Getting to Terrapin

some rise,
some fall,
some climb – to get to to Terrapin

– The Grateful Dead

The word terrapin is rooted in the language of native peoples of North America. It is derived from torope, which comes from the southern Algonquin, and more specifically, from the long-extinct Powhatan tongue. It’s no secret that words and phrases change over time, and when Europeans roll unfamiliar and exotic words around in their mouths, torope becomes terrapin. Early naturalists cemented the use of terrapin, apparently in use for at least a century before Blasius Merrem erected the genus Terrapene in 1820. Along with North American box turtles, Terrapene also included other forms, such as musk turtles. In 1825, Thomas Bell used the genus Terrapene for those turtles across the planet that he considered intermediate between land and aquatic forms, still including the North American box turtles. Over taxonomic time, other forms were sorted into other genera, and the lucky boxies retained sole ownership of Terrapene.

Salt marsh home for New Jersey terrapins

Europeans may have adopted and subsequently modified torope to terrapin for turtles, but there is some evidence that the Powhatan people actually had other terms for land turtles, and that torope originally referred to the tidewater turtle that must have been amazingly common and widespread along the coastline of eastern North America, even in the 18th century, when European naturalists made a muddle of things (see Adler et al 2016 for much more on this subject). I’m referring of course to the Diamondback Terrapin, Malaclemys terrapin, denizen of coastal marshes and so nice they named it terrapin twice. As a land-locked midwesterner, I was more than pleased to finally see the original terrapin in all its glory on a recent visit to New Jersey.

Terrapin heads

I spent ten days poking around in New Jersey with friends this past May, and during that time, we made two visits to protected marshlands along the Jersey shore. On our first visit, we arrived at mid-morning, and it wasn’t long before we spotted quite a few turtle heads poking out of the water. I hadn’t expected to see so many terrapins right away. The tide was going out, and the turtles were just drifting along with the current, only ducking under if we got too close to the bank.

A basker

Most of the diamondbacks we saw were in the water, and none of those were engaged in surface basking, But driving along a causeway, we spotted several turtles hauled out and basking on high spots. I managed a few photos, but terrapins are wary, and if we exited the car, they were quick to scuttle back to the safety of the water. Not quite the experience I had hoped for, but I had seen quite a few turtles.

Terrapin encountered on a causeway road

We came back to the marshes a few days later, and our encounters with terrapins on this second visit would be significantly different. To begin with, we encountered quite a few turtles crossing the causeway road, and along with getting some nice photos, we also escorted a number of turtles safely across the road. They all looked to be females, and as this was the advent of egg-laying season, that made sense.

Terrapin on the road

A lot of fishermen and other recreators roar up and down the causeway road, and no doubt a number a turtles meet a heartbreaking end under the wheels of trucks and boat trailers. This was confirmed when we ran into a turtle researcher involved with a project to create more nesting areas for female Malaclemys. Some turtles are lost to cars, but many of the local people are involved in protecting them, and there are a lot of ‘turtle crossing’ signs posted on the roads around the marshes.

Strong jaws and heavy duty beaks on a female. Note the healed injury to the front of the carapace.

As a result of our escort duties and our conversation with the turtle researcher, we got a close look at a number of terrapins. Their heads are quite large, with powerful jaws and strong, thick beaks to help them eat clams, snails, marine worms, and other invertebrates. Female terrapins are significantly larger than males and can crunch up larger prey items, such as crabs and mussels.

Surface-basking terrapin

We also figured out that we could get good looks at swimming terrapins by walking up on bridges that spanned estuary flows. The turtles didn’t seem to be so spooked by us if we were looking down at them from a height. On this day, quite a few turtles were surface-basking, and the tidal currents were not as strong. I was able to get some great photos and video, and I also just enjoyed watching them swimming around.

Malaclemys terrapin may be ‘locally abundant’ in those protected New Jersey tidal marshes, but as a whole, the species is in dire straits. Once upon a time, their range encompassed tidal zones and estuaries from Cape Cod in Massachusetts all the way to the coast of southern Texas. Prior to European settlement, their numbers must have been staggering. With Malaclemys, there is the sad old story of habitat loss, but for several hundred years they suffered the additional burden of being quite tasty. While native peoples included the terrapin in their diet, in the 19th century an insatiable demand for turtle soup brought Malaclemys to the brink of extinction.

The local community is involved but the sign-maker is a bit off the mark.

Nowadays terrapins have a variable patchwork of state protections, and in my mind they deserve federal protection to compensate. While the food market demand is much diminished, the diamondback terrapin still suffers from habitat loss, propeller accidents, and from getting caught and drowned in crab traps. The rise of ocean levels is also a threat, and like many other turtle species, eggs and neonates fall prey to out-of-control populations of raccoons and Norway rats.

Map turtles (Graptemys) are the closest relatives to Malaclemys – the two species have a common ancestor back in the late Miocene, perhaps 7-11 million years ago. It is likely that terrapins diverged from map turtles or from a map turtle ancestor, as taking up residence in salt marshes and tidal estuaries required some degree of specialization. While Malaclemys are not truly ocean turtles, they have evolved some mechanisms to help them tolerate an environment where the water is salty to varying degrees. They have small postocular lacrymal glands that help them to shed salt, and they are able to tolerate higher levels of sodium in the bloodstream and in tissues for a time. Unlike sea turtles, which are able to derive their water needs from sea water, terrapins require fresh water, and during heavy rains they will drink from a thin film of fresh water on the surface.

I can’t wait to see terrapins again and I hope there’s enough habitat left to sustain them going forward. It would be fun to see some juveniles, but if nothing else I’d like to spend more time watching them as they float on the surface of the marsh, or poking their gray speckled heads up out of the water.

For more on the fabled torope, do yourself a favor and find a copy of Diamonds in the Marsh: A Natural History of the Diamondback Terrapin by Barbara Brennessel. You might also want to give the Grateful Dead’s Terrapin Station a listen, just for grins.

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