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Full-Text Articles in Life Sciences

Distribution Patterns Of The Invasive Mussel Arcuatula Senhousia In Mission Bay, San Diego, California: Effects Of Sediment Grain Size And Byssus Thread Production On Predation, Samantha Ahlman May 2022

Distribution Patterns Of The Invasive Mussel Arcuatula Senhousia In Mission Bay, San Diego, California: Effects Of Sediment Grain Size And Byssus Thread Production On Predation, Samantha Ahlman

Theses

The ability of bivalves to avoid predation by using defensive behaviors such as burrowing and byssus production may vary depending on the sediment characteristics of a given habitat. The varying sediment characteristics that change with water velocity within estuaries may influence the distribution of bivalves and limit them to areas that optimize their ability to defend against predators. We examined the distribution patterns of the invasive Asian date mussel Arcuatula senhousia relative to the sediment grain size distribution in Mission Bay, an urban estuary located in San Diego, California, USA. Mussels and sediment were collected using an Ekman grab at …


Movement Patterns Of The Shovelnose Guitarfish (Pseudobatos Productus) And California Bat Ray (Myliobatis Californica) In The Southern California Bight, Annabel Gong Apr 2022

Movement Patterns Of The Shovelnose Guitarfish (Pseudobatos Productus) And California Bat Ray (Myliobatis Californica) In The Southern California Bight, Annabel Gong

Theses

While the movement patterns of large elasmobranch species have been studied extensively, those of smaller, mesopredatory species remain understudied. The shovelnose guitarfish (Pseudobatos productus) and the California bat ray (Myliobatis californica) are among the least studied elasmobranchs in the Southern California Bight. This study quantified the broad- and fine-scale movement patterns of these species using passive acoustic telemetry. Twelve guitarfish were surgically implanted with coded acoustic transmitters at a known aggregation site off La Jolla (San Diego County), California, USA and tracked for 849.5 days each, on average. Six bat rays were also implanted here and tracked for …


Crassostrea Gigas Invasion In Southern California: Macrofaunal Diversity And Local Community Impacts Of Ecosystem Engineers On Estuarine Habitats, Noah Jansen-Yee Jan 2022

Crassostrea Gigas Invasion In Southern California: Macrofaunal Diversity And Local Community Impacts Of Ecosystem Engineers On Estuarine Habitats, Noah Jansen-Yee

Theses

Many marine ecosystems are facing the growing threat of biological invasions. These invasions can have a variety of different impacts on ecosystems and their inhabitants. The Pacific oyster, Crassostrea gigas, is currently in the relatively early stages of invasion in San Diego estuaries. Crassostrea gigas is a large, filter-feeding bivalve that forms dense oyster beds on hard substrate. These oysters are known to outcompete native counterparts and drastically alter habitats where they are present. Crassostrea gigas is an ecosystem engineer that, through shell creation and formation of a dense oyster matrix, impacts ecosystems in a variety of direct and indirect …


The Distribution And Demography Of The Invasive Pacific Oyster, Crassostrea Gigas, And Native Olympia Oyster, Ostrea Lurida, In The San Diego River, Jason Langevin Oct 2019

The Distribution And Demography Of The Invasive Pacific Oyster, Crassostrea Gigas, And Native Olympia Oyster, Ostrea Lurida, In The San Diego River, Jason Langevin

Theses

Even though the introduction of the Pacific Oyster, Crassostrea gigas, to the west coast of North America, happened roughly a century ago, it has only been in the past 15 to 20 years that C. gigas has started to become an established and conspicuous species along Southern California’s coast. The establishment of C. gigas in Southern California has the potential to heavily influence many native species, as it has done globally. In Southern California, this invasion is particularly relevant for the native Olympia Oyster, Ostrea lurida. The Olympia oyster has both historical and present-day threats to its population, …