MapCoast uses a variety of tools for mapping subaqueous soils and surface benthic habitat characteristics. Some examples include:
Side-scan Sonar 'fish'
Acoustic tools and technology are a very valuable component to the data collection effort. Just as aerial photography is an essential source of information when mapping terrestrial soils, side-scan sonar images are equally important for mapping surficial benthic habitats, geology, and subaqueous soils. Because the acoustic data are collected simultaneously off each side of the survey vessel, the boat can motor back and forth over a study area to collect data very efficiently and completely. Please click here to view the acoustic images we have collected.
MapCoast uses some very technical tools to help them delineate and identify benthic habitats and subaqueous soil types. For example, in Quonochontaug Pond a statistical analysis was used to delineate and determine map units. A description of map units can be found here.Underwater video was also used to ground-truth these delineations.
Other ground-truthing tools include sediment profile images (SPI), underwater video, grab samples, and coring devices (see pictures below). For more information on all of these methods, please take a look at our issue of 41N.
|Example of a SPI image collected in Greenwich Bay showing the relationship between depth and redox potential (Eh)|
|Another example of a SPI image collected in Quonnie Pond showing an Ampelisa colony.|
|The SPI camera and housing ready to be deployed in Wickford Harbor.|
|A photographic still taken from an underwater video camera showing Zostera and floating red algae taken in Point Judith Pond.|
|A photographic still taken from an underwater video camera showing Ulva (algae) and fauna tracks taken in Point Judith Pond.|
|A McCauley peat sampler is a very efficient (and low-tech) hand-tool used to collect core samples in soft, highly-organic, silt loam subaqueous soils.|
|Plexiglass tubes are used for hammer cores in soft, highly organic subaqueous soils.|
|Vibra-cores are used to collect deeper samples of 1-3 meters in length in sandy soils.|
|Bucket auger are another example of low tech hand-tools that are used to provide a quick field description to about 50 cm below the subaqueous soil surface.|