New grant increases protections for horseshoe crabs and shorebirds

Money is intended to bolster programs that count migratory birds, track habitats
Credit: Don Manalo.
Red knots and sanderlings in flight; horseshoe crabs on beach

The quiet, empty beaches of South Jersey’s Delaware Bay shoreline will soon begin to stir with the sound of thousands of migrating shorebirds, pausing their long journeys from the Southern Hemisphere to the Canadian Arctic to refuel on the eggs of horseshoe crabs that emerge to spawn here each spring.

Along with this natural wonder comes a dedicated group of volunteers, called Shorebird Stewards, who assist biologists from the state and nonprofit organizations in their annual count of the bay’s most vulnerable migratory shorebirds, including the dunlin, sanderling, semipalmated sandpiper, short-billed dowitcher, ruddy turnstone and the red knot, a federally listed threatened species.

“I’ve been organizing the Shorebird Stewards since 2003, and it has always been a fairly small volunteer project, about 10-15 people,” said Larissa Smith, a biologist with the Conserve Wildlife Foundation, one of the Steward program’s partners. “This year, I’ve had more than 40 people interested.”

Reconnecting with nature

In a year upended by social distancing and hardship, Smith said, many people were nevertheless able to reconnect with the outdoors. “They want to help make a difference,” she said.

Smith and her colleagues are also anticipating an unprecedented influx in visitors to the Bayshore’s otherwise desolate beaches. “With COVID-19, people are really champing at the bit to get outside and be a part of nature,” said Capt. Al Modjeski, habitat restoration program director for the American Littoral Society, another Steward program partner.

Just in time for the rush, the Littoral Society has received an $86,700 grant from the National Fish and Wildlife Foundation, which Modjeski says will allow them and their program partners to enhance the volunteer effort this year and beyond. “This is really going to further engage people on why it’s important to have these natural areas,” he said. “Not just so they can visit and enjoy them, but also for the wildlife so it can survive.”

The arrival of the shorebirds, which begins around May 1, is one of the largest migration stopovers in the Western Hemisphere. It is fueled almost entirely by the excess eggs of the horseshoe crab, of which the Delaware Bay has one of the biggest breeding populations in the world. The crab’s eggs, more than any other food source, allow the birds to quickly rebuild the kind of fat stores required to both finish their journeys and breed once they’ve arrived at their destinations.

The horseshoe crab has long been utilized as bait by conch and eel fisheries, but in the 1990s, annual harvests skyrocketed from around 100,000 crabs in the early part of the decade to 2.5 million by 1998. The overharvesting triggered a devastating chain of population declines that began with the crabs and quickly ricocheted to the shorebirds.

Red knot under siege

The reduction in crab numbers has been most devastating for the red knot, whose annual 9,000-mile flight from the southern tip of South America to the Canadian Arctic is among the longest bird migrations on the planet. Additional threats, like habitat loss, prey depletion and climate change have also played a role in both the horseshoe crab and the red knot’s vulnerable and threatened statuses. Human disturbance is another crucial factor; research has found that frequent movement away from people reduces the shorebirds’ foraging time and causes them to expend energy that is critical to their migration.

Credit: Bill Reinert
Red knots and an upturned horseshoe crab in the intertidal

In the mid-1980s, the Department of Environmental Protection began monitoring the bay’s shorebirds, and, in 2003, it started restricting access between May and June to over a dozen Delaware Bay beaches that are vital to horseshoe crab spawning.

That same year, Conserve Wildlife Foundation organized the Shorebird Steward program. Volunteers were stationed at the restricted beaches to ensure that human disturbance was as limited as possible. Signs were also placed throughout the Bayshore, to educate people about the annual horseshoe crab spawn and shorebird stopover.

“When we first started doing surveys, the birds were more evenly spread out across both sides of the bay,” said Larry Niles, a wildlife biologist who has been one of the leaders of the annual shorebird count since its inception. “But in the last 10 years or so, the birds have shifted to this side of the bay, and I think one of the reasons for that is the Steward program, because the birds aren’t being chased around and they can stay still.”

With the grant from the National Fish and Wildlife Foundation, the American Littoral Society, along with Conserve Wildlife Foundation and Wildlife Restoration Partnerships, will be able to boost the Steward corps, ensuring that volunteers — and paid interns through the society’s armed forces veterans program — are stationed at restricted beaches throughout the day for most of May. Additional staffed locations this year will include East Point Lighthouse, in Cumberland County, among others.

Stewards will be armed with literature to hand out to visitors and be available to point out signs and answer questions people may have about the horseshoe crabs, shorebirds and the Bayshore habitat that is so important to their survival.

The society is also planning to produce a handful of one-minute social media videos that will highlight key information and feature interviews with biologists, stewards and local landowners who benefit from the annual event.

“Barnegat Bay and the Atlantic coast are always a draw for New Jersey, but I don’t think a lot of people know or care, necessarily, about how unique the Delaware Bayshore is,” said Quinn Whitesall, the American Littoral Society’s habitat restoration coordinator. “So we want to capture and share as widely as possible why the Delaware Bay is so special.”

Objecting to beach closures

Another challenge of restricting access to areas has come from concerns of resistance from local municipalities, where some residents may disapprove of beach closures. With the National Fish and Wildlife Foundation grant, the society is hoping to create stakeholder committees and lobby for municipal ordinances that will increase local understanding of the importance of sustaining a robust habitat for horseshoe crabs and shorebirds.

“Working with landowners and the local communities has always been a priority for us,” said Whitesall. “The more we get their perspective and views on the significance of this event, that will really allow us to get a broader message out to the general public.”

Last year, due to coronavirus restrictions, the steward program and annual counting of horseshoe crabs and shorebirds were drastically scaled back. But what the handful of biologists who were able to follow through with the survey found was alarming: In mid-May, when horseshoe crab spawning should have been at its height, few crabs were turning up on Delaware Bay beaches. As a result, there was about an 80% decline in red knot numbers from the previous year.

Credit: (Don Manalo)
Banded red knot feeding among sanderlings

According to Niles, the main driver of the drop in crab and shorebird numbers was climatic — a pair of tropical storms, exceedingly rare for that time of year, had moved up the East Coast, pushing cold air and water into the bay. The crabs finally emerged to spawn about two weeks later than normal, but for many of the red knots, it was too late.

“There were a lot of birds that just came here and left,” Niles said, “because there weren’t enough eggs.”

Another increasing cause for concern is the horseshoe crab bleeding industry. Pharmaceutical companies have for decades depended on the horseshoe crab’s blue blood to detect toxins during vaccine development. While Eli Lilly has produced an effective synthetic alternative, the industry standard remains the real thing.

“There’s little regulation of the bleeding industry,” Niles said. “There’s no control over how many they kill, and the only assessment you get of the data is their assessment.”

The process for testing the efficacy of coronavirus vaccines is no different — for every dose, some amount of horseshoe crab blood is required. At this point, it’s too early to determine what kind of impact, if any, the massive increase in global vaccine production will have on the already vulnerable horseshoe crab.

Currently, there are three bleeding companies operating in the Delaware Bay. “They’re making huge amounts of money, and they don’t put anything into the surveillance of crabs or restoration efforts,” said Niles. “So, my greatest fear right now is them.”

Looking toward the prospects for this year’s spawning event, Niles noted one horseshoe crab survey that has already been conducted by Virginia Tech that indicates the numbers for female horseshoe crabs — the preferred type for bleeding companies, since females are larger — are once again low. But, he added, another count by Delaware’s Division of Fish and Wildlife has shown a slight increase.

“I’m hoping for better this year, just because the trends are mixed,” Niles said. “But it might take a few years to really figure out the impact — we’ll just have to wait and see.”

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