Soil pollution threatens Bali's precious coral reefs

Soil pollution threatens Bali's precious coral reefs

By I Wayan Juniarta

DENPASAR, Bali (JP): Bali's world famous coral reefs,
increasingly important in attracting tourists to the paradise
island, are being threatened by soil pollution, according to
preliminary research by the World Wide Fund for Nature's (WWF)
Wallacea Program.

A WWF team of international scientists, who conducted the
research, presumed that some of the pollution was caused by the
excessive use of phosphorous and potassium fertilizers by
Balinese rice farmers.

"It is still too soon to draw definitive conclusions from this
research. However, the initial findings strongly suggest that the
coral reefs are in a serious condition due to the impact of soil
pollution, including agricultural runoff," deputy director of WWF
Indonesia's Wallacea Program Ketut Sarjana Putra said last week.

He said the team was still continuing the study.

Soil-based pollution is one of the major threats to coral
reefs, besides the crown-of-thorn sea star (Acanthaster plancii),
which in 1997 destroyed most of Bali's northern coastal coral
reefs. Government officials, environmental activists, tourism
operators and local fishermen killed at least 800,000 crown-of-
thorn during a battle to protect the coral reefs.

The WWF team comprises Ketut Sarjana Putra, Ghislaine Llewllyn
from the University of Connecticut in the United States and Jim
Kremer and Richard Murphy of Ocean Future Society.

Earlier this month, the team conducted a significant
comparative study on the condition of coral reefs in waters
located close to major rice-growing areas with those located far
from the areas.

After diving and observing at least 13 different sites around
Nusa Penida island, Candidasa, Sanur and Amed, the team concluded
that many of Bali's coral reefs are now in a dilapidated
condition.

Some coral reefs are being destroyed by "bomb fishing", coral
bleaching and crown-of-thorn outbreaks. The rapid growth of algae
also destructs numerous coral reefs in the island's waters.

"We took 50 algae tissue samples from reefs and rivers to
determine if the growth of algae was linked to fertilizer
runoff," Sarjana Putra commented, adding that those samples would
be sent to a a laboratory in the United States for further
scientific investigation.

He explained that fertilizer runoff resulted in excessive
nutrient levels which had harmful effects on both the freshwater
and marine ecosystems.

"Coral reefs, adapted to low nutrient conditions, are
particularly sensitive and vulnerable," he explained.

The vulnerable coral reefs trigger other marine species such
as algae to grow faster, occupying the living space of the reefs.
Excessive nutrients can also cause toxic algal blooms, which can
kill fish and make shellfish poisonous to eat. And it also
triggered the outbreak of the crown-of-thorns, which eat the
coral.

"Actually, the algae and reefs have a mutually beneficial
relationship. But, if excessive nutrient level takes place this
harmonious relationship will be destroyed. An excessive
phosphorous level, for instance, make reefs unable to absorb
calcium from the water," Murphy added.

Previously, in different research conducted from 1997 to 1998,
an American anthropologist, Stephen Lansing, in collaboration
with I Wayan Alit Artha Wiguna of Bali's Research Institute on
Agricultural Technology (IP2PT), discovered that much of the
phosphorous and potassium Balinese farmers apply to their rice
paddies was not really required.

"We found that the ground water emanating from the volcanic
soil of Bali is naturally rich in nutrients essential for rice
growth, so there is no actual need for the application of manmade
fertilizers," Lansing said.

Lansing, who is well-known for his in-depth work on Balinese
traditional rice-growing culture and institutions, added that the
findings of his research had been confirmed by several
traditional irrigation organizations, subak, in Tegalalang,
Gianyar.

"Those organizations have stopped using certain fertilizers
that contain nitrogen. That action did not affect the well-being
of their rice or paddy fields. Presently, most Balinese subak
enjoy a good harvest twice a year.

Both Lansing and the WWF team urged the central and provincial
government to critically review the current agricultural policy
that requires the application of fertilizers with a high level of
phosphorous and potassium.

The application of the fertilizers should be reduced to better
suit local conditions, otherwise Balinese farmers will suffer a
tremendous loss and the island's coral reefs will be in great
danger.