Borneo Lake Restoration Programme

An Environment project Sabah Malaysia

Removing the invasive water weed Salvinia molesta from Lake Tungog in the immensely bio-diverse Kinabatangan River north-east Borneo.

New stretch target

Any money beyond our initial £2000 target will be put towards additional man hours and equipment for the removal of weed covering the northern end of the lake. £10,000 will enable us to remove all remaining weed from Tungog Lake over the coming months. Thank you for all of your support!


Thank you to everyone who pledged towards the Tungog Lake restoration. The response was incredible, so good in fact that the original target was smashed and there is now a healthy budget available for the continued maintenance of the southern end, and the removal of some of the weed in the northern end of the lake. 

The boat was completed and put onto Tungog Lake yesterday (10/08/15) - see below. The people who'll be working on the weed have also now been appointed, so work will begin imminently. 

Once complete, we will post some before and after pictures. Thanks again to everyone who helped!

Project aim

Removing the invasive water weed Salvinia molesta from a pristine oxbow lake on the Kinabatangan River north-east Borneo. 


Short summary 

(for those of you who don’t care about the details and just want the highlights!)

The beautiful Tungog Lake in the Kinabatangan, Borneo, is severely under threat from an invasive weed known as Salvinia molesta. The weed entered the lake during floods in 2001, but was kept at bay for a number of years by local villagers who had been removing the weed manually. Early this year all funding sources dried up, resulting in the now uncontrolled spread of the weed. Salvinia today covers around 60% of the lake’s surface, and poses a severe threat to all aquatic life including three Otter species and a host of rare water birds such as Kingfishers and Oriental darters.

We hope to Crowd Fund the removal of Salvinia molesta from Tungog Lake. Money raised will cover the employment of 2 local people for a month, as well as the purchase of a boat and engine specifically for removing the weed. The boat will be fitted with a locally designed “Sawak”,  a device which acts as a scoop to remove the weed. Our primary target is to clear the entire Southern end of the lake within a single month, and provide local villagers with the tools required to maintain this part of the lake. This will breathe life back into the lake’s struggling ecosystem and provide open water for otters and water birds. Any additional funding that we receive beyond our target will be spent on further equipment and man hours to clear the northern part of the lake.

For more details about the Salvinia weed threat, the local village organisation behind this initiative (KOPEL), and a breakdown of how the funds will be spent, please read on below.



About the project

(the details)


In terms of biodiversity, there are few parts of the world which are as critically important as Borneo. To put it in perspective, the UK has approximately 100 types of mammal; Borneo has nearly 400 - set that against a backdrop of over 2000 types of tree, tens of thousands of species of invertebrates and you begin to see what we're talking about.

The Tungog Lake in north-east Borneo is an oxbow lake and an important feature in the wetlands surrounding the lower reaches of the famous Kinabatangan River. This region is made famous because it is home to some of Borneo's most charismatic inhabitants, including orangutans, elephants, hornbills, clouded leopards, sun bears, otters and proboscis monkeys. What makes this lake stand out is its mix of rare aquatic inhabitants and the unique mix of rare floodplain forests that surround it - both of which support abundant wildlife populations. 

Activities around the Tungog Lake include wildlife monitoring, reforestation, water quality monitoring and ecotourism all of which are operated by a local village-based cooperative called KOPEL.

Above: Rare form of Silver Leaf Monkey (Trachypithecus cristatus) at Tungog Lake

The problem

Tungog Lake is approximately 50 acres in size, and provides critical freshwater habitat for numerous species of mammals, birds, fish, reptiles and insects, many of which are endangered. The lake is also a vitally important nursery and breeding area for fisheries in the nearby river.

Today the Tungog Lake and all its inhabitants are under threat and face an uncertain future. The threat comes from a floating weed that carpets the lakes surface and suffocates all life within. The weed is called Salvinia molesta and it made its way into the lake during major floods in late 2001.

So what’s the big deal you may ask?

Salvinia originates from South America and has no natural predators in the local Borneon ecosystem. Once present in a waterbody, the Salvinia weed forms a dense carpet which effectively seals off the air/water interface. This is critical for oxygen levels in the water and the wellbeing of the lake and its residents.

What makes this weed so devastating is its ability to double in size approximately every 3-5 days. This aggressive growth rate means the Salvinia rapidly grows on top of itself, suffocating the older parts of the plant mass, and forcing a huge amount of dead Salvinia to drop to the lake bottom. Apart from the rapid sedimentation impacts and shallowing of the lake, the decay process starves the remaining waterbody of oxygen, which is vital for the survival of all aquatic life therein.

In terms of the wider Kinabatangan floodplain, what makes this problem of major significance, is that the Tungog Lake plays a vitally important role in restocking the neighbouring river system with fish - especially during the annual wet-season, when floods cause the lake and nearby river to merge. Ultimately the weeds presence is causing a complete collapse of the entire food web and ecosystem, not just in the lake itself but also in the surrounding floodplain. In the Tungog Lake itself, the weed threatens a vast array of native aquatic flora and fauna species. In turn, the weed is a major threat to three species of otter and a host of rare waterbirds, as these species no longer have access to the water or their natural source of food. 

The weed currently covers the entire north end of the Tungog Lake, and a significant proportion of the south side is also covered. In all, only about 40% of the lake remains uncovered. If left uncontrolled, the weed will eventually cover the entire lake which will have devastating consequences for the animal life that relies on it, and an even more devastating effect on the wildlife that currently lives inside it.



Above: Dense carpet of Salvinia completely smothering the northern end of the Tungog Lake 

Above: Up close view of the Salvinia water weed on Tungog Lake

Current control

In 2004 the local village cooperative KOPEL began work to remove the Salvinia weed both by hand and later with wooden boats made in the village. The work was started through seed funding from a local conservation organisation - LEAP. Later in 2007 KOPEL continued the ongoing removal of the weed through revenue earned from local ecotourism activities. In 2013 this revenue was cut in half due to a major drop in visitor arrivals. The drop was caused by international travel bans and security warnings for travellers along the entire north-east coastline of Borneo. Although far removed from coastal piracy or island kidnappings visitors have not yet returned to the upstream parts of the Kinabatangan floodplain.

For the last two years the village cooperative KOPEL has not been able to afford to restart the boat method because of the cost involved with purchasing boats and engines and has resorted to removing the Salvinia manually with hand scoops and nets. This literally means scooping the weed out of the lake with a net and dumping it on a floating pontoon before dragging it onto the nearby land to decompose. It goes without saying the current method is extremely slow and labour intensive. Further still, the availability of labour for this kind of work is piecemeal and difficult to sustain without additional funding - either via a major increase in visitor arrivals or external funding support.

What we want to do

Simply put, we want to remove the Salvinia from Tungog Lake. More precisely our primary goal is to completely remove the current growth of weed from the southern half of the lake. Any additional money will go towards removing the vast mat of Salvinia from the northern half of the lake.

1st Goal - £2000

Remove all Sylvania from the southern part of the lake, and all new growth from the centre of the lake.

£400 = 1 x new wooden boat - made locally (including all materials and labour) and fitted with a sawak

£1200 = 1 x new boat engine, and fuel

£400 = 2 x local people to both work on the lake, using the boat for 1 month each (the Malaysian minimum wage is £160/month).

The boat operates with a specially designed plough (a sawak) fitted to the front of the boat. It requires patience and skill to operate the boats with the heavy weight of Salvinia loaded on the front. The boat will then be used to push the weed off of the lake and directly on to the land. Together with funds for a month of dedicated man hours, the entire southern half of the lake will be completely rid of Salvinia. The boat and plough will then remain as an essential part of KOPEL’s ability to keep this southern end of the lake under control.

2nd Goal - £10,000

Remove Sylvania from the entire lake.

Any money beyond £2000 will be put towards further equipment and man hours. £10,000 would facilitate the removal of all remaining weed on Tungog Lake and it's continued maintenance.


Above: Stork-billed Kingfisher (Pelargopsis capensis) feeding on fish on Tungog Lake

Why help?

The spread of Salvinia molesta is one of the most significant environmental concerns in this region and has the potential to have a devastating effect on the unique wildlife of this area. The localised extinction of rare fresh water fish species in this region and the chain of other species associated with these is unfolding at an incredibly rapid pace. What is particularly disturbing is that this problem is completely reversible and could be stopped with a relatively small amount of funding, but the funding simply isn't available and the problem is not being addressed.

Simply put, Salvinia compromises the welfare of everything which relies on the lake - supporting this project will help reverse the impacts of the Salvinia weed and restore a vitally important lake ecosystem.