title: Effects of intertidal seagrass habitat fragmentation on turbulent diffusion and retention time of solutes.
abstract: An in-depth knowledge of solutes advection and turbulent diffusion is crucial to estimate dispersion area and retention time (t(R)) of pollutants within seagrass habitats. However, there is little knowledge on the influence of seagrass habitat fragmentation on such mechanisms. A set of dye tracer experiments and acoustic Doppler velocimeter measurements (ADV) were conducted. Solute transport conditions were compared in between fragmented (FM) vs homogeneous (HM) intertidal meadows, and in vertical gradients (canopy vs overlaying flow). Results showed the highest horizontal diffusion coefficient (K(y), c.a. 10(-3)m(2)s(-1)) on FM and at the canopy-water column interface, whereas t(R) (2.6-5.6 min) was not affected by fragmentation. It suggests that (1) FM are more vulnerable to pollution events in terms of dispersion area and (2) at low tide, advection rather than turbulent diffusion determines t(R). Furthermore, Taylor's theorem is revealed as a powerful tool to analyze vertical gradients on K(y) within seagrass canopies.
authors.affiliation: Department of Biology, Faculty of Marine and Environmental Sciences, University of Cadiz, Campus of International Excellence, CEIMAR, 11510 Puerto Real, Cadiz, Spain. miguel.lararayo@uca.es
authors.forename: M
authors.initials: M
authors.lastname: Lara
authors.forename: G
authors.initials: G
authors.lastname: Peralta
authors.forename: J J
authors.initials: JJ
authors.lastname: Alonso
authors.forename: E P
authors.initials: EP
authors.lastname: Morris
authors.forename: V
authors.initials: V
authors.lastname: González-Ortiz
authors.forename: J J
authors.initials: JJ
authors.lastname: Rueda-Márquez
authors.forename: J L
authors.initials: JL
authors.lastname: Pérez-Lloréns
mesh_terms: D017753:Ecosystem; D004784:Environmental Monitoring; D019015:Geologic Sediments / Q000032:analysis; D008956:Models, Chemical; D014872:Water Movements; D014873:Water Pollutants / Q000032:analysis*; D014876:Water Pollution / Q000706:statistics & numerical data; D035962:Zosteraceae
chemical_list: D014873:Water Pollutants