title: Patterns in nematode community during and after experimentally induced anoxia in the northern Adriatic Sea.
abstract: The effect of short and long-term induced anoxia on a benthic nematode community and its potential for recovery after reoxygenation were investigated in an in situ experiment on a silty-sand bottom in the Gulf of Trieste, the northern Adriatic Sea. Anoxia was created artificially by three underwater benthic Plexiglas chambers at a depth of 24 m. Treatments lasted for 2, 23 and 307 days. Control samples (Normoxia) were taken on 3 (Normoxia 1) and 25 (Normoxia 2) August 2010 outside the chambers (4-5 m further). After opening the chambers, recovery cores were taken after 7 days (Anoxia 2D), 30 days (Anoxia 23D) and 90 days (Anoxia 307D). Our results revealed that short-term anoxia (Anoxia 2D) did not affect nematode total density and diversity, community structure and their vertical distribution in the sediment. However, total and vertical nematode density, species richness and diversity decreased at 23 days and decreased further at 307 days anoxia. Some nematode species like Metalinhomoeus effilatus, Paralinhomoeus caxinus and Terschellingia longicaudata even survived at 307 days anoxia treatment. Our results also demonstrated that nematode community exposed to 23 days anoxia did not recover after 30 days sediment reoxygenation but, a full recovery was observed after 90 days for nematode community exposed to 307 days anoxia. Feeding type contribution (functional aspect) of the nematode community also changed at the anoxia treatments and during the recovery process. This change was most drastic at the Anoxia 23D and 307D treatments. At both Normoxia and Anoxia 2D treatments, selective deposit feeders (1A), non-selective deposit feeders (1B) and epistrate (diatom) feeders (2A) nematodes were observed in the dominant nematode community. Epistrate feeders disappeared from in the Anoxia 23D treatment epistrate and also selective deposit feeders did not belong to the dominant nematode species in the Anoxia 307D treatment. After the recovery process, epistrate feeders and selective deposit feeding nematodes reappeared again amongst the dominant nematode species after 30 and 90 days of recovery, respectively.
authors: Ghent University, Biology Department, Marine Biology Research Group, Krijgslaan 281, S8, 9000 Ghent, Belgium; Iranian National Institute for Oceanography and Atmospheric Science (INIOAS), 9, Etemadzadeh Avenue, West Fatemi Street, Tehran, Iran. Electronic address: Mehrshad.Taheri@ugent.be.
authors: Mehrshad
authors: M
authors: Taheri
authors: Marine Biology Station Piran, National Institute of Biology, Fornace 41, 6330 Piran, Slovenia.
authors: Mateja
authors: M
authors: Grego
authors: Department of Limnology and Oceanography, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria; UMR CNRS 6112 LPG-BIAF Bio-Indicateurs Actuels et Fossiles, Université d'Angers, 2 Boulevard Lavoisier, 49045 Cedex Angers, France.
authors: Bettina
authors: B
authors: Riedel
authors: Ghent University, Biology Department, Marine Biology Research Group, Krijgslaan 281, S8, 9000 Ghent, Belgium.
authors: Magda
authors: M
authors: Vincx
authors: Ghent University, Biology Department, Marine Biology Research Group, Krijgslaan 281, S8, 9000 Ghent, Belgium.
authors: Jan
authors: J
authors: Vanaverbeke
mesh_terms: D000693:Anaerobiosis; D000818:Animals; D044822:Biodiversity; D019015:Geologic Sediments / Q000737:chemistry*; D009348:Nematoda / Q000502:physiology*; D011156:Population Density; D017524:Slovenia; D013997:Time Factors
keywords: Adriatic Sea; Anoxia; Community structure; Gulf of Trieste; Marine nematodes; Recovery