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- Title
- Characterization of calpain activity in response to microplastic exposure in Donax variabilis.
- Author
- Schroeder, Hans Erik
- Abstract/Description
-
Coquina clams (Donax variabilis) are small multicolored bivalve mollusks that inhabit the intertidal zones of various southeastern beaches along the eastern coast of the United States where they are in great abundance and an essential part of the beach ecosystem. Because they are filter-feeders that are exposed to environmental hazards, Donax variabilis populations are a sign of the beach's ecological health. Potentially, this mollusk may be effective as a "canary in a coal mine" if...
Show moreCoquina clams (Donax variabilis) are small multicolored bivalve mollusks that inhabit the intertidal zones of various southeastern beaches along the eastern coast of the United States where they are in great abundance and an essential part of the beach ecosystem. Because they are filter-feeders that are exposed to environmental hazards, Donax variabilis populations are a sign of the beach's ecological health. Potentially, this mollusk may be effective as a "canary in a coal mine" if biological changes are easily measurable that may be sensitive to important environmental changes. One such mechanism are the calpains. Calpains are Ca2+-dependent cysteine proteases that are expressed in nearly all eukaryotes, but have rarely been studied in invertebrates like the Coquina clam. It is well established that calpains are essential to cellular homeostasis and have been implicated in a multitude of cellular functions, such as apoptosis and cellular stress. In recent years, microplastics, plastic particles that range in size but are less than 5mm, have become a serious hazard to the environment. Accumulation of microplastics have only recently been recognized to be harmful to marine organisms that ingest them and cause tissue damage on a cellular and subcellular level that may alter calpain activity. Although Coquina clams are in great abundance on the beaches and their ecological patterns have been studied thoroughly, the cellular and subcellular processes of the Coquina clam have not been studied extensively. Specifically, it is not understood how calpains function under normal conditions or how these molecules would be affected due to large ecological impacts in the form of contaminants like microplastics. It is our contention that Coquina clams can be used as a bioindicator of healthy beaches and aid in assessing the presence or absence of pollutants such as microplastics that can occur in the ecosystem, using cellular and subcellular processing by calpains as a measure.
Show less - Date Issued
- 2019, 2019
- Identifier
- 1153167661, WFE0000699
- Format
- Document (PDF)
- Title
- Habitat use of seagrass-associated fauna in St. Joseph Bay.
- Author
- Czaja, Raymond Edward
- Abstract/Description
-
Anthropogenic disturbances, such as habitat fragmentation, can disrupt seagrass microhabitat availability and increase the availability of seagrass bed edges. This research focused on microhabitat selection and substrate use of seagrass-associated invertebrates in St. Joseph Bay, Florida, emphasizing edge effects and habitat selection of the sea urchin Lytechinus variegatus. Monthly field surveys were conducted in Thalassia testudinum beds in St. Joseph Bay, Florida, in 2017 and 2018....
Show moreAnthropogenic disturbances, such as habitat fragmentation, can disrupt seagrass microhabitat availability and increase the availability of seagrass bed edges. This research focused on microhabitat selection and substrate use of seagrass-associated invertebrates in St. Joseph Bay, Florida, emphasizing edge effects and habitat selection of the sea urchin Lytechinus variegatus. Monthly field surveys were conducted in Thalassia testudinum beds in St. Joseph Bay, Florida, in 2017 and 2018. Microhabitat use pertained to edge effects and substrate use pertained to usage of pen shells, mussels, and seagrass by sea urchins. Settlement plates were deployed to analyze the importance of the semi-infaunal bivalve Atrina rigida (pen shells) for sessile invertebrates in seagrass habitat. Results show that L. variegatus prefers interior seagrass habitat compared to edge habitat, whereas other epibenthic macrofauna displayed mixed results for microhabitat selection. Sea urchins displayed a preference for Modiolus americanus mussel substrate. A sea urchin mortality event occurred during a cold spell. Results also suggest that sessile fauna utilize A. rigida as hard substrate due to a lack of alternative options. The results have implications for seagrass overgrazing events, seagrass-associated faunal responses to climate change, and habitat destruction.
Show less - Date Issued
- 2019, 2019
- Identifier
- 1152893868, WFE0000691
- Format
- Document (PDF)