Intertidal Marine Vegetation Strategies (IMVS)

The Intertidal Marine Vegetation Strategies (IMVS) are products of the NSW Marine Estate Management Strategy (MEMS). The separate reports and data packages cover the floodplains of NSW estuaries. The first IMVS covers the Tweed River estuary, and as IMVS for other estuaries and marine parks are released, the datasets will be added to SEED. The IMVS, supporting documents and geodata packages are centralised information sources to aid management of saltmarsh and mangrove habitats in NSW now and into the future.

Mapping of high macrophyte potential and identification of intertidal marine vegetation ‘hotspots’ where management actions may be meaningfully undertaken applies the methods outlined in the Marine Vegetation Management Strategies: a framework for estuary wide prioritization of protection and rehabilitation. This publication outlines the theoretical processes behind the applied prioritisation approach and provides comprehensive detail and justification on the study approach and methods used. 

Each estuary or marine park specific IMVS identifies macrophyte potential hotspots where a tailored suite of management actions has been developed to increase the resilience of intertidal marine vegetation. Actions address key threats and risks to saltmarsh and mangrove communities to safeguard the ongoing provision of ecosystem services and environmental, social, cultural, and economic values in response to sea level rise and other impacts. Importantly, a landholders’ right to carry out agricultural or developmental activities on their land is not altered by their properties being identified in any IMVS documents and any involvement in delivering recommended management actions is entirely voluntary.

The IMVS includes information on recommended management actions categorised under Hydrology, Sediments, Vegetation and People and Planning approaches. More detailed information on the objectives and suitability of these management approaches can be found in the following documents:

IMVS: Key approaches to Mitigate Risk and Support Adaptation 

IMVS: Integrated Landscape and Seascape Conservation

IMVS: Weed Management Guide.

Note that the recommendations are based on site-specific conditions and available information at the time of writing. As both environmental and anthropogenic conditions are dynamic, appropriate management strategies may be subject to change and current site assessments are required. Initiating changes to protect or restore hydrology or sedimentation may be complex and have unanticipated environmental, social, cultural and economic outcomes. When recommended projects are planned, expert assessment and a scrutiny of proposed actions by relevant authorities is still warranted as works may result in changes to the key ecological drivers of intertidal wetlands.

Implementation of recommended actions must comply with regulatory requirements. Proposal assessments must be undertaken on a case-by-case basis as the approval pathway is not the same for every relevant Local Environmental Plan or SEPP. The planning approval pathway also depends on how a proposal is classified, the specific works to be undertaken, the location and land zoning, and whether the proponent is a public authority or private entity. There may also be other regulatory approvals that apply. Given the complexities of jurisdiction and classifications of works it is important to seek and retain written planning advice (for example, from a town planner and relevant approval authorities) during the planning stage so that environmental protection actions can be demonstrated as being compliant with current legislation and policy.

The geodata packages include information on high macrophyte potential, identified hotspots, recommended management actions (under Hydrology; Sediments; Vegetation; and People and Planning approaches), current mapped intertidal macrophytes, and projected intertidal vegetation with 0.5m and 1.5 m sea level rise.  Links to relevant resources are also provided.

The IMVS datasets for the following study areas can be accessed in the Related Datasets section below.

Organization: Department of Primary Industries and Regional Development (DPIRD)