The impact of religious release fish on conservation

Abstract

In Taiwan, many hatchery-reared fish are released into wild waters for various reasons. Among those released individuals, few are documented by government agencies and academics, with almost no documentation by religious groups. Religious release data is scarce and the influence of released fish on the environment is not fully understood by the government, academics or religious groups. This study aimed to (1) investigate public cognition surrounding the relationship between the religious release of fish and conservation via questionnaire, (2) conduct two batches of mark and recapture studies fish used for religious release and (3) assess the impact of religious release fish on conservation based on the natural marks of recaptured specimens. Beginning in 2015, two batches of prayer black porgy (Acanthopagrus schlegelii), which were marked, released and recaptured were surveyed in cooperation with a Buddhist group. The results for overall respondents surveyed by questionnaire, 45% indicated that they were unsure of the impact of religious release fish on conservation. Based on the values of oxygen stable isotope in the core area of the otoliths discrimination, the hatchery-reared stock is thought to contribute to approximately 61% of the total black porgy population in the northern waters of Taiwan. The length distribution between hatchery-reared stocks and wild stocks was similar, suggesting that the two stocks that survive at sea may not interact with each other. The results of this study can be used as evidence for the impact of a religious release fish on environmental conservation.