South Bowers: Learning About Horseshoe Crabs and Phragmites

 

South Bowers, looking south from near the mouth of the Murderkill River

Right across the Murderkill River from Bowers Beach is South Bowers. But, unless you have a boat to cross the river, it’s a world away—specifically, a 14-mile drive.

It’s also a world away in the sense that it’s much smaller and quieter than Bowers Beach. It’s just a strip of houses along the bay and the river. There are no shops or services here, and there’s no real parking for visitors. I hopped out of our car at the northern end of South Bowers to catch this view of Bowers Beach across the Murderkill River.

View of Bowers Beach from South Bowers

And here’s the view of the mouth of the Murderkill River, with Bowers Beach to the left.

View of the mouth of the Murderkill River and Bowers Beach

At the south end of South Bowers is a turnoff with parking for just one or two cars. Looking north from the beach here, you can see Bowers Beach and also Kitts Hummock way off on the far right.

View of South Bowers, Bowers Beach, and Kitts Hummock on the far right

South Bowers is in the heart of the Delaware Bay’s horseshoe crab spawning ground, which runs from Port Mahon to Broadkill Beach. So this seems a good place to do a deep dive (no pun intended!) into horseshoe crabs, which are a big reason why the Delaware bayshore is so ecologically important.

Horseshoe crab

Horseshoe crabs have been around for 445 million years. Yes, that’s half a billion years, and that makes them older than dinosaurs or birds! They are not really crabs. They’re more closely related to ticks…and, now that you know that, doesn’t a horseshoe crab look like a giant tick? They’re pretty harmless, though—they don’t bite or sting, and their claws are very gentle. They live about 20 years.

The Delaware Bay is the world’s biggest spawning ground for horseshoe crabs. They come ashore in April through August (mostly in May and June) and burrow into the sand to lay their eggs. Waves bring some eggs to the surface that migrating birds eat. (The eggs on the surface would otherwise dry out and die, so the birds aren’t endangering horseshoe crabs.) The eggs are a particularly important food for red knots, which are an endangered species and make migration stops along the Delaware Bay. So preserving the Delaware Bay’s horseshoe crab spawning grounds is important to the survival of red knots.

Red knot

Humans have found three uses for horseshoe crabs. (They’re not really used for food; they have little meat, and it’s not particularly tender or tasty.) Through the first half of the 20^th century, horseshoe shells were ground into fertilizer, until chemical fertilizers ended that demand. Horseshoe crabs are also used as bait for eels, conch, and whelks.

The third use is the most interesting. Horseshoe crabs have a milky bright blue blood that is extremely good at detecting toxins (there’s a reason they’ve survived almost half a billion years!). So their blood is used to detect toxins in medical implants like stents and in injections like vaccines…including COVID-19 vaccines.

Horseshoe crab blood

Before you get grossed out thinking horseshoe crab blood is being injected into you—no, it’s only used to test a small fraction of each medical product. And, no, the crabs don’t need to be killed for their blood. The crabs are harvested, blood is drawn from them, their shells are notched so they have blood drawn only once in their lifetimes, and then they’re released back into the Bay. A proportion do die after they’re released, but estimates of how many vary.

Horseshoe crabs were clearly overharvested through the 1990s, and their population is down compared to decades ago. While they are not yet considered endangered or even threatened, they’re considered “near threatened.” If they continue to be overharvested for bait and for toxin detection, or if their spawning grounds are threatened by development, they could become endangered.

Enter the Ecological Research & Development Group (ERDG), a non-profit focused on the conservation of horseshoe crabs. It encourages communities in the spawning area of the Delaware Bay to declare themselves horseshoe crab sanctuaries, and Pickering Beach, Kitts Hummock, Slaughter Beach, Fowler Beach, Prime Hook Beach, and Broadkill Beach have done so. Every May and June, volunteers count horseshoe crabs in the spawning area. They also flip crabs turned over by waves; watch this adorable video to learn how. ERDG has also encouraged the development of synthetics for toxin detection, has developed bait bags that reduce the amount of horseshoe crab bait needed by the eel, conch, and whelk industry, and is looking into bait alternatives.

From DeepSeaNews.com

Enough of horseshoe crabs! Let’s move on to phragmites. On the way in and out of South Bowers, you’ll get a good view of the phragmites or reeds that are pervasive throughout the Delaware bayshore.

Phragmites near South Bowers

As the exhibit below from St. Jones Reserve explains, most of the phragmites you see along the Delaware Bayshore Byway are not native. They probably came from Europe, and here they are aggressive and invasive. They quickly grow very tall and dense, harboring ticks and mosquitos and crowding out native vegetation needed to support local wildlife. They dry out quickly in the fall, increasing the risk of wildfire. Oh, and one more gripe: they’re so tall that by late summer they can block the lovely Delaware bayshore views!

Sign at St. Jones Reserve

Because of all the problems non-native phragmites create, Slaughter Beach has a phragmite eradication program.

Among the phragmites outside South Bowers, we spotted two birds. We’re not birders, so if you know what they are, please let me know!

Now that we’ve covered horseshoe crabs and phragmites, let’s end this blog post with a historic building. As you leave South Bowers, you’ll probably drive by Sardis Methodist Church at the intersection of South Bowers Road, Thompsonville Road, and Milford Neck Road.

Sardis Methodist Church near South Bowers

A stone sign over the entrance says, “Milford Neck M. E. Church 1840 Built 1790 Called Sardis.” (M. E. means Methodist Episcopal.)

Stone sign over the entrance to Sardis Methodist Church

One final tip: The area around South Bowers has weak cellphone signals, so if you use a GPS, plot your route before you start out.