Geospatial Video Monitoring of Geospatial Video Monitoring of Benthic Habitats Using the Benthic Habitats Using the

Shallow-Water Positioning System (SWaPS)Shallow-Water Positioning System (SWaPS)

Diego Lirman and Greg DeAngeloDiego Lirman and Greg DeAngelo

Rosenstiel School of Marine & Atmospheric ScienceRosenstiel School of Marine & Atmospheric ScienceUniversity of MiamiUniversity of Miami

NOAA / National Geodetic SurveyNOAA / National Geodetic Survey

Shallow-Water Positioning System (SWaPS)Shallow-Water Positioning System (SWaPS)

SWaPS was developed by researchers from NOAA’s National Geodetic Survey

Video-based technology used to establish the location of objects underwater

Merges Visual and Position information

Multiple platforms (shallow draft skiff, remotely operated, diver-operated)

Used to survey seagrass, hardbottom, coral reef habitats

BASE STATION

GIMBALL ASSEMBLY

GPS ANTENNA

DIGITAL VIDEOCAMERA

GLASS PORT

RTK

SHALLOW-DRAFT SKIFF

SURVEY PLATFORMS . Shallow-draft skiff

SURVEY PLATFORMS . Remotely Operated SWaPS

SURVEY PLATFORMS . Diver-Operated SWaPS

DomeTransducer

Monitor

Batteries

Depth Sounder

Digital Compass &Tilt Meter

Camera

G.P.S.

Encoder

G.P.S. Antenna

DomeTransducer

Monitor

Batteries

Depth Sounder

Digital Compass &Tilt Meter

CameraG.P.S.

Encoder

G.P.S. Antenna

SWaPS. Precision and Accuracy

The precision of SWaPS was tested by deploying numbered ceramic tiles (15 cm x 15 cm) @ 1 m of depth in Biscayne Bay, Florida

The position the tiles was obtained from the video frames showing each tile

The following day, the tiles were relocated using an RTK-GPS navigation system

With the GPS unit as a guide, the boat was repositioned over each waypoint. If any portion of the tile could be seen on the video frame, the tile was counted as a hit

SWaPS can provide sub-meter precision consistently in shallow coastal areas. 80% of tiles were relocated within the video frame using only the

positions recorded during deployment

For the tiles that were not relocated within the video screen, the mean distance to the center of the frame was 75 cm

SWaPS. Precision and Accuracy

The accuracy of SWaPS was tested by deploying tiles on a Florida reef (2.5 m of depth) and a swimming pool (1.5 m), and determining their position using the diver SWaPS

The distance between tiles was calculated from GPS positions and compared to the same distances measured by divers in the field using tapes. Distances between tiles ranged from 2 m to 10 m.

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FIELD MAPSWaPS POSITIONS

The mean deviation between diver and SWaPS measurements was 22 cm (min = 1 cm, max 50 cm). These deviations were < 10 cm in the pool

Applications:

1) Benthic Monitoring: Assessment of Submerged Aquatic Vegetation in Shallow (< 1 m) , Nearshore Habitats not Easily Accessible by other Survey Platforms

2) Damage Assessment: Impacts of Boat Propellers on Seagrass Communities and Ship Groundings on Coral Reefs in an Accurate, Cost-Effective Manner

RICKENBACKER CSWY

TURKEY POINT

N = 249 SitesN = 249 Sites

20 - 30 M TRANSECTS20 - 30 M TRANSECTS

RANDOM IMAGES FROM EACH SITERANDOM IMAGES FROM EACH SITE

% COVER FOR EACH SPP/GROUP% COVER FOR EACH SPP/GROUP

NEARSHORE BENTHIC HABITATS OF BISCAYNE BAY

Data from all sites used to produce Data from all sites used to produce SAV abundance and distribution contoursSAV abundance and distribution contours

SWaPS SURVEYS IN THE VICINITY OF CANALS

Halodule wrightii Mean % Cover

0 - 10

10 - 20

20 - 40

40 - 60

60 - 80

80 - 100

Mean % Cover

Halodule wrightii Thalassia testudinum

• SWAPS can provide an ideal platform to assess damage and

recovery patterns by:

1) Documenting the precise location of impacted resources (e.g., seagrass scars, ship groundings)

2) Quantifying the extent of damage accurately and remotely without causing additional disturbance to the resources and without the need to deploy specialized personnel

3) Providing an objective, permanent visual record of damage patterns that can be used to assess recovery over time

DAMAGE AND RECOVERY PATTERNSDAMAGE AND RECOVERY PATTERNS

Damages from boating activities are a major cause of disturbance to coral reef and seagrass communities worldwide

SEAGRASS PROPELLER SCARSSEAGRASS PROPELLER SCARS

SHIP GROUNDINGSSHIP GROUNDINGS

1) The ability to survey large areas rapidly without the need

to deploy divers or specialized field personnel

2) The ability to return to precise locations with sub-meter

accuracy over and over without the need to establish

permanent markers

3) The ability to measure size and distance information

underwater to provide valuable tools in restoration and

damage assessment studies

4) Collection of a geocoded visual archive of the status of

resources that can be easily accessed for future reference

ADVANTAGES OF SWAPSADVANTAGES OF SWAPS

ACNOWLEDGEMENTSACNOWLEDGEMENTS

Funding SourcesFunding SourcesNOAA’s National Geodetic SurveyNOAA’s National Geodetic Survey

DOI’s NPS CESI ProgramDOI’s NPS CESI ProgramNGSNGS

Gerry MaderGerry Mader

NPSNPSSarah BellmundSarah BellmundRichard CurryRichard Curry

NOAANOAAJOE SerafyJOE Serafy

Joan BrowderJoan Browder

UMUMJimmy HerlanJimmy HerlanLexie BrownLexie Brown

Rachel ClausingRachel Clausing

GRACIAS!!