Macroalgal diversity along an inshore-offshore environmental gradient in the Jakarta Bay – Thousand Islands reef complex, Indonesia. (5th January 2018)

• Record Type: Journal Article
• Authors: Draisma, Stefano G.A.; Prud'homme van Reine, Willem F.; Herandarudewi, Sekar M.C.; Hoeksema, Bert W.
• Is Part Of: Estuarine, coastal and shelf science. Volume 200(2018)
• Page Start: 258
• Page End: 269
• Publication Date: 2018-01-05
• Subjects: Beta diversity -- Presence-absence data -- Reef algae -- Seaweeds -- Spatial turnover -- Taxon composition; Estuarine oceanography -- Periodicals; Coasts -- Periodicals; Estuarine biology -- Periodicals; Seashore biology -- Periodicals; Coasts; Estuarine biology; Estuarine oceanography; Seashore biology; Periodicals; 551.461805
• DOI: 10.1016/j.ecss.2017.11.010
• Languages: English
• ISSNs: 0272-7714

Abstract

Abstract: The Jakarta Bay – Thousand Islands reef complex extends to more than 80 km in northwest direction from the major conurbation Jakarta (Indonesia) along a pronounced inshore to offshore environmental gradient. The present study aims to determine to what extent environmental factors can explain the composition of macroalgal communities on the reefs off Jakarta. Therefore, the presence-absence of 67 macroalgal taxa was recorded for 27 sampling sites along the inshore-offshore disturbance gradient and analysed with substrate variables and water quality variables. The macroalgal richness pattern matches the pattern of other reef taxa. The 27 sites could be assigned to one of four geographical zones with 85% certainty based on their macroalgal taxon assemblages. These four zones ( i.e., Jakarta Bay and, respectively, South, Central, and North Thousand Islands) had significantly different macroalgal assemblages, except for the North and South zones. Along the nearshore gradient there was a greater shift in taxon composition than within the central Thousand Islands. The patterns of ten habitat and water quality variables resembled the macroalgal diversity patterns by 56%. All ten variables together explained 69% of the variation in macroalgal composition. Shelf depth, % sand cover, gelbstoff/detrital material, chlorophyll a concentration, seawater surface temperature, and % dead coral cover were the best predictors of seaweed flora composition. Furthermore, 44 macroalgal species represented new records for the area. The present study provides important baseline data of macroalgae in the area for comparison in future biodiversity assessments in the area and elsewhere in the region. Graphical abstract: Highlights: Seaweed richness is highest at locations where the reef shelf is deepest. Jakarta Bay (inshore) seaweed assemblages differ significantly from Thousand Islands (offshore) assemblages. Habitat and water quality variables explain 69% of the seaweed composition in the Jakarta Bay – Thousand Islands reef complex. 44 macroalgae are recorded new for the Jakarta Bay – Thousand Islands region.