Zoological Studies

Vol. 55, 2016

(update: 2016.5.31)

Larval Fish Assemblages and Hydrographic Characteristics in the Coastal Waters of Southwestern Taiwan during Non- and Post-typhoon Summers

Hung-Yen Hsieh1,2, Wen-Tseng Lo3, Hsiao-Hao Chen3, and Pei-Jie Meng1,2,*

1Graduate Institute of Marine Biology, National Dong Hwa University, Pingtung 94450, Taiwan
2National Museum of Marine Biology and Aquarium, Pingtung 94450, Taiwan
3Institute of Marine Biotechnology and Resources, National Sun Yat-sen University, Kaohsiung 80424, Taiwan

(Received 9 March 2015; Accepted 1 January 2016)

Hung-Yen Hsieh, Wen-Tseng Lo, Hsiao-Hao Chen, and Pei-Jie Meng (2016) Although research on the larval fish assemblages in the Taiwan Strait has progressively developed in the last two decades, it is difficult to study typhoons’ impacts on larval fish assemblages due to (1) the occurrence and path of a cyclone cannot be predicted accurately and (2) the severe weather condition makes shipboard measurements extremely difficult. Larval fish and zooplankton were sampled and hydrographic variables and chlorophyll a were measured in the waters of southwestern Taiwan during September 2009 (non-typhoon) and September 2012 (post-typhoon Tembin). Data from these collections were used to elucidate the effects of hydrographic dynamics after the typhoon event on species assemblage and abundance. The results showed that after the typhoon Tembin, the surface temperature and salinity decreased slightly, but the values of the measured chemical and biological parameters were much greater than those derived from the non-typhoon period due to enriched nutrients from entrainment of river runoff of the Kaoping River. Meanwhile, the abundance of larval fish also increased significantly, but the species composition became less diverse. Multivariate statistical analyses revealed two distinct larval fish assemblages that were closely correlated to sampling cruise. The dominant taxa of larval fish changed from Encrasicholina heteroloba, Nuchequula nuchalis, unidentified Sparidae, Equulites rivulatus, and Cyclothone spp. during the non-typhoon period to Engraulis japonicus, unidentified Engraulidae, Sillago sihama, Pennahia argentata, and E. rivulatus during the post-typhoon period. Canonical correspondence analysis revealed that, in the waters of southwestern Taiwan, the horizontal distribution of larval fish in late summer may be explained by the food availability. The magnitude of the enhancement of measured variables changed with sampling periods, suggesting the study area was at an unsteady status after the passage of the typhoon Tembin. The coastal ecosystem became more productive after the typhoon event.

Key words: Community structure; Engraulidae; Impact of typhoon Tembin; Taiwan Strait; Horizontal distribution.

Correspondence: Pei-Jie Meng contributed equally with Hung-Yen Hsieh to this work. E-mail: pjmeng@nmmba.gov.tw; hyhsieh@mail.ndhu.edu.tw

Vol. 55, 2016