Evaluasi Dampak Pengambilan dan Pengisian Material Pasir Terhadap Kualitas Air Laut di Konservasi Pantai Nusa Dua Tanjung Benoa

Abstract

Sand bypassing and beach nourishment are coastal conservation methods used to maintain shoreline stability and are commonly implemented along Bali’s coast, particularly in Nusa Dua and Tanjung Benoa. While these activities strengthen coastal protection, they may affect seawater quality due to sand extraction and nourishment operations. This study evaluates seawater quality during project implementation and examines potential impacts on physical and chemical parameters according to seawater quality standards for marine tourism areas. Field observations and seawater sampling were conducted at Nusa Dua and Tanjung Benoa Beaches. Laboratory analyses employed spectrophotometry to measure dissolved compounds such as ammonia, nitrate, and phenol; Atomic Absorption Spectrophotometry (AAS) to detect heavy metals; and organoleptic observations to assess physical parameters including color, odor, and turbidity. The results were evaluated in accordance with Bali Governor Regulation No. 16 of 2016. Most seawater quality parameters were within the established limits. However, the levels of free ammonia (NH₃-N), nitrate (NO₃-N), sulfide (H₂S), and phenol, exceeded the standards, likely resulting from nearby domestic and activities related to tourism. The outcomes of this research emphasize the necessity of continuous seawater monitoring to preserve the balance of Bali’s coastal ecosystems and to support sustainable coastal management