| "We didn't have data or information to confirm or refute any of their concerns." | |
| David Carter, Delaware Coastal Programs |
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The Holy Grail for coastal resource managers might be the ability to base all management decisions on sound, indisputable science. Changing political climates and priorities, fluctuating funds, and the time necessary for thorough research when decisions have to be made today are some of the obstacles managers face on this difficult quest.
For the past eight years, Delaware coastal resource managers have doggedly pursued the science necessary to manage migratory shorebirds and horseshoe crabs. Although managers there say more data are still needed, their research and monitoring efforts have already proven valuable in the decision-making process.
"The science is being done, and all of this time and effort on the part of so many people is starting to pay off for management," says David Carter, environmental program manager for the Delaware Coastal Programs.
Delaware managers are using the information to guide beach nourishment projects, regulate the siting of a marina, and identify ecologically important land appropriate for the state's acquisition.
Miles to Go
The data that Delaware managers are collecting document the arrival of hundreds of thousands of migratory shorebirds each spring upon the beaches of Delaware Bay.
As they make their journey of up to 9,000 miles from South America to the Arctic, shorebirds such as the red knot, ruddy turnstone, sanderling, and semipalmated sandpiper stop at the bay to rest and feed on horseshoe crab eggs. If the shorebirds aren't able to eat enough at this rest stop, they may not have enough fat reserves to survive.
While the migratory birds depend on the bay's habitat and the abundance of horseshoe crabs, they are not the only ones calling dibs on the area's beaches and crab population.
Fishermen sell the horseshoe crabs for use as bait, the biomedical industry depends on horseshoe crab blood to test pharmaceutical products, and recreational birders and ecotourists create disturbances, which can have profound negative impacts on shorebirds.
Unanswered Questions
In 1996, the Delaware Chapter of the Sierra Club and other environmental groups "put a spoke in the wheels" of a beach replenishment project when they challenged a state permit, citing concerns about potential toxins and the project's impacts on the horseshoe crabs and shorebirds.
"We got caught off guard," recalls Carter. "We didn't have data or information to confirm or refute any of their concerns."
With contention growing among user groups, the state was being asked to make "difficult decisions without knowing about the stock of horseshoe crabs, or understanding what was going on with the migratory bird population. We needed to get sound management information and find some common ground on the issue. We knew we needed to start with science," Carter says.
Finding the Answers
Initial investigations were able to answer some of the environmental groups' concerns, but this work brought to light serious data gaps.
Sampling easily showed that the beach sediments were clean, but there was no precise census of the total numbers of shorebirds passing through Delaware Bay during the spring migration, and historical data on horseshoe crabs were limited.
To fill in the gaps, a coalition of professional scientists and volunteers from the U.S., United Kingdom, and the Netherlands was cobbled together to form the Delaware Shorebird Monitoring Team.
Over the past six years, the Delaware Shorebird Monitoring Team has captured and collected data on more than 10,000 birds. Detailed records have been kept on bird populations, horseshoe crab egg abundance on the beaches, and the location and preferred types of habitats.
"The whole project is very labor intensive," notes Kim Cole, environmental scientist for the Delaware Coastal Programs. "It takes lots of volunteers, who have to be well trained and devoted."
To ensure that the best quality data are being gathered by the team, the U.S. Fish and Wildlife Service recently completed a scientific peer review of existing shorebird data.
Deciding Factors
What the researchers have discovered so far is that good horseshoe crab spawning beaches, and thus good shorebird habitat, include characteristics such as coarse beach sand, moderate to steep slope, protection from the wind, and a shallow nearshore bay bottom.
This information, says Stewart Michels, fisheries scientist in the Delaware Department of Natural Resources and Environmental Control's Division of Fish and Wildlife, led managers to look at the effect beach replenishment had on horseshoe crabs, and "devise a way to optimize the grain size of sediments to create better habitat."
"This is the type of research that we need to actively manage beach replenishment" and, ultimately, horseshoe crab populations, Michels says.
The data also proved vital when a property owner proposed putting a 42-slip marina in an area where research showed 60 to 70 percent of red knots take their migratory break. To protect the birds, the marina was reduced to eight slips.
"We didn't want to hinder the property owner from some use of his property, and we know the birds will adjust somewhat to some disturbance. By reducing the number of slips, we significantly improved and protected the condition for the birds," Carter says.
Because the data have helped identify key habitat sites, several agencies are currently working to help guide the state's acquisition of these lands.
Time Will Tell
Using the data to make these types of decisions, Carter says, is the reward for relentlessly pushing the need for research and monitoring. He believes it will take many more years, however, before the data will solidly be the basis for managing the resources.
"It will take 20 years to establish long-term trends with a reasonable level of confidence," Carter says. "We still have much to learn to effectively manage these species."
Carter acknowledges that changing political winds, lack of funds, and other obstacles can make long-term research and monitoring difficult for coastal managers, but he believes the quest for science-based management is important.
"Improving our understanding with long-term data is critical," he says. "With each passing year, we will be provided with better science to guide our management efforts."
For more information on the Delaware Shorebird Monitoring Team, point your browser to http://shorebirds.skalizar.net. You also may contact Kimberly Cole at (302) 739-3451, or kimberly.cole@state.de.us. You may contact David Carter at the same number, or e-mail david.carter@state.de.us.
