title: Foraminiferal biotopes and their distribution control in Ria de Aveiro (Portugal): a multiproxy approach.
abstract: Ria de Aveiro, which is located in the centre of Portugal (40° 38' N, 8° 45' W), is a well-mixed and complex coastal lagoon that is separated from the sea by a sandy barrier and connects with the Atlantic through an artificial inlet. Tidal currents are the main factor controlling the lagoon's hydrodynamics and, to a great extent, the sedimentary dynamic. The inner lagoonal zones receive input from several rivers and experience the pressure caused by the accumulation of organic matter and pollutants (namely, trace metals) from diverse anthropic activities. This paper is the first piece of work aiming to recognize, characterize and explain the main benthic foraminiferal biotopes in Ria de Aveiro. To provide a broad overview of this kind of setting, our results are compared to those of previous published studies conducted in similar transitional environments. The research is based on an investigation of 225 sites spread throughout this ecosystem. Utilizing a statistical approach, this study analyses the details of dead benthic foraminiferal assemblages composed of 260 taxa, the texture and composition (mineralogical and geochemical) of the sediment and physicochemical data. On the basis of the results of R-mode and Q-mode cluster analyses, several different biotopes can be defined as marsh biotope/near-marsh biotope; marginal urban/marginal urban mixing biotope; inner-outer lagoon biotope or enclosed lagoon; outer lagoon biotope, mixed sub-biotope; and outer lagoon, marine sub-biotope. These biotopes are related to foraminifera assemblages and substrate type and are influenced by local currents, water depth, chemical and physicochemical conditions, river or oceanic proximity, and anthropogenic impact, as evidenced by the mapping of the six factor loadings of the principal component analysis conducted herein. Based on a similar methodology of analysis as that applied in previous studies in the Lagoon of Venice, comparable biotypes were identified in Lagoon of Aveiro.
authors.affiliation: Faculdade de Geologia, Departamento de Estratigrafia e Paleontologia, Universidade do Estado do Rio de Janeiro, Av. São Francisco Xavier, 524, sala 4037 F, Maracanã, 20550-013, Rio de Janeiro, RJ, Brasil, virginia.martins@ua.pt.
authors.forename: Maria Virgínia Alves
authors.initials: MV
authors.lastname: Martins
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Frontalini
authors.forename: Lazaro L M
authors.initials: LL
authors.lastname: Laut
authors.forename: Frederico S
authors.initials: FS
authors.lastname: Silva
authors.forename: João
authors.initials: J
authors.lastname: Moreno
authors.forename: Silvia
authors.initials: S
authors.lastname: Sousa
authors.forename: Noureddine
authors.initials: N
authors.lastname: Zaaboub
authors.forename: Monia
authors.initials: M
authors.lastname: El Bour
authors.forename: Fernando
authors.initials: F
authors.lastname: Rocha
mesh_terms: D017753:Ecosystem; D004777:Environment; D004784:Environmental Monitoring; D056908:Foraminifera / Q000145:classification* / Q000254:growth & development; D019015:Geologic Sediments / Q000737:chemistry; D009792:Oceans and Seas; D011174:Portugal; D045483:Rivers / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis; D053833:Wetlands
chemical_list: D014874:Water Pollutants, Chemical