Skip to main content

Monitoring estuaries using non-permanent stations: practical aspects and data examples

Abstract

This paper deals with the performances of non-permanent environmental monitoring stations when recording at high-sampling interval (hour) over a long term (months, years) within estuarine waters. Information about data quality and system maintenance requirements are provided based on the experience gained with an autonomous station deployed during 2 years at the Guadiana Estuary (southern Portugal–Spain border). The station includes (1) a multi-parameter probe for water quality (temperature, conductivity, dissolved oxygen, turbidity, chlorophyll and pH) inserted in a tube through a surface-floating buoy; and, (2) a bottom-mounted current meter. The main issues for the continuous acquisition of valid data were biofouling on the optical (chlorophyll, turbidity, dissolved oxygen), conductivity sensors of the probe and high sediment dynamics at the bed. The definition of a detailed maintenance programme is required for the lengthening of (valid) data time series. The typical variability of the parameters is described at seasonal and tidal time scales and episodic events are identified (coastal upwelling and high freshwater inputs). These examples illustrate how integrated data analysis is fundamental to define and understand the changes induced by specific events on several interrelated parameters, and, more generally, how these systems can contribute to a better understanding of the hydro-ecological processes operating in estuaries.

This is a preview of subscription content, access via your institution.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9
Fig. 10
Fig. 11

References

  1. Bakun A (1973) Coastal upwelling indices, west coast of North America, 1946–71. NOAA Technical Report. US Dept of Commerce, Seattle

    Google Scholar 

  2. Bergquist D, Heuberger D, Sturmer L, Baker S (2009) Continuous water quality monitoring for the hard clam industry in Florida, USA. Environ Monit Assess 148(1):409–419

    Article  Google Scholar 

  3. Chapin T, Caffrey J, Jannasch H, Coletti L, Haskins J, Johnson K (2004) Nitrate sources and sinks in Elkhorn Slough, California: results from long-term continuous in situ nitrate analyzers. Estuaries 27(5):882–894

    Article  Google Scholar 

  4. Chícharo L, Chícharo MA, Ben-Hamadou R (2006) Use of a hydrotechnical infrastructure (Alqueva Dam) to regulate planktonic assemblages in the Guadiana estuary: basis for sustainable water and ecosystem services management. Estuar Coast Shelf Sci 70(1–2):3–18

    Article  Google Scholar 

  5. Colbert D, McManus J (2003) Nutrient biogeochemistry in an upwelling-influenced estuary of the Pacific northwest (Tillamook Bay, Oregon, USA). Estuaries Coasts 26(5):1205–1219. doi:10.1007/bf02803625

    Article  Google Scholar 

  6. Devlin M, Best M, Haynes D (2007) Implementation of the water framework directive in European marine waters. Mar Pollut Bull 55:1–29

    Article  Google Scholar 

  7. Dias JMA, Gonzalez R, Ferreira O (2004) Natural versus anthropic causes in variations of sand export from river basins: an example from the Guadiana river mouth (southwestern Iberia). In: Nawrocki J (ed) Rapid transgression into semi-enclosed basins, Gdansk, 8–10 May 2003. Polish Geological Institute Special Papers, pp 95–102

  8. Dronkers J (1986) Tidal asymmetry and estuarine morphology. Neth J Sea Res 20(2–3):117–131

    Article  Google Scholar 

  9. Dworak T, Gonzalez C, Laaser C, Interwies E (2005) The need for new monitoring tools to implement the WFD. Environ Sci Policy 8(3):301–306

    Article  Google Scholar 

  10. Garel E, Pinto L, Santos A, Ferreira Ó (2009a) Tidal and river discharge forcing upon water and sediment circulation at a rock-bound estuary (Guadiana estuary, Portugal). Estuar Coast Shelf Sci 84(2):269–281

    Article  Google Scholar 

  11. Garel E, Nunes S, Neto JM, Fernandes R, Neves R, Marques JC, Ferreira Ó (2009b) The autonomous Simpatico system for real-time continuous water-quality and current velocity monitoring: examples of application in three Portuguese estuaries. Geo Mar Lett 29:331–341. doi:10.1007/s00367-009-0147-5

    Article  Google Scholar 

  12. Glasgow HB, Burkholder JM, Reed RE, Lewitus AJ, Kleinman JE (2004) Real-time remote monitoring of water quality: a review of current applications, and advancements in sensor, telemetry, and computer technologies. J Exp Mar Biol Ecol 300:409–448

    Article  Google Scholar 

  13. Hattermann F, Wattenbach M, Krysanova V, Wechsung F (2005) Runoff simulations on the macroscale with the ecohydrological model SWIM in the Elbe catchment—validation and uncertainty analysis. Hydrol Process 19:693–714

    Article  Google Scholar 

  14. Hosegood P, van Haren H (2003) Ekman-induced turbulence over the continental slope in the Faeroe-Shetland Channel as inferred from spikes in current meter observations. Deep Sea Research I 50:657–680

    Article  Google Scholar 

  15. Huang W (2010) Hydrodynamic modeling and ecohydrological analysis of river inflow effects on Apalachicola Bay, Florida, USA. Estuar Coast Shelf Sci 86(3):526–534. doi:10.1016/j.ecss.2009.07.032

    Article  Google Scholar 

  16. Instituto Hidrografico (1990) Roteiro da Costa de Portugal, 2nd edn. Instituto Hidrografico, Lisboa

    Google Scholar 

  17. Lobo J, Plaza F, Gonzáles R, Dias J, Kapsimalis V, Mendes I, Rio VDd (2004) Estimations of bedload sediment transport in the Guadiana Estuary (SW Iberian Peninsula) during low river discharge periods. J Coast Res 41:12–26, Special Issue

    Google Scholar 

  18. Loureiro S, Newton A, Icely JD (2005) Microplankton composition, production and upwelling dynamics in Sagres (SW Portugal) during the summer of 2001. Sci Mar 69(3):323–341

    Article  Google Scholar 

  19. Morales JA, Delgado I, Gutierrez-Mas JM (2006) Sedimentary characterization of bed types along the Guadiana estuary (SW Europe) before the construction of the Alqueva dam. Estuar Coast Shelf Sci 70(1–2):117–131

    Article  Google Scholar 

  20. Onishi H, Otobe H (2006) Comparison of the currents measured by electromagnetic current meter and bottom mounted ADCP in Otsuchi bay. Coast Mar Sci 30(2):436–459

    Google Scholar 

  21. Pawlowicz R, Beardsley B, Lentz S (2002) Classical tidal harmonic analysis including error estimates in MATLAB using T_TIDE. Comput Geosci 28(8):929–937. doi:10.1016/s0098-3004(02)00013-4

    Article  Google Scholar 

  22. Relvas P, Barton E, Dubert J (2007) Physical oceanography of the western Iberia ecosystem: latest views and challenges. Prog Oceanogr 74(2–3):149–173

    Article  Google Scholar 

  23. Reuter R, Badewien TH, Bartholomä A, Braun A, Lübben A, Rullkötter J (2009) A hydrographic time series station in the Wadden Sea (southern North Sea). Ocean Dyn 59(2):195–211

    Article  Google Scholar 

  24. Rosón G, Pérez FF, Alvarez-Salgado XA, Figueiras FG (1995) Variation of both thermohaline and chemical properties in an estuarine upwelling ecosystem: Ria de Arousa; I. Time evolution. Estuar Coast Shelf Sci 41(2):195–213. doi:10.1006/ecss.1995.0061

    Article  Google Scholar 

  25. Silva AJd, Lino S, Santos AI, Oliveira (2003) A near bottom sediment dynamics in the Guadiana Estuary. In: Thalassas (ed) 4th Symposium on the Iberian Atlantic Margin. pp 180–182

  26. Torres R, Allen JI, Figueiras FG (2006) Sequential data assimilation in an upwelling influenced estuary. J Mar Syst 60(3–4):317–329. doi:10.1016/j.jmarsys.2006.02.001

    Article  Google Scholar 

  27. Trigo RM, Pozo-Vásquez D, Osborn TJ, Castro-Díez Y, Gámiz-Fortis S, Esteban-Parra MJ (2004) North Atlantic oscillation influence on precipitation, river flow and water ressources in the Iberian Peninsula. Int J Climatol 24:925–944

    Article  Google Scholar 

  28. Varney M (2000) Chemical sensors in oceanography, vol 1. Ocean science and technology. S. Gordon and Breach Science Publishers, Amsterdam

    Google Scholar 

  29. Warner RM (1998) Spectral analysis of time-series data. Guilford Press, New York, p 225

    Google Scholar 

  30. Wong K-C, Dzwonkowski B, Ullman WJ (2009) Temporal and spatial variability of sea level and volume flux in the Murderkill Estuary. Estuar Coast Shelf Sci 84(4):440–446

    Article  Google Scholar 

  31. Yamamoto T, Hatta G (2004) Pulsed nutrient supply as a factor inducing phytoplankton diversity. Ecol Modell 171:247–270

    Article  Google Scholar 

Download references

Acknowledgements

The authors are grateful to the Portuguese Hydrographic Institute for providing the offshore buoy data, to Instituto da Água for the freshwater discharge data and to Faro Airport Meteorological Station for the wind data. The SIMPATICO system was acquired through an FCT grant for the re-equipment of scientific institutions (Reeq/484/MAR/2005).

Author information

Affiliations

Authors

Corresponding author

Correspondence to Erwan Garel.

Additional information

This article is part of the Topical Collection on Multiparametric observation and analysis of the Sea

Responsible Editor: Pierre-Marie Poulain

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Garel, E., Ferreira, Ó. Monitoring estuaries using non-permanent stations: practical aspects and data examples. Ocean Dynamics 61, 891–902 (2011). https://doi.org/10.1007/s10236-011-0417-4

Download citation

Keywords

  • Biofouling
  • Environmental module
  • Multi-parametric probe
  • Coastal upwelling
  • Freshwater discharge