By: Brian Gregson, Spyglass Technologies, Inc., St. Petersburg, FL Frank Johnson, CSA Ocean Sciences Inc., Stuart, FL Strawn Toler, SRI International, St. Petersburg, FL

 

Background

Estuaries are fragile transition ecosystems that are subject to riverine and marine influences.

Because many coastal communities are dependent on estuaries for a number of industrial, commercial and recreational activities, disruptions to their chemical balance can have broad economic impacts. In order to understand the impacts that proposed community initiatives may have on given waterways, community stakeholders typically require that environmental assessments be conducted throughout the lifecycles of the initiatives.

USV-2600, integrated with a UMS, Echo Sounder, and CTD. Close up of sensors mounted on the below-hull adjustable “elevator.”

 

Effective environmental assessments may include a number of components, depending on the initiative and regulatory requirements, including geologic and wildlife surveys and economic impact studies. For initiatives involving chemical impacts, chemical surveys of relevant analytes may be included. Typical chemical survey methodologies rely primarily on “grab sampling” of water or sediment collected at discrete georeferenced points, with return to a traditional laboratory for analysis. Such traditional methods have a number of disadvantages. Depending on the area surveyed, the spatial resolution of the sample points may not be representative. Sample degradation during transfer to a laboratory may be a concern, along with sample contamination which may compromise survey results.

View of USV-2600 with sensors prior to launch; elevator in the fully retracted up position.

 

CSA Ocean Sciences Inc. partnered with Spyglass Technolgies and SRI International to demonstrate an integrated solution that includes an underwater mass spectrometer (UMS) on an unmanned surface vehicle (USV) for chemical surveying of potentially impacted waterways. The USV-UMS solution allows for real-time monitoring of relevant target analytes and can be operated in most weather conditions. Notably, the USV is capable of long run-times and can efficiently survey relatively large areas with greater sample resolution than traditional methods.

Project Location

The Bayou Chico watershed, located in southern Escambia County, Florida, represents a 10.36-square-mile drainage area into Pensacola Bay. Much of the area surrounding the bayou is urbanized, consisting of older, well-established residential subdivisions and industrial- and commercial-use areas. Decades of urban activity have increased sediment and nutrient loading into the watershed. Additionally, the submerged aquatic vegetation habitat of Bayou Chico, which provides habitat to fish, shrimp, crabs, and other estuarine species, was negatively impacted by the 2010 Gulf of Mexico Macondo oil spill. Overall restoration activities for the Bayou have been identified by the Florida Department of Environmental Protection’s Basin Management Action Plan¹. The City of Pensacola and Escambia County have partnered on specific projects with the expected outcomes to include restored and improved benthic habitat quality, increased biological diversity and productivity, and improved overall water quality in the Bayou Chico watershed.

USV-2600, integrated with survey sensors, underway in Bayou Chico.

 

Project Description

In partnership with the Pensacola-based Institute for Human and Machine Cognition (IHMC), working to demonstrate investigative technologies with the City of Pensacola, CSA, Spyglass, and SRI integrated UMS on the USV-2600 vehicle. The USV-2600 was integrated with other contextual sensors, including a Seabird SBE 19+ v2 CTD and an Odom 24/200 khz single beam echo sounder in additional to redundant positional sensors. A HYPACK survey profile was provided by Escambia County’s project surveyor and loaded into the USV Boat Control software module. A field configuration of the UMS, targeting analytes of interest to this survey, prepared the UMS to suit the mission at hand.

Following integration and dockside testing, the USV was launched out of the Pensacola Yacht Club. After being remotely helmed to a safe starting location, the USV was placed in automated survey mode, following the programmed HYPACK survey at a speed of approximately 4 knots. The survey was conducted in an area from the mouth of Bayou Chico to a point near the Pensacola Shipyard and Boat Ramp where the USV was recovered.

Table 1. Non-exhaustive list of select chemical ions monitored in parallel and in real-time by the UMS. The list shown is an example of analytes of highest interest and not a complete representation of the ions monitored during the described project.

Throughout the survey, continuous data were logged from the UMS, CTD, echosounder, and positional sensors as well as standard vehicle diagnostic sensors. A comprehensive report of the results is in process.

Summary

A USV was integrated and deployed with a UMS and other advanced hydrographic survey sensors to demonstrate the utility of the automated system for efficient chemical surveying of environmentally impacted coastal waterways.

• The USV-UMS integrated solution offers advantages over traditional survey methodology.

• The USV can be deployed in a broad range of weather and visibility conditions, reducing personnel resource requirements.

• Continuous in-situ sampling allows for greater sample resolution compared with traditional methods.

• The novel use of a mass spectrometer allows for a large number of analytes to be monitored with precision at low concentrations in real-time (see Table 1), eliminating the need to retrieve samples and transport them to a lab.

• Autonomous operations provide the potential for greater survey efficiency, potentially reducing overall survey costs while increasing sample fidelity and reliability.

For more information on this project or the USV-UMS integrated solution please visit www.spyglasswater.com or contact This email address is being protected from spambots. You need JavaScript enabled to view it..

¹ Florida Department of Environmental Protection. Basin Management Action Plan for the Implementation of Total Maximum Daily Loads for Fecal Coliform Adopted by the Florida Department of Environmental Protection in Bayou Chico (Pensacola Basin). Tallahassee: Florida Department of Environmental Protection, Bureau of Watershed Restoration, Watershed Planning and Coordination Section, Oct. 2011. www.dep.state.fl.us/water/watersheds/docs/bmap/bayou-chico-bmap.pdf.