The selection of the most appropriate management option should be informed by a robust and ideally simple appraisal, which enables the issues surrounding and the consequences of the management technique implemented to be fully understood. In most cases, it is likely that the simple qualitative/quantitative consideration of the types of functions and services that would be impacted will be sufficient to ensure that the ‘best’ decision is taken; while other cases are likely to require a more detailed appraisal of impacts to ensure that the right sort of outcome is achieved.

The table below provides an indication of the range of possible techniques or solutions available to combat saltmarsh erosion (as opposed to a change in the floral community or plant vigour), where it is determined that intervention is appropriate. The table includes situations where a saltmarsh may not be in immediate threat, (Category A), but where the technique could enhance or extend saltmarsh area. The circumstances in which different techniques should be used is indicated, based on the state of the saltmarsh (i.e. categories B to D), along with the cause(s) of saltmarsh loss that can be addressed in each case.

Aid to scheme selection: saltmarsh erosion  

Management option	Saltmarsh categories for which the option may be appropriate	Notes
Vegetation planting and/or Sedimentation fences	A, possibly B (i.e. consider the viability of implementing low cost maintenance and enhancement solutions)	Not suitable for areas suffering from wave erosion; More suited to aiding naturally recovering saltmarshes by enhancing accretion
Recharge (with mud)	A, B, possibly C	Needs repeated application to maintain mudflat levels on an eroding shore (i.e. erosion will not resolved by a single application); Does not mitigate the causes of erosion, but can stop further recession if the rate of recharge equals erosion (therefore probably not suitable for C and D)
Recharge (with gravel/sand)	A, B, C, possibly D (may not be sufficient in the latter case)	Banks of sand/gravel can be used to form artificial cheniers which may protect eroding marshes from wave and current erosion
Creative use of firm dredged spoil	A, B, C, possibly D	Can combat undercutting and collapse of the saltmarsh edge and current induced erosion; Care must be taken not to degrade the integrity/quality of important nature conservation sites (i.e. through the introduction of clay onto mud)
Nearshore rock sills/breakwaters	A, B, C, D	Can combat wave action; However, if not carefully designed, linear wave-breaks may exacerbate current induced erosion by channelling flows
Offshore wave breaks	A, B, C, D	Can combat wave induced erosion
Armouring saltmarsh cliff edge	C, D	Combats boat-wash, currents and waves
Managed realignment (or regulated tidal exchange)	A, B (consider as part of a long term strategy (i.e. 50 to 100 years) for coastal management), C, D	May be the only economically viable solutions in cases where it is not possible to re-establish or maintain the marsh (D)

It should be noted that it is normally not practical to attempt to combat saltmarsh loss caused by the widening and lengthening of creeks. Creeks lengthen in response to water flow from the marsh surface into the creek following tides that overtop the marsh and in response to changes in tidal prism. If vertical accretion lags behind sea level rise, the frequency of inundation will increase and, hence, creek length. Similarly, if the tidal prism increases the creek may lengthen in response. Possible management action includes the application of silt directly onto the saltmarsh surface to reduce inundation/prism and/or the erection of silt trapping structures. It may also be possible to armour creek banks (to below present sediment surface level) so that the response is to deepen the creek rather than widen it. However, these methods typically will be prohibitively expensive, except on a very local scale.

In all cases, but particularly in the case of ‘hard’ intervention (i.e. the use of clay, nearshore or offshore breakwaters and armouring the saltmarsh edge), care must be taken to ensure both the continued functioning of the wider coastal or estuarine system and that the ‘integrity’ of any important nature conservation sites is not damaged (e.g. the bird feeding value of a Special Protection Area (SPA) is not reduced by reducing the area of available mudflat). It is because of both the costs and the implications of hard engineering solutions for the wider functioning of coastal ecosystems, that soft solutions are now favoured and hard solutions rarely pursued.

Click here for further information on possible management solutions.

A method being used to compare management options where the decision-making process is more complex is the Appraisal Summary Table (AST). In this context, and for each option, a monetary value, as well as a quantitative assessment and qualitative description, can be placed on each potential impact (where this includes beneficial impacts). The approach taken to decision-making in this case is likely to vary according to the number of impact categories/criteria that are being considered (which will be dependent on the complexity of the decision being made) and that can be expressed in monetary rather than non-monetary terms (where it is most likely to be necessary to compare both).