Authors

Proserpina G. Roxas

Author

Renoir A. Abrea

Co-author

Wilfredo H. Uy

Co-author

Mindanao State University at Naawan, 9023 Naawan, Misamis Oriental, Philippines

*Corresponding author: [email protected]

ABSTRACT

Impacts of previous interventions on the coastal habitats in Panguil Bay, Philippines were determined by assessing the bay's mangroves, seaweed and seagrass communities, coral reefs, marine sanctuaries, and artificial reefs using standard and modified methods. The bay has 21 true mangrove and 15 mangrove-associated species that serve as habitat for commercially important fish and crustaceans, particularly the mud crab, Scylla spp. Mangrove resources, however, are continuously threatened by fishpond development and other uses resulting in a significant decline in cover to only 4.36% of the estimated cover in 1950. The seaweed community is comprised of 26 species of green algae, 18 brown algae, 24 red algae, and 4 blue green algae. The present number is lower compared to the 105 species recorded in 1991. Most seagrasses and seaweeds are found only near the bay's mouth, while only few species represented by Enhalus acoroides , Enteromorpha and Neomeris are found in the inner part of the bay. The average cover of seaweeds and seagrass decreases from the mouth towards the inner side of the bay. There is a significant reduction in the cover since 1991 except for the seaweeds in Maigo, Lanao del Norte and the seagrasses in Clarin, Misamis Occidental. In several stations, seagrass cover is already less than 20% of that reported in 1991. Coral reef development is restricted to areas around the mouth of Panguil Bay where the overall condition of the habitats has declined in less than two decades. Results of the present assessment indicate a negative development index for all coral reef sites compared with positive development index obtained in 1991 and 1996. Their present status may be considered “poor” with average hard coral cover of less than 25%. Some coral reef and non-coral reef areas that have been protected as marine sanctuaries have relatively high fish species richness, abundance and biomass compared to the unprotected and poorly managed coral reefs. The artificial reefs in the bay also have relatively higher fish species richness than in the natural coral reefs although the present number of 157 reef fish species is slightly lower than the 160 species obtained in 1996. Observations of declining habitat quality in Panguil Bay suggest that these habitats have to be holistically managed to ensure their protection and sustainability.