TASIK Berombak and the melaleuca forest around it are vital for regulating the natural ecosystem and flood control in Setiu, Terengganu, says a marine environment expert.
Assoc Prof Dr Jamilah Mohd Salim of Universiti Malaysia Terengganu (UMT) said the lake’s floor was made of a layer of peat soil, formed from the organic matter shed by the melaleuca trees.
“Thanks to its fibrous structure, this type of soil has excellent water retention capacity, allowing the lake to double as a flood buffer during monsoon season and a catchment area during dry spells,” she said.
Spanning 1,000ha, Tasik Berombak measures about 38km in perimeter and is between 2m and 3m deep.
Jamilah said there was a lack of awareness about this ecosystem in the earlier days.
“As a result, a sizeable tract of the forest was cleared to make way for plantations and aquafarms,” she said.
She noted that those activities had affected the volume of water at the lake. This proved costly in 2010 when fishermen and aquafarmers along Setiu’s coastline began reporting reduced catches, she said.
She added that aquafarming was the dominant economic activity in the district that was home to several fishing villages.
Jamilah, who is also UMT Tropical Biodiversity and Sustainable Development Institute deputy director, said the lake acted as a reservoir where the freshwater filtered into aquifers and flowed to the sea.
“This balances the salinity along the shoreline, creating an optimal condition for aquatic life.
“But the drop in freshwater has caused an increase in salinity, which is unfavourable for local species,” she explained.
According to a UMT survey, 30 species of fish are found at Tasik Berombak including haruan (snakehead murrel), keli (catfish) and belida (bronze featherback),
Jamilah said many fishermen would head to the lake during monsoon season when they could not sail to sea.
But the fishes may come under threat as recent observations found that bakong air (Hanguana malayana) was proliferating at the lake, she added.
Jamilah said the aquatic plants were thriving due to a decline in the population of melaleuca trees.
“If left unchecked, they may cause the lake surface to be covered and prevent sunlight from reaching the organisms inside the water.
“This can also harm the food chain,” she said.
On its formation, she said Tasik Berombak was part of an ecosystem known as Bris (beach ridges interspersed with swales) that formed over time when sand and sediments accumulated along coastlines, leaving swales inland.
“Eventually, the swales filled with water from rain and nearby rivers, forming marshy landscapes.
“As time goes by, the swales might become completely disconnected from the sea, forming freshwater lakes,” she elaborated. — By FARID WAHAB
