The Wet Part of the Property

Living with wetlands in the San Juan Islands from the San Juan Islands Conservation District

This article is part three of a five part series from the San Juan Islands Conservation District providing education around streams and wetlands in the islands. To learn more or to receive technical assistance from the San Juan Islands Conservation District on your property, please visit: https://www.sanjuanislandscd.org/streamsandwetlands

Learning to See a Wetland

A wetland does not always make itself clear. It may have no cattails, no permanent pond, no great blue heron standing in the shallows. Within the household it may be known simply as “the low spot,” “the back field,” or “where the mower gets stuck.”

In the San Juan Islands, where water is both abundant and scarce, wetlands are especially ambiguous. Winter rain gathers in shallow basins, old drainageways, and coastal swales; then summer rearranges the evidence. A place that seems dry in July may still be a wetland. What matters is not whether it holds water every day, but whether water remains long enough, and returns often enough, to shape the soil and the community of plants adapted to it. Wetlands vary accordingly: some are tidal and saline, some forested, some grassy and seasonal, and some little more than a darkening of the ground that becomes intelligible only after several winters of attention.^[1]

This can be disappointing news to a landowner who has already imagined a garden, guest cottage, driveway, or particularly level croquet lawn. Wetlands have long suffered from our conviction that every piece of land ought to declare a productive purpose. If a place was wet, it could be ditched. If it was brushy, it could be cleared. If it could not be farmed or built upon, it could at least receive several wheelbarrows of lawn clippings.

But a wetland is not vacant land. It is land already at work.

During heavy rains, wetlands hold water and release it gradually. They slow runoff, retain sediment, transform or store nutrients, and reduce the force with which water reaches downstream channels and shorelines. Some receive groundwater; others help replenish it. Many do both at different points in the year. These functions arise from a wetland’s position within a watershed—from its soils, plants, microbes, topography, and connection to other waters—not from a single feature.^[1]

For wildlife, the wet center is only part of the arrangement. A northern red-legged frog (Rana aurora) may breed in still or slow water and spend much of the rest of its life in damp woods and thickets. The wetland and its upland edge are not separate amenities. Together, they make a habitat.

The vegetated ground around a wetland is called its buffer, a word for something quite alive. A buffer filters runoff, slows floodwater, shades shallow water, stabilizes soil, and gives animals a route between feeding, breeding, and sheltering places. Cutting a narrow opening through it can seem harmless. Ecologically, it may resemble cutting a doorway into the wall of a quiet room: light, wind, pets, noise, and repeated human movement begin to pass through.

A dense margin of slough sedge (Carex obnupta), Pacific willow (Salix lasiandra), red-osier dogwood (Cornus sericea), or hardstem bulrush (Schoenoplectus acutus) may look untidy beside a mown yard. But its apparent disorder is structural. Roots bind soil; stems interrupt runoff; leaves intercept rain; dead vegetation feeds the small organisms at the base of wetland food webs.

The Islands as a Resting Place

Coastal wetlands have a second geography, one that cannot be read from a parcel map. The San Juan archipelago lies within the Pacific Flyway, the broad migration corridor linking Arctic and subarctic breeding grounds with wintering areas farther south. To a bird crossing the Salish Sea, a shallow marsh, tidal flat, protected lagoon, or wet pasture can function as both dining room and refuge: a place to replace the energy spent in flight and wait out wind, tide, or weather. Wetlands are especially valuable during migration because they concentrate food—seeds, aquatic plants, insects, crustaceans, mollusks, and small fish—within shallow, accessible water.^[1]

The birds make the continental scale of this local habitat visible. Dunlin (Calidris alpina) probe exposed mud with quick, sewing-machine movements. Black-bellied plovers (Pluvialis squatarola) pause, watch, and run. Western sandpipers (Calidris mauri) gather along soft margins; brant (Branta bernicla) feed in protected marine shallows; great blue herons (Ardea herodias) work drainage channels and tidal edges with severe patience. The U.S. Fish and Wildlife Service lists all of these among the birds that frequent the San Juan Islands National Wildlife Refuge.^[3]

The refuge itself was created in 1960 to protect habitat for migratory birds and other wildlife. Its eighty-three rocks, reefs, and islands are best known for marine birds, including pigeon guillemots (Cepphus columba), rhinoceros auklets (Cerorhinca monocerata), black oystercatchers (Haematopus bachmani), and double-crested cormorants (Nannopterum auritum). The refuge’s purpose is a reminder that the archipelago is not merely scenery between ferry terminals. It is an inhabited link in a hemispheric system of movement.^[2][3]

Privately owned coastal wetlands enlarge that system. A marsh behind a berm, an estuarine pocket at the mouth of a small stream, or a seasonally flooded field near the shore may be modest in acreage yet consequential in position. Migratory birds do not experience habitat as a set of isolated preserves. They encounter a chain of usable places. When one link is drained, hardened, mown to the edge, or repeatedly disturbed, the distance to the next safe feeding and resting site grows longer.

This is why disturbance can matter even when it leaves no obvious scar. A dog charging through a flock does not fill a wetland or cut down a shrub, but it forces birds into the air and makes them spend energy they arrived to recover. Repeated interruptions can make otherwise suitable habitat functionally unavailable. The quieter margins of coastal wetlands are therefore part of their value, especially during migration and winter, when short days, cold water, and storms narrow the birds’ margin for error.

This does not mean that a wetland must become a forbidden kingdom, observed only through binoculars from the kitchen. Walking, birdwatching, photography, and other quiet activities can be compatible with wetland health when routes are carefully placed and use is adjusted to the season. A modest path outside saturated soils is different from a trail that becomes a drainage channel. Occasional observation is different from repeated disturbance during nesting, breeding, or migratory stopovers.

The governing principle is less “keep out” than “tread lightly, and notice what happens.”

Visit the same place through the year. Photograph it from a fixed point each month. Notice where water enters and leaves, which plants stay green longest, where frogs call, where swallows feed, and where the soil remains dark after the surrounding ground has dried. Watch the shoreline in October and again in March. The birds that appear for only a few days may reveal as much about the wetland’s importance as the species that live there year-round.

Over time, what first appeared to be an inconvenient patch of wet ground becomes legible. The standing water in January, the frog chorus in March, the sedges in June, the dragonflies in August, and the shorebirds arriving with the autumn tide are not separate events. They are expressions of one system moving through the year.

Property ownership encourages a particular grammar: my woods, my field, my pond. Wetlands quietly complicate the possessive. Water arrives from uphill and leaves for a neighbor’s land. Birds pass between continents. Amphibians cross survey lines. Groundwater moves beneath them. What happens in one place becomes part of the conditions somewhere else.

To live with a wetland is to discover that the wettest portion of the property may also be the part least confined by it.

To learn more or to receive technical assistance from the San Juan Islands Conservation District on your property, please visit: https://www.sanjuanislandscd.org/streamsandwetlands