Thoreau's Cape Cod: Ecology, Nature, and Early Environmentalism

Introduction: Thoreau as Naturalist on Cape Cod

Henry David Thoreau was a student of nature for virtually all of his adult life. During his lifetime, Cape Cod was a relatively unspoiled area rich with natural life and people who worked closely with nature, such as farmers and fishermen. Those who lived on Cape Cod tended to be independent sorts, and Thoreau preferred their company to that of people engaged in commerce or other business-related occupations.

In his small book Cape Cod, Thoreau recounts his experiences on walking excursions around Cape Cod during the mid-1800s. In the process, he described much about the unspoiled nature present throughout the Cape at that time.

In the opening chapter, Thoreau talks about the ecology of living along the ocean. In the midst of a desperate sight — the wreck of a boat loaded with immigrants, most of whom drowned — he saw people gathering seaweed to use as fertilizer. The seaweed had been tossed up on the shore by the same storm that sank the ship. Thoreau valued such practical use of what nature had to offer.

His unusual perspective about both people and nature is revealed in this sentence: "I sympathized rather with the winds and waves, as if to toss and mangle these poor human bodies was the order of the day. If this was the law of Nature, why waste any time in awe or pity?" The statement seems insensitive but reveals his deep love of nature in all its forms.

Coastal Ecology and the Ocean Environment

Throughout the book, Thoreau notes things that we would celebrate today, such as exceptionally clean water. He describes swimming in such water with great delight and comments on the fish he can see clearly swimming around his feet. This suggests that fish were more bountiful then than now, and the water considerably cleaner. He also notes the thorn-apple growing around the edges of a small island, suggesting an ecological balance in which the plant helped fight the erosion of that little island.

Further on his walk, Thoreau makes note of several different kinds of seaweed and the environments that produce them. He noted very few, if any, stones near Wellfleet and observed that he saw no rockweed — a water plant that anchors itself to rock. He saw masses of kelp in the water and cut some open to study its structure.

Thoreau spoke poetically about the birds he observed along the coast, noting their differences from woodland songbirds:

"Mackerel-gulls were all the while flying over our heads and amid the breakers, sometimes two white ones pursuing a black one; quite at home in the storm, though they are as delicate organizations as sea-jellies and mosses; and we saw that they were adapted to their circumstances rather by their spirits than their bodies. Theirs must be an essentially wilder, that is, less human, nature than that of larks and robins."

About the ocean itself, Thoreau wrote: "Though once there were more whales cast up here, I think that it was never more wild than now. We do not associate the idea of antiquity with the ocean, nor wonder how it looked a thousand years ago, as we do of the land, for it was equally wild and unfathomable always. The Indians have left no traces on its surface, but it is the same to the civilized man and the savage. The aspect of the shore only has changed. The ocean is a wilderness reaching round the globe, wilder than a Bengal jungle, and fuller of monsters, washing the very wharves of our cities and the gardens of our sea-side residences."

Plant Life, Adaptation, and Natural Selection

As Thoreau begins the walking portion of his trip, he describes the effects of the environment — a sandbar thrust out into the ocean — on the plants of the area. He describes the area as barren, with few trees except for occasional isolated specimens and apple groves. He notes how the windswept nature of the land affected the development of the trees. Many had flat tops or branched from very low on the ground, suggesting that the trees had adapted to the danger of fierce storms by reshaping themselves. Pruning from storms no doubt contributed to this process. He described these patterns as "habits of growth."

He noted that apple groves on the Cape had trees no taller than a man, with no ladders needed to pick the apples. Presumably this demonstrates some degree of natural selection. It seems unlikely that settlers planted only dwarf apple trees; it seems more plausible that apple trees adapted best to the environment of Cape Cod. Later in his book he notes other trees that also grow smaller than they do on the mainland, including oak and pine.

Thoreau noted similar variety among plants along the shore and observed that different plants thrived in different circumstances. He noted the many different varieties of grass and the different kinds of seaweed, which he correctly identified as algae. This careful attention to environmental variation in plant life reflects a mind attuned to what would later be recognized as ecological niche differentiation.