Identifying the main sources of silicate in coastal waters of the Southern Gulf of Valencia (Western Mediterranean Sea)

• Autorzy: Sospedra J. , Niencheski L.F.H. , Falco S. , Andrade C.F.F. , Attisano K.K. , Rodilla M.
• Języki publikacji: EN

Abstrakty

EN

Silicon is a major nutrient for siliceous primary producers, which can become a potential limiting nutrient in oligotrophic areas. Most of the silicon inputs to the marine environment come from continental discharges, from both superficial and ground waters. This study analyses the main sources of silicon and their dynamics along the southernmost 43 km of shoreline in the Gulf of Valencia (Western Mediterranean Sea). The salinity and silicate concentration in the different compartments (springs, freshwater wells, beach groundwater, surf zone and coastal waters) in this coastal area were determined. In addition, chlorophyll a and phytoplankton community were analyzed in the surf zone and coastal waters. Silicate concentrations in freshwater wells ranged between 130 and 150 μM, whereas concentrations of this nutrient declined to 49 μM in freshwater–seawater mixture transects. At the same time, there was a positive gradient in silicate for both freshwater and coastal waters southward. An amount of 18.7 t of dissolved silicate was estimated in the nearest first kilometre nearest to the coastline, 6 t of this silicate belonged to the background sea level. On the other hand, the sum of the main rivers in the area supplies 1.6 t of dissolved silicate per day. This implies that a large amount of the remaining 11.1 t must derive from submarine groundwater discharges, which would thus represent 59% of the coastal dissolved silicate budget. Overall, it is suggested that a subterranean transport pathway must contribute considerably to silicate concentrations throughout this zone, which is characterized as permeable.

Słowa kluczowe

EN

silicon; coastal water; Valencia Gulf; Mediterranean Sea; salinity; discharge; nutrient; marine environment

• Wydawca: -
• Czasopismo: Oceanologia
• Rocznik: 2018
• Tom: 60
• Numer: 1
• Opis fizyczny: p.52-64,fig.,ref.

Twórcy

autor

Sospedra J.

• Institut d'Investigacio per a la Gestio Integrada de Zones Costaneres (IGIC), Universitat Politecnica de Valencia, Grau de Gandia 46730, Spain

autor

Niencheski L.F.H.

• Instituto de Oceanografia, Universidade Federal do Rio Grande, Rio Grande, Brazil

autor

Falco S.

• Institut d'Investigacio per a la Gestio Integrada de Zones Costaneres (IGIC), Universitat Politecnica de Valencia, Grau de Gandia, Spain

autor

Andrade C.F.F.

• Instituto de Oceanografia, Universidade Federal do Rio Grande, Rio Grande, Brazil

autor

Attisano K.K.

• Centro CEP, Campus Sao Lourenco do Sul, Universidade Federal do Rio Grande, Sao Lourenco do Sul, Brazil

autor

Rodilla M.

• Institut d'Investigacio per a la Gestio Integrada de Zones Costaneres (IGIC), Universitat Politecnica de Valencia, Grau de Gandia, Spain

Identyfikatory

DOI

10.1016/j.oceano.2017.07.004