The abundance of Scleractinia corals in relation to water quality in the maricultural area of Menjangan Island, Karimunjawa National Park

• Published in: Aquaculture, Aquarium, Conservation & Legislation Vol. 15; no. 6; pp. 3107 - 3120
• Main Authors: Putro, Sapto P, Ramadhon, M F, Munasik, Hariyati, R, Adhy, Satryo
• Format: Journal Article
• Language: English
• Published: Cluj-Napoca Bioflux SRL 30.12.2022
• Subjects: Abundance; Anthropogenic factors; Biodiversity; Coastal zone; Coastal zone management; Coasts; Composition; Coral reefs; Corals; Destructive fishing; Disturbances; Ecosystem disturbance; Ecosystems; Environmental protection; Fish; Fisheries; Human populations; Hydrodynamics; Marine aquaculture; Marine invertebrates; Marine resources; National parks; Nitrates; Nutrient concentrations; Nutrient sources; Nutrients; Phosphates; Population growth; Resource utilization; Scleractinia; Seasonal variation; Seasonal variations; Storms; Water quality; Zoning; Indonesia
• ISSN: 1844-8143; 1844-9166

Coral reefs ecologically provide nurseries for many species of commercially important fish, and protection of coastal areas from storm waves. Unfortunately, coral reefs worldwide have been degraded in the last few decades, along with human population growth and marine resource utilization. As the main biotic component of coral reef, hard corals (order Scleractinia) are susceptible to environmental disturbances, both natural and anthropogenic induced disturbances. In particular, excessive nutrient concentration could affect hard coral physiologically and ecologically. This study aimned to understand further relationship between nitrate and phosphate and hard coral abundance in the mariculture area. Menjangan Besar island (Site 1-3) was selected as a study site to represent the mariculture area, with Geleang island (Site 4) as a reference site. Coral coverage in Site 1-3 was lower than non-mariculture yet did not indicate damage to coral reefs. No significant difference in coral coverage of Scleractinia at all sites was found (F(1,20)=74.51, p>0.05). However, the genus composition in Site 1 was significantly different compared to other sites. Phosphate concentration in the non-mariculture area (Site 4) is the highest among all sites, while nitrate is the second highest. Site 2 (x=0.40, SD=0.03) has significant difference in nitrate concentration (F(1,20)=121.19), p<0.05) compared to Site 1 (x=1.46, SD=0.81) and Site 4 (x=1.28, SD=0.47). Significant difference in phosphate concentration (F(1,20)=27.73), p<0.05) was found between Site 1 (X=0.06, SD=0.01) and Site 3 (X=0.35, SD=0.20). Nutrient concentration in the water ecosystem of the study sites was found to affect the genus composition in Sites 2 and 3. However, they did not correlate significantly to coral abundance (nitrate: R2=0.0002, phosphate: R2=0.11), that may relate to seasonal variation in ocean hydrodynamics and nutrient sources caused by anthropogenic activities. Further studies may be required for a more comprehensive review with bigger sample size and physical variables that affect the nutrient distribution.