Word: Ayu Arman
Let’s explore the Mimika mangrove forest and discover how these unique ecosystems serve as living fortresses for biodiversity. In this region, mangroves act as climate guardians, coastal protectors, and economic assets for the local community.
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Papua has the largest mangrove forests in Indonesia, accounting for 58% of the country’s total mangrove area and approximately 12% of the world’s mangroves.
In late 2024, we navigated the Wania River to witness the breathtaking Mimika mangrove forest. From an aerial viewpoint, the sight of extensive, lush mangroves appearing like tiny islands amid the rivers and beaches left us in awe.
Mangroves were abundant—lining the rivers, estuaries, and coastlines. The pristine mangroves of Mimika cover 186,000 hectares and encompass 42 different species, making it the fourth-largest mangrove area in Papua.
While mangrove forests might seem uninviting due to their muddy terrain and the presence of mosquitoes, snakes, spiders, and other insects, they are teeming with life. If you were to scoop a teaspoon of mangrove mud and examine it under a microscope, you would discover over ten billion bacteria. These microorganisms play a crucial role in breaking down fallen leaves and natural debris, contributing to the health of this ecosystem.
Mangrove trees and their canopies provide essential habitats for various birds, insects, mammals, and reptiles. The roots of mangroves stabilize the environment and offer shelter for diverse species of plants and animals beneath the water.
The soft substrate in mangrove forests creates habitats for numerous species, while the spaces between the roots provide food and refuge for mobile creatures such as shrimp, crabs, and fish.
Mangroves also help combat coastal erosion by serving as wave breakers, reducing the impact of storm surges and wave energy. They are excellent carbon sinks, absorbing carbon from the air and sea over extended periods. Therefore, mangroves are not just trees; they are vital lifelines for biodiversity, climate balance, and coastal protection.
As our speedboat entered the Ajkwa Estuary, we were greeted by flocks of herons and pelicans flying gracefully or perched on tree branches. Inside the mangroves, time seemed to stand still.
Wild insects, mollusks, and crabs emerged from twisting branches and creeping vines, showcasing various shapes and colors. Some creatures were the size of a thumb, others as large as a child’s hand, and some measured the size of two adult palms.
We observed crabs feeding on fish remains atop driftwood when the tide receded. On the sandy beach, countless crab tracks decorated the surface.
I had the opportunity to speak with a member of the Kamoro tribe, the indigenous people of this coastal area.
“When the leaves of the mangrove trees turn yellow, the crabs are laying eggs. They hide in holes near the roots. During that time, I avoid collecting them and wait until they grow bigger,” explained the local villager.
The mangrove species in question is the Xylocarpus moluccensis, which can grow over four meters tall, while “karaka” refers to the commercially important mangrove crab found in Mimika.
Monitoring of Mimika’s mangroves has documented 41 species of crustaceans, including 37 species of crabs, three species of shrimp, one species of hermit crab, and one species of mud lobster.
The two primary crab families found in Mimika’s mangrove forests are Ocypodidae, which typically inhabit the lower beaches near estuaries, and Sesarmidae, which can survive in drier environments and often climb the roots and trunks of mangrove trees.
For the Kamoro people, the mangroves along Mimika’s coast serve as a “supermarket” where they understand the best times to gather various resources. These mangroves provide an abundance of food, including different types of fish, shrimp, crabs, shellfish, and a delicacy known as tambelo, which the Kamoro people particularly enjoy.
The estuaries of the Mimika rivers also offer plentiful food reserves. The transition from sandy beaches to mangrove swamps creates a unique ecosystem rich with life, inhabited by birds, fish, shrimp, and even saltwater crocodiles.
Our journey took us from the Ajkwa Estuary mangrove forest to the Pomako mangrove forest, located near the Pomako Fish Landing Port. The Pomako Mangrove Ecotourism area spans 300,000 hectares, with trees reaching heights of up to 30 meters. It has become a prime destination for ecological tourism and mangrove education in Papua and Indonesia.
Facilities at Pomako include parking areas, office buildings, a mangrove information center, restrooms, gazebos, meeting halls, and a culinary center. Additionally, a three-kilometer wooden boardwalk has been constructed, resembling a mangrove crab from above, serving as a scenic trail through the mangrove forest.
As we walked along the wooden boardwalk, we experienced a tranquil atmosphere surrounded by nature. The towering mangrove trees created a magical ambiance with their hanging roots and branches.
The sounds of rustling leaves and cheerful bird chirping filled the air. At the end of the boardwalk, we admired eagles soaring freely in the open sky beyond the lush foliage.
We were fortunate to visit the Pomako mangrove forest during low tide, which allowed us to observe exposed mudflats alive with small crabs, mollusks—particularly gastropods and bivalves—monitor lizards, kingfishers, and other wildlife.
A study conducted by PT Freeport Indonesia and the Research Center for Oceanography of the Indonesian Institute of Sciences confirmed that Mimika’s mangrove forests host a greater number of crustacean species than any other mangrove forests worldwide.
As we made our way back, the tide began to rise, and water flowed over the mud, submerging the roots once again. Witnessing the rhythm of nature firsthand was an unforgettable experience.
Beyond the mangroves, the tropical rainforests extend like lush green carpets, serving as a paradise for countless animal species and providing sustenance and shelter for the Kamoro people. These forests are home to endemic species of Papua, many of which have yet to be identified. The Kamoro also harvest wood from these forests to create their intricate carvings, reflecting their rich cultural heritage.
If you are seeking a rejuvenating natural experience and wish to witness the wonders of mangrove and tropical rainforest ecosystems, Mimika is a destination you cannot miss. You will journey through rivers and along the coastlines of southern Papua. Remember to keep the environment clean to help preserve nature for future generations, and capture your memories with your camera as a keepsake.