Japan Geoscience Union Meeting 2022

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[J] Oral

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

[A-CG42] Coastal Ecosystems - 1. Water Cycle and Land-Ocean Interactions

Fri. May 27, 2022 10:45 AM - 12:15 PM 104 (International Conference Hall, Makuhari Messe)

convener:Ryo Sugimoto(Faculty of Marine Biosciences, Fukui Prefectural University), convener:Makoto Yamada(Faculty of Economics, Ryukoku University), Masahiko Fujii(Faculty of Environmental Earth Science), convener:Tomohiro Komorita(Faculty of Environmental and Symbiotic Sciences, Prefectural University of Kumamoto), Chairperson:Ryo Sugimoto(Faculty of Marine Biosciences, Fukui Prefectural University), Tomohiro Komorita(Faculty of Environmental and Symbiotic Sciences, Prefectural University of Kumamoto), Makoto Yamada(Faculty of Economics, Ryukoku University)

11:30 AM - 11:45 AM

[ACG42-09] Dense occurrence of invertebrate burrows in the nearshore zone of sandy beaches: effect of benthic filtering on seafloor ecosystems

*Koji Seike1,2, Kotaro Komori1,2, Toru Tamura1,2 (1.Geological Survey of Japan, National Institute of Advanced Industrial Science and Technology (AIST), 2.Department of Natural Environmental Studies, Graduate School of Frontier Sciences, The University of Tokyo)

Keywords:benthos, filtering, sandy beach

Sandy beach is the commonest environment type in coastal settings facing the open ocean and comprises ~30% of the ice free coastlines worldwide. However, interactions between benthic organisms and the seafloor environment are less well understood for sandy beach ecosystems. In particular, organism-environment interactions in the nearshore zone (water depths of <30 m and 2-3 km offshore from the coastline, sensu Short, 1999) remain poorly understood. Recently, Seike et al. (2020) revealed that the effect of benthic filtering by the suspension feeding shrimp Austinogebia narutensis (Decapoda: Upogebiidae) on the abundance of primary producers (chlorophyll a concentration) in the water column along the Kashimanada coast, central Japan, facing the northwestern Pacific Ocean. Suspension feeding of the shrimp reduces the abundance of primary producers in the bottom water. Here, we report a similar phenomenon from the nearshore zone of the Kujukuri coast, central Japan. Burrows of a filter feeding upogebiid shrimp occurred densely in the sea bottom where chlorophyll a concentration was remarkably low. We concluded that the filtering effect of the shrimp has a profound impact on coastal marine ecosystems, and may have occurred in nearshore settings since the Mesozoic.


References

Seike, K., Banno, M., Watanabe, K., Kuwae, T., Arai, M., & Sato, H. (2020). Benthic filtering reduces the abundance of primary producers in the bottom water of an open sandy beach system (Kashimanada coast, Japan). Geophysical Research Letters, 47(1), e2019GL085338.
Short, A. D. (1999). Handbook of beach and shoreface morphodynamics. Chichester, UK: Wiley.