| Abstract: | - 1. An abundance gradient from high inside to low outside a no‐take marine reserve may indicate net emigration of adult fish from the reserve (‘spillover’).
- 2. We examined spatial patterns of abundance of fish across two ～900 m long sections of coral reef slope at each of two small Philippine islands (Apo and Balicasag). One section sampled the entire length of a no‐take reserve and extended 200–400 m outside the two lateral reserve boundaries. The other section, without a reserve, was a control. The reserves had had 20 (Apo) and 15 (Balicasag) years of protection when sampled in 2002.
- 3. Significant spatial gradients of decreasing abundance of target fish occurred across only one (Apo Reserve northern boundary = ARNB) of four real reserve boundaries, and across none of the control ‘boundaries’. Abundance of non‐target fish did not decline significantly across reserve boundaries.
- 4. Abundance of target fish declined sharply 50 m outside the ARNB, but enhanced abundance extended 100–350 m beyond this boundary, depending on fish mobility.
- 5. Density of sedentary target fish declined 2–6 times faster than density of highly vagile and vagile target fish across the ARNB.
- 6. Habitat factors could not account for these ARNB results for target fish, but did influence abundance patterns of non‐target fish.
- 7. The lack of abundance gradients of target fish at Balicasag may reflect reduced fishing outside the reserve since it was established.
- 8. Apo Reserve had a gradient of abundance of target fish across at least one boundary, a result consistent with spillover.
Copyright © 2006 John Wiley & Sons, Ltd. |
