The Humboldt Bay beaches and dunes are the largest continuous dune system in northern California. Stretching along a thin 34-mile section of our coast, this unique and vulnerable area encompasses a variety of wildlife habitats. In a narrow strip less than a mile wide, you can experience the pounding surf on ocean beaches, wildflowers of the dune mat, wetland hollows, open sand dunes and beach pine forests. You can become a positive force in preserving and restoring the dunes by learning more about the area, its unique plants and animals, cultural history and natural beauty.
Cultural History
Wiyot people have long lived around Wigi, or Humboldt Bay. This place was and still is, the center of their culture. For thousands of years, native people enjoyed the abundant and varied resources surrounding the bay. The Wiyot territory extends from Little River to Bear River and as far east as the prairies of Kneeland. Not long ago, Wiyot people used the dunes of the north and south spits to gather and hunt for what they needed in their daily lives, such as surf fish and various berries that were dried in the sun. Women would gather food and prepare weaving materials while the men would fish and make new tools to replace old ones.
By the mid 1800's, the quest for gold and timber brought settlers to the area seeking to make their fortune. Tragically, greed for land and resources led to brutal acts of violence against the Wiyot people. Violent clashes along with exposure to foreign diseases such as smallpox nearly annihilated native people. The newcomers displaced the Wiyot and changed the landscape around Humboldt Bay. Marshy areas were drained and diked for cattle pasture, and railroads were built to take logs out to waiting ships. Towns grew and people used the bay and coast mainly as a transportation hub for industry.
Today, Wiyot people still fish and gather in some areas around the bay, but land usage has changed, and many of the plants once collected are not in the abundance they once were. The Wiyot are actively involved in protecting areas for gathering as well as establishing economic, health and educational projects and revitalizing aspects of traditional culture such as language, ceremonies and the arts.
Dune Formation
The key ingredients needed to build a dune system include a source of sand, a shoreline perpendicular to the prevailing winds and a low landscape over which dunes can migrate. In addition, plant species that are adapted to survive the drying winds and shifting sands are needed to help shape and build the dunes. Here in the Humboldt Bay area, the Mad and the Eel rivers supply most of the sand. Winter storms flood these rivers and transport sand to the ocean. Sand is carried by currents along the coast and pushed up on to the beach by gentle summer waves. Once dry, the sand is moved by the prevailing summer winds from the northwest. This dynamic process has created of a variety of dune habitats within a narrow stretch of coastline.
Dune Habitats
The waveslope is the area of the beach that shows evidence of having been washed by waves during the last tidal cycle. Beachcombing here you can find everything from eelgrass, pacific razor clam shells, sand dollars, to the carcass of a gray whale. This is also the feeding area for a number of shore birds. They feed on small invertebrates in the sand and in the seaweeds washed on shore. The upper end of the waveslope is the strand. Here you may find plants such as sea rocket and native dune grass starting to colonize the bare sands.
The series of dunes and ridges paralleling the beach are collectively called the foredunes. In areas that are relatively undisturbed by invasive species, you can find a unique community of plants referred to as the dune mat. Here, a wide array of wildflowers adapted to the drying conditions of the dunes help stabilize the shifting sand. The dune mat is home to two federally listed endangered plant species, the Humboldt Bay wallflower and the beach layia. Take care to stay on the main trails through these areas.
Hollows/Swales form when the summer wind has removed the sand down to the water table, allowing water-loving plants to move in. During winter storms the water table rises and forms seasonal ponds in these areas. Tadpoles of the pacific tree frog and red-legged frog can be found here. Eventually forests may develop in these areas.
Few plants can survive the open sands of moving dunes. Look for mammal tracks of nocturnal animals like gray fox, skunk and raccoon crossing from the different areas. In some places, you can see that these moving dunes are slowly covering the dune forest. Large beach pine and Sitka spruce create an area that is surprisingly different and diverse. Developed soils allow for thick plant growth, with huckleberry, silk tassel, red-flowering currant and salal. The forest is also home to many species of lichens, including puffy mats of reindeer lichens, more characteristic of northern forests.
Salt marshes and estuaries are recognized by biologists as among the most productive habitats in the world. The nutrient rich waters form the basis of the salt marsh food chain. Plants such as pickleweed and salt grass are specially adapted to tolerating the salty conditions of a tidal area.
Protecting Endangered Species
The Humboldt county beaches and dunes are home to two federally listed endangered plant species; the Humboldt Bay wallflower and the beach layia. In addition, the western snowy plover, a small shorebird, is listed as a threatened species. The coastal habitats for these species are subjected to development pressures, recreational uses including off highway vehicles, and encroachment by invasive plant species. The Endangered Species Act provides a mechanism to protect these species and the ecosystem upon which they depend. By conserving the dunes, we protect endangered species.
The Western Snowy Plover
The western snowy plover is a small, sparrow-sized shorebird with dark patches on each side of the upper breast. Snowy plovers usually nest in open sandy areas, laying their eggs in a bare sand depression. The eggs and birds blend in amazingly well with the environment and can be accidentally disturbed or crushed. During plover breeding season, March 1 to September 30, limit beach activities to the wet sand of the waveslope and dogs on a leash in order to avoid disturbing nesting plovers.
Snowy plovers prefer nesting sites that are open, with sparse vegetation in order to see approaching predators. The invasion of European beach grass has drastically reduced appropriate nesting sites by creating a thick, vegetative cover that reduces visibility for the plovers and provides shelter for predators. Loss of habitat along with increased recreational use of beach areas has also led to a dramatic decline in the snowy plover population in Humboldt County. Restoring native dune habitat and increasing public awareness are essential elements of the plover's recovery.
Restoring the Dunes
In the dune system that depends on change, invasive plants have upset the ecological balance by inhibiting sand movement, changing soil chemistry and crowding out native plants. Many non-native, invasive species were first introduced to the dunes for the purpose of stabilizing the shifting sands. Restoration of the dunes focuses on hand removal of non-native, invasive plant species. This helps restore native plant biodiversity and return natural processes to the dune ecosystem. You can get involved in restoring local dunes by participating in a public restoration day.