Relation of Coral Reef Fish Larval Distributions to Island Scale Circulation Around Barbados, West Indies
Abstract:An interdisciplinary study was undertaken to test whether larval reef fish are readily retained in the vicinity of an island in association with eddies embedded in the downstream flow. Theoretical and empirical data have suggested the existence of either stationary eddies or shedding eddy fields (i.e., von Karman vortex streets) in the vicinity of isolated islands, and reef fish ecologists have considered such eddies to be important in the retention and eventual return of reef fish larvae to the island reefs. Our physical data do not support the hypothesis that either a stationary or shedding eddy field exists downstream of the island of Barbados. Although eddies may exist, evidence suggests that the main oceanographic features and flow are topographically steered, being strongly influenced by subsurface (300 m) ridges running northwest and south of the island. The result is essentially longshore flow on the leeward side of the island, offshore convergences located at the southwest and northwest corners of the island, and possibly a downstream (∼50 km) return flow which follows the northwest ridge. Our preliminary analysis of larval reef fish distribution suggests a strong concordance with certain features of the physical flow, notably the offshore flowing convergence and the return flow northeast of the island. Additionally, larval reef fish densities are extremely high very nearshore (<1.5 km) at mid-island suggesting either a region of low flow, onshore flow, and/or active behavior on the part of the larvae resulting in the retention and/or return of larvae in this vicinity. Analysis of the vertical distribution of the larvae shows highest concentrations at 10–30 m and 30–60 m depths, with some family level differences. Onshore flow is also evident (especially nearshore) at depths of about 50 m corresponding to the depths of high larval concentration. These preliminary data are intriguing in the sense that they suggest a simpler, more general mechanism for larval retention and ultimate return to the reef habitat. With primarily longshore flow around the island due to topographic features and some nearshore, onshore flow at mid-depths, the larvae are essentially in a similar physical regime as shelf environments. Therefore, larval behaviors and adaptations may not need to be so complex as to be island specific, rather the same general adaptations and behaviors required of reef fish larvae from coastal areas may be successful for island populations as well.
Document Type: Research Article
Publication date: 1994-01-01
More about this publication?
- The Bulletin of Marine Science is dedicated to the dissemination of high quality research from the world's oceans. All aspects of marine science are treated by the Bulletin of Marine Science, including papers in marine biology, biological oceanography, fisheries, marine affairs, applied marine physics, marine geology and geophysics, marine and atmospheric chemistry, and meteorology and physical oceanography.
- Editorial Board
- Information for Authors
- Subscribe to this Title
- Terms & Conditions
- Ingenta Connect is not responsible for the content or availability of external websites