mangrove restoration

New Research on Mangrove Restoration for Bonaire

Nederlands below.

 

Since 2020, the Mangrove Maniacs have planted over 1500 mangroves along the southwest coast of Bonaire. A new collaborative project with Van Hall Larenstein University of Applied Sciences monitored and mapped these newly planted mangroves. A healthy fringing mangrove forest will provide new habitat, nursery, and foraging grounds as well as a vital line of coastal defense for the southern wetlands.

 

Red mangrove. Photo credit: Jasper Raijmakers

IMPORTANCE OF MANGROVES

Worldwide, mangroves become more important each day due to the threats of climate change and sea level rising. Unfortunately, Bonaire is no exception to these threats. Mangroves provide multiple ecosystem goods and services (EGS). One of the main EGS is coastal protection due to their ability to attenuate waves, prevent erosion and increase sedimentation. Furthermore, they are important for their ability to store blue carbon, which is carbon stored in coastal and marine ecosystems. Mangroves sequestrate and store more carbon per unit area than tropical rainforests due to their woody prop roots and dense above and belowground biomass. Also, they have a high biodiversity, serve as a fish and bird nursery, and provide opportunities for ecotourism.

 

RESEARCH

Recently, Jasper Raijmakers, an undergraduate from the International Forest and Nature Management program of Van Hall Larenstein University of Applied Sciences, worked with the Mangrove Maniacs to map and monitor the planting sites along the southwest coast, as well as compare and evaluate two mangrove restoration techniques. For all large planting sites, the numbers of alive, dead and tagged red and black mangrove outplants were counted in a grid and presented in a heat map (an example can be seen below).

To compliment the maps, the success rate of the standard outplanting mangrove restoration technique was compared against the thesis work of student Shamyi Lanjouw, a WUR MSc Forest and Nature Conservation student, who was conducting her thesis on mangrove restoration with the use of BESE-elements®. BESE-elements® are biodegradable 3D structures that offer structural stability for intertidal vegetation. Interestingly, using both techniques found high survival rates and statistically speaking there was no significant difference between the relative growth rates between the two methods. The implications of this show that, in this particular case, investing in additional restoration material is not more effective than using traditional methods.

 

IMPACT ON FUTURE

These maps will be a vital management tool for mangrove restoration in the future. Using these maps, land area managers can quickly access an overview of the large planting sites, as well as have information needed to support monitoring of the outplants, track the project’s progress, as well as aid in identifying future planting sites. In addition, these maps will provide helpful visuals for publications and social media of the Mangrove Maniacs. A healthy fringing mangrove forest will provide the first line of coastal defense along the southern wetlands. Buffering against rising sea levels, worsening storms and erosion, these mangroves will protect the fragile salt pans and lakes located throughout the south. Furthermore, by providing a physical buffer between land and sea, this will also help mitigate human pressure along the south, also serving to protect the iconic nearshore coral reefs within this area.

Example heat map for Red Slave outplanting site.

 

For more information you can find the full reports of Jasper Raijmakers and Shamyi Lanjouw using the links below.

Lanjouw, S. 2022. Testing a biodegradable engineering product for mangrove restoration along a high wave-energy coastline. Wageningen University and Research. Thesis Report.

Raijmakers, J.R. 2022. Map mangrove planting sites and compare and evaluate mangrove restoration techniques. Van Hall Larenstein, University of Applied Sciences. Thesis Report.

 

____________________________________________________________________________________________________________________________________________________________________________

 

Nieuw onderzoek naar mangroverestauratie voor Bonaire

Sinds 2020 hebben de Mangrove Maniacs meer dan 1500 mangroven geplant langs de zuidwestkust van Bonaire. In een nieuw samenwerkingsproject met Hogeschool Van Hall Larenstein zijn deze nieuw aangeplante mangroven gemonitord en in kaart gebracht. Een gezond mangrovebos aan de zuidwestkust zal nieuwe leefgebieden, kraamkamers en foerageergebieden creëren. Net zoals een vitale kustverdedigingslinie voor de zuidelijke wetlands.

BELANG VAN MANGROVEN

Wereldwijd worden mangroven elke dag belangrijker door de dreigingen veroorzaakt door klimaatverandering en zeespiegelstijging. Helaas is Bonaire geen uitzondering op deze bedreigingen. Mangroven leveren meerdere diensten. Een van de belangrijkste dienst is kustbescherming doordat ze golven dempen, erosie voorkomen en sedimentatie vergroten. Bovendien zijn ze belangrijk voor het vastleggen van CO2. Mangroven leggen meer CO2 vast dan tropische regenwouden vanwege hun houtachtige luchtwortels en dichte boven- en ondergrondse biomassa. Ze hebben een hoge biodiversiteit, dienen als broedplaats voor vogels en habitat voor juveniele vissen. Ook bieden ze kansen voor ecotoerisme.

 

ONDERZOEK

Onlangs heeft Jasper Raijmakers, een student van de opleiding Internationaal Bos- en Natuurbeheer van Hogeschool Van Hall Larenstein, samen met de Mangrove Maniacs gewerkt aan het in kaart brengen en monitoren van de mangroven langs de zuidwestkust, en het vergelijken en evalueren van twee mangroverestauratie technieken. Voor alle grote aanplantgebieden werden de aantallen levende, dode en gemonitorde rode en zwarte mangroven geteld in een raster en weergegeven in een hittekaart.

Als aanvulling op de kaarten werd het succespercentage van de standaard uitplantingstechniek voor mangroveherstel vergeleken met de scriptie van student Shamyi Lanjouw, een WUR MSc-student Bos- en natuurbescherming, die haar scriptie uitvoerde over mangroveherstel met behulp van BESE-elementen®. BESE-elementen® zijn biologisch afbreekbare 3D-structuren die structurele stabiliteit bieden voor inter-getijdenvegetatie. Bij beide technieken werden hoge overlevingspercentages gevonden. Statistisch gezien was er geen significant verschil tussen de relatieve groeisnelheden tussen de twee methoden. Dus in dit specifieke geval investeren in aanvullend restauratiemateriaal is niet effectiever dan het gebruik van traditionele methoden.

 

IMPACT OP DE TOEKOMST

Deze kaarten zullen in de toekomst een essentieel beheersinstrument zijn voor het herstel van mangroven. Met behulp van deze kaarten hebben beheerders snel toegang tot een overzicht van de grote aanplantgebieden, evenals informatie die nodig is om het monitoren van de mangroven te ondersteunen, de voortgang van het project te volgen en te helpen bij het identificeren van toekomstige aanplantgebieden. Bovendien zullen deze kaarten nuttige beelden bieden voor publicaties en sociale media van de Mangrove Maniacs. Een gezond mangrovebos langs de zuidwestkust zal de eerste kustverdedigingslinie vormen langs de zuidelijke wetlands. Deze mangroven bufferen tegen stijgende zeespiegels, extremere stormen en erosie. Hierdoor zullen de kwetsbare zoutpannen en meren in het zuiden worden beschermd. Deze fysieke buffer zal ook dienen als bescherming van de iconische koraalriffen in dit gebied.

Voor meer informatie kunt u de volledige scripties van Jasper Raijmakers en Shamyi Lanjouw vinden via onderstaande links.

Lanjouw, S. 2022. Testing a biodegradable engineering product for mangrove restoration along a high wave-energy coastline. Wageningen University and Research. Thesis Report.

Raijmakers, J.R. 2022. Map mangrove planting sites and compare and evaluate mangrove restoration techniques. Van Hall Larenstein, University of Applied Sciences. Thesis Report.

 

 

Published in BioNews 55.

 

Date
2022
Data type
Media
Theme
Research and monitoring
Geographic location
Bonaire

Bonaire Hosts an International Mangrove Restoration Workshop

Between October 25th and 28th, Bonaire’s Mangrove Maniacs hosted their first Mangrove Restoration Workshop .  The goal was to provide a platform for researchers, conservationists, park authorities or anyone passionate about nature restoration to share ideas and knowledge on mangrove restoration techniques.  With representatives from over 12 countries, including 20 in person and 40 virtual participants, this workshop strengthens the mangrove conservation network across the Caribbean.

Mangrove Restoration Workshop Presentations. Photo credit: Mangrove Maniacs

 

International Collaboration

Representatives from around the world including Aruba, Bonaire, Curaçao, the Bahamas, Jamaica, St. Lucia, Martinique, the Netherlands, Mexico, Belize, Costa Rica and the United States tuned in to share ideas for mangrove restoration practices.  Throughout this four-day event, participants engaged in meaningful dialogue, swapping ideas and tips on ways to maximize conservation efforts.  In addition, the last two days provided hands on experience in mangrove restoration, building and maintaining mangrove nurseries, as well as outplanting both along the coast and within degraded areas.

Funding and support was provided by the Regional Activity Centre for the Specially Protected Areas and Wildlife (CAR SPAW), Mangrove Maniacs, STINAPA Bonaire and the Dutch Caribbean Nature Alliance.  Presentations throughout the workshop spanned from expert University partners to representatives from NGOs to enthusiastic citizens.  In total, over 20 people were able to attend the workshop in person and over 40 participants logged in to attend the workshop virtually.

 

Lessons Learned

Participants in mangrove channel. Photo credit: Jessica Johnson

In addition to creating new networks and collaborative partnership opportunities, this workshop provided firsthand experience in the field of mangrove restoration.  Mangroves are continuing to gain recognition not only for their ability to provide critical habitats and coastal protection but also as a significant tool for building resilience against climate change.  This workshop provided key insight into the importance of maintaining environments to serve as carbon sinks as well as the ability to leverage Blue Carbon in future reporting and financing prospects.

DCNA’s director, Tadzio Bervoets, took the opportunity to stress the importance of supporting and growing research and education opportunities for students within the Caribbean region.  Caribbean islands have the unique ability to showcase a wide variety of natural habitats, perfect for conducting research and staying on the cutting edge of habitat restoration and conservation techniques.  Fostering this thirst for knowledge and educational growth within local Caribbean populations will be key to pushing the Caribbean to the forefront of environmental research.  Knowledge sharing opportunities, such as these, provide unique opportunities to bring together a wide range of people to maximize communal understanding of mangrove forests.  As climate change and human-driven pressures continue to increase, interventions from all levels will be required.

Members from Bonaire’s STINAPA and Aruba’s FPNA working together to plant buttonwood tree. Photo credit: Mangrove Maniacs

More Information

To learn more about the workshop, please visit the Mangrove Maniacs’ webpage (www.mangrovemaniacs.org/workshop2021).  From here you will find links to most of the presentations as well as contact information for presenting participants.  For more information on how you can get involved, contact your local park authority or join the Mangrove Maniacs mailing list by using this link.

 

Article published in BioNews 49

Date
2021
Data type
Media
Theme
Education and outreach
Research and monitoring
Geographic location
Aruba
Bonaire
Curacao
Author

Testing a biodegradable engineering product for mangrove restoration along a high wave-energy coastline

Abstract

Human development, extreme weather events and rising sea levels are driving the loss anddegradation of many of the world’s mangrove ecosystems. Mangrove forests are natural coastalbarriers that provide protection from erosion and storms while also supplying material andbiodiversity services tohuman andnon-humancommunities worldwide. In recent years innovativeand novel products of ecological engineering have emerged to safeguard and restore coastalecosystems. Biodegradable Ecosystem EngineeringElements(BESE) are one such innovation thathave been shown to stabilize sediment, attenuate waves, and mimic dense root mats to facilitatethe establishment of coastal vegetation. This studyinvestigatesthe effect of a built BESE structureon abiotic factors andRhizophora mangletransplant responsesalong a high-wave energy coastlineon the island of Bonaire, Dutch Caribbean. Results reveal that BESEelementsdo not significantlyalter wave-energy and sediment mobility, or increase transplant survival, shoot growth rate andbiomass allocation. Survival rate of transplants was significantly higher when secured by rockscompared to BESE structures and bare sediment, highlighting simple, local, and low-cost methodsfor restoration. Despite not being significant, there were indications of the potential for BESEstructures toattenuate a minimal amount of waves and stabilize propagules for greater investmentin above-ground biomass during establishment. Yet, longer monitoring is needed to validate this.Limitations ofthe BESE structuressuggest thattheymay be more optimally used below-ground onsediment substrate, in larger clustered structures, or within interconnected foreshore ecosystemsfor landscape-level coastal protection and resilience.

Date
2022
Data type
Research report
Theme
Research and monitoring
Geographic location
Bonaire

MAP MANGROVE PLANTING SITES & COMPARE AND EVALUATE MANGROVE RESTORATION TECHNIQUES

Abstract

This thesis assignment consists of two parts: mapping mangrove planting sites along the southwest 
coast of Bonaire, and comparing and evaluating the outplanting with the BESE-elements® mangrove 
restoration techniques.

The Mangrove Maniacs asked to map the mangrove planting sites along the 
southwest coast as part of their mangrove restoration project. The focus was mainly on the large 
planting sites with a couple of hundred mangrove seedlings planted close to each other. The planting 
pattern of each planting site is random, so maps of the planting sites were needed to create an 
overview of each site. However, an efficient way to map the large numbers of mangrove outplants 
had to be found to create the maps. So, the objective of the mapping part of the thesis assignment 
was to find an efficient way to map the large mangrove planting sites along the southwest coast of 
Bonaire. The maps can be used to track the success rate of the mangrove restoration project, support 
outplant monitoring, identify potential planting areas, and use the maps in publications and on social 
media. The type of research that was involved was fieldwork. 

The second part was focused on the outplanting and BESE-elements® mangrove restoration 
techniques. Since the start of the mangrove restoration project, the Mangrove Maniacs have used 
the standard outplanting technique. However, there was still a knowledge gap in the success rate of 
the outplanting technique at the different planting sites. Apart from the outplanting, the BESE- 
elements® restoration technique was introduced to the mangrove restoration project by a WUR MSc 
Forest and Nature Conservation student. The Mangrove Maniacs asked to include the BESE- 
elements® in this thesis assignment and continue monitoring the red mangrove propagules planted 
in the BESE-elements®. The BESE-elements® mangrove restoration technique was included to see if it 
has the potential to improve the mangrove restoration project along the southwest coast of Bonaire. 
The types of research that were involved were literature study and fieldwork. The two main 
questions are: What is the most efficient way to map different mangrove planting areas, focusing on 
large planting sites, to provide an overview of the success rate of the mangrove restoration project 
along the southwest coast of Bonaire? And how can the mangrove restoration project along the 
southwest coast of Bonaire be improved? The research method that has been used for the mapping is 
fieldwork. A 5 by 10 metres grid was used to map the large numbers of outplants. This grid was 
drawn on-site, and the digital maps were created with GIS in ArcMap. The research method for both 
the outplanting and BESE-elements® techniques was fieldwork. The survival and growth rate of the 
outplants were monitored biweekly. Survival of the propagules in the BESE-elements® was 
monitored once a week and the growth once a month. An Anova test was conducted for the 
outplants to see if the relative growth rates of the planting sites differed significantly from each 
other. T-tests were conducted for the BESE-elements® and control sites for each study site's survival 
and relative growth rates. Two types of maps have been created. Based on the grid, heat maps were 
made for the large planting sites. In comparison, the smaller planting sites were mapped without a 
grid. The survival rate of the red mangrove outplants at the different planting sites is generally high. 
The Anova Single Factor test showed no significant difference between the relative growth rates of 
the tagged outplants at the nine planting sites (p=0.137). The lowest average survival rate of all BESE- 
elements® and control sites was at a BESE-elements® site. The results of the t-tests showed that the 
survival and relative growth rates are not significantly different between the BESE-elements® and 
control sites at all four study sites. In conclusion, a grid was the most efficient way to map large 
planting sites with outplants planted closely together. Drawing a grid has low costs, but it is time- 
consuming. Research on more sophisticated mapping methods is needed if the planting sites grow 
significantly in the future. The BESE-elements® showed no significant difference between survival 
and growth rate regarding the control sites in the short term. So, long-term monitoring is necessary 
to see if the BESE-elements® merit the time and financial investment.

Date
2022
Data type
Research report
Theme
Research and monitoring
Geographic location
Bonaire

Mangrove RESCUE Mangrove Resilience for Enhanced Safety of Coastal Urbanizations and Environments

Presentation from the Mangrove Restoration Workshop.  

Date
2021
Data type
Media
Theme
Education and outreach
Research and monitoring
Geographic location
Aruba
Bonaire
Curacao
St. Maarten
Author