Degradation of Dagupan River results in fishkills — study

NATIVIDAD, Pangasinan — The quality of the waters of the once pristine Dagupan River in this province’s premier city continues to be degraded.

Indicating this are "fishkills" brought in by the sprouting of fishpens and fishcages in Dagupan City’s main waterway, among other factors.

These fishkills have been the result of poor planning and zoning of the river, said researcher Merlina Andalecio of the University of the Philippines Visayas-College of Fisheries and Ocean Sciences and Philip Cruz of the Cruz Aquaculture Corp.

The two recorded their observations in their joint study entitled "Integrating Aquaculture in Coastal River Planning: The Case of Dagupan City, Philippines."

The scientific study won the National Research and Development Paper award given by the Department of Agriculture-Bureau of Agriculture Research (DA-BAR) during the 17th National Research Symposium held on the occasion of the 7th National Agriculture and Fisheries R&D Week (2005).

The award-winning study of Andalecio and Cruz aimed to develop a strategy in integrating aquaculture into the coastal planning of Dagupan River and to recommend a zoning plan for its multiple use for legislation purposes.

The study, according to UPV’s Nanette Cunanan, recommended a planning strategy that includes the use of a standardized fishpen design and layout for small-scale fishfarmers and the zoning of the areas into four, as follows:

• Zone 1 — a regulated zone covering 47.3 hectares. The maintenance of the river system of Dagupan City and neighboring towns is recommended.

The researchers said aquaculture and fishing structures should be strictly limited to not more than five percent of the area to maintain the river’s health.

• Zone 2-7 — a 300-hectare mariculture and fishing zone tagged as a priority zone to be set aside for capture fishing and fish culture.

• Zone 8 — a 41.7-hectare non-fishing zone that should be closed to culture and capture activities for at least two years, or until such time when the water quality reaches an acceptable level.

• Zone 9-10 — a 147.4-hectare fishpond priority zone to promote progressive pond culture practices and preserve the traditional Bonoan bangus farming system.

These recommendations, according to Andalecio and Cruz, would impact on river resources and the aquaculture industry, including better water flow, maximum utilization of space, 33 percent lower labor cost, and 53 percent lower fishpen cost.

The two researchers added that these could serve as major inputs to City Ordinance No. 1768-2003, or the Dagupan City Coastal Fisheries Resource Management Ordinance 2003.