The present study demonstrates that using non-identified composites
of trash fish as main feed sources bears the risk of introducing
new, unknown and potentially disease causing as well as
zoonotic parasites into Indonesian grouper mariculture facilities.
Consequently, the natural fish feed opens a new route of parasite
dispersal, causing unpredictable parasite infections. Different
management practices result in different parasite infection patterns
in each of the five sampled mariculture facilities, suggesting
necessary improvements for already existing treatments in order
to prevent parasite spread and disease outbreaks. In combination
with the regular transport of grouper seed and juveniles throughout
the archipelago and the Life Reef Food Fish trade to Hong Kong
and Singapore, mariculture activities can have expansive consequences,
resulting in parasite-borne disease outbreaks not only in
Indonesia, but also in the whole South-East Asian region. The recent
intensification of the grouper production spread this activity
throughout the Indonesian archipelago. However, fish production
in open net cages and the lack of standardized treatment and cultivation
methodologies results in an unpredictable quality range
of the marketed product, which is a constraint for future grouper
producing industries.