Mapping Milford Haven Waterway

Marine Habitat Mapping
Mapping Milford Haven Waterway

project description

A detailed map and dataset of sedimentary habitats of the Milford Haven Waterway (MHW) was compiled for the Milford Haven Waterway Environmental Surveillance Group (MHWESG) from seafloor images collected in May, 2012 using sediment-profile and plan-view imaging (SPI/PV) survey techniques.

An interpretative framework was developed that classified each station within a ‘facies’ that included information on the location within the waterway and inferred sedimentary and biological processes. The facies approach provides critical information on landscape-scale habitats including relative location and inferred sediment transport processes and can be used to direct future monitoring activities within the MHW and to predict areas of greatest potential risk from contaminant transport. Intertidal sediment ‘facies’ maps have been compiled in the past for MHW; this approach was expanded to map the subtidal portions of the waterway. Because sediment facies can be projected over larger areas than individual samples (due to assumptions based on physiography, or landforms) they represent an observational model of the distribution of sediments in an estuary.

This model can be tested over time and space through comparison with additional past or future sample results. This approach provides a means to evaluate stability or change in the physical and biological conditions of the estuarine system. Initial comparison with past results for intertidal facies mapping and grain size analysis from grab samples showed remarkable stability over time for the MHW. The results of the SPI/PV mapping effort were cross-walked to the European Nature Information System (EUNIS) classification to provide a comparison of locally derived habitat mapping with European-standard habitat mapping.

PROBLEMThe need for an accurate map of sedimentary habitats of the Milford Haven Waterway for local resource managers.

APPROACHConducted a comprehensive synoptic assessment of sediment distribution and benthic habitat composition of the Milford Haven Waterway using sediment-profile and plan-view imaging (SPI/PV) survey techniques at 559 stations covering over 40 km2 of subtidal habitats.


OUTCOME
A detailed map and dataset of sedimentary habitats of the Milford Haven Waterway (MHW) was compiled. In the context of the MHW, an interpretative framework was developed that classified each station within a ‘facies’ that included information on the location within the waterway and inferred sedimentary and biological processes. Our findings were detailed in a peer-reviewed publication in the Journal of Sea Research.

 

Assessment aspects of project:
  • Ecological Assessment
  • Habitat Mapping
  • Published Research
  • EUNIS Habitat Types and Cross-Walk To Facies Model
Pullout map of survey area with SPI examples.
MilfordHavenSPI
Sediment Profile Image – MHW Project
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