Extirpation of N otropis simus simus (Cope) and N otropis orca Woolman (Pisces: Cyprinidae) from the Rio Grande in New Mexico, with Notes on Their Life History

The Rio Grande bluntnose shiner, Notropis simus simus, and the phantom shiner, Notropis orca, once occupied warm water reaches of the Rio Grande in New Mexico, but have not been collected there since 1964 and 1949, respectively. Notropis s. simus was widespread and common until 1950; N. orca was apparently never abundant. Our collections indicated that both forms are extirpated from New Mexico, and each may be extinct. Two other cyprinids, Rio Grande shiner, Notropis jemezanus, and speckled chub, Hybopsis aestivalis, also disappeared from the Rio Grande around 1949 and 1964, respectively. A fifth cyprinid, the Rio Grande silvery minnow, Hybognathus amarus, is presently reduced in distribution and abundance. Irrigation withdrawals and mainstream dams altered natural discharge patterns of the Rio Grande prior to 1930 and probably reduced populations of this suite of mainstream fishes. Drought and increased water withdrawal after 1950 periodically dried extensive reaches of warm water Rio Grande habitat and probably eliminated remaining small populations of the aforementioned species except H. amarus. Life history attributes of N. s. simus, and the distribution and habitat of all of the other extirpated forms do not indicate special requirements other than a flowing mainstream environment. Short-lived fishes that occupy exclusively mainstream riverine environments are especially susceptible to extirpation when flow regimes are altered

Colonization and extinction in dynamic habitats: an occupancy approach for a Great Plains stream fish assemblage

Despite the importance of habitat in determining species distribution and persistence, habitat dynamics are rarely modeled in studies of metapopulations. We used an integrated habitat-occupancy model to simultaneously quantify habitat change, site fidelity, and local colonization and extinction rates for larvae of a suite of Great Plains stream fishes in the Arikaree River, eastern Colorado, USA, across three years. Sites were located along a gradient of flow intermittency and groundwater connectivity. Hydrology varied across years: the first and third being relatively wet and the second dry. Despite hydrologic variation, our results indicated that site suitability was random from one year to the next. Occupancy probabilities were also independent of previous habitat and occupancy state for most species, indicating little site fidelity. Climate and groundwater connectivity were important drivers of local extinction and colonization, but the importance of groundwater differed between periods. Across species, site extinction probabilities were highest during the transition from wet to dry conditions (range: 0.52-0.98), and the effect of groundwater was apparent with higher extinction probabilities for sites not fed by groundwater. Colonization probabilities during this period were relatively low for both previously dry sites (range: 0.02-0.38) and previously wet sites (range: 0.02-0.43). In contrast, no sites dried or remained dry during the transition from dry to wet conditions, yielding lower but still substantial extinction probabilities (range: 0.16-0.63) and higher colonization probabilities (range: 0.06-0.86), with little difference among sites with and without groundwater. This approach of jointly modeling both habitat change and species occupancy will likely be useful to incorporate effects of dynamic habitat on metapopulation processes and to better inform appropriate conservation actions.KEYWORDS: Stream fishes, Species occurrence, Great Plains, USA, Intermittent streams, Groundwater, Joint habitat occupancy modeling, Metapopulation

Headwater Streams and Wetlands are Critical for Sustaining Fish, Fisheries, and Ecosystem Services

Headwater streams and wetlands are integral components of watersheds that are critical for biodiversity, fisheries, ecosystem functions, natural resource-based economies, and human society and culture. These and other ecosystem services provided by intact and clean headwater streams and wetlands are critical for a sustainable future. Loss of legal protections for these vulnerable ecosystems would create a cascade of consequences, including reduced water quality, impaired ecosystem functioning, and loss of fish habitat for commercial and recreational fish species. Many fish species currently listed as threatened or endangered would face increased risks, and other taxa would become more vulnerable. In most regions of the USA, increased pollution and other impacts to headwaters would have negative economic consequences. Headwaters and the fishes they sustain have major cultural importance for many segments of U.S. society. Native peoples, in particular, have intimate relationships with fish and the streams that support them. Headwaters ecosystems and the natural, socio-cultural, and economic services they provide are already severely threatened, and would face even more loss under the Waters of the United States (WOTUS) rule recently proposed by the Trump administration

Effectiveness of light traps for detecting Razorback Sucker larvae

Poster presented at the Colorado State University Graduate Student Showcase 2017.Detection of endangered Razorback Sucker Xyrauchen texanus larvae by light traps is used to prompt flow releases to inundate Green River floodplains crucial to survival. However, little is known about the efficacy of light traps to capture or retain larvae. We investigated effects of trap set time, release distance from trap, light presence, and turbidity on capture and retention rates of early life stages. Laboratory capture rates were 90% and decreased 60% with increasing fish size. Retention exceeded 70% overall, but increased 25% with increasing fish size. Relationships between set time and distance should be investigated, along with field testing.Warner College of Natural Resources - Top Scholar

Extirpation of N otropis simus simus (Cope) and N otropis orca Woolman (Pisces: Cyprinidae) from the Rio Grande in New Mexico, with Notes on Their Life History

The Rio Grande bluntnose shiner, Notropis simus simus, and the phantom shiner, Notropis orca, once occupied warm water reaches of the Rio Grande in New Mexico, but have not been collected there since 1964 and 1949, respectively. Notropis s. simus was widespread and common until 1950; N. orca was apparently never abundant. Our collections indicated that both forms are extirpated from New Mexico, and each may be extinct. Two other cyprinids, Rio Grande shiner, Notropis jemezanus, and speckled chub, Hybopsis aestivalis, also disappeared from the Rio Grande around 1949 and 1964, respectively. A fifth cyprinid, the Rio Grande silvery minnow, Hybognathus amarus, is presently reduced in distribution and abundance. Irrigation withdrawals and mainstream dams altered natural discharge patterns of the Rio Grande prior to 1930 and probably reduced populations of this suite of mainstream fishes. Drought and increased water withdrawal after 1950 periodically dried extensive reaches of warm water Rio Grande habitat and probably eliminated remaining small populations of the aforementioned species except H. amarus. Life history attributes of N. s. simus, and the distribution and habitat of all of the other extirpated forms do not indicate special requirements other than a flowing mainstream environment. Short-lived fishes that occupy exclusively mainstream riverine environments are especially susceptible to extirpation when flow regimes are altered

Resolving taxonomy and historic distribution for conservation of rare Great Plains fishes: Hybognathus (Teleostei: Cyprinidae) in eastern Colorado basins

Listed online under Additional publications list as no. 4.Includes bibliographical references

Appendix B. Trait values for the freshwater native and nonnative fish species of the Colorado River Basin examined in our study.

Trait values for the freshwater native and nonnative fish species of the Colorado River Basin examined in our study

Appendix B. Values of range size (species' rarity), frequency of local extirpation, and perceived level/source of extinction risk for native fishes of the Lower Colorado River Basin examined in our study.

Values of range size (species' rarity), frequency of local extirpation, and perceived level/source of extinction risk for native fishes of the Lower Colorado River Basin examined in our study

Appendix C. Terminal node predictions of the decision trees for species' rarity from Fig. 1, frequency of local extirpation from Fig. 2, and perceived level/source of extinction risk from Fig. 3.

Terminal node predictions of the decision trees for species' rarity from Fig. 1, frequency of local extirpation from Fig. 2, and perceived level/source of extinction risk from Fig. 3