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When life gives you lemons

An 8 second exposure of mating horseshoe crabs (ISO 1250, 14mm, f 7.1) – I like these kinds of shots, but they give the false impression of the scene being static and dreamy.

An 8 second exposure of mating horseshoe crabs (ISO 1250, 14mm, f 7.1) – I like these kinds of shots, but they give the false impression of the scene being static and dreamy.

Last weekend I drove with a couple of friends to Delaware to watch what surely must be one of the most amazing natural spectacles in North America, the annual mass spawning of Atlantic horseshoe crabs. I do it almost every year, and over time the eight hour drive from Boston to Delaware Bay has become a ritual, my way of communing with the ancient arthropods. (It is also an opportunity for me to gorge on delicious things I normally try to avoid – gas station donuts, Big Macs – after all, there is simply no way to eat healthily while on the road, right?)

A trip to Delaware allows me to flex my photographic muscles and try new approaches to capturing a scene that has been photographed a zillion times already, but this year the circumstances were not particularly favorable for photography. In fact, they could not have been worse. High tides, which is the time when horseshoe crabs emerge from the ocean to lay eggs, were late at night, long after the sun had set. It was new moon and the sky was overcast, hiding the stars. This challenge presented me with three possible options. I could forget about pictures and simply enjoy the show with a beer in my hand – I have already taken thousands of photos of horseshoe crabs, and didn’t really need to take any more. Very tempting. I could also shoot with flashes and get crisp, clinical shots of the crabs’ aggregations. Boring. Or I could think of a new, unorthodox way to shoot them.

Once I used some fill-in light I was able to capture the true, dynamic character of the scene – waves crashing over the bodies of horseshoe crabs tumbling in the brown waters of the Delaware Bay.

Once I used some fill-in light I was able to capture the true, dynamic character of the scene – waves crashing over the bodies of horseshoe crabs tumbling in the brown waters of the Delaware Bay.

Photographing horseshoe crabs is not easy even under the best of circumstances – the light is usually low, salt water splashes on the equipment, waves move the tripod. In the near darkness of the new moon things were even tougher. Still, I was determined to get at least one interesting shot. The idea was to capture the dynamic nature of the spectacle and convey the darkness of its surroundings. I decided to go for a low angle shot of the animals tumbling in the waves, while showing the darkening skyline. I used my Canon 7D with a Canon 14mm fisheye, mounted on a tripod (dug deep into the sand to stabilize it) and positioned less than a foot above the crabs in the splash zone. I had to wipe the camera and lens every minute, but soon they were both dripping wet. I tried a bunch of simple, long exposures (30 seconds or longer), but those produced static, if somewhat dreamy pictures, where the waves turned into a silky mist enveloping the animals. I needed extra light to capture individual waves.

Horseshoe crabs, like some of their distant arachnid cousins, fluoresce under ultraviolet light. A dark, moonless night last weekend was a good opportunity to photograph it.

Horseshoe crabs, like some of their distant arachnid cousins, fluoresce under ultraviolet light. A dark, moonless night last weekend was a good opportunity to photograph it.

A pop of flash often works very well in such situations, freezing some of the action, while the rest of the exposure time allows for the scene to become more diffused and messy. But I did not like the harshness of the flash, and even my headlamp produced illumination that was too bright for a long, ISO 1600 exposure. Only after I wrapped it in a few layers of paper towels did the light become diffused and soft enough for me to start “painting” the scene with it. In the end I was able to capture an image very close to what I had in mind – a melee of animals among waves splashing against their bodies, while the last traces of sunlight reflect off the clouds above. The shot is grainy and dark, but to me it feels right and true to the circumstances. I guess the lesson here is that when life gives you lemons, you photograph them.

During the day, when horseshoe crabs were deep in the ocean, I photographed other things. Great Blue Heron hunting mud crabs in the marshes of the Prime Hook Nature Reserve made for an interesting subject.

During the day, when horseshoe crabs were deep in the ocean, I photographed other things. A Great Blue Heron hunting mud crabs in the marshes of the Prime Hook Nature Reserve made for an interesting subject.

Natural areas surrounding the Delaware Bay are full of amazing creatures. I found this Eastern Mud Turtle (Kinosternon subrubrum) on a country road near the ocean.

Natural areas surrounding the Delaware Bay are full of amazing creatures. I found this Eastern Mud Turtle (Kinosternon subrubrum) on a country road near the ocean.

The Greatest Show on Earth, happening now

The best time to see Atlantic horseshoe crabs (Limulus polyphemus) is on the nights of the full and new moon in May and June.

The best time to see Atlantic horseshoe crabs (Limulus polyphemus) is on the nights of the full and new moon in May and June.

I am still in Mozambique, and will be here for a few more weeks, but I simply must take a quick break from describing African nature to highlight a spectacular phenomenon that is taking place right now along the eastern coast of North America – the mass spawning of the Atlantic horseshoe crabs (Limulus polyphemus). Watching these magnificent animals is to me one of the most beautiful natural events that one can witness, and I encourage everybody living on the East Coast to take a trip to the beach this and next month (this year the best time to see them are nights of May 24th, and June 9th and 23rd.) What follows is a short excerpt from my book “Relics” (Chicago University Press 2011), describing my experience of watching horseshoe crabs on the beaches of the Delaware Bay.

“As hundreds of biting flies did their best to drain us of every drop of blood, my friend and fellow photographer Joe Warfel and I stood on the beach, waiting for the spectacle to begin. The sun grew dim, and the high tide was nearing its peak. There were a few people on the beach when we first arrived, but by now they had all disappeared, and we were the only witnesses to what was about to unfold. I started to tell Joe how strange it was that nobody else stayed to watch, but swallowed a fly and decided to quietly enjoy the rest of the evening. First came the big females. Nearly all had males in tow. In the dimming light we could see spiky tails of hundreds more as they tumbled in the waves, trying to get to the dry land. By the time the sun fully set, the beach was covered with hundreds of glistening, enormous animals. Females dug in the sand, making holes to deposit their eggs, nearly 4,000 in a single nest, while the males fought for the privilege of fathering the embryos. Fertilization in horseshoe crabs is external, and often multiple males share the fatherhood of a single clutch. Equipped with a pair of big, compound eyes (plus eight smaller ones), capable of seeing the ultraviolet range of the light spectrum, male horseshoe crabs are very good at locating females even in the melee of waves, sand, and hundreds of other males.

Delaware Bay is the best place in the world to see these magnificent animals. On a good night one could easily see 100,000 horseshoe crabs.

Delaware Bay is the best place in the world to see these magnificent animals. On a good night one could easily see 100,000 horseshoe crabs.

Horseshoe crabs have been around longer than most groups of organisms that surround us now. A recent discovery in the fossil deposits of Manitoba, an interesting little creature named Lunataspis aurora, proves that horseshoe crabs quite similar to modern forms were already present in the Ordovician, 445 million years ago. By the time the first dinosaurs started terrorizing the land in the Triassic (about 245 million years ago), horseshoe crabs were already relics of a long-gone era. And yet they persisted. Dinosaurs came and went, the Earth changed its polarity and climate many times over, but horseshoe crabs slowly plowed forward. Yet during this time they changed surprisingly little. Species from the Jurassic were so similar to modern forms that I doubt I would notice anything unusual if one crawled in front of me on the beach in Delaware. Somehow horseshoe crabs had stumbled upon a lifestyle and morphology so successful that they were able to weather changes to our planet that wiped out thousands of seemingly more imposing lineages (dinosaurs and trilobites immediately come to mind.) But despite claims to the contrary by creationists and other lunatics, they kept evolving. Modern horseshoe crabs, limited to three species in Southeast Asia and one in eastern North America, differ in many details from their fossil relatives. We know, for example, that many, if not most of fossil horseshoe crabs lived in freshwater, often in shallow swamps overgrown with dense vegetation, and some might have even been almost entirely terrestrial. Currently only the mangrove horseshoe crab Carcinoscorpius rotundicauda from the Malayan Peninsula routinely enters rivers, and is the only species to lay eggs in fresh or brackish water.

Even Sir David Attenborough, the man who probably witnessed more natural spectacles than any other human being, is fascinated by the spawning of horseshoe crabs. Here he demonstrates the improper way of holding a horseshoe crab (never hold them by their telson) while on the beach in Delaware during the filming of the BBC series "Life in the Undergrowth".

Even Sir David Attenborough, a man who probably witnessed more natural spectacles than any other human being, is fascinated by the spawning of horseshoe crabs. Here he demonstrates the improper way of holding a horseshoe crab (never hold them by their telson) while on the beach in Delaware during the filming of the BBC series “Life in the Undergrowth”.

The following morning Joe and I found the beach covered with horseshoe crab eggs. Well-rested and ready to start a bright new day the flesh-piercing flies attacked us with a renewed enthusiasm. Flailing our arms and swatting dozens at a time we went about flipping crabs stuck on their backs in the sand, and started to look for particularly big clutches of eggs. Although females burry the eggs in the sand, the returning tide washes out many of them. Freshly laid eggs are small, not larger then half a grain of rice. Surprisingly, the eggs grow as they develop, eventually becoming more than twice as large. This, of course, is impossible. The “growth” is an illusion, the result of the production of an external, thin membrane by the developing embryo. A fully developed egg, which at this stage has spent two weeks in the sand, resembles a tiny glass aquarium, with a petite horseshoe crab twirling inside, impatient to break the walls of its miniature prison. Once free, the larva (or at least the lucky ones) catches a wave back into the ocean and will spend about a week floating freely, before settling on the bottom of the shallow shore waters to begin life akin to that of its parents.[…]”

Tiny horseshoe crab larvae, known as the trilobite larvae, twirling in their aquarium-like egg shells. Soon they will break free to begin a short pelagic period, after which they settle on the bottom of the ocean to begin a lifestyle similar to that of their parents.

Tiny horseshoe crab larvae, known as the trilobite larvae, twirling in their aquarium-like egg shells. Soon they will break free to begin a short pelagic period, after which they settle on the bottom of the ocean to begin a lifestyle similar to that of their parents.

Just like their distant relatives, scorpions, horseshoe crabs display green fluorescence under the ultraviolet light.

Just like their distant relatives, scorpions, horseshoe crabs display green fluorescence under the ultraviolet light.

Limulus5

Atlantic horseshoe crabs on the Prime Hook Beach near Milford, Delaware.