Marine Biology Commons^™

Historical Change Of Seagrasses In The Mississippi And Chandeleur Sounds, Linh Thuy Pham

Dissertations

Seagrasses are important coastal resources facing numerous stressors, and losses have been documented from local to global assessments. Under the broad theme of habitat loss and fragmentation, a study of historical change in total area and landscape configuration of seagrasses in the Mississippi and Chandeleur Sounds was conducted. Mapping data was collated from a multitude of previous projects from 1940 to 2011.

Comparisons of seagrass area among various studies that used different mapping methods can result in overestimation of area change and misleading conclusions of change over time. The vegetated seagrass area (VSA) data were generalized to a common resolution …

Hardbottom Mapping And Community Characterization Of The West-Central Florida Gulf Coast, December 2011 - June 2016, Brian K. Walker, Rene Baumstark, Sean Keenan, Cory Ames

Marine & Environmental Sciences Faculty Datasets

The continental shelf off Florida’s west coast is a mosaic of fish habitats including seagrass beds and carbonate reef outcroppings (hard bottom) classified by the National Marine Fisheries Service (NMFS) as Essential Fish Habitat. Habitat maps and community baseline data, however, are nonexistent for a majority of the region. This collaborative effort between Nova Southeastern University, Florida Fish and Wildlife Conservation Commission, NMFS and other scientists will characterize and map continental shelf seagrass and hard bottom habitats in nearshore areas fished by many recreational fishermen. Objectives include: 1) map hard bottom and seagrass beds using various data types including sonar …

The Population Genetics Of Morro Bay Eelgrass (Zostera Marina), Julia Gardner Harencar

Master's Theses

Seagrass populations are in decline worldwide. Zostera marina (eelgrass), one of California’s native seagrasses, is no exception to this trend. In the last 8 years, Morro Bay, California has lost 95% of its eelgrass. Eelgrass is an ecosystem engineer, providing important ecosystem services such as sediment stabilization, nutrient cycling, and nursery habitats for fish. The failure of recent restoration efforts necessitates a better understanding of the causes of eelgrass decline in this estuary. Previous research on eelgrass in California has demonstrated a link between population genetic diversity and eelgrass bed health, ecosystem functioning, and resilience to disturbance and extreme climatic …

Role Of Habitat And Predators In Maintaining Functional Diversity Of Estuarine Bivalves, Cassandra N. Glaspie, Rochell D. Seitz

VIMS Articles

Habitat loss is occurring rapidly in coastal systems worldwide. In Chesapeake Bay, USA, most historical oyster reefs have been decimated, and seagrass loss is expected to worsen due to climate warming and nutrient pollution. This loss of habitat may result in declining diversity, but whether diversity loss will equate to loss in ecosystem function is unknown. A bivalve survey was conducted in a variety of habitat types (seagrass, oyster shell, shell hash, coarse sand, detrital mud) in 3 lower Chesapeake Bay sub-estuaries from spring 2012 through summer 2013 to examine the correlation between bivalve densities, habitat type, habitat volume (of …

Green Sea Turtles (Chelonia Mydas) In Bermuda Exhibit An Ontogenetic Diet Shift Despite Overexploitation Of Resources In Their Developmental Habitat, Claire Margaret Burgett

FIU Electronic Theses and Dissertations

Green sea turtles in Bermuda are overgrazing the seagrasses on which later life stages are thought to specialize. I hypothesized that larger green turtles in Bermuda would display individual diet specializations during seagrass scarcity. Stable isotope methods were used to determine the diet composition of green sea turtles from the Bermuda Platform as a function of size class and in turtles captured in successive years. Individual turtles had a wide range of diets, however, the variation in diets was driven by differences among size class rather than within the size classes of larger turtles, indicating that green turtles undergo a …

Sediment Burial Stress Response, Bio-Indicators And Thresholds For A Tropical Multi-Species Seagrass Assemblage: Report Of Theme 5 - Project 5.5.2 Prepared For The Dredging Science Node, John Statton, Kathryn Mcmahon, Roisin Mccallum, Gary Kendrick, Paul Lavery

Research outputs 2014 to 2021

Deterioration in water clarity by resuspension of dredged sediments is presumed to be a major mechanism by which dredging can impact seagrasses. This report presents findings from a controlled light experiment that aimed to determine the effects of low light stress on the growth of three seagrass species found in the northwest of Western Australia.

Aims

• To determine the effects of sediment burial stress under dredge-simulated conditions on the growth and health of three seagrass species found in the northwest of Western Australia.
• Provide guidance and protocols for the application of the research outputs (e.g. seagrass burial stress:response relationships, sub-lethal …

Response And Recovery Of A Mixed Tropical Seagrass Assemblage To Variation In The Frequency And Magnitude Of Light Deprivation. Report Of Theme 5 - Project 5.5.3 Prepared For The Dredging Science Node, John Statton, Kathryn Mcmahon, Rosin Mccallum, Gary Kendrick, Paul Lavery

Research outputs 2014 to 2021

The capacity of seagrasses to cope with episodes of light deprivation from overlying turbid waters may not only depend on the absolute quantity of light they receive during that episode, but also on how the light deprivation varies through time. For example, turbidity and therefore light reduction may be relatively constant over the episode or it may fluctuate depending on the frequency of pulsed turbidity events.

This report presents findings from a controlled mesocosm experiment that aimed to determine the responses of seagrasses to, and recovery from, differences in the pattern of the delivery of light. The study focussed on …

Muddy Waters: Unintentional Consequences Of Blue Carbon Research Obscure Our Understanding Of Organic Carbon Dynamics In Seagrass Ecosystems, E. Fay Belshe, Miguel-Angel Mateo, Lucy Gillis, Martin Zimmer, Mirta Teichberg

Research outputs 2014 to 2021

The recent surge in research on organic carbon sequestration by seagrass ecosystems has begun to reveal the complexity of the carbon cycle within these ecosystems. In this prospective we discuss two areas of investigation that require further scrutiny: (1) why organic carbon is stabilized in seagrass sediments, and (2) how long organic carbon resides within these sediments. By delving into these topics, pointing out current pitfalls, and highlighting methodological advances, our motive is to focus future efforts and provide a frame work to manage the complexity found within the diverse seagrass bioregions. The high rate of seagrass degradation and loss, …

Genetic Variability Within Seagrass Of The North West Of Western Australia: Report Of Theme 5 - Project 5.2 Prepared For The Dredging Science Node, Kathryn Mcmahon, Udhi Hernawan, Kor-Jent Van Dijk, Michelle Waycott, Ed Biffin, Richard Evans, Paul Lavery

Research outputs 2014 to 2021

This study was the first of its kind to examine the patterns of genetic diversity in seagrasses in the Pilbara region of WA. Three species were assessed: Halophila ovalis (6 populations), Halodule uninervis (8 populations) andThalassia hemprichii (3 populations) at a range of spatial scales, within a meadow (centimetres−metres), among meadows at a local scale (2−60 km) and among meadows at a regional scale (up to 500 km). Due to the varied distribution of species all species across the same spatial scale and range of environments could not be sampled, so a nested approach was designed, with sites …

Natural Dynamics: Understanding Natural Dynamics Of Seagrasses Of The North West Of Western Australia. Report Of Theme 5 - Project 5.3 Prepared For The Dredging Science Node, Mat Vanderklift, Douglas Bearham, Mick Haywood, Hector Lozano-Montes, Roisin Mccallum, James Mclaughlin, Kathryn Mcmahon, Nick Mortimer, Paul Lavery

Research outputs 2014 to 2021

Relatively little is known of the spatial and temporal dynamics of seagrass meadows in the northwest of Western Australia, but such knowledge is needed when designing and evaluating studies that aim to detect potential dredging-related impacts on seagrass, and when making predictions about the likelihood of, and speed of recovery from such impacts. This study was undertaken to improve our understanding of the spatial and temporal patterns in seagrass composition, abundance and reproductive phenology in the Pilbara. We also characterised key environmental parameters, especially light, that influence seagrass survival and can be altered by dredging.

Aims

To improve our understanding …

Seagrass Survivor. Subjects: Life Science / Biology, Environmental Science, Marine / Ocean Science Grades: 6-8, Amanda Bromilow

Reports

This role-play and decision-making game allows students to simulate predator-prey interactions between fish and blue crabs in a seagrass bed. Students will then make inferences about the influence of habitat and body size on juvenile blue crab survival.

Understanding Changes In Seagrass Communities: Impacts From Local Environmental Factors, Chesapeake Bay National Estuarine Research Reserve In Virginia

Reports

Grade Level: 7-12

Subjects: Life Science, Biology, and Environmental Science

Students will work in groups to determine what happened to seagrass communities during June and August in 2010 and 2011. Students will estimate percent cover visually at four locations along a mock transect and analyze trends in the data collected. Students will use water quality data to help understand the trends in seagrass cover.

Seagrasses Of The North West Of Western Australia: Biogeography And Considerations For Dredging-Related Research: Report Of Theme 5 - Project 5.1.2 Prepared For The Dredging Science Node, Kathryn Mcmahon, John Statton, Paul Lavery

Research outputs 2014 to 2021

This review was undertaken to identify which seagrass primary producers (species or different functional groups) that collectively cover the bio-geographic range of key primary producers in the northwest of Western Australia are most appropriate for the focus of subsequent research into thresholds and indicators of response to dredging-related pressures (i.e. Theme 5). An assessment framework was developed based on six criteria: biogeographic range; ecological relevance (life-history strategy, habitats, natural dynamics and ecological services); current knowledge on thresholds and bioindicators; likelihood that species are sensitive and resilient to dredging related stressors; extent of improvement in applied knowledge; and likelihood of being …

Effects Of Dredging-Related Pressures On Critical Ecological Processes For Organisms Other Than Fish Or Coral. Report Of Theme 9 - Project 9.1 Prepared For The Dredging Science Node, Jessie Short, Matthew Fraser, Dianne Mclean, Gary Kendrick, Maria Byrne, Julian Caley, Doug Clarke, Andy Davis, Paul Ertemeijer, Stuart Field, Sam Gustin-Craig, John Huisman, John Keesing, Mick Keough, Paul Lavery, Ray Mansini, Kathryn Mcmahon, Kerrie Mergersen, Michael Rasheed, John Statton, Jim Stoddart, Paul Wu

Research outputs 2014 to 2021

This study reviewed environmental windows for organisms other than corals and fish such as sessile invertebrates, macroalgae and seagrasses. Environmental windows are periods of critical importance to the life history of a marine species, like reproduction and recruitment.

Aims

• To review the scientific literature on the timing and spatial extent of critical ecological processes relevant to tropical WA for marine primary producers and invertebrates (i.e. organisms other than coral and finfish) and the state of knowledge regarding potential effects of dredging on these key ecological processes. The review also had a particular focus on ecological processes in marine primary producers …

A Marine Heat Wave Drives Massive Losses From The World’S Largest Seagrass Carbon Stocks [Dataset], Ariane Arias-Ortiz, Oscar Serrano, Pere Masqué, Paul Lavery, Ute A. Mueller, Gary A, Kendrick, Mohammad Rozaimi, Alba Esteban, James W, Fourqurean, Núrià N. Marbà, Miquel-Angel Mateo, Kathy Murray, Michael Rule, Carlos M. Duarte

Research Datasets

The database compiles published data (in Arias-Ortiz et al., 2018) on biogeochemical characteristics (density, organic carbon, stable carbon isotopes and sediment grain size) of soils underneath seagrass meadows in Shark Bay, Western Australia. Pb-210 concentrations of the first 20 cm are included along with C-14 raw ages. The dataset compiles data for a total of 49 cores, 25 - 300 cm-long (11 cores with Pb-210 and C-14 data). Enquiries about the dataset may be sent to Ariane Arias-Ortiz: ariane.arias@uab.cat

Investigating The Effects Of Changes In Light Quality On Different Life History Stages Of Seagrasses, Simone Strydom

Theses: Doctorates and Masters

Seagrass meadows provide crucial ecosystem services to the coastal zone but globally are threatened. Seagrass loss to date has mainly been attributed to anthropogenic activities that reduce light quantity, such as dredging, declining water quality from urban and agricultural run-off and eutrophication. However, light quality (wavelengths of light) is also altered by these anthropogenic stressors as well as natural events. This study consisted of three main components: (1) characterising light quality to which seagrasses are exposed across a local natural estuarine-ocean gradient and with a human impact pressure; (2) the influence of monochromatic light quality (blue λ=451 nm; green λ=522 …