Species richness and abundance of non-cryptic fish species in the Philippines: a global center of reef fish diversity

Abstract

The Philippines is dubbed the ‘global center of marine biodiversity’ for having the greatest number of reef fish species per unit area in the world, mainly based on analysis of museum collections. However, to date, there is no national assessment of the status of Philippine reef fish species based on species abundance and distribution. We conducted underwater visual census belt transect surveys of all non-cryptic reef fish, to explore spatial trends in fish biodiversity and to assess the national status of Philippine reef fish species. We found that most places in the Philippines still hold high numbers of non-cryptic reef fish species, with 54 % of the surveyed transects having ≥22 reef fish species per 100 m2. However, only 13 % of all recorded species had high abundances (≥0.81 individuals per 100 m2) and wide distributions (≥291,964 km2) (category A species), while 33 % had either low abundances or restricted distributions (category B species), and 54 % exhibited both low abundances and restricted distributions (category C species). In addition, 97 % of the large-bodied species (maximum TL > 30.1 cm) were assigned to category B or C—a matter of concern, since 47 % of the recorded large-bodied species in our study are food-fish. The findings of our study present the most recent (2012–2013) national assessment for all non-cryptic reef fish species using standardized methods, and highlight the need for conservation action for many Philippine reef fish species, upon which many Filipinos derive benefits such as food, income, livelihood, and recreation.