Mangrove Forests Aquaculture in Mahakam Delta, Kalimantan
By Sharon Kertawidjaja
Keywords: Cheonggyecheon, Restoration, Ecosystems, History, Change, Shrimp Ponds, Kalimantan, Mangroves, Deforestation, Aquaculture
Summary
This paper explores the transformation of the Mahakam Delta in Kalimantan, Indonesia. Considering the mixture of freshwater and saltwater conditions, thick vegetation from various species of mangroves adapted to the challenging conditions of coastal environments predominantly occupies the site. The structure of mangrove forests typically consists of several distinct zones, each influenced by factors such as tidal inundation, salinity levels, and substrate type. For instance, in the low tidal zone, species like Sonneratia spp., Avicennia spp., and Rizophora spp are dominant (Fawzi & Husna, 2021, p. 4). Meanwhile, the central zone being strongly influenced by the freshwater condition from the river is dominated by Nypa fruticans species and a mixture of other species (p. 4). Thus, each zone possesses distinct characteristics and species composition, contributing significantly to biodiversity and serves as vital resources for local communities.
Historically, perceived as marginal lands, the delta witnessed significant human intervention driven by economic interests, particularly in aquaculture. Historical shifts, including the rise of oil exploration and shrimp farming, has led to extensive mangrove conversion. This resulted in ecological and socio-economic challenges such as soil compaction, altered nutrient cycles, and increased salinity intrusion, resulting in the abandonment of ponds. Despite governmental control under forestry laws, informal land tenure systems prevail, complicating management. Looking ahead, the paper emphasizes the need for a nuanced understanding of these challenges and proposed solutions, such as silvofishery practices to balance environmental conversion with sustainable development goals. |
Google Earth
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Ecological Genealogy
The islands in the delta of the Mahakam River were historically perceived as “marginal or empty lands,” characterized as a hostile environment unsuitable for human settlement (Persoon & Simarmata, 2014, p.43). The scarcity of exploitative resources and the absence of viable alternative land use contributed to this classification. Historically, the first settlement in the delta dates back to the end of the 19th century, mainly settlers of Bugis and Bajo descents (Baten, 2009, p. 36). For the years to come, the mangrove ecosystem of the delta was relatively untouched as the settlers mainly engaged in rice production, coconut culture, pepper plantation, and fishing (36). It wasn’t until the early 1970s that a major change in resource use of oil exploration and production started (p. 37). Labour opportunities and infrastructure development by oil companies led to the steady influx of workers and settlers into the region. During this period, the mangroves were still in relatively good condition as their activities were primarily confined to the water bodies. However, the rise of aquaculture in the early 1990s, specifically the increasing development of shrimp ponds, marked the beginning of development activities that transformed the islands from a natural ecosystem into a mostly completely domesticated landscape (Persoon & Simarmata, 2014; Fawzi & Husna, 2021, p. 4).
The deforestation of mangrove forests for aquaculture in the Mahakam Delta involved important historical events that led to the acceleration of mangrove conversion. The timeline begins in the late 1970s and early 1980s, marked by governmental interventions and economic shifts that significantly influenced the land use patterns in the region. Firstly, government regulation No. 39/1980, which addressed the ban on trawl fishing, initiated the momentum of shrimp farming as a lucrative alternative of livelihood source in the Delta (Sidik, 2008, p. 16). The beginning of intensive shrimp culture was also shaped by several factors, such as the influence of success stories in Taiwan and Japan, the simplicity of growing tiger shrimp fry in hatcheries, and the considerable financial support from cold storage companies (p.16). Furthermore, the economic crisis that struck Indonesia from 1996-2001 and the fall of Soeharto (Indonesia’s president at the time) in 1998 created a volatile socio-political environment (Persoon & Simarmata, 2014, p. 47; Sidik 2008, p. 16). The devaluation of the Indonesian rupiah against the US dollar inflated shrimp prices in the local currency and increased its profitability. During this time, governmental control on natural resource development weakened and allowed the uncontrolled mangrove conversion for ponds in the Mahakam Delta. As mentioned by Sidik (2008), satellite imagery indicated a substantial increase in the areas of ponds in the delta, reaching 2.8 to 3.6 thousand hectares by 1992 (p. 16). As a result, the previously overlooked islands became valuable assets for economic exploitation, attracting new and powerful players into the scene and intensifying competing claims for land and resources. |
Figure 1. Aquaculture development on Mangrove forests in Mahakam Delta from 1989 to 2020 (Source: Fawzi & Husna, 2021, p. 5)
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Present tense
The consequences of the extensive conversion of mangroves into aquaculture in the Mahakam Delta, where approximately 62% has been altered or lost, are multifaceted (Arifanti et al., 2019, p. 2). It has not only led to the degradation of coastal ecosystems but also resulted in several ecological and socio-economic challenges, affecting water quality, soil composition, and disrupting nutrient cycles. The consequences extend to the release of greenhouse gases, or lack of capture with the removal of mangroves, contributing to both environmental and ecological degradation in at least three ways.
First, a study by Arifanti et al. (2019) revealed higher bulk density in abandoned shrimp ponds, including decreased soil porosity that leads to soil compaction, suggesting significant alterations in soil structure due to aquaculture activities (p. 19-21). For instance, the lack of drainage capacity exacerbates the risk of waterlogging, creating unfavourable conditions for both terrestrial and aquatic species. As waterlogged areas expand, the oxygen availability in the soil diminishes, adversely affecting the microorganisms responsible for nutrient cycling and impacting the availability of essential elements for plant growth and overall ecosystem productivity. Second, the loss of mangrove forests and other vegetation severely impacts the salinity intrusion of the landscape (Sidik, 2008, p. 6). Mangroves play a crucial role in maintaining the hydrological balance between freshwater and saltwater in coastal areas. However, their removal can disrupt this balance, leading to increased salinity intrusion into freshwater areas, causing detrimental effects on the availability of freshwater for both aquatic ecosystems and human populations relying on the delta for water resources. Third, the repercussion of this extensive mangrove loss is evident in the significant number of abandoned aquaculture sites, many of which are in a degraded state. The degradation from mangrove loss affected the degradation in shrimp and fish productivity. Mangroves play a crucial role in coastal ecosystems by providing a natural buffer against environmental pollution, including contaminants like pyrite and its byproducts. As mangrove forests are cleared or degraded, their protective function diminishes, leaving coastal communities more vulnerable to the impact of pyrite poisoning. Pyrite poising typically occurs through exposure to pyrite dust or the run-off from pyrite-rich soils, particularly in areas affected by mining or industrial activities. This is relevant to the Mahakam delta, as the river runoff coming from the mainland is heavily influenced by mining activities. A study by Fawzi & Husna (2021) stated that the oxidation of pyrite in ponds has resulted in the leaching of pyrite acid into the system, causing a decline in the productivity of shrimp farms due to pyrite poisoning (p. 4). As shown, shrimp productivity was estimated to be 100-300 kg ha-1 yr-1 in the first year of opening the pond, while it decreased to about 45 kg ha-1 yr-1 only after three to five years of operation (p. 4-5). In addition, research conducted by Aslan et al. (2021) indicates a wide variability in the lifespan of shrimp ponds within the delta, “[varying] between 1 and 22+ years, with most of the ponds having productive lifespans of 10 to 13 years” (p. 2). This highlights the transient and unsustainable nature of these aquaculture sites. Between 2000 and 2011 water continued to intrude into many shrimp ponds located near the coastline resulting in their abandonment. Unironically, as aquaculture development halted, the abandoned ponds regained their ability to regenerate naturally, mostly in the middle and lower tidal zones with species like Nypa fruticans, Avicennia spp., and Rizophora spp. (Fawzi & Husna, 2021, p. 5). More specifically, as stated by Dutrieux et al. (2014), “over 17% of the delta in 2011” was able to naturally recolonize abandoned shrimp aquaculture ponds, as seawater flow was able to transport seeds, allowing secondary succession to occur (p. 10). In terms of legal and ownership frameworks, the Mahakam Delta is administrated by the Forestry Department and falls under the National Forest Law No. 41/1999, which states that all forests within Indonesia are under the control of the state. However, the Mahakam Delta lacks a centralized governmental structure for managing the area, leading to informal land tenure systems (Persoon & Simarmata, 2014, p. 50). Buginese migrants initiated the establishment of shrimp ponds without the Ministry of Forestry's approval, exploiting perceived “empty lands”. Village heads also issued unofficial permits (called SPPT) to legitimize ownership, creating a complex legal landscape characterized by informal agreements and patronage networks rather than formal governmental oversight (p. 50). |
Figure 2. Freshwater reach comparison between 1986 and 2006. (Source: Sidik, 2008, p. 6)
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future trajectory
The ongoing alterations in the landscape, such as land clearing, channel dredging, and infrastructure development, primarily driven by the deforestation of mangrove forests for aquaculture, signal a critical moment in the delta’s ecological history. The unintended consequences of the rapid deforestation of mangrove forests for aquaculture have transformed the Mahakam Delta into a novel ecosystem, altering the delta’s ecological structure and functions. Unlike traditional, naturally evolving ecosystems, the Mahakam Delta bears the imprints of human activities, showcasing a landscape shaped by intentional modifications and anthropogenic influence. Furthermore, the changes in the Mahakam Delta can have far-reaching implications for nearby ecosystems, the altered hydrological processes, nutrient cycles, and soil composition may disrupt the delicate balance that neighbouring ecosystems depend on. The increased salinity intrusion and changes in water quality may extend to impact coastal areas, influencing marine biodiversity and fisheries in that region. Therefore, underscores the need for a nuanced understanding of the interconnected challenges and opportunities within this changing ecosystem. This includes comprehensively assessing the ecological, socio-economic, and cultural impacts of mangrove deforestation and aquaculture expansion. This would also mean exploring solutions that balance environmental conservation with sustainable development goals.
The future trajectory of the Mahakam Delta witnesses ongoing pressure driven by economic interests in aquaculture, potentially perpetuating the cycle of creation and abandonment of shrimp ponds. This cycle poses long-term environmental risks, as we have currently witnessed such as soil compaction, altered nutrient cycle, and hydrological processes. However, increased efforts in grassroots restoration exist today. Evolving legal and regulatory frameworks, exemplified by East Kalimantan’s sustainability policies, have a crucial role in shaping the delta’s path. Furthermore, growing discussions around the adoption of sustainable pond management, particularly silvofishery practices, have been a topic of debate. Silvofishery is a cultivation system that prioritizes sustainable aquaculture, its guiding principles include “minimizing additional input in embankments, avoiding the use of chemical and medical compounds, producing as little waste as possible, and prioritizing recirculation in nutrient use for embankments to increase productivity” (Hardi et al., 2023, p. 2). Therefore, instead of the intensive approach that maximizes production yield and short-term benefits, this method focuses more on a model that balances economic benefits and environmental sustainability. |
Figure 3. Silvofishery management comparison. (Wetlands Indonesia Publication, n.d.)
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References
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Baten, M. A. (2009). Property rights in mangroves: A case study of the Mahakam Delta, East Kalimantan, Indonesia [Master’s dissertation, Stockholm University]. Retrieved from https://www.diva-portal.org/smash/get/diva2:383325/FULLTEXT01.pdf
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Hardi, E. H., Susmiyati, H. R., Diana, R., Palupi, N. P., Angriandini, M., Saptiani, G., Asikin, A. N. & Agustina. (2023). Traditional polyculture as a mangrove restoration solution in Delta Mahakam, East Kalimantan Indonesia. IOP Conference Series: Earth and Environmental Science, 1208(1). Retrieved from 10.1088/1755-1315/1208/1/012056
Persoon, G. A. & Simarmata, R. (2014). Undoing ‘marginality’: The islands of the Mahakam Delta, East Kalimantan (Indonesia). Journal of Marine and Island Culture, 3(2), p. 43-53. Retrieved from https://doi.org/10.1016/j.imic.2014.11.002
Sidik, A. S. (2008). The changes of mangrove ecosystem in Mahakam Delta, Indonesia: A complex social-environmental pattern of linkages in resource utilization. Retrieved from https://library.enaca.org/mangrove/publications/mahakam-delta-paper-revised.pdf
Storms, J. E. A., Hoogendoorn, R. M., Dam, R. A. C., Hointink, A. J. F. & Kroonenberg, S. B. (2005). Late-Holocene evolution of the Mahakam Delta, East Kalimantan, Indonesia. Sedimentary Geologist, 180(3-4), p. 149 166. Retrieved from https://doi.org/10.1016/j.sedgeo.2005.08.003
Aslan, A., Rahman, A. F., Robeson, S. M. & Ilman, M. (2021). Land-use dynamics associated with mangrove deforestation for aquaculture and the subsequent abandonment of ponds. Science of The Total Environment, 791. Retrieved from https://doi.org/10.1016/j.scitotenv.2021.148320
Baten, M. A. (2009). Property rights in mangroves: A case study of the Mahakam Delta, East Kalimantan, Indonesia [Master’s dissertation, Stockholm University]. Retrieved from https://www.diva-portal.org/smash/get/diva2:383325/FULLTEXT01.pdf
CDP. (n.d.). Addressing environmental challenges through multi-stakeholder governance in East Kalimantan Province. Retrieved from https://www.cdp.net/en/articles/states-and-regions/addressing-environmental-challenges-through-multi-stakeholder-governance-in-east-kalimantan-province
Dutrieux, E., Proisy, C., Fromard, F., Walcker, R., Ilman, M., Pawlowski, F., Ferdiansyah, H. & Ponthieux, O. (2014). Mangrove restoration in the vicinity of oil and gas facilities. HAL Open Science. Retrieved from https://hal.science/hal-03667240/document
Fawzi, N. I. & Husna, V. N. (2021). Aquaculture development monitoring on mangrove forest in Mahakam Delta, East Kalimantan. Conference Series: Earth and Environmental Science, 750. Retreived from https://iopscience.iop.org/article/10.1088/1755-1315/750/1/012002/pdf
Hardi, E. H., Susmiyati, H. R., Diana, R., Palupi, N. P., Angriandini, M., Saptiani, G., Asikin, A. N. & Agustina. (2023). Traditional polyculture as a mangrove restoration solution in Delta Mahakam, East Kalimantan Indonesia. IOP Conference Series: Earth and Environmental Science, 1208(1). Retrieved from 10.1088/1755-1315/1208/1/012056
Persoon, G. A. & Simarmata, R. (2014). Undoing ‘marginality’: The islands of the Mahakam Delta, East Kalimantan (Indonesia). Journal of Marine and Island Culture, 3(2), p. 43-53. Retrieved from https://doi.org/10.1016/j.imic.2014.11.002
Sidik, A. S. (2008). The changes of mangrove ecosystem in Mahakam Delta, Indonesia: A complex social-environmental pattern of linkages in resource utilization. Retrieved from https://library.enaca.org/mangrove/publications/mahakam-delta-paper-revised.pdf
Storms, J. E. A., Hoogendoorn, R. M., Dam, R. A. C., Hointink, A. J. F. & Kroonenberg, S. B. (2005). Late-Holocene evolution of the Mahakam Delta, East Kalimantan, Indonesia. Sedimentary Geologist, 180(3-4), p. 149 166. Retrieved from https://doi.org/10.1016/j.sedgeo.2005.08.003