title: Intertidal nematode communities in the Mekong estuaries of Vietnam and their potential for biomonitoring.
abstract: Nematode communities in eight Mekong estuaries were investigated during the dry season. The aim of the study was to identify the structure and the diversity of the communities in relation to the main environmental characteristics. In each estuary, three to four intertidal sampling stations were identified at regular distances from the mouth to up to 45 km land inward. The nematode communities showed a strong correlation with sediment composition and to a lesser degree with chlorophyll a concentrations. Multivariate analysis resulted in the identification of four types of communities. We identified two types of Desmodora communities in the sandy mouth stations and two types of Parodontophora communities in the silty sand stations. One of the silt associated communities showed a preference for higher chlorophyll a concentrations, resulting in higher densities and higher diversity, mainly of monhysterid species. Because of the strong association between community structure and sediment composition, nematodes are a meaningful tool for monitoring changes in their environment. In case their community deviates from what is expected based on sediment, it may serve as an early warning for disturbance.
authors.affiliation: Division of Environmental Quality, Atmospheric Science and Climate Change & Faculty of Environment and Labour Safety, Ton Duc Thang University, Ho Chi Minh City, Vietnam. ngoxuanquang@tdt.edu.vn.|Department of Environmental Management and Technology, Institute of Tropical Biology, Vietnam Academy of Science and Technology, 85, Tran Quoc Toan, Dist.3, Ho Chi Minh City, Vietnam. ngoxuanquang@tdt.edu.vn.
authors.forename: Ngo Xuan
authors.initials: NX
authors.lastname: Quang
authors.affiliation: Department of Nematology, Institute of Ecology and Biological Resources, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet, Cau Giay, Hanoi, Vietnam.
authors.forename: Nguyen Ngoc
authors.initials: NN
authors.lastname: Chau
authors.affiliation: Postgraduate International Nematology Course, Biology Department, Ghent University, Ledeganckstraat 35, B-9000, Ghent, Belgium.
authors.forename: Nic
authors.initials: N
authors.lastname: Smol
authors.affiliation: Institute of Biology and Soil Science (IBSS) FEB RAS, Vladivostok, Russia.
authors.forename: Larisa
authors.initials: L
authors.lastname: Prozorova
authors.affiliation: Marine Biology Research Group, Biology Department, Ghent University, Krijgslaan 281, S8, B-9000, Ghent, Belgium.
authors.forename: Ann
authors.initials: A
authors.lastname: Vanreusel
mesh_terms: D000818:Animals; D002734:Chlorophyll; D000077194:Chlorophyll A; D004777:Environment; D004784:Environmental Monitoring / Q000379:methods*; D063366:Estuaries; D019015:Geologic Sediments / Q000737:chemistry; D009348:Nematoda / Q000502:physiology*; D012621:Seasons; D014744:Vietnam
chemical_list: D002734:Chlorophyll; D000077194:Chlorophyll A
keywords: Biomonitoring; Desmodora; Environment; Mekong estuary; Nematode communities; Paradontophora