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Temporal changes in hamlet communities (Hypoplectrus spp., Serranidae) over 17 years
K Hench1, W O Mcmillan2, R Betancur-R3
1GEOMAR Helmholtz Centre for Ocean Research Kiel, Evolutionary Ecology of Marine Fishes, Düsternbrooker Weg 20, 24105 Kiel, Germany.
Journal of Fish Biology
|October 11, 2017
Summary
The yellowtail hamlet (Hypoplectrus chlorurus) has increased in abundance but declined in density over 17 years in Puerto Rico. Increased seawater turbidity may be driving these changes in hamlet fish communities.
Area of Science:
- Marine biology
- Ichthyology
- Ecology
Background:
- Hamlet communities (Hypoplectrus spp.) are important components of Caribbean reef ecosystems.
- Previous studies have noted changes in fish populations, but the drivers are not fully understood.
- Seawater turbidity has increased in La Parguera, Puerto Rico, due to terrestrial sedimentation.
Purpose of the Study:
- To compare hamlet fish community structure in La Parguera, Puerto Rico, between 2000 and 2017.
- To investigate the ecological drivers influencing changes in hamlet communities, particularly the yellowtail hamlet (Hypoplectrus chlorurus).
Main Methods:
- Transect surveys of 14,000 m² across 16 reefs.
- Comparison of current survey data with a 2000 survey.
- Analysis of Hypoplectrus spp. abundance, density, and distribution patterns.
Main Results:
- A >30% increase in the relative abundance of Hypoplectrus chlorurus on inner reefs.
- A decline in H. chlorurus density and a shift in distribution to shallower depths.
- H. chlorurus shows a positive association with increased seawater turbidity.
Conclusions:
- The hamlet community structure has changed significantly over 17 years.
- Increased seawater turbidity is proposed as a key ecological driver influencing hamlet communities.
- Further research is needed to understand the long-term impacts of turbidity on reef fish populations.
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