Laguna Lake

Page - September 29, 2010
The Laguna de Bay, one of the five largest freshwater lakes in the whole of Southeast Asia and a major source of food and livelihood for thousands of people, is slowly dying from industrial and household pollution.

The Laguna de Bay, one of the largest freshwater lakes in Southeast Asia, has always been historically, economically, and ecologically significant to the people living along its shoreline and environs. As of 2007, there are a total of 8.3 million persons living around Laguna Lake Basin who are directly affected by any changes, good or bad, to the lake and its natural ecological balance.

Laguna Lake in history

The Laguna Lake has always played a significant role in the lives of the people who live on its shores. Lakeshore dwellers of different religions use the lake for baptismal rites, while Catholic faithful hold fluvial parades in its waters. The lake is also close to some significant historical sites. The Angono Petroglyphs, a world cultural heritage site containing prehistoric drawings in the lakeshore town of Angono, Rizal, is proof that the lake has had a major impact on the lives of Filipinos since time immemorial.

Another major historical site is the home of the Philippines’ national hero, Dr. Jose Rizal, in the town of Calamba, Laguna. Writing during the time of the Spanish occupation, Dr. Rizal talked about the significance of the lake and the Pasig River to the daily lives of the people in one of his novels.

Other places of interest in the Laguna Lake Watershed area include Mt. Makiling, an extremely biodiverse mountain and protected area that has mystical significance to Filipinos, the spectacular Pagsanjan Falls -- a world-famous tourist attraction – and the various centuries-old churches in the towns of Pakil, Pangil and Majayjay in Laguna Province.

Laguna Lake and the environment

The Laguna Lake Watershed is an extremely biodiverse area containing 48% of the flowering plants and ferns that are endemic, or native, to the Philippines. Mt. Makiling, located between the provinces of Batangas and Laguna, is also rich in biodiversity, with more than 2,000 species of flowering plants and ferns. It has 381 species of vertebrates, including 45 species of reptiles, 22 species of amphibians, and 181 species of birds.

Mt. Banahaw in Quezon, another mystical mountain located in the Laguna Lake Basin, has a high endemicity with 66-76% of its plants and animals endemic to the area. The LLB is known to hold 15 species of globally threatened birds, 21 species of bird of very restricted breeding ranges, and at least 10% of the congregatory birds of Asia.

The lake basin also has rich aquatic life, with an estimated 269 species of plants, fishes, and various other aquatic organisms. A total of 33 species of fish have thrived in the lake at different times, 14 species of which are indigenous, 5 migratory, and 19 introduced or exotic.

Laguna Lake and the economy

The lake is of great economic importance to the region as it provides for many of the region’s needs. It is currently used for fisheries, as a source for domestic water supplies, and industrial cooling, as a transport route, as a source for power generation and irrigation, and as a place for recreation.

The lake is a vital fishing ground, with open water capture fisheries and aquaculture pens dotting its surface. Since 1960, the lake has been heavily exploited by the aquaculture industry with the introduction of fishpens and cages. This trend peaked in the 1980s when the total area covered by fishpens amounted to an estimated 35,000 hectares. Over the years, changes in the species composition and the relative abundance of fish in the open water was observed. In the early 60s to the 70s the main catch was composed of Silverperch (Leiopotherapon plumbeus) and White goby (Glossogobius giurus). In the 90s, Tilapia and Bighead Carp dominated the catch. However, there has been an alarming increase in the number of janitor fish, an introduced species, in the catch since the year 2000.

Threats to the lake

The Laguna Lake and its surrounding areas are under immediate threat from household and industrial pollution. Household or domestic wastes constitute 77% of the lake’s total pollution load, industry contributes 11%, 11% from agriculture and 1% from forests. Solid and liquid wastes enter the lake by way of the 22 major tributaries and the more than 100 minor tributaries, including the periodically back-flowing Pasig River. At present, Laguna Lake is still classified as suitable for fisheries and aquaculture development. It is also considered a source for drinking water which is subject to treatment. This, however, is not the whole story.

In 2007, Greenpeace released the report Cutting Edge Contamination which showed possible contamination of freshwater resources. Water samples were taken from communities living near or around electronics and semiconductor facilities in the area and tested for contamination. The samples were mostly taken from handpumps that the community used for drinking water. Many of the samples contained differing levels of contaminants, including VOCs and some trihalomethanes. Some samples contained elevated levels of zinc and vanadium.

In three of the samples that were tested, Greenpeace found that the levels of one or more chlorinated ethanes exceeded the maximum recommend levels for drinking water set by the World Health Organization (WHO) and the US Environmental Protection Agency (EPA). One of the samples also clearly showed tetrachloroethene (a Volatile Organic Compound) levels that were nine times the WHO guidance value and 70 times the EPA maximum contaminant level.

What does it all mean?

Greenpeace’s findings clearly indicate that the figures for industrial pollution don’t tell the whole story. While the figures may indicate that the bulk of pollution comes from household wastes, industry is guilty of releasing heavy metals and other deadly toxins into the water. Many of these toxins are known as Persistent Organic Pollutants (POPs) because once they get into the water and into the environment, they are almost impossible to remove. They also become more concentrated with every addition of toxins because they cannot be degraded by natural means. This means that with every passing year, the concentration becomes heavier and heavier, resulting in a kind of toxic soup that is deadly to people and other living things.

While the Laguna Lake may already be threatened by toxic materials, it’s not too late to arrest the pollution and eventually reverse it. Greenpeace’s Project Clean Water aims to catch and report polluters and to keep them from continuing their dirty practices by getting them to commit to Clean Production processes.