Turning power plant waste into fish houses, a new hope for fishermen

Maickhel Awee, a 55-year-old fisherman, usually leaves for Holtekamp Beach in Jayapura City at 6 a.m. and travels up to 10 kilometers offshore to fish.

He said changing ocean currents had made it increasingly difficult to find fish near the shore, forcing fishermen to venture farther out in search of productive fishing grounds.

Maickhel, who has been fishing since high school, is familiar with the waters off Holtekamp Beach.

He noted that fish have recently been moving farther from the shore due to coastal abrasion, damaged coral reefs, and household waste pollution. As a result, fishermen need to understand fish migration patterns and track their movements across different areas to improve their chances of making a catch.

To help address the problem, state-owned electricity company PT PLN is supporting fishermen by constructing fish houses, also known as artificial reefs. The structures are made using Fly Ash and Bottom Ash (FABA), a solid waste product generated by coal combustion at the Holtekamp Steam Power Plant (PLTU).

In collaboration with the EAB Outdoor community, PLN is developing these artificial habitats to help restore coastal ecosystems while supporting the local economy.

EAB Outdoor representative Fendy Joyo said the project began with observations of the Holtekamp coastline, which is dominated by sandy stretches and has relatively few coral reefs.

Based on these observations, the community explored the possibility of developing underwater structures that could provide shelter for fish and support marine life. They subsequently identified FABA as a potential material for constructing the structures.

Approximately two tons of FABA are used to build 50 fish houses. The material is mixed with sand, cement, and crushed stone, with FABA accounting for around 30 percent of the composition. After being molded, each fish house, weighing approximately 130 kilograms, is left to harden for more than a month.

"The structure is designed in the shape of a pyramid, with cavities that provide shelter for fish and surfaces where marine organisms can attach and grow," Fendy explained.

Once fully hardened, the fish houses are transported and lowered onto the seabed using a crane owned by the PLTU. Four EAB Outdoor divers then assist in positioning the structures in the waters off Holtekamp Beach.

The fish houses are placed at a depth of approximately five meters during low tide, with the depth reaching eight meters at high tide. The installation sites are carefully selected to ensure that they do not interfere with shipping traffic.

According to Fendy, monitoring conducted over 60 days following installation showed the presence of marine organisms around the structures. However, the team also found sea urchins, whose populations could potentially disrupt fish habitats if they increased significantly.

To support the optimal growth of coral reefs and other marine organisms, EAB Outdoor conducts routine underwater monitoring twice a month. If natural coral growth is considered too slow, the diving team will carry out coral transplantation.

Safeguarding marine ecosystems

Despite the hope of creating new habitats for fish, the use of FABA in the marine environment still raises questions regarding the safety of the material and its impact on the ecosystem.

Academic from the Department of Marine and Fisheries Sciences, Cenderawasih University, Dr. Yunus P. Paulangan, said that FABA could serve as a material for fish houses if properly processed and deemed environmentally safe.

However, the use of these materials requires serious attention to the characteristics of the material, the potential for releasing pollutants into sea water, and the durability of the structure in the aquatic environment.

From an ecological perspective, fish houses provide physical structures with gaps, cavities, and hard surfaces that fish can use for shelter, feeding, and other activities. These surfaces can also serve as attachment sites for benthic organisms, which contribute to habitat formation.

Furthermore, the process of forming a new ecosystem takes time as fishes begin visiting the artificial structure within days or weeks, whereas colonization by attached organisms takes longer.

The formation of a more complex and relatively stable biota community can even take several years, depending on environmental conditions and the availability of biota resources in the surroundings.

Yunus said ecosystem restoration takes time, adding that artificial structures are just one of several approaches to protecting marine life.

He also reminded that their effectiveness depends on environmental conditions, regular monitoring, and sustainable management.

PLN, through its Social and Environmental Responsibility (TJSL) program, continues to strengthen the implementation of Environmental, Social, and Governance (ESG) principles.

By using FABA, the company connects its energy supply operations with environmental protection initiatives while generating social and economic benefits for the people of Papua.

Nanang Eka Saputra, Senior Supervisor of Operations at the Holtekamp PLTU Generating Unit, conveyed that the fish house program is part of an innovative approach to utilize residual combustion materials from the PLTU through the Creating Shared Value (CSV) approach.

Meanwhile, the General Manager of PLN UIW Papua and West Papua, Roberth Rumsaur, stated that FABA is not merely a waste product of the production process, but can also be utilized to support development.

The FABA utilization program at the Holtekamp PLTU began in 2022. Previously, FABA was categorized as B3 waste, or hazardous and toxic materials. Following the issuance of Government Regulation Number 22 of 2021 concerning the Implementation of Environmental Protection and Management, FABA was then categorized as non-hazardous waste, registered with codes FA N106 and BA N107.

Holtekamp PLTU also has a Technical Details Document (DRT) for the Management of Non-hazardous FABA Waste. The document provides guidelines on management procedures, technical requirements, facility design, and FABA handling and storage practices to ensure environmental safety.

The document also stated FABA utilization can extend beyond the power plant, allowing external parties to benefit directly from its use.

The fish houses offer new hope for fishermen in the waters off Holtekamp Beach. However, continuous monitoring and management remain essential to ensure that these artificial structures provide suitable habitats for marine life while delivering benefits to coastal communities.

Related news: Indonesia calls for global cooperation to end illegal fishing

Related news: US eyes wider Southeast Asian role in Pacific crime fight