503
Plans and actions aiming at estuarine conservation must take into account the
seasonal fluctuations of ecocline along cycles of retention and flush of dissolved and
particulate components, including environmental contaminants and, consequently,
how hydrodynamics affect water quality. In Western Atlantic estuaries, annual rainfall patterns, vertical salinity structure during dry periods and river flow to the systems are very important factors to develop explanatory and predictive models
aiming at conservation (Figs. 16.7 and 16.8). However, the large majority of studies
consider only patterns of spatial changes of ecological variables, and sampling is
based on distance to sources of interference. Not accounting for temporal variability
of water quality leads to faults in predicting whether estuaries are able to withstand
human modifications, or not. This is also important if considered that the main
cause of habitat loss in Western Atlantic estuaries is related to control and uptake of
freshwater flowing into the systems.
16.4.2 Recommendations for Future Estuarine Conservation
Understanding and working in favour of estuarine ecocline is also important to
guarantee the conservation of socio-economically relevant estuarine-dependent fish
species. Each ontogenetic stage exhibits different strategies to bear the spatial and
temporal variability of abiotic compartments across the changeable estuarine habitats in order to complete their life cycles. Reliable ecological data are fundamental
in managerial actions because planed ecological data can explain how environmental gradients influence trophic organization, distributional patterns, reproductive
timing, peaks of abundance and temporary nursery habitats within estuarine fish
assemblages, and estuarine communities (Table 16.1).
The concepts and importance of working in favour of ecocline are gaining attention, and recommendations for conservation in protected areas are being restructured (Storm et al. 2005; Slater 2016). This is the case of the Natural Park S’Albufera
in Majorca (Balearic Islands, Espain), a Wetland of International Importance under
the Ramsar Convention, which recently was defined as a marsh aquatic system with
a saline-freshwater gradient (ecocline) containing a series of ecotones (communities), resulting in dynamic niches for plants and animals (Slater 2016). In the RhineMeuse estuary, one of the most important wetland in the Netherlands, a program of
remedial action has been emerged aiming a healthier ecosystem by recovery the
estuarine processes (Storm et al. 2005). In this study, it is suggested that the restoration of tidal and river dynamics in polders are the best option for ecological rehabilitation (Slater 2016).
Even when managerial plans are consistent with ecological processes, they may
enter in conflict with the lack of basic sanitation, the worst concern in estuarine
systems pollution and degradation. Ecological information concerning interactions
among biota and contaminants along estuarine ecocline provides information on
critical periods for bioaccumulation and its further consequences, risk of higher
plastic debris ingestion (macro or micro) and unsuitable water quality due to oxygen
16 Estuarine Ecoclines and the Associated Fauna: Ecological Information as the Basis…
Plans and actions aiming at estuarine conservation must take into account the
seasonal fluctuations of ecocline along cycles of retention and flush of dissolved and
particulate components, including environmental contaminants and, consequently,
how hydrodynamics affect water quality. In Western Atlantic estuaries, annual rainfall patterns, vertical salinity structure during dry periods and river flow to the systems are very important factors to develop explanatory and predictive models
aiming at conservation (Figs. 16.7 and 16.8). However, the large majority of studies
consider only patterns of spatial changes of ecological variables, and sampling is
based on distance to sources of interference. Not accounting for temporal variability
of water quality leads to faults in predicting whether estuaries are able to withstand
human modifications, or not. This is also important if considered that the main
cause of habitat loss in Western Atlantic estuaries is related to control and uptake of
freshwater flowing into the systems.
16.4.2 Recommendations for Future Estuarine Conservation
Understanding and working in favour of estuarine ecocline is also important to
guarantee the conservation of socio-economically relevant estuarine-dependent fish
species. Each ontogenetic stage exhibits different strategies to bear the spatial and
temporal variability of abiotic compartments across the changeable estuarine habitats in order to complete their life cycles. Reliable ecological data are fundamental
in managerial actions because planed ecological data can explain how environmental gradients influence trophic organization, distributional patterns, reproductive
timing, peaks of abundance and temporary nursery habitats within estuarine fish
assemblages, and estuarine communities (Table 16.1).
The concepts and importance of working in favour of ecocline are gaining attention, and recommendations for conservation in protected areas are being restructured (Storm et al. 2005; Slater 2016). This is the case of the Natural Park S’Albufera
in Majorca (Balearic Islands, Espain), a Wetland of International Importance under
the Ramsar Convention, which recently was defined as a marsh aquatic system with
a saline-freshwater gradient (ecocline) containing a series of ecotones (communities), resulting in dynamic niches for plants and animals (Slater 2016). In the RhineMeuse estuary, one of the most important wetland in the Netherlands, a program of
remedial action has been emerged aiming a healthier ecosystem by recovery the
estuarine processes (Storm et al. 2005). In this study, it is suggested that the restoration of tidal and river dynamics in polders are the best option for ecological rehabilitation (Slater 2016).
Even when managerial plans are consistent with ecological processes, they may
enter in conflict with the lack of basic sanitation, the worst concern in estuarine
systems pollution and degradation. Ecological information concerning interactions
among biota and contaminants along estuarine ecocline provides information on
critical periods for bioaccumulation and its further consequences, risk of higher
plastic debris ingestion (macro or micro) and unsuitable water quality due to oxygen
16 Estuarine Ecoclines and the Associated Fauna: Ecological Information as the Basis…