the Association of Commonwealth Universities, Nekton Foundation and many others – are also engaged as Blue Charter partners.

PAST EVENT: World Oceans Day – Mapping the Commonwealth one coral reef at a time

The Commonwealth is organising an interactive virtual event on 8 June to mark World Oceans Day.

The event will highlight the work of three Commonwealth Blue Charter Action Groups on:

  • Ocean and climate change
  • Coral reef protection and restoration
  • Mangrove ecosystems and livelihoods

Register for the event

Commonwealth Blue Charter

The Commonwealth Blue Charter is a commitment by all 54 member countries to actively cooperate to solve pressing ocean challenges and meet global commitments for sustainable ocean development. The Blue Charter is implemented by 10 action groups, led by 13 champion countries.

Partnering for coral reefs

The virtual event will also present the strategic partnership between the Commonwealth Secretariat and Vulcan to support critical decision-making to sustain, protect and restore coral reefs across the Commonwealth.

A new tool will help countries map, monitor and manage coral reefs, using satellite data and analysis provided through an interactive coral reef map to be hosted on the Commonwealth Innovation Hub.

The event will additionally premier a new short video about the Commonwealth Blue Charter.

Enquiries

For media enquiries, contact:

Josephine Latu-Sanft
Senior Communications Officer
[email protected]
+44 20 7747 6476

Coral mapping technology to accelerate reef restoration and protection in the Commonwealth

The Commonwealth Secretariat is joining forces with Vulcan Inc. to help member countries manage their ocean spaces via cutting-edge mapping technology.

Commonwealth countries are responsible for more than a third of the world’s coastal ocean, and 45 per cent of its coral reefs.

Harnessing satellite technology

The new tool will use satellite technology to create country-specific data and generate high-resolution images to help map, manage and monitor coral reefs in the Commonwealth.

Announcing the initiative on World Reef Awareness Day, 1 June, Secretary-General Patricia Scotland said: “The threats to the health of our ocean are numerous and can be perceived by governments as overwhelming, with 90 per cent of coral reefs at risk of disappearing within the next few decades as a result of climate change.

“That is why Commonwealth leaders launched the Commonwealth Blue Charter in 2018, which is a shared commitment from all 54 member countries to tackle urgent ocean issues together and by offering mutual support. Our partnership with Vulcan Inc, as well as with others in the private sector, academia and science networks, will work to translate our vision into meaningful on-the-water actions.”

Allen Coral Atlas

Building on the technology behind Vulcan’s Allen Coral Atlas – a public platform that converts data from a range of sources to generate detailed maps, images and alerts on coral reefs – a dynamic interactive coral reef map will be hosted online on the Commonwealth Innovation Hub. The information it contains will support marine ecosystem planning, management, governance and community action in member countries.

Chuck Cooper, Managing Director of Government and Community Relations at Vulcan said: “We have already lost 50 per cent of the world’s coral reefs which support the safety, well-being, and economic security of hundreds of millions of people.

The Allen Coral Atlas is helping to provide foundational data which inform critically important conservation efforts. Working with Commonwealth countries, we can change the trajectory of the coral reef crisis.”

World Oceans Day

The joint project will be unveiled with a special virtual presentation on World Oceans Day, 8 June.

This event, titled ‘Mapping the Commonwealth one coral reef at a time,’ will also feature presentations from three Blue Charter Action groups, focusing on:

  • Coral Reef Protection and Restoration
  • Ocean and Climate Change
  • Mangrove Ecosystems and Livelihoods

The Commonwealth Blue Charter is implemented by 10 country-driven action groups that share experiences and coordinate action to tackle ocean challenges. The presentations will highlight how the groups work together and the importance of accurate and live data to support management decisions.

Register for the event