An unlikely group of four keen anglers and officers from Singapore's national water agency PUB took a boat out onto the waters of Lower Seletar Reservoir in the wee hours of a Saturday last month.
Instead of casting their rods, they homed in on a 1m-deep secluded spot and gingerly lowered a handmade tray of plants into the water.
Their mission: to rebuild fish habitats by installing plant shelters in water bodies.
This will give the fish spaces to hide and rear their young, leading to a more sustainable fish population, said Mr Tan Tien Yun, president of conservation group Gamefish and Aquatic Rehabilitation Society.
This project is five years in the making. The group of 20 who come from diverse backgrounds - from ateachers to businessmen - have been pushing to play a part in restoring waterway habitats.
They recently got approval from PUB to start a trial project on fish habitat rehabilitation at the designated fishing zone in Lower Seletar Reservoir.
Part of the programme will encourage anglers to adopt better fishing practices, such as not using live bait and nets to catch the fish.
But Mr Tan, 32, said the group's key focus is on improving fish habitats, at a time when fishing at reservoirs is becoming more popular.
By some estimates, the angler community here is about 200,000 strong - a number that has quadrupled in the past three years.
Said Mr Tan, who works in the IT industry: "If there is no fish left, what is the point of reminding people not to litter or pollute the water with discarded bait?"
He became interested in the cause after he realised that the number of fishing spots he can hang out at during the weekends has dwindled.
"We want to tackle the root of the problem of why the fishes are disappearing," he said.