New computer program helps determine strategic habitat areas

By Richard Davis
Fish-Eye Staff

Biologists with the N.C. Division of Marine Fisheries have a powerful new tool to assist with managing the state’s coastal resources.

They are using the computer program MARXAN, developed by the University of Queensland in Australia, to locate areas of exceptional marine habitat. Designating these areas as “strategic habitats” is a key element of implementing the Coastal Habitat Protection Plan (CHPP).

Scott Chappell is the division’s point man for the MARXAN mapping project.

“It’s a site selection tool. It’s doing work we couldn’t manually. The number of maps, calculations and time involved would make it impossible. But the program is able to handle huge amounts of data and produce results that best reflect the selection criteria,” Chappell said.

According to Chappell, computer assistance is critical to the success of this complex task because the six habitats covered by the CHPP occur within an area covering 2.5 million acres of water and coastal wetlands.

Chappell explained that analyzing all the factors impacting each of those millions of acres would take many researchers working years. MARXAN makes it possible for a small team of biologists and analysts to do the work in much less time.



Habitat Hexigons - This MARXAN images shows
hexigons being considered near Roanoke Island.

MARXAN incorporates information from databases created by different state and federal agencies and uses it to select habitat. The program works in hexagon-shaped segments of a map, with each hexagon covering 125 acres.

The division’s first use of MARXAN focuses on the Albemarle Sound Region. There are about 40,000 hexagons in the region, which extends from the headwaters of the Chowan River in southern Virginia down to Oregon Inlet, and includes the coastal ocean.

Chappell explained the purpose of using MARXAN, “We’re using this program to find areas for enhanced protection or focus, whether it be through research, regulatory action, voluntary programs or land acquisition.”

He added, “MARXAN tries to find the subset of a habitat area that is the least altered. It does this in as small an area as possible. It does a lot of calculating that eventually gives us a solution that achieves our habitat protection objectives. Once MARXAN does its work we consider the areas it has selected and determine the best methods to protect them.”

“We need to have a clear idea of what we want to do with these areas so the public can evaluate how it might affect their land. It’s not just what the computer says. We also depend on, and value the public input we receive.”

And habitat protection is not the only benefit that has come from using MARXAN.

“We’ve discovered some things that could be improved with the way DENR and the agencies within DENR collect and store their data so it’s easier to use. So it’s going to help with the coordination within our divisions,” Chappell said.

The initial MARXAN selections for the Albemarle Sound Region should be completed in late spring or early summer. Those selections will be reviewed and modified by federal, state, and university experts who will determine what can be done to protect the selected areas in addition to what is already being done. Once recommendations have been made the selections and options will be presented for public input.

Chappell summed up the MARXAN project, “In the future, the process will go faster and that will help us avoid possible habitat loss.”

For more information regarding MARXAN and its role in habitat protection, contact Scott Chappell at (252) 808-8071 or (800) 682-2632 or Scott.Chappell@ncmail.net.

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