Publications

The removal of dams has recently increased over historical levels due to aging infrastructure, changing societal needs, and modern safety standards rendering some dams obsolete. Where possibilities for river restoration, or improved safety, exceed the benefits of retaining a dam, removal is more often being considered as a viable option. Yet, as this is a relatively new development in the history

Executive Summary The study described in this report represents the first time that a satellite model has been used to identify potential Southwestern Willow Flycatcher (Empidonax traillii extimus) (hereinafter referred to as “flycatcher”) breeding habitat rangewide for 2013–15. Fifty-seven Landsat scenes were required to map the entire range of the flycatcher, encompassing parts of six States and

Originally reported from California, the cutthroat trout virus (CTV) has now been isolated from eight species of salmonids in North America. Early work focused on the replication and physical characteristics of the small, round virus, but not until 20 years later was it determined to be most closely related to viruses causing hepatitis E in humans or infecting avian and mammalian hosts. The genome

The first fish paramyxovirus was isolated from normal adult Chinook salmon returning to a coastal hatchery in Oregon in the fall of 1982. Subsequently, the virus was isolated from other stocks of adult Chinook salmon and one stock of adult coho salmon in California, Oregon, Washington and Alaska, leading to its designation as the Pacific salmon paramyxovirus (PSPV). The slow-growing virus can be i

Local populations that fluctuate synchronously are at a greater risk of extinction than those that do not. The closer the geographic proximity of populations, the more prone they are to synchronizing. Shorebird species select habitat broadly, and many breed across regions with diverse nesting habitat types. Under these conditions, nearby populations may experience conditions sufficiently different

Solar power towers produce electrical energy from sunlight at an industrial scale. Little is known about the effects of this technology on flying animals and few methods exist for automatically detecting or observing wildlife at solar towers and other tall anthropogenic structures. Smoking objects are sometimes observed co-occurring with reflected, concentrated light (“solar flux”) in the airspace

The Amargosa River Canyon, located in the Mojave Desert of southeastern California, contains the longest perennial reach of the Amargosa River. Because of its diverse flora and fauna, it has been designated as an Area of Critical Environmental Concern and a Wild and Scenic River by the Bureau of Land Management. A survey of fishes conducted in summer 2010 indicated that endemic Amargosa River pupf

Viral erythrocytic necrosis (VEN) is a disease of marine and anadromous fish that is caused by the erythrocytic necrosis virus (ENV), which was recently identified as a novel member of family Iridoviridae by next-generation sequencing. Phylogenetic analysis of the ENV DNA polymerase grouped ENV with other erythrocytic iridoviruses from snakes and lizards. In the present study, we identified the ge

Survival of out-migrating juvenile Chinook salmon (Oncorhynchus tshawytscha) in the Sacramento–San Joaquin River delta, California, USA, varies by migration route. Survival of salmonids that enter the interior and southern Delta can be as low as half that of salmonids that remain in the main-stem Sacramento River. Reducing entrainment into the higher-mortality routes, such as Georgiana Slough, sho

Walruses are large benthic predators that rest out of water between foraging bouts. Coastal “haulouts” (places where walruses rest) are formed by adult males in summer and sometimes by females and young when sea ice is absent, and are often used repeatedly across seasons and years. Understanding the geography and historical use of haulouts provides a context for conservation efforts. We summarize

Diversion dams can negatively affect emigrating juvenile salmon populations because fish must pass through the impounded river created by the dam, negotiate a passage route at the dam and then emigrate through a riverine reach that has been affected by reduced river discharge. To quantify the effects of a main-stem diversion dam on juvenile Chinook salmon in the Yakima River, Washington, USA, we u

The influence of streamflow on survival of emigrating juvenile Pacific salmonids Oncorhynchus spp. (smolts) is a major concern for water managers throughout the northeast Pacific Rim. However, few studies have quantified flow effects on smolt survival, and available information does not indicate a consistent flow–survival relationship within the typical range of flows under management control. In