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Full-Text Articles in Life Sciences

Historical Ecology Of The San Diego Sport Fishery: Catch Composition, Species Trends, And Fishing Effort From 1959 To 2011, Rebecca Schwartz Lesberg Apr 2021

Historical Ecology Of The San Diego Sport Fishery: Catch Composition, Species Trends, And Fishing Effort From 1959 To 2011, Rebecca Schwartz Lesberg

Theses

Like ocean systems around the world, species targeted by the San Diego sportfishery are subject to myriad threats from human activity, with several species already showing documented decline. However, long-term fisheries datasets are often lacking, limiting natural resource managers’ ability to appropriately manage these ecologically and economically important species. Therefore, this study used daily reports published in two Southern California newspapers to examine changes in catch composition, effort, and catch per unit effort (CPUE) from 1959-2011 for the San Diego commercial passenger fishing vessel (CPFV) sportfishery. This study then tested the relationship between those patterns and three large scale oceanographic …


Using Aerial Photogrammetry And Sexually Dimorphic Measurements To Investigate Seasonal Differences In School Composition Of Delphinus Spp. Off Southern California, Samantha Gm Leander Jan 2021

Using Aerial Photogrammetry And Sexually Dimorphic Measurements To Investigate Seasonal Differences In School Composition Of Delphinus Spp. Off Southern California, Samantha Gm Leander

Theses

Insights into school composition can provide a means to understand basic biology and ecology, including reproductive patterns. They can also be applied to conservation assessments, allowing for better understanding of the potentially differential vulnerability of demographic groups to natural or anthropogenic disturbances that may influence their populations. However, the two subspecies of common dolphins in the waters off California (Delphinus delphis delphis and D. d. bairdii) form large, energetic groups that make characterization of school composition difficult. Remotely controlled drones now offer the opportunity for the study of school composition in Delphinus spp., allowing for precise morphometric measurements …


Developing A Method To Track Marine Snow Aggregation Through Individual Collisions Using Stereoscopic Imaging, Riley Henning Jan 2021

Developing A Method To Track Marine Snow Aggregation Through Individual Collisions Using Stereoscopic Imaging, Riley Henning

Theses

The aggregation of individual phytoplankton into marine snow allows particles to sink more quickly, thus resulting in the transport of particulate organic carbon from surface waters to the deep ocean. Aggregate formation has previously been measured in experiments indirectly by quantifying how particle size or particle concentration changes over time. Here, I present my thesis in which I applied high-resolution imaging to quantify aggregate formation using two different methodologies.

We conducted experiments to investigate aggregate formation using stereoscopic imaging, tracking individual particles directly in a 3D volume. Phytoplankton cultures were rolled in cylindrical tanks and imaged by two cameras illuminated …


The Effects Of Temperature And Body Size On The Metabolism And Hypoxia Tolerance Of White Abalone (Haliotis Sorenseni) And Red Abalone (H. Rufescens), Stephanie Fan Jan 2021

The Effects Of Temperature And Body Size On The Metabolism And Hypoxia Tolerance Of White Abalone (Haliotis Sorenseni) And Red Abalone (H. Rufescens), Stephanie Fan

Theses

In 2001, white abalone, Haliotis sorenseni, became the first marine invertebrate to be listed under the U.S. Endangered Species Act. Allee effects due primarily to overharvesting and disease resulted in individuals being too far apart for successful fertilization. Despite the fishery closure in 1996, H. sorenseni still shows no signs of recovery. Today, the White Abalone Recovery Consortium (WARC), a group that includes federal and state agencies, aquaculture organizations, academic institutions, and public aquaria, is working to recover this endangered species back from the brink of extinction.

In order to better understand the metabolic demands and hypoxia tolerance of the …


Otolith Microchemistry Reveals Low Habitat Connectivity Of California Killifish (Fundulus Parvipinnis) Across A Range Of Spatial Scales, Lisa Robison Jan 2021

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 …


Diet Of An Important Wetland Resident, The California Killifish, Fundulus Parvipinnis, In A Natural And Created Marsh Habitat In Mission Bay, California, Katie Robinson-Filipp Jan 2021

Diet Of An Important Wetland Resident, The California Killifish, Fundulus Parvipinnis, In A Natural And Created Marsh Habitat In Mission Bay, California, Katie Robinson-Filipp

Theses

The California killifish, Fundulus parvipinnis Girard, is an ecologically important marsh resident. Fundulus parvipinnis is a low-level carnivore, displaying high-site fidelity and occurring in high densities across a range of environmental conditions. Despite the importance of F. parvipinnis to the ecosystem functions of the threatened coastal wetlands of southern California and the Baja California Peninsula, there are critical gaps in our knowledge of this species. In particular, information on their diet and food habits is lacking.

Understanding wetland food web linkages, interactions, and trophic transfer is essential for informing effective habitat management and contributes to our ability to evaluate the …