Patterns of reef fish energy flow in a transitional zone
Journal
Coral Reefs
ISSN
0722-4028
1432-0975
Date Issued
2025-08-19
Author(s)
Abstract
Energy flow—through the production, transfer, and consumption of biomass—is fundamental to ecosystem functioning. On coral reefs, fishes are key contributors to ecological processes that mediate energy transfer, and their rapid responses to environmental and anthropogenic changes make them reliable indicators of ecosystem health. Yet, fish-mediated energy flow remains understudied, particularly across natural environmental gradients, where its variation can provide valuable insights into reef ecosystem dynamics. Here, we surveyed reef fish assemblages using stereo-video transects across five regions of Taiwan spanning a tropical-subtropical transition and quantified energy flow with three metrics: biomass, productivity, and turnover. We applied generalized linear mixed models to assess the influence of biotic (benthic composition and fish trophic groups) and abiotic (environmental and anthropogenic variables) factors on fish energy flow. Our results revealed distinct regional patterns of energy flow: subtropical reefs were primarily sustained by planktivorous fish, whereas tropical reefs were supported by both herbivorous and planktivorous pathways. Energy flow was influenced by benthic community composition and varying scales of reef structural complexity, each favoring a different group of fishes. Reduced energy flow may indicate underlying reef degradation, even in areas where structurally complex corals persist—suggesting a potential decoupling between habitat structure and ecosystem functioning that warrants further investigation. Overall, our study identifies contrasting energy flow pathways between tropical and subtropical reefs, emphasizes the importance of habitat in maintaining ecological processes, and provides a regional baseline for assessing variation in reef functioning in response to climate change and human impacts.
Subjects
Biological conservation
Ecological processes
Ecosystem functioning
Nutritional subsidy
Productivity
Structural complexity
Publisher
Springer Science and Business Media LLC
Type
journal article