Estuarine Ecosystems (ES)
In the Discovery Islands
• Estuarine ecosystems occur where a creek meets the sea. Estuaries are where fresh and saltwater mix and become part salty or brackish water that mixes with deposited sediments and where everything is also influenced by the rise and fall of the tide.
• Estuaries are typically small; occurring as meadows, marshes, and tidal flats, with a range of vegetation tolerant to fresh, brackish or totally salt conditions.
• Estuarine ecosystems are critically important areas for many marine and terrestrial lifeforms – from essential micro-organisms, tiny invertebrates and lush plants to migrating salmon and foraging bears.
Estuarine ecosystems are transitional areas with a complex food web fueled by dynamic nutrient and oxygen-rich conditions that create some of the most biologically productive ecosystems on Earth. Resident invertebrates, fish, and plant species must be adapted to survive the physical challenges peculiar to estuaries. In the Discovery Islands, many of the larger creeks and inlets have small meadow or marsh estuarine ecosystems.
Just as an estuary is where physical elements of ocean and land converge, it is also where the lifecycles of aquatic and terrestrial species intermingle. Salmon are one of the major catalysts of this interface. They utilize estuarine habitats at various points throughout their lifecycle when they come to reproduce, feed, or rest and refuel on their migrations. In exchange, both adult and juvenile salmon provide food for the many avian and terrestrial species that rely on estuarine ecosystems for their food supply.
WHEN YOU EXPLORE estuaries, take care to protect the soil and vegetation. Walking on estuary plants crushes their fragile structure and can also damage anything living on or under them. Sediments are unstable, yet they are vital and erosion causes loss of valuable habitat.
Look For Typical & Rare Species in Estuarine Ecosystems
FAUNA Black bear, mink, great blue heron, bald eagle, mallard duck, American widgeon, common merganser, Canada goose, trumpeter swan, belted kingfisher, western garter snake, raccoon, Pacific lamprey, beach crab, pale tiger swallowtail, American dipper, river otter, coho salmon.
FLORA Alaska plantain, ditch-grass, eel grass, entire-leaved gumweed, hard-stemmed bulrush, Lyngby’s sedge, northern rice-root, seashore salt-grass, sickle-leaved rush, dune wildrye, common spike-rush,
SPECIES AT RISK Small spike-rush (Blue), Vancouver Island beggerticks (Blue, Special Concern), Henderson’s checker-mallow (Blue), salt marsh Philadelphia fleabane (Red), double-crested cormorant (Blue) green heron (Blue), pointed rush (Blue), yellow sand verbena.
*For comprehensive species lists & rarity explanation, click here.