52 Weeks of Charity

Spending a Night NYC Horseshoe Crab Monitoring

Here are things you may not know about Atlantic horseshoe crabs:

• They are one of the world’s oldest species. Scientists have discovered fossils of horseshoe crab ancestors that lived over 445 million years ago (dinosaurs appeared 200 million years ago).
  
• Horseshoe crab blood is blue. Their blood is copper-based, not iron-based like ours.
  
• One mamma horseshoe crab will lay up to 120,000 eggs during a single spawning season.
  
• Horseshoe crabs, and their eggs, glow under UV light/blacklight. The younger the crab, the brighter they glow.
  
• Certain endangered migrating shore birds depend on horseshoe crab eggs to survive, including the Red Knot

High tide hit Big Egg Marsh in Queens at 10:52 p.m. on Tuesday June 20^th. The incoming tidewater lapped against my knees… a good 3 or 4 inches above the tops of my rainboots… as I carefully and slowly walked along the shoreline trying not to step on the hundreds of horseshoe crabs who had migrated in this night to mate and spawn their eggs.

The only light coming from my headlamp and with the wind pushing the incoming tide, it was a bit disorienting to determine where to put my next step.

The bodies of female adult horseshoe crabs are the size of dinner plates. If you include their tails, they could easily be two feet long. Males are smaller, faster. Tails quickly moving back and forth as they skitter through the water. They use their tails for stability, not for protection, a fact for which I was grateful as dozens of them swarmed around my feet.

The mosquitoes were intense and unforgiving. Any new skin exposed to the air without a layer of bug spray would quickly be covered in mosquitoes looking for a late-nite dinner. In the time it took me to push my long sleeves back from my wrist up to my elbows and spray a good dose of bug repellent, I counted no less than a dozen mosquitoes landing on my arm for a feast.

I was part of a small team of volunteers with the NYC Audubon Society, there to monitor the horseshoe crabs by counting them, checking for (and recording) pre-tagged crabs, and then tagging a few of our own after catching them, measuring them and checking for a few specific characteristics before releasing them back into the bay.

If you’ve never caught a live horseshoe crab it is like picking up a piece of ancient earth. Shells hard and dark, sometimes covered in barnacles, they’re faster than you think. They can weigh up to 11 pounds. All of which makes catching them in the water in the complete dark, under a new moon, using only your headlamp to track them, a challenge.

Picking them up means placing your hands on either side of the center edges of their body shells and quickly flipping them up and over so their 10 pairs of legs are flailing about in the air. From here, upside down, you can see their claws, their gills, and their jawless mouths, which, if you touch it, feels a bit like you’re running your finger along extra sturdy toothbrush bristles.

Their tail – while not a weapon – does whip up and down when you pick up a crab, as if it is doing violent sit ups. It’s an effort to thrust the tail up and down in hopes you drop them back into the water so they can escape. It is a bit unnerving if you have never done it. The tail may not be a weapon but it still pinches when it whaps you in the face.

One thing you should never do is catch them or hold them by their tail. It may look sturdy, but it is very fragile and easily damaged and if injured means it cannot properly navigate the waters. The tail also has photoreceptors that allow it to sense light, helping it understand where the shore is.

Our group had arrived at the site in the dark around 9:30. We took some initial shoreline measurements and set up our equipment. Dottie – our leader from the Audubon Society – took us through the process of what was to come and gave us tons of information about the crabs. Horseshoe crabs are not really crabs at all. They’re actually closely related to scorpions. A fact that also made me grateful they do not use their tails as weapons or for defense.

The crabs only come to shore in May and June during new and full moons – leaving the safety of the deep water to make their way up the Atlantic coast to breeding grounds where they mate and spawn eggs. Lots of eggs. They arrive by the hundreds of thousands along the shallow waters along the beaches.

Mating is unique. Males migrate to the inshore waters first and wait for the females to arrive. The females are much larger than the males. In the shallow waters, as the females begin to make their way towards the beach, the males battle to attach their front legs to a female’s shell.

There could be a dozen males vying for one female. When the female moves onto the very edge of the water, just at the very edge of the beach, she digs a small hole (a nest) where she deposits strands and strands of eggs, sometimes thousands at a time. At the same time the male releases his sperm over the eggs to fertilize them. It is not unusual for another male to come charging in and also release his sperm over the eggs too.

Females lay as many as 4,000 eggs in one nest and will create 5 to 7 nests in one visit to the beach. Each female returns to the shore many times during spawning season.

The eggs are the size of pearl couscous, almost indistinguishable from the sand except they glow under blacklight/UV light. We saw several nests of eggs during our time on the beach.

They will hatch in 2-4 weeks, during a high tide where the eggs are covered by the water. They use the waves to carry them out to sea.

We came across a nest of early eggs who were hatching. If you were to scoop some up in your hands you would see they are shaped exactly like their parents. Tiny, miniature versions of their earlier generations.  

It’s hard to believe something so tiny will hatch and make its way to the enormous ocean to one day become a full-grown adult.

NYC Audubon has dozens of teams spread out across several sites in Queens and Brooklyn tonight and for 12 – 15 nights in total (depending on migration pattern and moon phase). These beaches have the highest densities of horseshoe crabs on the East Coast.

Our monitoring of the population is part of a statewide project to survey spawning populations. The NYC Audubon is partnering with Cornell Cooperative Extension’s Marine program and Stony Brook University as well as the NY State Department of Environmental Conservation. The information is used to create conservation and management plans.

11 species of migrating birds, including several endangered and threatened ones, rely on the eggs to replenish their fat supplies as they migrate to northern breeding grounds. The horseshoe crabs and birds have developed an interesting symbiosis. Female horseshoe crabs will often dig up existing nests where all or some of the eggs did not hatch. This makes the eggs available to the birds – making it easy for the birds to get nourishment that way instead of needing to dig up fresh nests.

The crabs are threatened in many ways, all of which are human:

• Biomedical use – Because horseshoe crab blood is copper-based and contains a special clotting component, an extract of it is used to test pharmaceuticals and medical devices for bacteria (to insure there is none). Vaccines and implants are primary areas where horseshoe crab blood is used for such testing. Pharmaceutical companies typically harvest the crabs by hand during spawning season. They transport them to labs where they are cleaned and then 1/3 of their blood is removed. After a bit of care to be sure the crab is healing, they return them about a week later to the ocean. This interferes with spawning. It is not uncommon for the crabs to die during the process.
  
• Climate change is changing the temperature of the ocean, the patterns of ocean circulations, changing the temperature, height and depth of the water along the coastlines. This affects the migration and breeding of the crabs. Additionally, as humans build sea walls and other interventions to fight sea level rise, it often negatively affects their breeding grounds
  
• Pollution of the water and beaches
  
• Bait fisheries often harvest horseshoe crabs and cut them up to use as bait for eel. More breeding areas have been set aside as protected areas where such harvesting is not permitted, but the activity still exists.

During our count tonight we came across several crabs that had been tagged in previous years. The goal with these was to catch them to measure and inspect them, get a photograph of the tag, and then record it so it can be tracked throughout its life. One horseshoe crab we found was over 10 years old. Each of us in the group found at least one tagged specimen.

After completing the counting, it was time for each of us to pick up a sample crab for measuring and tagging. I picked up a female. She was about 2 feet long and very dark, meaning old (the shells of the older crabs are darker than the younger ones). She had barnacles on her back section.

I tagged her with a tracking number and released her wondering where her journey would take her.

Making my long journey back from the beach in Queens to Manhattan NYC on the A train Subway at 1:30 in the morning, wet clothes and smelling like sea water, I was feeling exhausted, excited and amazed.

It was humbling to be able to hold and examine one of the Earth’s oldest living species – unchanged for 400 million years.

I could not help but wonder….. Horseshoe crabs have survived the prior 5 mass extinctions of Earth’s history. Even outliving the dinosaurs. Would they survive this current man-made one?

I am eager to learn more about the population pattern (increasing/decreasing) and I am already looking forward to helping out again next year!

Thank you for joining my journey this week,

Penny

If you’d like to learn more about NYC Audubon, get involved, or support their programs, please check out: Who We Are | NYC Audubon

To learn more about the New York Horseshoe Crab Monitoring Network, check out: New York Horseshoe Crab Monitoring Network (nyhorseshoecrab.org)

Volunteering with the Billion Oyster Project

When you think of oysters, what comes to mind? Fresh oysters on the half shell served with horseradish or lemon or sriracha sauce?  Broiled Rockefeller style oysters, topped with herbs, butter and breadcrumbs? YUM!

What about as a keystone species that plays both an essential role in the ecosystems of shorelines, and can help solve the challenges of the impact of climate change?

The Billion Oyster Project (BOP) is focused on this unassuming, yet very powerful, resource, by pledging to restore 1 billion oysters to the NY harbor by 2035.

Since 2014 BOP has worked with various NYC communities, schools, scientists, and volunteers, to restore oysters at 18 active restoration sites across the 5 NYC boroughs.

They have developed a K-12 STEM curriculum and work with over 100 schools across NYC with hands-on activities to help students become citizen-scientists working to solve local environmental challenges.

They work with the Urban Assembly NY Harbor School, helping prepare students of the HS on Governors Island for maritime careers. And they also have involved almost 15,000 volunteers at various projects to help be part of the restoration process. Building a community focused on helping the community!

Why Oysters?

Top 3 key environmental roles the oyster plays:

1. One single adult oyster filters up to 50 gallons of water a day! They absorb nitrates, ammonia, phosphates, plankton, and bacteria, and reduce excess algae and sediment. Oysters help keep the water clean and full of oxygen.
2. The reefs oysters create together are natural barriers that protect shorelines from erosion, tides, and storm surge (reducing flooding, softening the blow of large waves, and preventing erosion).
3. Like coral reefs, oyster reefs foster biodiversity by providing a 3-D living. clean, oxygen-filled habitat for hundreds of species of marine wildlife.

Back before Henry Hudson traveled up the New York river that was to eventually be given his name, oysters were everywhere and had long been a staple food of the local Lenape peoples. Archeological evidence of mounds of shells (called middens) up to 4 feet high date back to 6950 BCE ⁽¹⁾ and reveal that oysters were not only plentiful, but were much larger than the kind we see today – up to a foot long on average and many much longer! ⁽²⁾ 

Oysters, Oysters Everywhere!

In the early 1600’s, with the arrival of Henry Hudson and the Europeans, the New York harbor was home to over 350 sq. miles⁽³⁾ of oyster beds.

It is said, from writings at that time, it was easy to reach into the water and pluck out large oysters like fruit from a tree.

Through the late 1700s, nearly half the world’s oysters were produced in the NY Harbor.⁽²⁾

In fact, Oysters were the original street vendor food. In the mid to late 1700s and early 1800s (long before the hot dog), street cart vendors selling oysters along with hot corn, peanuts and buns, were ubiquitous throughout the streets of New York.

By 1927, however, oysters in the New York harbor were all but extinct due to:

• Over-farming/over-consumption,
• The expansion of NY – the dredging of the harbor and extension of the tip of NY was built over oyster beds,
• Pollution – The drastic increase in shipping and boat traffic in the harbor along with (up until 1972, with the passage of the Clean Water Act) the dumping of millions of gallons of raw, untreated sewage in the harbor every day, killed oyster beds in droves. Note here – unfortunately NYC’s combined sewer system still ejects sewage with storm water during peak flow – once it hits 1/4 inch high – continuing to damage beds and pollute the waterways).⁽⁴⁾ EWWW!

Volunteering

As a volunteer, I was signed up to help a group build oyster reef structures, called gabions, and prepare shells for the hatchery by sifting through them for unwanted debris. It was a 5-hour shift (including a lunch break). There were about 15-20 people volunteering that day.

We started the day with a group meeting where our host-leader, Inca, had us introduce ourselves and explained all about the process of growing oysters and creating a reef. They also gave us some of the history of the Billion Oyster Project. It was very interesting! Throughout the day Inca was there to give guidance and answer the tons of questions we seemed to have. They were wonderful and kept us motivated and the day exciting!

A gabion is a steel mesh cube that fits snugly into a raw bar steel frame. There are hollow columns in the middle of the structure to allow water, air, and nutrients to flow through (as well as marine life). The structure provides a strong, current-resistant, 3-D environment.

It is filled with juvenile oysters that have attached themselves to recycled oyster shells (they are called spat). The juveniles are raised in a safe environment at the Harbor School Hatchery then, once established and strong enough, moved into the gabions.

The gabions are then placed in areas where reefs are being developed. Over time, the mesh degrades, but the steel frame remains, while the newly-planted oysters grow and cement together.

Our job was to construct as many of the mesh gabions as possible during our shift. Staff from the BOP were on hand to provide educational lessons and to answer our ongoing questions.

Since 2014, BOP has restored 100 million juvenile oysters in the harbor. Over the past year or so they have found the oysters are starting to reproduce by themselves in the harbor. An exciting sign the population can become self-sustaining! In addition, BOP is now finding a wider variety of marine life around the oyster reefs, such as crabs, seahorses, pufferfish, herring, striped bass, red bearded sponges and more.

In order to grow the oysters to create the reefs, BOP needs millions and millions of shells.

So… where do all the shells come from? 

BOP partners with over 70 restaurants in NYC to collect the discarded shells of oysters consumed by their patrons.

BOP provides special buckets for collection and then partners with a shell collection service to pick them up and dump them onto long, 4-5 foot high piles of shells on Governors Island (middens).
These 70+ restaurants can donate up to 7,000 pounds of shells a week!

Since 2014 they have collected over 2+ million pounds of recycled shells, repurposing them to build the oyster reefs and keeping them out of landfills. Yet another way BOP is caring for the environment.

The second part of the volunteer shift was to help look through the middens (the piles of recycled shells donated by restaurants) for objects that don’t belong such as plastic bags and bottles, metal forks and other cutlery, rocks, etc. We also threw away any mussel shells since those would harm the oyster beds.

The middens were 4 to 5 feet tall about 25-30 feet long. They shells deposited there are first picked clean by the birds and critters and cleaned by the sun and rain. The piles are turned intermittently so they can get exposed to all that happens. They rest there about a year. Then there’s a manual cleaning with a tumbler that scrubs them the rest of the way so they are ready to be taken to the hatchery to become part of the project.

The hatchery is a set of semi-open, topless shipping containers where the baby oysters are able to latch onto the cleaned shells and grow to juveniles in a less hostile environment than the open harbor.

Harbor water still flows through the hatchery, but the hatchlings are semi-protected until they are deemed strong enough to be put into the open harbor.

By the end of the day’s volunteer shift, we’d made about 6 or 7 of the gabions and had learned tons from our BOP guide and team member.

It was a fascinating day!

I hope you enjoyed the journey with me. XO XO

How do I Learn More and Get Involved?

To learn more about the Billion Oyster Project and oyster reefs, or donate to this amazing cause, please visit their website at: https://www.billionoysterproject.org/

If you are a teacher and are interested in their resources and educational materials/curriculum, please check out: https://www.billionoysterproject.org/educators
(note – they have wonderful materials for every classroom – you do NOT need to be a NYC school to participate or find value in the materials)

Source Citations:

(1) Wood, S. (n.d.). Pearls of Old New York. Fraunces Tavern Museum. https://www.frauncestavernmuseum.org/pearls-of-old-new-york

(2) Nigro, C. (2011, June 2). History on the Half Shell: The Story of New York City and Its Oysters. Blog of the New York Public Library. Retrieved April 2, 2023, from https://www.nypl.org/blog/2011/06/01/history-half-shell-intertwined-story-new-york-city-and-its-oysters

(3) Kurlansky, M. (2007). The Big Oyster: History on the Half Shell. Random House Trade Paperback.

(4) Hynes, T. (2022, August 4). Aw Shucks: The Tragic History of New York City Oysters. Untapped New York. Retrieved April 2, 2023, from https://untappedcities.com/2022/08/04/history-new-york-oysters/

(5) Ellis, E. R. (2004). Epic of New York City: A Narrative History. Basic Books, Reprint Edition. https://doi.org/ISBN-13:‎ 978-0786714360