Alternative site for the Global ecosystem typology with additional information for ecosystem profiles and indicative maps.
This site is maintained by jrfep
The Transitional waters biome includes coastal inlets that ae influenced by inputs of both fresh and marine water, respectively, from terrestrial catchments and ocean tides, waves and currents. They include deepwater coastal inlets or fjords restricted to high latitudes, and estuaries, bays and lagoons, which are scattered around coastlines throughout the world. Gradients in water regimes, depth, temperature, size and salinity critically influence the function, productivity, diversity and trophic structure of transitional ecosystems. The balance between marine or freshwater influences varies seasonally and interannually, depending on the climate and between inlets with differing geomorphology, catchment size, climate, and exposure to waves and currents. Some inlets are permanently connected to the ocean but others are only intermittently connected, influencing exchanges of water, nutrients and biota between ecosystems. The dynamics of connection and closure of shallow inlets is regulated by variations in steam flow inputs and wave activity. Strong horizontal and vertical salinity gradients, varying with freshwater and marine inputs, structure biotic communities and traits the equip species for occupation of different salinity niches. Autochthonous energy generated by primary production from aquatic macrophytes, phytoplankton, macroalgae and diatoms is subsidised by allochthonous inputs from inlet shorelines, freshwater streams and marine incursion. These high levels of energy availability support complex trophic networks including large populations of macroinvertebrates, fish, waterbirds, seabirds and some mammals and reptiles. Many inlets function as fish-nurseries and bird breeding sites.