This thematic program focuses on the state, dynamics and health of the aquatic ecosystems of the Doñana Protected Areas. These include rivers, channels, and tributary streams; permanent and temporary lagoons; as well as brackish and salt marshes. Includes the following monitoring topics:
3.1. Hydrodynamics: in the Doñana Protected Areas are found a wide diversity of aquatic ecosystems, which differ widely in their characteristics and seasonality. Also, most of the inflows and outflows are not measured. Monitoring the basic hydrodynamics of Doñana requires an extensive effort, which aim to provide basic data from the representative sites of all these ecosystems.
These data include:
3.1.1 Flood levels: the monitoring of hydrodynamics in the Doñana National Park has historically been based on the reading of 44 limnimetric scales located mainly in the marsh and, since 2005, also on the records of 6 automatic limnimeters that acquire data every 10 minutes. View a summary of data.
3.1.2. Hydroperiod of marshes: the hydroperiod estimates are made from Landsat images, available since 1974, and are based on a Digital Elevation Model developed with LIDAR data taken in 2002 for the entire surface of the Doñana marshes. See methodology and a summary of the data.
Both flooding and hydroperiod in Doñana marshes are estimated periodically (at least once a year) by remote sensing, through a cooperation between ICTS-RBD and the GIS and Remote Sensing Laboratory (LAST-EBD).
3.2. Aquatic biota: to cover the wide biological and environmental diversity of Doñana's aquatic ecosystems, the Monitoring Program uses a combination of taxa-specific sampling. These surveys coincide at least once a year both temporally (in spring, coinciding with maximum abundance and diversity levels for most taxa) and spatially (around 20 sites are sampled for all taxa). However, each sampling includes additional locations and/or events, to cover the specific requirements of each ta xon.
These samplings include:
3.2.1. Macroinvertebrates: the monitoring of aquatic macroinvertebrates populations began in the hydrological year 2003-2004. Initially, three annual campaigns were carried out during the flooding period of the marshes and lagoons (between October and June), which were later reduced to two campaigns, one autumn-winter (between October and March) and another spring (between April and June). From the year 2016-2017, the interanual evolution of the macroinvertebrates is analyzed exclusively with the spring campaign. See protocols (macroinvertebrates in water pipes and aquatic macroinvertebrates). See data summary.
3.2.2. Fish: monitoring fish populations, in the same way as for aquatic macroinvertebrates, began in 2003 (see section 3.2.1 Macroinvertebrates). From 2016-2017, the winter campaign has also been suspended and only a summer campaign has also been carried out in September to discover the ichthyofauna refuges during the most unfavorable season. In addition, monitoring in water pipes that connect the marsh with the estuary has also been incorporated. See protocol, and a summary of the data.
3.2.3. Amphibians: in Doñana exist an important and diverse community of amphibians, associated with the large network of ponds and temporary lagoons and the extensive seasonal marshland of fresh and brackish waters. The community is composed on 11 species, eight anurans and three urodeles, of which six are Iberian endemisms, such as the Iberian midwife toad (Alytes cisternasii). Monitoring amphibian community began in 2003, and has two annual samplings, one in autumn-winter (October-February) and another in spring (April-May). Individuals are detected with visual surveys, listening, water scrounge or shrimp traps, depending on the species and the aquatic environment in which they are found. Currently, the sampling includes seven sites in the marsh, 16 in lagoons/ponds in the sands, and one in an inlet channel. Observations are used to estimate site occupancy and local abundance by species. See protocol and summary of data.
3.2.4. Invasive alien species: biological invasions are particularly problematic in Doñana's aquatic ecosystems. The surveys described above are also used to monitor the spread and abundance of exotic species in the Doñana wetlands, including the water fern (Azolla filiculoides), the red swamp crayfish (Procambarus clarkii), and various fish such as eastern mosquitofish (Gambusia holbrooki), carp (Cyprinus carpio), goldfish (Carassius auratus), mummichog (Fundulus heteroclitus), largemouth bass (Micropterus salmoides), lack bullhead catfish (Ameiurus melas) and pumpkinseed (Lepomis gibbosus). View a summary of the data.
3.2.5. Aquatic plants: monitoring aquatic plants are surveyed once a year, at the time of peak vegetative development and coinciding with flowering/fruiting (mid/late spring). Currently, the survey comprises 10 sampling sites in the marsh, 15 in sandy lakes/ponds, and 1 in an inflowing stream. Measurements include large-scale estimates of total cover of emergent, floating and submerged vegetation; and plot-based estimates of cover per species.