Fish-kill factors in Lower Kinabatangan
SANDAKAN: A year-long water quality sampling and analysis exercise of two rivers in the Lower KinabatanganSegama Wetlands, Malaysia’s largest and most biologically diverse wetlands ecosystem, show abnormally low dissolved oxygen and high ammonia levels, a combination that is lethal to aquatic life.
The exercise which was carried out from October 2017 to September this year at the upper and lower sections of Sungai Melangking and Sungai Kerapu helped fishery communities in this region to pin point factors for the recurrence of fish deaths which have negatively impacted livelihoods.
By integrating citizen science, traditional ecological knowledge and equipped with the latest technology in in-situ water sampling, the water quality unit of Mumiang collected water samples twice monthly from 18 sampling points and tested these for parameters such as dissolved oxygen, pH, total dissolved solids, electric conductivity, specific seawater gravity, oxidation reduction potential, ammonia, nitrate, salinity and blue-green algae presence.
Sabah Forestry Department Chief Conservator of Forests Datuk Mashor Mohd Jaini congratulated the communities for their efforts in carrying out the sampling.
“I wish to encourage other stakeholders to provide the necessary support to them in order to solve this problem.
“I hope the data and findings of the water quality monitoring project will raise awareness of this issue and improve the water quality of the wetlands. We need research that meets the need of the people,” Mashor said in his opening speech during the stakeholders meeting held on October 5 at the Sabah Forestry Department auditorium.
Readings from over 18,000 samplings was interpreted to conclude the findings of the water quality monitoring work and was presented earlier this month to key government agencies, palm oil industry representatives and neighbouring villages from the Ramsar Site at the Sabah Forestry Department headquarters.
The community of Mumiang had partnered with Sabah Forestry Department, LEAP, Kopel and Forever Sabah and with water quality experts to investigate factors for fish kills, leading them to discover dissolved oxygen levels dropping to as low as 1 mg/L on numerous months and ammonia levels to as high as 46.9 mg/L at both rivers.
Facilitating the presentation, Neville of LEAP said it is scientifically known that eutrophication, characterized by an overly enriched water body which induces excessive algae bloom and has a greenish appearance, often occurs in water that is polluted by excess artificial mineral, nutrient, phosphate-containing fertilizers, or bio-waste discharged into the rivers by agriculture and other socio-economic activities.
“The large aquatic biomass created by the algae bloom is destined to degrade and decompose when its lifecycle ends, thus excessive amount of dissolved oxygen in the water is consumed in the decomposition process.
“The problem is further intensified during rainy days when the lack of sunlight reduces photosynthesis and causes more algae die outs thus increasing the decomposition loading. Such factors reduce dissolved oxygen to anoxic levels in water and regarded as the main causes of the sudden fish kills,” Neville said.
Observations and water quality data collected by the communities consistently indicated eutrophication thus supporting the argument that the Melangking and Kerapu rivers were polluted by agrochemicals that induce excessive algae bloom. The uncontrolled run-off of nutrients must be addressed, added Rosli Jukrana of Kopel.
Water quality data was also collected from pristine water bodies in Tabin Wildlife Reserve to serve as a reference, a scientifically necessary step to compare against data in the two rivers to ascertain the level of deviation, thus signifying the degree of water quality degradation.
The data was also interpreted against the National Water Quality Standard, including the marine water standard.
The Lower KinabatanganSegama Wetlands is also a critical nursery area for aquatic life, which serves as a source of livelihoods to traditional villages and approximately 20,000 coastal fishermen from Sandakan.
Unfortunately, coastal fisheries in the area are currently under threat from agriculture and other socio-economic activities that occur upriver.
A dialogue session involving community and civil society representatives with government agencies and palm oil players was held following presentation of findings from the water quality monitoring project saw several recommendations being made.
Karangan Agriculture Sdn Bhd, a palm oil company operating in Sungai Merah, was the only palm oil company which attended the event and was exploring the possibility of working with the community.
Next steps for action include expanding the community-based water quality monitoring project, increasing the scope to identify the extent of riparian buffers that need to be established to mitigate agro chemical run offs and developing an early warning system for low dissolved oxygen through multilevel partnerships.
The discussion also noted Sabah’s commitment to full Certified Sustainable Palm Oil through the Malaysian Sustainable Palm Oil and Jurisdictional Certification to Roundtable on Sustainable Palm Oil that will facilitate the enforcement of laws for supporting adequate river reserves, and reduce run offs and industrial waste discharge by estates and mills.
The community-based watermonitoring project is an initiative of the Ramsar Community Group 8, a long-term project to advance governance and management of natural resources in the Lower Kinabatangan-Segama Wetlands.
The project is facilitated by Forever Sabah with RCG8 and has the Sabah Forestry Department and LEAP as its key partners.
The project is also supported by The International Union of Conservation of Nature, the Global Environment Facility Small Grants Programme Malaysia and the Ministry of Water, Land and Natural Resources.