Marine Biology Commons^™

Spatial Variability In The Diversity And Structure Of Faunal Assemblages Associated With Kelp Holdfasts (Laminaria Hyperborea) In The Northeast Atlantic, Harry Teagle, Pippa J. Moore, Helen Jenkins, Dan A. Smale

Research outputs 2014 to 2021

Kelp species are ecologically-important habitat-formers in coastal marine ecosystems, where they alter environmental conditions and promote local biodiversity by providing complex biogenic habitat for an array of associated organisms. While it is widely accepted that kelps harbour significant biodiversity, our current understanding of spatiotemporal variability in kelp-associated assemblages and the key environmental drivers of variability patterns remains limited. Here we examined the influence of ocean temperature and wave exposure on the structure of faunal assemblages associated with the holdfasts of Laminaria hyperborea, the dominant habitat-forming kelp in the northeast Atlantic. We sampled holdfasts from 12 kelp-dominated open-coast sites nested …

Distributions Of Total And Size-Fractionated Particulate 210po And 210pb Activities Along The North Atlantic Geotraces Ga01 Transect: Geovide Cruise, Yi Tang, Maxi Castrillejo, Montserrat Roca-Marti, Pere Masque´, Nolwenn Lemaitre, Gillian Stewart

Research outputs 2014 to 2021

Vertical distributions of total and particulate polonium-210 (²¹⁰Po) and lead-210 (²¹⁰Pb) activities in the water column were measured at 11 stations in the North Atlantic during the GEOTRACES GA01 transect: GEOVIDE cruise in May–June 2014. Total ²¹⁰Po activity was on average 24% lower than ²¹⁰Pb activity in the upper 100m, and it was closer to unity in the mesopelagic (100–1000m). The partitioning coefficients (K_d) along the transect suggest the preferential association of ²¹⁰Po relative to ²¹⁰Pb onto particles. The prominent role of small particles in sorption was confirmed by …

A Marine Heatwave Drives Massive Losses From The World’S Largest Seagrass Carbon Stocks, A. Arias-Ortiz, Oscar Serrano, Pere Masque´, Paul S. Lavery, Ute Mueller, G. A. Kendrick, Mohammad Rozaimi, Alba Esteban, J. W. Fourqurean, N. Marba, Miguel-Angel Mateo, K. Murray, M. J. Rule, C. M. Duarte

Research outputs 2014 to 2021

Seagrass ecosystems contain globally significant organic carbon (C) stocks. However, climate change and increasing frequency of extreme events threaten their preservation. Shark Bay, Western Australia, has the largest C stock reported for a seagrass ecosystem, containing up to 1.3% of the total C stored within the top metre of seagrass sediments worldwide. On the basis of field studies and satellite imagery, we estimate that 36% of Shark Bay’s seagrass meadows were damaged following a marine heatwave in 2010/2011. Assuming that 10 to 50% of the seagrass sediment C stock was exposed to oxic conditions after disturbance, between 2 and 9 …

Factors Controlling The Community Structure Of Picoplankton In Contrasting Marine Environments, Jose Luis Otero-Ferrer, Pedro Cermeno, Antonio Bode, Bieito Fernandez-Castro, Josep M. Gasol, Xose Anxelu G. Moran, Emilio Maranon, Victor Moreira-Coello, Marta M. Varela, Marina Villamana, Beatriz Mourino-Carballido

Research outputs 2014 to 2021

The effect of inorganic nutrients on planktonic assemblages has traditionally relied on concentrations rather than estimates of nutrient supply. We combined a novel dataset of hydrographic properties, turbulent mixing, nutrient concentration, and picoplankton community composition with the aims of (i) quantifying the role of temperature, light, and nitrate fluxes as factors controlling the distribution of autotrophic and heterotrophic picoplankton subgroups, as determined by flow cytometry, and (ii) describing the ecological niches of the various components of the picoplankton community. Data were collected at 97 stations in the Atlantic Ocean, including tropical and subtropical open-ocean waters, the northwestern Mediterranean Sea, and …

Modeling Canopy Effect In The Great Lakes Cladophora Model, Ankita Bakshi

Dissertations, Master's Theses and Master's Reports

Cladophora glomerata is a filamentous green alga native to the Great Lakes. However, its nuisance growth in phosphorus rich waters negatively affects the lakes’ aesthetic and water quality. The Great Lakes Cladophora Model (GLCM) v1, developed in 1982, was the first mechanistic model to simulate Cladophora growth basing phosphorus availability and environmental conditions followed by Cladophora Growth Model and GLCM v2. In this study, the light and temperature mediation factors for Cladophora net growth are revised as a necessary step prior to the development of a self-shading algorithm. The concept of a fixed-value, maximum achievable biomass (carrying capacity) employed in …

Determining The Subsidence Rate Of The Cascade Seamount Using Strontium Isotope Stratigraphy, Sarah L. Vorsanger

Theses and Dissertations

The Cascade Seamount is a wave-planated feature located on the microcontinent of the East Tasman Plateau (ETP). The minimum subsidence rate of the Seamount and the ETP can be estimated by dividing the present-day depth of the wave-cut surface (640 m) by the age of Cascade Seamount basalts as determined by potassium-argon (K-Ar) dating (33.4 and 36 Ma). This approach yields a subsidence rate of 18 m/Myr. However, a significantly more rapid subsidence rate of the ETP since the Eocene-Oligocene transition has been proposed based on sedimentological and biostratigraphic techniques. The late Eocene paleodepths determined by Stickley et al. (2004) …

Evidence For Extra-Gastric Expression Of The Proton Pump H+/K+ -Atpase In The Gills And Kidney Of The Teleost Oreochromis Niloticus, Ebtesam Barnawi

Theses and Dissertations (Comprehensive)

It is well known that stomach acid secretion by oxynticopeptic cells of the gastric mucosa is accomplished by the H⁺/ K⁺-ATPase (HKA), which is comprised of the HKα1 (gene: atp4a) and HKβ (gene: atp4b) subunits. However, the role of the HKA in extra-gastric organs such as the gill and kidney is less clear especially in fishes. This pump may contribute to active ion and/or acid-base regulation either through direct ion transport or through secondary transport proteins against unfavorable concentration gradients via the energy derived from ATP hydrolysis. In the present work I have demonstrated …

The Spatial Context Of “Winning” In Mpa Network Design: Location Matters, Andrew S. Kough, Claire B. Paris, Mark J. Butler Iv

Biological Sciences Faculty Publications

(First paragraph) Chollett et al. (2017) make the case that a local network of marine protected areas (MPAs) enhances fisheries for Caribbean spiny lobster (Panulirus argus) off the coast of Honduras. However, their simulation focused on one ecoregion where self-recruitment is predicted to be among the highest in the Caribbean (Cowen, Paris, & Srinivasan, 2006). The shallow banks and scattered cays of the Honduran-Nicaraguan Rise, separating the Cayman and Colombian basins, create an obstacle to the powerful southern Caribbean jet (Richardson, 2005), fostering an ideal location for topographically steered eddies and larval retention. Local management,whether based on traditional …

Remobilization Of Heavy Metals By Mangrove Leaves, Hanan Almahasheer, Oscar Serrano, Carlos M. Duarte, Xabier Irigoien

Research outputs 2014 to 2021

Several studies have been carried out on heavy metal pollution in mangrove ecosystems. However, the role of mangroves in heavy metal remobilization is still relatively unknown. On one side, mangrove woody organs and soils sequester heavy metals for long time periods, but on the other hand, senescence of mangrove leaves may return these metals collected by roots to the upper layers of the soil. Here, we analyzed the concentration of chemical elements (Al, As, Cd, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Sr, V, and Zn) as a function of age in mangrove leaves to understand heavy metals retention by …

Short-Term Responses Of Posidonia Australis To Changes In Light Quality, Simone Strydom, Kathryn M. Mcmahon, Gary A. Kendrick, John Stratton, Paul S. Lavery

Research outputs 2014 to 2021

Seagrass meadows are highly productive ecosystems that provide ecosystem services to the coastal zone but are declining globally, particularly due to anthropogenic activities that reduce the quantity of light reaching seagrasses, such as dredging, river discharge and eutrophication. Light quality (the spectral composition of the light) is also altered by these anthropogenic stressors as the differential attenuation of wavelengths of light is caused by materials within the water column. This study addressed the effect of altered light quality on different life-history stages of the seagrass Posidonia australis, a persistent, habitat-forming species in Australia. Aquarium-based experiments were conducted to determine …

Millennial-Scale Trends And Controls In Posidonia Oceanica (L. Delile) Ecosystem Productivity, Carman Leiva-Dueñas, Lourdes López-Merino, Oscar Serrano, Antonio Martínez Cortizas, Miguel-Angel Mateo

Research outputs 2014 to 2021

Posidonia oceanica is a marine phanerogam that buries a significant part of its belowground production forming an organic bioconstruction known as mat. Despite Posidonia seagrass mats have proven to be reliable archives of long-term environmental change, palaeoecological studies using seagrass archives are still scarce. Here we reconstruct four millennia of environmental dynamics in the NE coast of Spain by analysing the carbon and nitrogen stable isotopic composition of P. oceanica sheaths, the proportion of different seagrass organs throughout the seagrass mat and other sedimentological proxies. The palaeoenvironmental reconstruction informs on long-term ecosystem productivity and nutrient loading, which have been linked …

Sequestration Of Macroalgal Carbon: The Elephant In The Blue Carbon Room, Dorte Krause-Jensen, Paul Lavery, Oscar Serrano, Nu´Ria Marba, Pere Masque´, Carlos M. Duarte

Research outputs 2014 to 2021

Macroalgae form the most extensive and productive benthic marine vegetated habitats globally but their inclusion in Blue Carbon (BC) strategies remains controversial. We review the arguments offered to reject or include macroalgae in the BC framework, and identify the challenges that have precluded macroalgae from being incorporated so far. Evidence that macroalgae support significant carbon burial is compelling. The carbon they supply to sediment stocks in angiosperm BC habitats is already included in current assessments, so that macroalgae are de facto recognized as important donors of BC. The key challenges are (i) documenting macroalgal carbon sequestered beyond BC habitat, (ii) …

Microorganisms Facilitate Uptake Of Dissolved Organic Nitrogen By Seagrass Leaves, Flavia Tarquinio, Jeremy Bourgoure, Annette Koenders, Bonnie Laverock, Christin Säwström, Glenn A. Hyndes

Research Datasets

The database compiles data (used in Tarquinio et al. 2018, ISME Journal, accepted for publication) obtained from nitrogen stable isotope analysis (IRMS) and Nanoscale secondary ion mass spectrometry (NanoSIMS) of seagrass (Posidonia sinuosa) leaves and associated microorganisms. Row data (IRMS) are presented for bulk tissue ¹⁵N enrichment of P. sinuosa leaves at different times of incubation (plotted as bar chart in the manuscript), as well as the enrichment detected through the drawing of regions of interest (ROI) from NanoSIMS image analysis and plotted as box plots in the manuscript.

Managing Seagrass Resilience Under Cumulative Dredging Affecting Light: Predicting Risk Using Dynamic Bayesian Networks, Paul Pao-Yen Wu, Kathryn Mcmahon, Michael A. Rasheed, Gary A. Kendrick, Paul H. York, Kathryn Chartrand, M. Julian Carey, Kerrie Mengerson

Research Datasets

Coastal development is contributing to ongoing declines of ecosystems globally. Consequently, understanding the risks posed to these systems, and how they respond to successive disturbances, is paramount for their improved management. We study the cumulative impacts of maintenance dredging on seagrass ecosystems as a canonical example. Maintenance dredging causes disturbances lasting weeks to months, often repeated at yearly intervals. We present a risk-based modelling framework for time varying complex systems centred around a dynamic Bayesian network (DBN). Our approach estimates the impact of a hazard on a system's response in terms of resistance, recovery and persistence, commonly used to characterise …

Effects Of Small-Scale, Shading-Induced Seagrass Loss On Blue Carbon Storage: Implications For Management Of Degraded Seagrass Ecosystems, Stacey M. Trevathan-Tackett, Caitlin Wessel, Just Cebrian, Peter J. Ralph, Pere Masque´, Peter I. Macreadie

Research Datasets

1. Seagrass meadows are important global ‘blue carbon’ sinks. Despite a 30% loss of seagrasses globally during the last century, there is limited empirical research investigating the effects of disturbance and loss of seagrass on blue carbon stocks.

2. In this study, we hypothesised that seagrass loss would reduce blue carbon stocks. Using shading cloth, we simulated small-scale die-offs of two subtropical seagrass species, Halodule wrightii and Thalassia testudinum, in a dynamic northern Gulf of Mexico lagoon. The change in quantity and quality of sediment organic matter and organic carbon were compared among kill, control and bare plots before the …

Latitudinal Variation In Seagrass Herbivory: Global Patterns And Explanatory Mechanisms, Adriana Vergés, Christopher Doropoulos, Robert Czarnik, Kathryn Mcmahon, Nil Llonch, Alistair G. B. Poore

Research Datasets

Aim: The aim was to quantify latitudinal patterns in seagrass–herbivore interactions in the context of a warming climate.

Location: We carried out a global meta‐analysis combined with a field experiment across 1,700 km and 12° of latitude in Western Australia.

Time period: 1984–2014. Major taxa studied: Seagrasses.

Methods: We first synthesized the global literature on herbivore exclusion experiments in seagrasses to test whether differences in herbivore impacts are related to latitude and sea surface temperature. We then quantified leaf production and consumption rates in the field at nine meadows of the seagrass Amphibolis antarctica across 1,700 km, from tropical to …

The Distribution And Trophic Ecology Of Golden Ghost Crabs (Ocypode Convexa), Caitlin Rae

Theses: Doctorates and Masters

Sandy beaches make up approximately three-quarters of the world’s shorelines. They are important ecosystems, hosting abundant invertebrate macrofaunal communities that provide food resource for vertebrate predators such as shorebirds, seabirds, marine mammals and fish. Although possessing a terrestrial appearance, food input on sandy beaches is derived predominantly from the sea. Such food input includes detrital matter, mostly in the form of wrack, and has the potential to support a great diversity of species, as well as stabilising energy fluxes and dynamics of consumer populations. The movement of detritus, along with other vectors such as organisms and nutrients, across ecosystem boundaries …

Comment On 'Geoengineering With Seagrasses: Is Credit Due Where Credit Is Given?', Peter I. Macreadie, Carolyn J. Ewers-Lewis, Ashley A. Whitt, Quinn Ollivier, Stacey M. Trevathan-Tackett, Paul Carnell, Oscar Serrano

Research outputs 2014 to 2021

Over the past decade scientists around the world have sought to estimate the capacity of seagrass meadows to sequester carbon, and thereby understand their role in climate change mitigation. The number of studies reporting on seagrass carbon accumulation rates is still limited, but growing scientific evidence supports the hypothesis that seagrasses have been efficiently locking away CO2 for decades to millennia (e.g. Macreadie et al 2014, Mateo et al 1997, Serrano et al 2012). Johannessen and Macdonald (2016), however, challenge the role of seagrasses as carbon traps, claiming that gains in carbon storage by seagrasses …

Evaluating Elasmobranch Bycatch And Shark Depredation In The Georgia Shrimp Fishery, Matthew M. Scanlon

College of Graduate Studies: Theses & Dissertations

The Georgia shrimp fishery has seen a dramatic decrease in profit and productivity since the 1980’s due to a number of economic factors. Additional, yet undocumented, pressures on this fishery include interactions between foraging sharks with trawl gear. Fishermen report that sharks frequently bite nets in an attempt to prey on netted fish, resulting in large holes in the gear. Further elasmobranch interactions with trawl gear occur as bycatch; shrimp trawls represent nearly 100% of elasmobranch commercial bycatch in Georgia state waters, the species composition of which is largely unstudied. Shark interactions with nets were detailed through fishery-dependent observations on …

Environmental And Physiological Regulation Of Yellow Stingray Color Change, Theresa Rose Gunn

College of Graduate Studies: Theses & Dissertations

Many reef fishes exhibit dynamic coloration and body patterns that can change under nervous or hormonal control. Several species of benthic sharks and rays likely alter melanin in the skin to provide background matching for camouflage. The yellow stingray (Urobatis jamaicensis) is a benthically-oriented elasmobranch with elaborate spot patterns that provide effective camouflage within its habitats. This patterning, when coupled with the ability to alter melanin in response to background color, could increase background matching effectiveness in these species. The yellow stingray has been anecdotally noted to lighten or darken skin color.However, it is unclear whether this type …