Physical Sciences and Mathematics Commons^™

Coastal Watershed Monitoring And Management: Geomorphology, Geochemistry, And Hydrologic Modeling Of Los Peñasquitos Creek, Ca, Ravleen Khalsa-Basra

Theses

Rivers in semi-arid climates are directly influenced by local geographic and hydrologic conditions and impacted by modifications to hydrology via urbanization. Changes can influence erosion, morphology, habitat sustainability, and watershed health. In highly urbanized southern California coastal regions, these rare open spaces provide vital ecosystem services. Los Peñasquitos Creek in San Diego County is one such watershed. Using stream surveying and laboratory methods we quantified channel characteristics, grain size distribution, total metal concentration [M], organic carbon (%OC), and phosphate to longitudinally characterize the creek for improved management. Results identified three distinct reaches in the watershed (upper, middle, lower). Downstream, depth …

Otolith Microchemistry Reveals Low Habitat Connectivity Of California Killifish (Fundulus Parvipinnis) Across A Range Of Spatial Scales, Lisa Robison

Theses

As wetlands face continued fragmentation worldwide, an understanding of habitat connectivity and how fishes that rely on these environments is imperative to conduct effective marine management. Site fidelity and habitat connectivity are vital measures of the interdependence of fish populations living in neighboring marshes (or in regions of a single marsh).

Here, we examine the habitat connectivity, site fidelity, and movement of California killifish (Fundulus parvipinnis) within and among three estuaries in Southern California through otolith microelemental analysis. Assessing the site fidelity of estuarine fishes is important to determine the level of connectivity between spatially distinct populations within …

Artisanal Mining Impacts In Urbanized Semi-Arid Environments: Lessons From Historic Arsenic Mining Near San Diego, California, James A. Wright

Theses

Anomalously elevated arsenic concentrations occur at an abandoned artisanal mine site in an open space recreational park in urban San Diego County, California. Although mining at the site ceased 100 years ago little to no remediation efforts took place leaving shafts, adits, waste piles and derelict infrastructure accessible by inquisitive hikers and adventurers frequenting Black Mountain Open Space Park. This study evaluates the geochemical mechanisms of As transport downgradient from the mine and examines the contribution of both climate and urbanization on the restriction of As mobility. Sediment As concentrations reach 2,320 mg/kg (483 times background crustal concentrations; n=73) along …