The following article has been reproduced with the permission of the Lahaina News:

New studies link groundwater to algae blooms

July 24, 1997

BY MARK VIETH

Editor

WEST MAUI -- After exhaustive study the culprit is... groundwater.

The state Department of Health announced Tuesday that just-completed studies concluded that nutrient rich groundwater seeping into the ocean and favorable environmental conditions are behind the nuisance growth of hypnea alga (a red algae) in West Maui's coastal waters.

A dozen studies on the biology of nuisance algae and the factors causing blooms are finished and available for public review. The research, conducted by Hawaii and Mainland scientists, was coordinated by the Lahaina-based West Maui Watershed Project, a DOH project.

"This research has vastly improved our understanding of algal blooms in the West Maui area," said Dr. Bruce Anderson, the state's deputy director for environmental health.

"We now know that nutrient inputs from land are required to support the large amount of hypnea that occurs at specific locations along the shore; naturally-occurring oceanic nutrients alone are not sufficient."

Due to public concern about West Maui beach scenes like this, the state, Environmental Protection Agency and National Oceanic and Atmospheric Administration have been funding studies to investigate the causes of nuisance algae growth.

According to the scientists, the major source of nutrients for West Maui algal blooms is the constant seepage of groundwater into the ocean at the shoreline. The nutrient levels are boosted by fertilizers used in agriculture and the disposal of sewage through cesspools.

Researchers have also concluded that hypnea benefits from favorable environmental conditions in the West Maui area, which include a rocky shoreline and moderate wave action. These factors help keep the nutrients confined.

Evidence has also shown that cesspools are contributing to nutrient loading in some near shore areas. "If these results are confirmed, this finding suggests that future management efforts may be needed to reduce the impact of cesspools in the area," said Anderson.

Experts believe nutrients from wastewater injection wells enter the ocean, but the wastewater nutrients were not detected in the shallow waters where the nuisance algae blooms are the problem.

According to the state, hypnea -- a weed introduced to Hawaii, with no natural controls from disease and herbivores -- has been a problem on West Maui beaches for about 10 years. There have been problem cladophora (green algae) blooms in West Maui waters in 1989 and 1991.

To help curb algae growth, efforts are under way to harvest algae and convert it to products of commercial value, apply improved best management practices for fertilizer use, and identify other sources of nutrients that can be controlled on Maui, said Dr. Wendy Wiltse, West Maui Watershed Coordinator.

Land and water management practices for protecting the ocean are available through guides produced by the watershed project. There's a booklet geared for individuals, and next month, a "Watershed Owners Manual" will be available for use by corporations, plantations and government agencies.

For more information, call 661-7856.

Psy 412 Miami University. Last revised: Thursday, April 18, 2002 at 23:54:06. This document has been accessed 1,052 times since July 15, 1997. Comments & Questions to R. Sherman .