Trophic importance of benthic microalgae to macrozoobenthos in coastal bay systems in Korea:dual stable C and N isotope analyses

• Published in: Marine Ecology Progress Series
• Main Authors: Kang, CK, Kim, JB, Lee, KS, Lee, PY, Hong, JS
• Other Authors: 해양대학원, 10098613
• Format: Article in Journal/Newspaper
• Language: English
• Published: Inter-research 2003
• Subjects: stable isotope ratios; food webs; benthic microalgae; tidal flat; macrozoobenthos; Korean coast; ESTUARINE FOOD WEBS; SALT-MARSH; ORGANIC-MATTER; CARBON-ISOTOPE; MARENNES-OLERON; EMS ESTUARY; SPARTINA-ALTERNIFLORA; RELATIVE IMPORTANCE; DELTA-C-13 EVIDENCE; TIDAL RESUSPENSION; FOOD-WEB STRUCTURE; NITROGEN ISOTOPES; CRASSOSTREA-GIGAS; BROWN SHRIMP; Crassostrea gigas
• Online Access: https://oasis.postech.ac.kr/handle/2014.oak/25111; https://doi.org/10.3354/meps259079

The role of benthic microalgae as the source of primary organic matter for the macrozoobenthos community was examined in 3 bay systems of the south coast of the Korean peninsula using stable carbon and nitrogen isotope ratios (delta(13)C and delta(15)N) as a dual tracer. The delta(13)C and delta(15)N of riverine particulate inputs, primary producers and macrozoobenthos collected from the intertidal and subtidal habitats of the bays were measured and compared with those from adjacent offshore waters. Extensive intertidal flats occurred with wide marsh plains (primarily Phragmites australis) at the uppermost part of the intertidal zone in all 3 bay systems, but different hydrologic features were exhibited among bay systems. There were no systematic variations in delta(13)C for the same plant taxa, but different producer groups were clearly separated by their delta(13)C values. Benthic microalgae and macroalgae, which had similar delta(13)C values, were separated by their delta(15)N values. The VC values of macrozoobenthos collected from the offshore areas were similar to those of phytoplankton. Macrorzoobenthos collected from all 3 bay habitats had simila delta(13)C ranges, and their delta(13)C values (means of all consumers, feeding types and species) were less negative than those of the offshore macrozoobenthos. Isotopic linkage between sources and benthic consumers, based on the documented trophic fractionation for C and N, indicated that benthic microalgae and phytoplankton are the major sources of organic matter supporting macrobenthic consumers in the bay systems. A 2-source mixing model revealed that pelagic feeders in both the intertidal and subtidal habitats subsisted in equal shares on marine phytoplankton and benthic microalgae, whereas the food source of benthic feeders was derived predominantly from benthic microalgae. Phragmites or riverine particulate inputs appeared to have made little contribution to the diets of consumers in the bay systems. Our collective isotopic data set suggested that benthic ...