Shoreline Habitat Classification

Estuarine, intertidal, mixed fine, lagoon, eulittoral

Lagoons are formed when longshore water-borne sediments are deposited to form a spit closing off (partially or totally) an embayment.  Open lagoons are regularly flushed by freshwater and tidal action through a channel, while enclosed ones have no permanent channel and rarely flush.  The latter are usually filled gradually by salt marsh vegetation.  Some lagoons drain completely at low tide, while others retain water because of a sill in the channel. Water in the lagoon evaporates, concentrating salts. Interstitial salinities can reach as much as 80 ppt, but are more commonly in the euhaline range. Toward the landward end of these lagoons, the salinity can grade to < 0.5 ppt if there is freshwater influence.  Productivity is high because of marsh vegetation, eelgrass, microalgae, and terrestrial input. Shorebirds, waterfowl, river otters, and hawks all use these habitats.  Tidal creeks draining lagoons tend to contain mixed-coarse substrata and are occupied by a unique set of plants and animals using this high-flow, variable-salinity habitat.  Probably the inhabitants of each lagoon creek are different, although all will contain filter feeders, epifaunal and infaunal.  Few surveys of benthic organisms in lagoons were found.

Class ID
79
Class name
Estuarine, intertidal, mixed fine, lagoon, eulittoral
Length
149.00
Primary substrate
Sand
Secondary substrate
Mud
Tertiary substrate
Gravel
Substrate stability
Mobile
Substrate key details
Few stable surface features
Wave exposure
Protected, Very protected
Blue book classes
Estuarine intertidal sand or mixed-fine: Lagoon
Map/survey site examples
Inner Westcott Bay, mouth of Union River, Oak Harbor marsh
Diagnostic species
Salicornia depressa
Leukoma staminea
Distichlis spicata
Zostera marina
Neotrypaea
Macoma balthica
Leptocottus armatus
Lumpenus sagitta
Parophrys vetulus
Cymatogaster aggregata
Platichthys stellatus
VEC common associates
Crassostrea gigas
Macoma nasuta
Mya arenaria
Habitat classification system