scholarly journals Strontium isotopes reveal ephemeral streams used for spawning and rearing by an imperilled potamodromous cyprinid Clear Lake hitch Lavinia exilicauda chi

2019 ◽  
Vol 70 (12) ◽  
pp. 1689 ◽  
Author(s):  
Frederick Feyrer ◽  
George Whitman ◽  
Matthew Young ◽  
Rachel C. Johnson
Keyword(s):  
Life Stage ◽  
Strontium Isotopes ◽  
Ephemeral Streams ◽  
Clear Lake ◽  
Lake County ◽  
Resource Managers ◽  
Natal Habitat ◽  
Freshwater Habitats ◽  
Conservation Actions ◽  
And Migration

Identification of habitats responsible for the successful production and recruitment of rare migratory species is a challenge in conservation biology. Here, a tool was developed to assess life stage linkages for the threatened potamodromous cyprinid Clear Lake hitch Lavinia exilicauda chi. Clear Lake hitch undertake migrations from Clear Lake (Lake County, CA, USA) into ephemeral tributary streams for spawning. An aqueous isoscape of strontium isotopic ratios (87Sr/86Sr) was constructed for Clear Lake and its watershed to trace natal origins and migration histories of adult recruits. Aqueous 87Sr/86Sr differentiated Clear Lake from 8 of 10 key tributaries and clustered into 5 strontium isotope groups (SIGs) with 100% classification success. Otolith 87Sr/86Sr showed all five groups contributed variably to the population. The age at which juveniles migrated from natal streams to Clear Lake ranged from 11 to 152 days (mean±s.d., 43±34 days) and was positively associated with the permanency of natal habitat. This information can be used by resource managers to develop conservation actions for Clear Lake hitch. This study demonstrates the utility of strontium isotopes in otoliths as a tool to identify important freshwater habitats occupied over the lifespan of an individual that would otherwise be challenging or impossible to trace with other methods.A

Description and preliminary interpretation of core CL-80-2, Clear Lake, Lake County, California

1981 ◽  
Author(s):  
J.D. Sims ◽  
M.J. Rymer ◽  
J.A. Perkins ◽  
L.A. Flora
Keyword(s):  
Clear Lake ◽  
Lake County

The Impact of the Fishery upon the Midge Populations of Clear Lake, Lake County, California

1964 ◽  
Vol 57 (6) ◽  
pp. 701-707 ◽  
Author(s):  
S. F. Cook ◽  
J. D. Conners ◽  
R. L. Moore
Keyword(s):  
Clear Lake ◽  
Lake County ◽  
The Impact

scholarly journals Migration: A means to create work–life balance?

2017 ◽  
Vol 24 (2) ◽  
pp. 279-294 ◽  
Author(s):  
Suzette Dyer ◽  
Yiran Xu ◽  
Paresha Sinha
Keyword(s):  
Tertiary Education ◽  
Work And Family ◽  
Work Life ◽  
Work Life Balance ◽  
Cultural Work ◽  
Human Resource Managers ◽  
Life Balance ◽  
Complex Processes ◽  
Resource Managers ◽  
And Migration

AbstractIn this article, we examine the postmigration work–life balance or conflict experiences of 15 Chinese-born mothers living in New Zealand. Our analysis contributes theoretically to the work–life balance and migration literatures. It does so by revealing that balance and conflict is influenced by the interrelationship between the socio-cultural, work, and family domains; and that this interrelationship has both a complex and nuanced influence on postmigration balance and conflict. Thus, balance or conflict was influenced by the interrelationship between the participants’ unique experiences within the three domains, including experiencing satisfaction in all three domains and through complex processes of negative spillover, compensation, renegotiation and removal. The postmigration experiences highlight the need for a comprehensive and concerted approach by government, tertiary education institutions, and human resource managers to develop responsive policy initiatives that support migrants to settle into all aspects of their lives.

Major stopover regions and migratory bottlenecks for Nearctic-Neotropical landbirds within the Neotropics: a review

2017 ◽  
Vol 28 (1) ◽  
pp. 1-26 ◽  
Author(s):  
NICHOLAS J. BAYLY ◽  
KENNETH V. ROSENBERG ◽  
WENDY E. EASTON ◽  
CAMILA GÓMEZ ◽  
JAY CARLISLE ◽  
...  
Keyword(s):  
Sierra Nevada ◽  
Migratory Birds ◽  
Current Knowledge ◽  
Boreal Winter ◽  
Long Distance ◽  
Important Distinction ◽  
Conservation Actions ◽  
Neotropical Migratory Birds ◽  
And Migration ◽  
Multiple Species

SummaryNearly 300 species of landbirds, whose populations total billions, migrate between the Neotropics and North America. Many migratory populations are in steep decline, and migration is often identified as the greatest source of annual mortality. Identifying birds’ needs on migration is therefore central to designing conservation actions for Nearctic-Neotropical migratory birds; yet migration through the Neotropics is a significant knowledge gap in our understanding of the full annual cycle. Here, we synthesise current knowledge of Neotropical stopover regions and migratory bottlenecks, focusing on long-distance, migratory landbirds that spend the boreal winter in South America. We make the important distinction between “true” stopover—involving multi-day refuelling stops—and rest-roost stops lasting < 24 hours, citing a growing number of studies that show individual landbirds making long stopovers in just a few strategic areas, to accumulate large energy reserves for long-distance flights. Based on an exhaustive literature search, we found few published stopover studies from the Neotropics, but combined with recent tracking studies, they describe prolonged stopovers for multiple species in the Orinoco grasslands (Llanos), the Sierra Nevada de Santa Marta (Colombia), and the Yucatan Peninsula. Bottlenecks for diurnal migrants are well described, with the narrowing Central American geography concentrating millions of migrating raptors at several points in SE Mexico, Costa Rica, Panama and the Darién. However, diurnally migrating aerial insectivores remain understudied, and determining stopover/roost sites for this steeply declining group is a priority. Despite advances in our knowledge of migration in the Neotropics, we conclude that major knowledge gaps persist. To identify stopover sites and habitats and the threats they face, we propose a targeted and collaborative research agenda at an expanded network of Neotropical sites, within the context of regional conservation planning strategies.

A Study of the Primary Productitivy of Clear Lake, Lake County California

Ecology ◽  
1963 ◽  
Vol 44 (2) ◽  
pp. 283-294 ◽  
Author(s):  
Charles R. Goldman ◽  
Robert G. Wetzel
Keyword(s):  
Clear Lake ◽  
Lake County

scholarly journals Spatial and temporal escape from fungal parasitism in natural communities of anciently asexual bdelloid rotifers

2013 ◽  
Vol 280 (1765) ◽  
pp. 20131255 ◽  
Author(s):  
Christopher G. Wilson ◽  
Paul W. Sherman
Keyword(s):  
Field Experiments ◽  
Life Stage ◽  
Red Queen Hypothesis ◽  
Bdelloid Rotifers ◽  
Antagonistic Coevolution ◽  
Freshwater Habitats ◽  
Spatio Temporal ◽  
The Red Queen ◽  
Natural Communities

Sexual reproduction is costly, but it is nearly ubiquitous among plants and animals, whereas obligately asexual taxa are rare and almost always short-lived. The Red Queen hypothesis proposes that sex overcomes its costs by enabling organisms to keep pace with coevolving parasites and pathogens. If so, the few cases of stable long-term asexuality ought to be found in groups whose coevolutionary interactions with parasites are unusually weak. In theory, antagonistic coevolution will be attenuated if hosts disperse among patches within a metapopulation separately from parasites and more rapidly. We examined whether these conditions are met in natural communities of bdelloid rotifers, one of the longest-lived asexual lineages. At any life stage, these microscopic invertebrates can tolerate the complete desiccation of their ephemeral freshwater habitats, surviving as dormant propagules that are readily carried by the wind. In our field experiments, desiccation and wind transport enabled bdelloids to disperse independently of multiple fungal parasites, in both time and space. Surveys of bdelloid communities in unmanipulated moss patches confirmed that fungal parasitism was negatively correlated with extended drought and increasing height (exposure to wind). Bdelloid ecology therefore matches a key condition of models in which asexuals persist through spatio-temporal decoupling from coevolving enemies.

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