Eucyclogobius newberryi

This is the broad concept Eucyclogobius newberryi that includes E. kristinae. Swift et al. (2016) described E. kristinae as distinct based on genetic and morphological analyses, thus confirming previous studies which found that the southern California populations of E. newberryi have diverged genetically from populations farther north, that evolutionary bifurcation is in the vicinity of Los Angeles, and that shallower phylogenetic breaks segregate the northern populations into five groups in three geographic clusters (Dawson et al. 2001; Ahnelt et al. 2004; USFWS 2007).

Discontinuous distribution along the coast of California; characterized by small isolated populations; about 112 extant populations; no longer occurs in about 17 percent of historically known localions; primary threats are habitat loss and degradation, but these are now believed to be not as serious as previously thought; may comprise more than one species.

Range includes discrete brackish coastal lagoons and coastal creeks in California (~1,600 mile coast) from Tillas Slough (mouth of the Smith River), Del Norte County) near the Oregon border south to Cockleburr Canyon (northern San Diego County (formerly farther south, to Agua Hedionda Lagoon, San Diego County) (Swift et al. 1989, USFWS 2007). The species is naturally absent (due to lack of suitable habitat) between the Eel River (Humboldt County) and Ten Mile River (Mendocino County), between Lagoon Creek (Mendocino County) and Salmon Creek (Sonoma County), and between the Salinas River (Monterey County) Monterey Bay and Arroyo del Oso (San Luis Obispo County) (Swift et al. 1989, USFWS 2007). Habitat loss and other anthropogenic factors have eliminated the species from the area between northern Los Angeles County and northern San Diego County (USFWS 2007).

Historically this species occurred in at least 135 localities; current number of extant populations is believed to be about 112 (USFWS 2011).

This species is threatened, or potentially threatened, by: (1) coastal development projects that result in the loss or alteration of coastal wetland habitat; (2) water diversions and alterations of water flows upstream of coastal lagoons and estuaries that negatively impact the species' breeding and foraging activities; (3) groundwater overdrafting; (4) channelization of the rivers where the species occurs; (5) discharge of agricultural and sewage effluents; (6) cattle grazing and feral pig activity that results in increased sedimentation of coastal lagoons and riparian habitats, removal of vegetative cover, increased ambient water temperatures, and elimination of plunge pools and undercut banks utilized by tidewater goby; (7) introduced species that prey on tidewater goby (e.g., bass (Micropterus spp.) and crayfish (Cambarus spp.)); (8) inadequacy of existing regulatory mechanisms; (9) drought conditions that result in the deterioration of coastal and riparian habitats; and (10) competition with introduced species, such as the yellowfin goby (Acanthogobius flavimanus) and chameleon goby (Tridentiger trigonocephalus) (USFWS 2007, 2011).

Current laws and regulations have reduced or eliminated both large- and small-scale habitat loss and alteration. However, some threats to the tidewater goby are still ongoing. These include limited loss and alteration of habitat resulting from development projects, flood control, anthropomorphic breaching of coastal lagoons, and freshwater withdrawal. Also, predation by and competition with native and non-native species continue to be a concern (USFWS 2007).

About 50 percent of the remaining populations are considered vulnerable to extinction due to severe habitat degradation (USFWS 2007).

Populations in large habitats that are close to other occupied habitats are most likely to persist, but habitat alteration and introduced species may eliminate the species from even large habitats (Lafferty et al. 1999).

Failure of tidewater gobies to recolonize habitats after local extirpation may result of habitat degradation of the extirpated locality, rather than an inability to recolonize.(Lafferty et al. 1999).