The threshold value of BPI for a healthy benthic faunal community and its application to Jinhae Bay in the southern coast of Korea

Abstract

For the determination of benthic community health criteria of BPI, macrobenthic fauna were investigated in a reference area, Deukryang Bay designated as a fisheries protection area of South Korea in 2012. The macrobenthos were classified into 4 functional groups according to their feeding and life history strategies, and the BPI was calculated using the abundance data of these functional groups. Amphipods belonging to Group II were dominant species in Deukryang Bay at all seasons, the mean value of BPI in this reference area, which was assumed as the threshold value for healthy communities, was fluctuated seasonally form 55 to 61. The overall mean value of the BPI in the reference area was estimated as 60. We proposed an assessment tool for a macrofaunal community health using BPI by categorizing the BPI values into 5 grades, each indicating the healthy status of macrobenthic community. The macrobenthic community will be Excellent (Grade 1), if the BPI value is more than 60, and Good (Grade 2), if between 40 and 60, Fair (Grade 3), if between 30 and 40, Poor (Grade 4), if between 20 and 30, and Very Poor (Grade 5), if the BPI value is less than 20. This assessment tool was applied to macrobenthic communities in Jinhae Bay including the Special Management Area of South Korea. In Jinhae Bay, the functional group IV containing a spionid species, Paraprionospio patiens was the most dominant group. Theto 4 functional groups according to their feeding and life history strategies, and the BPI was calculated using the abundance data of these functional groups. Amphipods belonging to Group II were dominant species in Deukryang Bay at all seasons, the mean value of BPI in this reference area, which was assumed as the threshold value for healthy communities, was fluctuated seasonally form 55 to 61. The overall mean value of the BPI in the reference area was estimated as 60. We proposed an assessment tool for a macrofaunal community health using BPI by categorizing the BPI values into 5 grades, each indicating the healthy status of macrobenthic community. The macrobenthic community will be Excellent (Grade 1), if the BPI value is more than 60, and Good (Grade 2), if between 40 and 60, Fair (Grade 3), if between 30 and 40, Poor (Grade 4), if between 20 and 30, and Very Poor (Grade 5), if the BPI value is less than 20. This assessment tool was applied to macrobenthic communities in Jinhae Bay including the Special Management Area of South Korea. In Jinhae Bay, the functional group IV containing a spionid species, Paraprionospio patiens was the most dominant group. The