11 April 2025, Port Moresby - Papua New Guinea (PNG) is home to one of the largest mangroves covers and seagrass species in the Pacific, as well as globally.
Growing up, Ms Marzena Ann Marinjembi witnessed first-hand how vital mangroves, seagrass beds, and marine biodiversity are to the wellbeing of local communities, both environmentally and economically. This fostered in her a deep respect for PNG’s coastal ecosystems.
Today, Marzena is living her dream as a Programme Officer for the Marine Division at PNG’s Conservation & Environment Protection Authority (CEPA).
Recently, she participated in the MACBLUE project-organised blue carbon assessment training and fieldwork in Kavieng, New Ireland Province, PNG. Her role involved assisting with soil core sampling and mangrove tree assessments, biodiversity surveys, and collection of geo-referencing data and entry.
Blue carbon refers to the carbon stored in coastal and marine ecosystems such as mangroves, seagrasses, and salt marshes.
These ecosystems play a vital role in combating climate change by absorbing carbon dioxide from the atmosphere, protecting coastlines from erosion and storm surges, supporting marine life, and providing sustainable livelihood opportunities for local communities through fishing, eco-tourism, and conservation efforts.
Reflecting on her experience during the MACBLUE blue carbon field assessment, Marzena said: “This assessment creates a win-win situation, where conservation directly supports economic resilience. Healthy ecosystems support sustainable fisheries, which are a major source of income for local families. It improves our understanding of the health and distribution of critical coastal ecosystems like mangroves and seagrass meadows.
“Training is essential for communities, NGOs, and government staff to build skills in project implementation, monitoring, and data analysis. Strengthening local leadership ensures that conservation efforts are community-driven.”
Marzena shared that one unexpected finding during the fieldwork was the high diversity of mangrove species recorded at Tome Bay during the mangrove tree diameter at breast height (DBH) assessment.
“During our engagement with the local community, they informed us of the presence of bull sharks and hammerhead sharks in the area,” she said. “This was a valuable observation, highlighting the bay’s ecological significance as a potential habitat or migratory corridor for larger marine species. It also reinforced the importance of integrating local ecological knowledge into field assessments.”
The additional support from the local communities provided a significant boost to the blue carbon assessment.
“The local community and stakeholders in Kavieng were very supportive and welcoming. Many were eager to learn about the assessment process, how samples were collected, and how mangrove trees were measured. Some community members expressed interest in using mangrove and seagrass identification guides to conduct their own observations,” added Marzena.
“Their positive engagement made our fieldwork smoother and more meaningful. Most importantly, their insights helped guide our work and enriched our understanding of the local environment.”
However, the fieldwork was not without its challenges.
According to Marzena, although the sites were accessible, many areas were very swampy, especially during high tide, posing the risk of sinking into the mud.
“The dense network of mangrove roots also made it difficult to move around and carry equipment safely,” she said.
“Despite these challenges, we had a strong, supportive, and well-coordinated team. By working together, helping each other through the tough spots, and staying focused on our goal, we managed to complete the data collection and successfully assess all the selected sites.”
.jpg)
Blue carbon conservation is vital to PNG’s efforts to meet its climate goals, including its commitments under the Paris Agreement. These ecosystems naturally sequester large amounts of carbon which help reduce greenhouse gas levels in the atmosphere.
“Mangroves and seagrasses protection ensures the long-term sustainability of fisheries, supporting food security and economic stability. This opens opportunities for income through guided tours, cultural experiences, and environmental education.”
Marzena is also the PNG’s Turtle National Coordinator. She shared that the strong ecological connection between turtles and blue carbon ecosystems such as mangroves and seagrass meadows cannot be denied.
“Green turtles are herbivores and are known to feed extensively on seagrass, playing a crucial role in maintaining healthy seagrass meadows by grazing, which promotes new growth and prevents overgrowth.
“Mangroves serve as important shelter and nursery areas for many marine species, including juvenile turtles. These habitats provide protection from predators and human disturbances, food, and enhance the survival rates of young turtles as they develop.
“The training (blue carbon) has deepened my understanding of the importance of these habitats not only for their roles in climate change mitigation and coastal protection but also as critical ecosystems that support a diverse range of marine life, including our turtle populations.”
Looking ahead to the expected release of the findings in August, Marzena hopes it will help decision-makers prioritise key mangrove and seagrass areas for protection and restoration, as well as raise community awareness and engagement.
“This focus can guide conservation efforts to maximize ecological and carbon benefits, encouraging more local participation. Conservation should be both top-down and bottom-up, reflecting the needs, values, and aspirations of local people,” she said.
“PNG’s integration of local knowledge and participation shows how vital community engagement is for conservation. The combination of traditional ecological knowledge and modern science provides a well-rounded approach to coastal management that is both culturally respectful and scientifically sound.”
As a way forward, Marzena shared that continued research is necessary to understand the carbon potential of PNG’s blue carbon ecosystems and determine the best practices for restoration and management.
“Local participation is key to successful and lasting conservation. This leads to stronger conservation outcomes and improved wellbeing.”
The MACBLUE project is jointly implemented by the Secretariat of the Pacific Regional Environment Programme (SPREP), the Pacific Community (SPC) and the Deutsche Gesellschaft für internationale Zusammenarbeit GmbH (GIZ) in close cooperation with their four partner governments, Fiji, Papua New Guinea, Vanuatu and the Solomon Islands.
The project is funded by the German Federal Ministry for Environment, Nature Conservation, Nuclear Safety and Consumer Protection (BMUV) through its International Climate Initiative (IKI).