Fish farm effluents alter reef benthic assemblages and reduce coral settlement. (April 2020)

• Record Type: Journal Article
• Authors: Quimpo, Timothy Joseph R.; Ligson, Charlon A.; Manogan, Dana P.; Requilme, Jeremiah Noelle C.; Albelda, Ritzelle L.; Conaco, Cecilia; Cabaitan, Patrick C.
• Is Part Of: Marine pollution bulletin. Volume 153(2020)
• Publication Date: 2020-04
• Subjects: Fish farm -- Coral settlement -- Settlement assay -- Benthic assemblage -- Pocillopora acuta -- Philippines; Marine pollution -- Periodicals; Marine Biology -- Periodicals; Water Pollution -- Periodicals; Mer -- Pollution -- Périodiques; Publications périodiques; Pollution des mers; Lutte antipollution; Electronic journals; 363.7394
• DOI: 10.1016/j.marpolbul.2020.111025
• Languages: English
• ISSNs: 0025-326X

Abstract

Abstract: Fish farming in coastal areas is a rapidly growing industry. However, unregulated fish farming practices that release massive amounts of unconsumed feed and fecal material into the water column, can result in a nutrient-enriched environment that extends to nearby reef systems. To understand the impact of fish farm effluent on coral settlement, we tested the settlement rate of Pocillopora acuta larvae on artificial substrates conditioned for 12 weeks at three sites with increasing distance (2–10 km) from fish farms in Bolinao, Philippines. Sites far from the fish farms had higher biofilm and crustose coralline algae cover. In contrast, the site closest to the fish farms, where nutrient levels were higher, had greater sediment and turf algae cover. Tiles conditioned at the farther sites promoted higher (6–8%) larval settlement whereas tiles from the nearer site had lower settlement (3%). These findings show that fish farm effluents can indirectly affect coral settlement on adjacent reefs by promoting growth of other biota that may inhibit larval settlement and by reducing the availability of suitable substrate. Highlights: Impacts of fish farm effluents on reef benthic assemblages and coral settlement were examined Reefs near (2 km away) the fish farm zone were characterized by high algal cover and low hard coral cover Settlement tiles conditioned at the reef near the fish farm zone induced low coral settlement