This, along with volcanism, effects sediment supply to the Estuary, which is comparatively low to other estuarine environments. Seismology The estuary's tectonic environment is prone to low severity deep-focus earthquakes. Flora and Fauna The Columbia River Estuary is an extremely biodiverse system, playing host (at some stage in their lifetime or another) to over 70 species of fish, hundreds of species of birds and many reptiles, mammals and amphibians. The number of invertebrate species has not been counted. A comprehensive list containing all the animal species can be found here. Conservation Despite hosting a myriad of life, in the modern era the Estuary has been subject to major changes due to human impact, such that it has undergone many physical changes regarding both the land and water in and around it. Consequently, local biodiversity has been put at risk as many species rely on an evolved and diverse environment in the estuary. The predominant human activities that have historically altered the estuary are jetty construction, diking and dredging. The direct results of these (among less pertinent natural changes) are huge losses of marshes and other shoreline habitats, reduced tidal prism and reduced tidal mixing. Of the higher than 50% of total wetlands that have been lost in the estuary's history, over 70% was due to diking and filling. Meanwhile, it is estimated that at this moment had the estuary remained untouched it would have been able to support up to 138 times the number of herbivores it currently does. Two conservation organisations that operate in the Columbia River Estuary have been working for decades to preserve the environment, working in a wide variety of fields that span from habitat restoration planning and implementation to environmental monitoring and GIS mapping. Between them, the Lower Columbia Estuary Partnership (LCEP) and the Columbia River Estuary Study Taskforce (CREST) have completed many projects that serve to maintain the estuary's ecosystem. Batwater Station Floodplain Restoration Project Run by LCEP, this project reconnected of marshes to the Columbia River Estuary. The project rejuvenated habitats that are used by endangered fish species while simultaneously reintroducing local flora. Structures for beavers were installed and land was revegetated to induce natural environmental processes. Louisiana Swamp Restoration Run by LCEP, this restoration reconnected of habitat to the estuary. The swamp was surrounded and inaccessible to fish, such that the project involved allowing tidal waters to flow in and out in