Japan Geoscience Union Meeting 2023

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[J] Oral

A (Atmospheric and Hydrospheric Sciences ) » A-CG Complex & General

[A-CG41] Coastal Ecosystems 2. Coral reefs, seagrass and macroalgal beds, and mangroves

Thu. May 25, 2023 1:45 PM - 3:15 PM 102 (International Conference Hall, Makuhari Messe)

convener:Yu Umezawa(Tokyo University of Agriculture and Technology), Tomihiko Higuchi(Atmosphere and Ocean Research Institute, The University of Tokyo), Takashi Nakamura(School of Environment and Society, Tokyo Institute of Technology), Kenta Watanabe(Port and Airport Research Institute), Chairperson:Yu Umezawa(Tokyo University of Agriculture and Technology), Tomihiko Higuchi(Atmosphere and Ocean Research Institute, The University of Tokyo), Takashi Nakamura(School of Environment and Society, Tokyo Institute of Technology), Kenta Watanabe(Port and Airport Research Institute)

2:40 PM - 2:55 PM

[ACG41-04] Reconstruction of ecological history of mangrove fishes using analytical chemistry technique

Kotaro Shirai1, *Tomihiko Higuchi1 (1.Atmosphere and Ocean Research Institute, The University of Tokyo)

Keywords:Mangrove, oxygen isotope, fish otolith

Recent degradation and loss of tropical estuaries due to human impact have made necessary the protection of essential habitats for estuarine fishes. A better understanding of estuarine use patterns contributes greatly to identifying essential habitat conditions. Stable isotope analyses of muscle tissue (d13Cmuscle and d15Nmuscle) and otoliths (d13Cotolith and d18Ootolith) were conducted for mangrove fishes (including coral reef fish as reference of seawater living). Muscle stable isotopes exhibited a spatial change from inshore to offshore habitats associated with growth, possibly related to the reef-ward movement of the fish (Le et al. 2019). Moreover, the salinity histories of 3 species of estuarine mangrove fishes, often dominant in tropical East Asian estuaries, viz. the apogonid Fibramia amboinensis, the pomacentrid Neopomacentrus taeniurus and the terapontid Terapon jarbua, were examined by analyzing their otolith. The d18Ootolith ranges of −5.4 to −2.3‰ for F. amboinensis and −3.7 to −2.3‰ for N. taeniurus corresponded to 6 to 30 psu and 19 to 30 psu, respectively, when compared to the 2 extreme salinity values of the reference fishes. T. jarbua, in contrast, exhibited a d18Ootolith range of −3.0 to −1.8‰, corresponding to 25 to 34 psu (Shirai et al. 2018). We proposed potential of analytical chemistry technique to reconstruct ecological history of mangrove fishes. We will discuss how these technique can be used for coastal and mangrove conservation strategies.
Reference:
Shirai et al. (2018) Reconstruction of the salinity history associated with movements of mangrove fishes using otolith oxygen isotopic analysis. Marine Ecology Progress Series 593, 127-139.
Le et al. (2019) Isotopic evidences of connectivity between the inshore vegetated lagoon as nursery habitat and coastal artificial reefs as adult habitats for the reef fish, Lethrinus lentjan, from East coast of Peninsular, Malaysia. Marine and Freshwater Research 70, 1675-1688.