Study

A test of trophic cascade theory: fish and benthic assemblages across a predator density gradient on coral reefs

  • Published source details Casey J.M., Baird A.H., Brandl S.J., Hoogenboom M.O., Rizzari J.R., Frisch A.J., Mirbach C.E. & Connolly S.R. (2017) A test of trophic cascade theory: fish and benthic assemblages across a predator density gradient on coral reefs. Oecologia, 183, 161-175

Actions

This study is summarised as evidence for the following.

Action Category

Control human activity in a marine protected area with a zonation system of restrictions

Action Link
Marine Fish Conservation
  1. Control human activity in a marine protected area with a zonation system of restrictions

    A site comparison study in 2009–2014 of a coral reef area off San Miguel Island in the Philippine Sea, Philippines (Casey et al. 2017) found more fish species and a higher overall fish abundance of commercially important fish in a no-entry zone of a marine protected area, compared to two partially fished zones and unprotected fished areas 10-15 years after implementation, and the effect of protection varied between individual species groups and sizes. Across all years, the average species richness and fish abundance of commercially important species was highest inside the no-entry zone (species: 11–12, abundance: 28–41 fish/transect) and was similar between partially fished protected zones (species: 3–8, abundance: 5–30 fish/transect) and non-protected fished areas (species: 4–7, abundance: 10–15 fish/transect). For the top six commercial fish family groups, the abundance of market-sized individuals of five groups differed between all three levels of protection, whereas for non-target sizes only one differed (see paper for individual data). The San Miguel Island Marine Protected Area was designated in 1998 and had two zones with different levels of protection: a 1.0 km2 sanctuary area (no fishing or recreational activity) and a 1.25 km2 partially protected area (traditional fishing - gill net, spear, traps and line - permitted), with an outer 100 m buffer protected zone. The unprotected area was fished with active (e.g. seines) and passive gears. In May 2009 and 2010 and December 2014, fish were surveyed in each of the three zones and the adjacent unprotected open area by underwater visual census along a total of 10 haphazardly placed transects (50 m2) at least 10 m apart. Transects were located at reefs 1.3 km offshore and at depths of 9–21 m.

    (Summarised by: Khatija Alliji)

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