- Dr Machin is a marine and coastal ecosystem specialist with more than 15 years working on mangrove/ coastal ecosystem... moreDr Machin is a marine and coastal ecosystem specialist with more than 15 years working on mangrove/ coastal ecosystem projects in Australia, Sth East Asia (including Myanmar, Indonesia, Vietnam, Singapore and Thailand) and South America for a range of government, international donor and private sector clients. He was most recently Team Leader on a European Union funded mangrove restoration project in Guyana, Sth America providing support to government policies on sea defence, climate change and mangrove management and to provide Technical Assistance to the Mangrove Action Committee and the Project Unit in the implementation of the National Mangrove Management Action Plan. In this role he provided technical assistance in the review of institutional arrangements for mangrove management in Guyana, selection of potential mangrove planting sites across Guyana, design of mangrove planting activities, monitoring programs and establish-ment of a GIS monitoring system. An important part of his role has been the introduction of alternative techniques for mangrove restoration including planting of Spartina grasses as nurse species suitable for mangrove propagules, fencing to remove grazing animals and allow for natural regeneration. Dr Machin has also been responsible for initiating studies into effect of the movement of coastal mud banks on coastal restoration efforts and vulnerability assessments on coastal mangrove ecosystems.
In Singapore, Dr Machin was responsible for implementation of an Environment Monitoring and Management Plan for two mangrove restoration projects. The scope of Dr Machin’s work includes monitoring of newly planted mangroves and existing standing mangrove forests, daily site supervision of construction activi-ties, online turbidity and vessel speed monitoring, and monthly water quality and bioaccumulation surveys. On this project, Dr Machin also managed a team of local Singaporean consultants, trained local consultants, played an important QA/QC role for project deliverables.
In Vietnam, Dr Machin was Acting Team leader on the Coastal Wetlands Protec-tion and Development Project (CWPDP), 6-year, US$59m rural development project operating across 6 provinces in Vietnam. On this project Dr Machin was based in Ca Mau for a six month period where he oversaw the management of the initial mobilisation of the project, establishing project offices and procuring of-fice equipment implemented financial systems and developed systems to man-age the project’s budget (including a large payroll and equipment budget), development and implementation of a project procedures manual and oversight of the initial recruitment and contracting of a large team of administration and national consulting staff working at the provincial, district and commune level across the 6 project sites. Dr Machin also played an important role in liaison key project stake-holders including national, provincial and commune level government agencies, and universities and the World Bank and DANIDA.
In Thailand, Dr Machin worked with the United Nations Environment Program (UNEP) to develop a project concept paper “Mangrove conservation and the Sus-tainable Management of Shrimp aquaculture in South East Asia” which was sub-mitted by UNEP to the Global Environment Fund (GEF). Dr Machin also worked with the Royal Thai Forest Department in its mangrove research and manage-ment division in Bangkok as well as at a field station in Southern Thailand. In this role he was responsible for implementing mangrove research projects, community education and awareness and developing management initiatives for the Ranong Biosphere Reserve.
In Myanmar Dr Machin advised the European Union funded Myanmar Sustainable Aquaculture Project on the development of mangrove restoration activities and led a Remote sensing /GIS exercise to map the extent of mangroves in a shrimp farming zone in the Eastern Irrawaddy delta.
Dr Machin is available for short term consultancies in the field of mangrove restoration globally. Dr Machin is also available to provide pro bono, desk top advice on the design of mangrove restoration projects in developing countries.edit
Mangrove forest restoration projects undertaken globally to date have had significant issues and limitations and “most attempts to restore mangroves often fail completely or fail to achieve the stated goals” (Lewis, 2005). The root cause... more
Mangrove forest restoration projects undertaken globally to date have had significant issues and limitations and “most attempts to restore mangroves often fail completely or fail to achieve the stated goals” (Lewis, 2005). The root cause of many of the issues associated with mangrove restoration is that knowledge of the underlying factors controlling spatial patterns in mangroves is often lacking or not integrated into design of restoration projects, impeding the successful restoration of these critical ecosystems.
To improve the success of restoration and address many of the issues associated with the current paradigm for mangrove restoration, there is a need to develop an evidence based approach to the planning and implementation of mangrove restoration projects. The current thesis demonstrates the need for an evidence based approach to mangrove restoration through implementation of case studies in lower intertidal mangrove communities of the Ngao river, located in the Kraburi river estuary, Ranong province, southern Thailand and development of a series of recommendations on how to incorporate this improved evidence base into different phases of mangrove restoration projects.
The case studies target identified gaps in knowledge of the different stages of the mangrove tree life cycle through: observational studies on mature tree forest composition and spatial patterns in two forest types; observational studies and experiments examining the dispersal and development of mangrove propagules and seeds and establishment of released propagules in experimental enclosures; and experiments examining the survival and growth of transplanted seedlings in the two lower intertidal forest communities, with distance from the Ngao river and inside and outside canopy gaps.
The final chapter of the thesis summarises the results of the case studies and makes recommendations for how to incorporate each aspect of the improved evidence base arising from the case studies, into different phases of mangrove restoration projects. A table making explicit links between the case studies and restoration is included as was a concept for a decision support system for restoration of lower intertidal forests in the form of a flow chart based on results of studies of mature forest, propagules and seeds and mature seedlings. The flow chart demonstrates how each piece of evidence could potentially be applied in practice to enable the best decisions on which mangrove restoration approach to adopt to be made in an objective manner. For example information on hydroperiod, combined with information on site exposure and level of natural recruitment at the site would result in a specific recommendation for restoration of a site with either A.corniculatum, S.alba or A.alba seedlings where natural recruitment at the selected site was insufficient. Incorporated together with the improved evidence base on lower intertidal forests developed through the three case studies, the decision support system can potentially serve as a practical tool for the integration of scientific knowledge about mangrove ecosystems into restoration planning and ultimately improve the results of restoration and assist in the recovery of these essential ecosystems.
To improve the success of restoration and address many of the issues associated with the current paradigm for mangrove restoration, there is a need to develop an evidence based approach to the planning and implementation of mangrove restoration projects. The current thesis demonstrates the need for an evidence based approach to mangrove restoration through implementation of case studies in lower intertidal mangrove communities of the Ngao river, located in the Kraburi river estuary, Ranong province, southern Thailand and development of a series of recommendations on how to incorporate this improved evidence base into different phases of mangrove restoration projects.
The case studies target identified gaps in knowledge of the different stages of the mangrove tree life cycle through: observational studies on mature tree forest composition and spatial patterns in two forest types; observational studies and experiments examining the dispersal and development of mangrove propagules and seeds and establishment of released propagules in experimental enclosures; and experiments examining the survival and growth of transplanted seedlings in the two lower intertidal forest communities, with distance from the Ngao river and inside and outside canopy gaps.
The final chapter of the thesis summarises the results of the case studies and makes recommendations for how to incorporate each aspect of the improved evidence base arising from the case studies, into different phases of mangrove restoration projects. A table making explicit links between the case studies and restoration is included as was a concept for a decision support system for restoration of lower intertidal forests in the form of a flow chart based on results of studies of mature forest, propagules and seeds and mature seedlings. The flow chart demonstrates how each piece of evidence could potentially be applied in practice to enable the best decisions on which mangrove restoration approach to adopt to be made in an objective manner. For example information on hydroperiod, combined with information on site exposure and level of natural recruitment at the site would result in a specific recommendation for restoration of a site with either A.corniculatum, S.alba or A.alba seedlings where natural recruitment at the selected site was insufficient. Incorporated together with the improved evidence base on lower intertidal forests developed through the three case studies, the decision support system can potentially serve as a practical tool for the integration of scientific knowledge about mangrove ecosystems into restoration planning and ultimately improve the results of restoration and assist in the recovery of these essential ecosystems.
Research Interests: Mangrove Ecology, Study of Mangrove Species, Mangrove Restoration, Mangrove and coastal lagoons, Mangrove Analysis, and 4 moreMangrove forest, Mangroves, Coastal Management, Physico Chemical Parameters on Mangroves, and Marine Ecology, Mangroves and Near-shore Ecosystems; Conservation Biology, Environmental Policy
The organizing committee is pleased to welcome you to Georgetown, Guyana for the 1st Guyana Mangrove Forum, Restoring and Managing Mangrove Ecosystems in a changing world. We are excited to have a strong turnout with more than 100... more
The organizing committee is pleased to welcome you to Georgetown, Guyana for the 1st Guyana Mangrove Forum, Restoring and Managing Mangrove Ecosystems in a changing world. We are excited to have a strong turnout with more than 100 attendees, 4 exhibitors and 16 poster presentations with broad participation from government, Non Government organisations, universities and private sector in Guyana and from 9 countries in the immediate region. As part of the forum we have also organized an educational exhibition focusing on the importance of mangroves and efforts in Guyana, the region and internationally to restore and conserve mangrove ecosystems for a broader audience of school children and community members who we expect to attend portions of the forum proceedings. Our 27 presenters at the forum will address all aspects of mangrove restoration and management from the technical aspects of mangrove restoration to approaches to restoration and sustainable use of mangroves, coastal processes and engineering solutions to mangrove loss, institutional issues associated with mangrove restoration and management and emerging areas of blue carbon and GIS/ remote
sensing technologies which can be applied to management of mangrove ecosystems.
We selected the theme for the forum “Restoring and Managing mangrove ecosystems in a changing world” to highlight the realities of mangrove restoration
on the ground in Guyana which is occurring in the context of an extremely dynamic coastline and the realities of sea level rise and a complex socio-economic and institutional environment. The Forum, is an important event of the Guyana
Mangrove Restoration Project (GMRP), a project co-funded by the Government of Guyana and the European Union, as it provides an opportunity for the project to share experience and reflect on the work completed over the last two years since project
inception and hear from other mangrove practitioners in the region on their experiences on related projects. Importantly, the forum also provides an
opportunity to capture lessons learnt from the above and to look forward to the next phase of mangrove restoration and management in Guyana including the potential for ongoing cooperation and collaboration with regional partners. We wish you an enjoyable and successful forum. The Organising Committee
sensing technologies which can be applied to management of mangrove ecosystems.
We selected the theme for the forum “Restoring and Managing mangrove ecosystems in a changing world” to highlight the realities of mangrove restoration
on the ground in Guyana which is occurring in the context of an extremely dynamic coastline and the realities of sea level rise and a complex socio-economic and institutional environment. The Forum, is an important event of the Guyana
Mangrove Restoration Project (GMRP), a project co-funded by the Government of Guyana and the European Union, as it provides an opportunity for the project to share experience and reflect on the work completed over the last two years since project
inception and hear from other mangrove practitioners in the region on their experiences on related projects. Importantly, the forum also provides an
opportunity to capture lessons learnt from the above and to look forward to the next phase of mangrove restoration and management in Guyana including the potential for ongoing cooperation and collaboration with regional partners. We wish you an enjoyable and successful forum. The Organising Committee
Research Interests:
Ecological Mangrove Restoration, Principals and Lessons from large scale restoration projects in Florida, USA and Guyana, South America Machin, James*1, Lewis, Robin2 1DHI Water and Environment, Singapore, 2Lewis Environment Services,... more
Ecological Mangrove Restoration, Principals and Lessons from large scale restoration projects in Florida, USA and Guyana, South America
Machin, James*1, Lewis, Robin2
1DHI Water and Environment, Singapore, 2Lewis Environment Services, Florida, USA.
jama@dhi.com.sg
Ecological Mangrove Restoration encompasses a series of 5 principles defined by Lewis and Marshall (1997) which are considered critical steps are necessary to achieve successful mangrove restoration. This paper describes the rationale for development of these principles and provides case studies of their application in Florida, USA and Guyana, South America.
Case studies in Florida include long term ecological mangrove restoration projects in the West Lake, Hollywood, and Rookery Bay National Wetland Reserve to restore >500ha of mangrove forest impacted by changes in hydrology brought about by infrastructure development. Results of monitoring of forest cover, density and diversity at these 2 sites over an extended period (>6 years) are presented as are lessons learnt and recommendations for future projects.
In Guyana, the Guyana Mangrove Restoration Project (GMRP) began in 2010 and has successfully restored 35 ha of mangroves with survivorship of 58.7% of the 441.599 mangrove seedlings, primarily Avicennia germinans installed at twelve locations. While initial efforts were less successful, success increased as pre-planting surveys and surveys of the topography of both successful and unsuccessful planting areas showed that surface elevations of +2.0- +2.5 m MSL unvegetated mudflats were required in order to support planted mangroves.
The project has also adopted a new approach and is trialling ecological mangrove restoration methods as an alternative/complementary initiative to mangrove planting as a way of increasing the recovery of the mangroves along the Guyanese coast at a faster rate and at lower cost.
Techniques being trialed include:
• planting of coastal grasses (e.g. Spartina) to facilitate stabilisation of sediments in areas subject to heavier wave energy, as well as natural recruitment of mangrove seedlings through entrapment of propagules,
• fencing to enable natural recruitment by naturally available mangrove seeds without pressure from grazing animals,
• trials of techniques to restore natural hydrological processes in degraded mangrove forest areas to again allow for natural recovery of these mangrove areas and
• establishment of coastal engineering structures such as geotextile breakwaters and low cost Brushwood dams to reduce wave energy and facilitate accretion of sediments prior to mangrove planting.
Machin, James*1, Lewis, Robin2
1DHI Water and Environment, Singapore, 2Lewis Environment Services, Florida, USA.
jama@dhi.com.sg
Ecological Mangrove Restoration encompasses a series of 5 principles defined by Lewis and Marshall (1997) which are considered critical steps are necessary to achieve successful mangrove restoration. This paper describes the rationale for development of these principles and provides case studies of their application in Florida, USA and Guyana, South America.
Case studies in Florida include long term ecological mangrove restoration projects in the West Lake, Hollywood, and Rookery Bay National Wetland Reserve to restore >500ha of mangrove forest impacted by changes in hydrology brought about by infrastructure development. Results of monitoring of forest cover, density and diversity at these 2 sites over an extended period (>6 years) are presented as are lessons learnt and recommendations for future projects.
In Guyana, the Guyana Mangrove Restoration Project (GMRP) began in 2010 and has successfully restored 35 ha of mangroves with survivorship of 58.7% of the 441.599 mangrove seedlings, primarily Avicennia germinans installed at twelve locations. While initial efforts were less successful, success increased as pre-planting surveys and surveys of the topography of both successful and unsuccessful planting areas showed that surface elevations of +2.0- +2.5 m MSL unvegetated mudflats were required in order to support planted mangroves.
The project has also adopted a new approach and is trialling ecological mangrove restoration methods as an alternative/complementary initiative to mangrove planting as a way of increasing the recovery of the mangroves along the Guyanese coast at a faster rate and at lower cost.
Techniques being trialed include:
• planting of coastal grasses (e.g. Spartina) to facilitate stabilisation of sediments in areas subject to heavier wave energy, as well as natural recruitment of mangrove seedlings through entrapment of propagules,
• fencing to enable natural recruitment by naturally available mangrove seeds without pressure from grazing animals,
• trials of techniques to restore natural hydrological processes in degraded mangrove forest areas to again allow for natural recovery of these mangrove areas and
• establishment of coastal engineering structures such as geotextile breakwaters and low cost Brushwood dams to reduce wave energy and facilitate accretion of sediments prior to mangrove planting.
Research Interests:
Research Interests:
The Guyana Mangrove Restoration Project (GMRP) is a project co-funded by the Government of Guyana and the European Union under the Global Climate Change Alliance. The overall objective of the program is to abate climate change (carbon... more
The Guyana Mangrove Restoration Project (GMRP) is a project co-funded by the Government of Guyana and the European Union under the Global Climate Change Alliance. The overall objective of the program is to abate climate change (carbon sequestration through reforestation and forest preservation) and to mitigate its effects via sea defenses.
Mangrove restoration has been a major focus of the GMRP and project planting activity in 2010-2012 combined has enabled more than 330,000 Avicennia germinans seedlings to be planted across 5.59km of the coastline at ten locations, equating to approximately 35ha in area. Evaluation of field results indicates that where mangrove seedlings are planted in optimal environmental conditions, recovery of the coastal protective belt can be rapid. These successful sites can be compared to neighbouring planting sites which have experienced near total mortality of seedlings during the same period. Evaluation of environmental conditions at the different field sites suggests that mud elevation and associated sediment condition and wave energy levels is the primary differentiating factor between these two groups of field sites, with positive correlations between survival and seedling growth rate observed at three field sites.
To reduce the risk of planting at unsuitable planting sites, the project has developed a comprehensive site selection processes prior to future planting involving assessments at different scales (1- macro scale, using Satellite imagery and Aerial photography from the GIS database to identify presence of mud banks and predict their movements) and 2) Micro scale at each potential planting site to assess suitability of different locations within planting sites in terms of known tolerance limits of mangroves to variation in mud elevation, soil conditions and wave action.
The project has also adopted a new approach and is trialling ecological natural restoration methods as an alternative/complementary initiative to mangrove planting as a way of increasing the recovery of the mangroves along the Guyanese coast at a faster rate and at lower cost.
Techniques being trialed include:
• planting of coastal grasses (e.g. Spartina) to facilitate stabilisation of sediments in areas subject to heavier wave energy, as well as natural recruitment of mangrove seedlings through entrapment of propagules,
• fencing to enable natural recruitment by naturally available mangrove seeds without pressure from grazing animals,
• trials of techniques to restore natural hydrological processes in degraded mangrove forest areas to again allow for natural recovery of these mangrove areas and
• establishment of coastal engineering structures such as geotextile breakwaters and low cost Brushwood dams to reduce wave energy and facilitate accretion of sediments prior to mangrove planting.
Mangrove restoration has been a major focus of the GMRP and project planting activity in 2010-2012 combined has enabled more than 330,000 Avicennia germinans seedlings to be planted across 5.59km of the coastline at ten locations, equating to approximately 35ha in area. Evaluation of field results indicates that where mangrove seedlings are planted in optimal environmental conditions, recovery of the coastal protective belt can be rapid. These successful sites can be compared to neighbouring planting sites which have experienced near total mortality of seedlings during the same period. Evaluation of environmental conditions at the different field sites suggests that mud elevation and associated sediment condition and wave energy levels is the primary differentiating factor between these two groups of field sites, with positive correlations between survival and seedling growth rate observed at three field sites.
To reduce the risk of planting at unsuitable planting sites, the project has developed a comprehensive site selection processes prior to future planting involving assessments at different scales (1- macro scale, using Satellite imagery and Aerial photography from the GIS database to identify presence of mud banks and predict their movements) and 2) Micro scale at each potential planting site to assess suitability of different locations within planting sites in terms of known tolerance limits of mangroves to variation in mud elevation, soil conditions and wave action.
The project has also adopted a new approach and is trialling ecological natural restoration methods as an alternative/complementary initiative to mangrove planting as a way of increasing the recovery of the mangroves along the Guyanese coast at a faster rate and at lower cost.
Techniques being trialed include:
• planting of coastal grasses (e.g. Spartina) to facilitate stabilisation of sediments in areas subject to heavier wave energy, as well as natural recruitment of mangrove seedlings through entrapment of propagules,
• fencing to enable natural recruitment by naturally available mangrove seeds without pressure from grazing animals,
• trials of techniques to restore natural hydrological processes in degraded mangrove forest areas to again allow for natural recovery of these mangrove areas and
• establishment of coastal engineering structures such as geotextile breakwaters and low cost Brushwood dams to reduce wave energy and facilitate accretion of sediments prior to mangrove planting.
Research Interests:
First Guyana Mangrove Forum " Restoring and managing mangrove ecosystems in a changing world "
Research Interests:
Research Interests:
Mangroves in Guyana The predominant mangrove species found in Guyana are Avicennia germinans, Laguncularia racemosa and Rhizophora mangle (Pastakia, 1990). Avicennia germinans is often found in monospecific stands along much of the coast... more
Mangroves in Guyana The predominant mangrove species found in Guyana are Avicennia germinans, Laguncularia racemosa and Rhizophora mangle (Pastakia, 1990). Avicennia germinans is often found in monospecific stands along much of the coast often characterised by a thin fringe of Laguncularia racemosa growing on its landward margin. Rhizophora mangle is commonly found in the river banks and the coasts adjacent to mouths of rivers and creeks (Pastakia, 1990). The 400km Guyanese coast forms part of part of a 1600 km-long muddy coastal system dominated by massive mud banks that migrate from the mouth of the Amazon river in Brazil to that of the Orinoco river in Venezuela (Augustinus. 1978; Anthony et al., 2010). The mud-bank activity is characterised by 'bank' and 'inter-bank' phases, which induce patterns of rapid shoreline accretion and/or erosion of the mudbanks and fringing mangrove forests (up to hundreds of metres a year) (Anthony et al., 2010). Importance of mangroves in Guyana The mangroves of Guyana provide a number of major ecosystem services including stabilisation of the Guyanese shoreline, sustenance of coastal fisheries and as a habitat for water birds and other wildlife. Shoreline protection The entire Guyanese coastal zone lies between 0.5 and 1.0 m below the Atlantic spring high tides, and is protected sea defenses that range from earthen banks to concrete walls and natural defenses. The vulnerability of Guyana's coastal zone is made more acute by predictions of a climate change-driven rise in mean sea level of as much as 0.88m by 2100 (NMMAP 2010). The ability of the sea defense structures to protect the land behind them has historically been reinforced by a wide belt of mangrove forest extending as much as a mile into the intertidal zone and acting as a wave energy-dissipating buffer to threats from storms and high tides. Fisheries values Guyana's mangroves offer breeding and nursery grounds to marine life in tropical coastal waters. Twenty seven species of fish species have been recorded from Guyana's mangroves while recent studies in neighbouring Suriname have shown that 60-80% of all fish sold at coastal fish markets originated from mangrove areas (Finlayson and Moser, 1991). Habitat for water birds and other wildlife Guyana's mangroves are important as feeding and /or breeding areas for coastal bird species including migratory species and permanent residents. Of the migratory species, twenty-six (26) species, are identified as either Austral, Nearctic or Caribbean Migrants. Species of note in the Guyanese mangrove forests are the Scarlet Ibis (Eudocimus ruber), the Little Blue Heron (Egretta caerulea) and the white necked heron (Ardea cocoi). The crab-eating raccoon (Procyon cancrivorus) is commonly found in mangrove areas while other larger animals such as the spectacled cayman (Cayman crocodylus) and the manatee (Trichcus manatus) are less common visitors (Pastakia 1990).
Research Interests:
This paper introduces a large-scale mangrove restoration project, the Guyana Mangrove Restoration Project(GMRP) which aims to address the decline in mangrove forest area in Guyana. The paper initially describes issues associated with... more
This paper introduces a large-scale mangrove restoration project, the Guyana Mangrove Restoration Project(GMRP) which aims to address the decline in mangrove forest area in Guyana. The paper initially describes issues associated with losses of Guyana’s mangroves (both anthropogenic and natural), summarises the results of the project’s mangrove restoration component, and describes the adaptive approach taken by the project to address these issues including the application of alternative restoration methods.
Patterns of mudbank migration across Guyana’s coastline result in intermittent ‘bank’ and ‘inter-bank’ phases and patterns of rapid shoreline accretion and erosion. The mudbanks and economically and ecologically important fringing mangrove forests erode and accrete in increments of up to hundreds of meters a year. The impact of these natural processes working alongside anthropogenic pressures has resulted in a 75 % decline in Guyana’s mangrove forest area over the last three decades.
The Guyana Mangrove Restoration Project has successfully restored 35 ha of mangroves across 12 sites. Evaluation of monitoring results showed a highly variable overall survivorship of 58.7 % of the 421,599 planted Avicennia germinans seedlings. Overall growth rates of planted seedlings across the five sites, for which growth data were available, were similarly variable.
Where mangrove seedlings were planted at sites with optimal environmental conditions, recovery of the coastal protective belt was rapid. These successful sites can be compared to neighbouring sites which experienced near total mortality of seedlings during the same period and others where, although survival was high, growth rates were reduced. Evaluation of environmental conditions at the different field sites suggests that mud banks were present at all sites and that surface elevation and associated sediment condition and wave energy levels were the primary differentiating factor between these groups of field sites, with positive correlations recorded between surface elevation and seedling growth rate observed at four field sites.
High rates of survival and growth suggest that it is possible to restore mangrove forests along the coast of Guyana. This meets the project’s performance criteria in less than two years and at a substantially lower cost than constructing sea walls over similar areas of coastline. The limited “window of opportunity” in which to establish a resilient mangrove buffer raises questions as to whether slower growth sites will be able to recover a protective forest within the limited period provided during the current “Bank phase”.
Site selection criteria incorporating known tolerance limits of mangroves to variation in surface elevation and hydroperiod, soil conditions and wave action were applied to select future planting sites. Results suggest that future sites suitable for successful direct planting of mangroves along the coast of Guyana are very limited, necessitating the use of alternative Ecological Mangrove Rehabilitation (EMR) options, such as planting of coastal grasses, hydrologic restoration, and construction of low cost coastal engineering structures.
The scale of the problems facing Guyana’s mangroves necessitates an integrated response from the Government of Guyana. Mangrove restoration is just one response component alongside other initiatives focusing on sustainable management of mature forests.
Keywords: Mangrove restoration, Mangrove monitoring, Hydrology, Community co-management, Institutional reform
Patterns of mudbank migration across Guyana’s coastline result in intermittent ‘bank’ and ‘inter-bank’ phases and patterns of rapid shoreline accretion and erosion. The mudbanks and economically and ecologically important fringing mangrove forests erode and accrete in increments of up to hundreds of meters a year. The impact of these natural processes working alongside anthropogenic pressures has resulted in a 75 % decline in Guyana’s mangrove forest area over the last three decades.
The Guyana Mangrove Restoration Project has successfully restored 35 ha of mangroves across 12 sites. Evaluation of monitoring results showed a highly variable overall survivorship of 58.7 % of the 421,599 planted Avicennia germinans seedlings. Overall growth rates of planted seedlings across the five sites, for which growth data were available, were similarly variable.
Where mangrove seedlings were planted at sites with optimal environmental conditions, recovery of the coastal protective belt was rapid. These successful sites can be compared to neighbouring sites which experienced near total mortality of seedlings during the same period and others where, although survival was high, growth rates were reduced. Evaluation of environmental conditions at the different field sites suggests that mud banks were present at all sites and that surface elevation and associated sediment condition and wave energy levels were the primary differentiating factor between these groups of field sites, with positive correlations recorded between surface elevation and seedling growth rate observed at four field sites.
High rates of survival and growth suggest that it is possible to restore mangrove forests along the coast of Guyana. This meets the project’s performance criteria in less than two years and at a substantially lower cost than constructing sea walls over similar areas of coastline. The limited “window of opportunity” in which to establish a resilient mangrove buffer raises questions as to whether slower growth sites will be able to recover a protective forest within the limited period provided during the current “Bank phase”.
Site selection criteria incorporating known tolerance limits of mangroves to variation in surface elevation and hydroperiod, soil conditions and wave action were applied to select future planting sites. Results suggest that future sites suitable for successful direct planting of mangroves along the coast of Guyana are very limited, necessitating the use of alternative Ecological Mangrove Rehabilitation (EMR) options, such as planting of coastal grasses, hydrologic restoration, and construction of low cost coastal engineering structures.
The scale of the problems facing Guyana’s mangroves necessitates an integrated response from the Government of Guyana. Mangrove restoration is just one response component alongside other initiatives focusing on sustainable management of mature forests.
Keywords: Mangrove restoration, Mangrove monitoring, Hydrology, Community co-management, Institutional reform
Research Interests:
Knowledge of the underlying factors controlling spatial patterns in mangrove ecosystems is fundamental for restoration of mangrove communities damaged or degraded by natural or anthropogenic influences. Unfortunately, the spatial patterns... more
Knowledge of the underlying factors controlling spatial patterns in mangrove ecosystems is fundamental for restoration of mangrove communities damaged or degraded by natural or anthropogenic influences. Unfortunately, the spatial patterns within lower intertidal mangrove communities are not well understood which creates impediments to their successful restoration when degraded by economic activities. Results of an observational study carried out in two lower intertidal mangrove communities of the Ngao river, in the Kraburi river estuary, Ranong province, southern Thailand show that the two forest types were low in mangrove tree species diversity with only six species found in total with S.alba, A. alba and A.corniculatum the dominant species. Community assemblages of mature trees differed between the two forest types based on species similarity, largely due to the greater densities of A.corniculatum trees in the “Aegiceras forest”. When all species were pooled, trees (based on tree ...