BayMap Sets Approach for Habitat Mapping

Prior to 2004, Rhode Island resource managers and scientists had limited and outdated means to effectively study, manage, conserve, and sustain submerged paleocultural landscapes and coastal ecosystems, specifically in shallow-subtidal environments, due to financial and technological constraints.

Habitat maps, at the time, were several decades old and were developed with technology that had poor spatial resolution, and which did not account for climate change and increased coastal development. To fill this knowledge gap, Rhode Island Sea Grant invested in the development of BayMap, a collection of marine habitat maps for Narragansett Bay and surrounding coastal ponds for use by resource managers and scientists.

“People did not generally map in less than five meters of water,” said Dr. John King, oceanography professor at the University of Rhode Island Graduate School of Oceanography, and the principal investigator supported by Sea Grant on this project. “It was too difficult to get boats in and many people had the attitude that ‘if you can see it why map it?’… But you can’t ignore [shallow environments] where a lot of activity occurs around very valuable habitat. That’s where the quahoggers operate and where seagrass beds are located.”

Sea Grant first funded King’s team in 2004 to utilize fledgling multi-beam, backscatter, sidescan, and sub-bottom sonar imaging technology to produce high-resolution datasets of sea bottom sediments for Rhode Island coastal waters in order to update maps that were first made 20 years prior, as well as add new details about shallow habitats and potential submerged cultural sites. Sea Grant continued funding the project over the course of six years to assist in refining the technology using interferometric sonar to simultaneously map bathymetry and bottom type via side scan sonar, and to continue mapping efforts across Narragansett Bay and coastal salt ponds.

Now more than 80 percent of Narragansett Bay and coastal salt ponds have been mapped, providing a spatial inventory of both biological and geological habitat characteristics. This type of interdisciplinary collaboration between biologists and geologists, says King, is one of the greatest outcomes from BayMap because it opened the door to this type of mapping approach and set the tone for the future of habitat mapping.

Since its completion in 2011, BayMap has had wide utility and diverse application resulting not only from the data collected, but from the new methodologies and protocols developed for habitat mapping, especially in shallow water.

On a local level, data from BayMap has been used as a guide by aquaculturists, such as American Mussel Harvesters, to assist in identifying aquaculture sites based on sediment type for gear placement. Protocols and technologies from BayMap were also applied in a survey near Providence Harbor that ultimately led to the discovery of 29 historic submerged vessels being

High resolution side scan sonar of submerged shipwrecks in Providence Harbor.

considered as “Rhode Island’s largest ship graveyard,” which has significant cultural merit. The Rhode Island Department of Environmental Management is also applying the same protocols and technologies to study rocky bottom habitats for stock assessments of scup, black sea bass, and tautog in Narragansett Bay.

BayMap protocols were also applied to seafloor mapping efforts needed to develop a comprehensive science-based framework for managing the state’s offshore waters via the Ocean Special Area Management Plan (Ocean SAMP). The survey helped delineate benthic habitat distribution, as well as help developers, like Deepwater Wind, identify regions with sufficient thicknesses of unconsolidated sediments to allow installation of foundation structures by pile driving that would facilitate the construction of a wind farm. The Ocean SAMP also used BayMap methodologies in evaluating the relationship between benthic habitats and fish communities in the transitional seas of Rhode Island Sound and Block Island Sound to guide placement of development that preserves the ecological and economic value of the area. The same methodologies, in combination with magnetometry, were also applied to help develop a process for identifying submerged ancient Native American archaeological resources to assist the Bureau of Ocean Energy Management (BOEM), individual States, and tribal communities in evaluating proposed offshore wind-energy projects. Since its adoption in 2011, the Ocean SAMP has guided and streamlined the state’s offshore permitting process that launched the construction of the nation’s first offshore wind farm currently underway off of Block Island, which has already generated 300 local jobs.

“More than 15,000 years ago, Narragansett tribal ancestors lived out where the ocean is now, but had to suddenly abandon their homes when the ocean rose overnight.”

That was the oral history told by the late Ella Sekatau, a Narragansett elder medicine woman, according to Doug Harris, preservationist for ceremonial landscapes for the Charlestown-based Narragansett Indian Tribal Historic Preservation Office in Charlestown, R.I.

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On a national scale, BOEM has launched a 5-year, $2 million project, as a result of the mapping efforts from the Ocean SAMP, to develop best practices for identifying submerged paleolandscapes  to avoid or mitigate adverse effects to National Register-eligible or -listed ancient Native American archaeological sites as it relates to offshore development. BOEM has also funded a 4-year, $400,000 project utilizing BayMap protocols applied for the Ocean SAMP to investigate offshore sand and gravel deposits. To date, large deposits have been found that are considered adequate to meet Rhode Island’s need for beach replenishment sand for the foreseeable future, alleviating pressures on limited land-based resources. Locating and utilizing this resource will be vital for Rhode Island as continued sea level rise and increased storm intensities accelerate erosion. The project is still underway to evaluate potential negative impacts of sand removal to fisheries habitat and paleocultural sites.

BayMap was also used as a pilot project that helped to refine and develop NOAA’s Coastal and Marine Ecological Classification Standard (CMECS), which has been adopted as a national standard for collecting data to provide a “structure for developing and synthesizing data so that ecosystems can be identified, characterized, and mapped in a standard way across regional and national boundaries.”

The National Park Service is also currently applying both CMECS and BayMap protocols in a 4-year, $3.5 million project to develop an inventory of all submerged land holdings at four locations along the East Coast. The goal of this project is to better understand habitat lost and formed post Sandy, as well as help establish a future monitoring program.

Overall, BayMap methodologies, protocols and technologies, such as interferometric sonar and side scan sonar, have leveraged nearly $10 million in both regional and national projects by demonstrating the ability to do geological and biological habitat mapping in both offshore and shallow (0-5 m) waters. This has enabled resource managers and scientists to look at marine habitats more holistically to gain better knowledge of these systems for better management and conservation efforts, both ecological and cultural.

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