Economic losses and damages in aquaculture production caused by extreme weather events: an empirical assessment at the household scale in Quang Ngai province, Vietnam

Annual extreme weather events (EWEs) significantly threaten the coastal aquaculture sector in Quang Ngai (QN) province in Vietnam. A survey was conducted on 91 participants to assess the extent of losses and damages (LDs) caused by EWEs to coastal aquaculture production at the household level. The data were processed and analyzed through descriptive statistics using the open source RTool (R version 4.4.0) and market price methods to compare LDs at different production forms (estuaries, sand, and lagoons), scales (small, medium, and large), and EWEs. Three-way ANOVA was employed to assess the contribution of factors on the LDs. Our survey indicated that the small-scale production in the lowlands (estuaries and lagoons) and the medium- and large-scale households (HHs) farming on the sand were greatly affected by EWEs. Due to floods and typhoons, lowlands lost about 8-9% of income and 10-20% of initial investment. For farming on the sand, our study found that heat waves and extreme rainfall caused a loss of about 12% and 9%, respectively, compared to profit and initial investment. This study also showed that the type and size of farms and the interaction between the type of EWEs and the aquaculture form and production scales contributed significantly to the loss of coastal aquaculture HHs in QN province. The results and findings of the study herein described are meant to develop mitigation and adaptation strategies at the household and local fisheries sector levels in QN province.