title: Effects of organic enrichment on nematode assemblages in a microcosm experiment.
abstract: Marine nematodes from subtidal tropical sediments of Cienfuegos Bay were subjected to organic enrichment in a microcosm experiment for 32 days. Nematode abundance and diversity decreased, and the taxonomic and trophic structure was altered. The results suggested that the nematodes were not food limited in the microcosms or in their natural environment. Chemical stressors such as ammonia and hydrogen sulfide derived from reduced conditions in sediments may be important factors affecting the assemblages. Hypoxic conditions occurred in all experimental units, as well as in the field, suggesting a nematode assemblage adapted to naturally enriched sediments. However, tolerant species showed a grade of sensitivity to reduced conditions. In agreement with the model by Pearson and Rosenberg (1978), we predict that further organic enrichment in sediments from Cienfuegos Bay may cause a phase shift into a strongly depleted benthic fauna and reduced conditions in water and sediments.
authors.affiliation: Centro de Investigaciones Marinas, Universidad de La Habana, 16 # 114, CP 11300, Playa, Habana, Cuba. maickel@cim.uh.cu
authors.forename: Maickel
authors.initials: M
authors.lastname: Armenteros
authors.forename: José Andrés
authors.initials: JA
authors.lastname: Pérez-García
authors.forename: Alexei
authors.initials: A
authors.lastname: Ruiz-Abierno
authors.forename: Lisbet
authors.initials: L
authors.lastname: Díaz-Asencio
authors.forename: Yusmila
authors.initials: Y
authors.lastname: Helguera
authors.forename: Magda
authors.initials: M
authors.lastname: Vincx
authors.forename: Wilfrida
authors.initials: W
authors.lastname: Decraemer
mesh_terms: D000818:Animals; D044822:Biodiversity; D004784:Environmental Monitoring; D019015:Geologic Sediments / Q000737:chemistry; D009348:Nematoda / Q000145:classification / Q000187:drug effects*; D014873:Water Pollutants / Q000032:analysis / Q000633:toxicity*
chemical_list: D014873:Water Pollutants