Alanna Lecher

Alanna Lecher
Lynn University · Natural and Applied Sciences

Doctor of Philosophy

About

36
Publications
6,534
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
418
Citations
Introduction
For more information on my projects see my research website: www.drlecher.net

Publications

Publications (36)
Article
Full-text available
Submarine groundwater discharge (SGD) is an important source of nutrients to coastal ecosystems. The flux of nutrients associated with SGD is governed by the volumetric discharge of groundwater and the concentrations of nutrients in groundwater within the coastal aquifer. Nutrient concentrations in the coastal aquifer, in turn, are controlled by pr...
Article
Full-text available
Submarine groundwater discharge (SGD) is a global and well-studied geological process by which groundwater of varying salinities enters coastal waters. SGD is known to transport bioactive solutes, including but not limited to nutrients (nitrogen, phosphorous, silica), gases (methane, carbon dioxide), and trace metals (iron, nickel, zinc). In additi...
Article
Coastal low-lying archaeological sites are known to be at risk due to sea-level rise associated with climate change. However, not all of the potential impacts of sea-level rise on these sites have been documented. In this interdisciplinary study we set out to document the effects of rising groundwater tables induced by rising sea level on middens l...
Article
Full-text available
Submarine groundwater discharge (SGD) links terrestrial and marine systems, but has often been overlooked in coastal nutrient budgets because it is difficult to quantify. In this Review, we examine SGD nutrient fluxes in over 200 locations globally, explain their impact on biogeochemistry and discuss broader management implications. SGD nutrient fl...
Article
Full-text available
Radium has been commonly used as a tracer of submarine groundwater discharge to the ocean and embankments, as radium activities are commonly input into box models to calculate a groundwater flux. Similarly, isotopes of radium (Ra 224 , Ra 223 , Ra 226 , Ra 228) have been used to calculate water mass ages, which have been used as a proxy for residen...
Article
Full-text available
Lake Okeechobee is Florida's largest lake, the largest lake in the Southeast United States, and the second largest lake contained entirely within the United States. The history of this inland sea is marked both by natural processes, and more recently human development and intervention. Adventurers can explore this behemoth of a waterway via the Lak...
Chapter
Historic, intriguing, and important in so many ways, the Obama presidency will be studied by scholars and students for years to come. With the rise in hyperpartisanship, legislative gridlock, political dysfunction, “fake news,” and other negative trends, it is imperative that academicians weigh in with a rigorous assessment of Obama’s presidency. T...
Presentation
Podcasts are radioshows distributed through the internet and apps. Various methods of implementing podcasts into the undergraduate classrooms have shown positive and negative outcomes (Fernandez, et al., 2015). However, podcasts have been shown to be most effective when integrated into a lesson through implementation of a learning theory, which man...
Article
Full-text available
Ten factors that help liberal arts undergraduate students succeed could also increase the odds for student success in geoscience graduate programs.
Book
Environmental statistics exposes students to data collection, descriptive and inferential statistics, geospatial analysis, error, modeling, and reporting of data within the environmental science and policy realm. Each topic is explored with Microsoft Excel 2016 with the Analysis ToolPak, with step by step descriptions of how to execute analyses in...
Article
Full-text available
The Gulf of Alaska is a highly productive ecosystem that supports fisheries and subsistence harvesting of marine resources. The highly productive summer season begins with a bloom that is dominated by diatoms. Both river and submarine groundwater discharge have been recognized as substantial terrestrial nutrient (nitrate and silicate) sources to th...
Article
Grasslands throughout the world are responding in diverse ways to changing climate and environmental conditions. In this study we analyze indicators of phosphorus limitation including phosphorus concentrations, phosphorus to nitrogen and carbon ratios as well as oxygen isotope ratios of phosphate in vegetation, and enzyme activity in soil. The stud...
Article
Full-text available
Groundwater discharge, including submarine groundwater discharge, discharge to lakes and rivers, and subglacial discharge, affects freshwater and marine ecosystems across the globe. The implications for biogeochemistry include the transport of nutrients, metals, and gases to these systems. The Arctic is one region of the globe that has been underst...
Article
Sources of dissolved methane (CH4) at Toolik Lake, Alaska include both diffusion from lake sediments and groundwater entering the lake from its perimeter. Here we use hydrogen and oxygen isotopes in water (H2O), carbon and hydrogen isotopes in CH4, and carbon isotopes in dissolved inorganic carbon (DIC) to calculate the relative importance of lake...
Article
Primary productivity in both the Arctic Ocean and the Gulf of Alaska (GOA) is nitrogen limited in the summerwhen light limitation is relieved, and stratification in the GOA inhibits nutrientfluxes from deep water sources.Concentrations of nutrients and trace metals in these regions are higher closer to shore, and thus rivers havebeen attributed as...
Article
Monterey Bay, California (CA) receives nutrients from multiple sources, including river discharge, upwelling of deep water, and submarine groundwater discharge (SGD). Here we evaluate the relative importance of these sources to Northern Monterey Bay with a mixing model that integrates radium isotopes (Ra224, Ra223, Ra228) and nutrient concentration...
Article
Assessing the magnitude of groundwater discharge in high latitude areas during climate change is critical. While global warming trends continue to remodel aquifer systems affecting water and constituent fluxes to areas of discharge, the present status of groundwater fluxes in high latitudes is yet not well constrained. Here we report assessments of...
Article
Here, we quantify the flux of methane to the coastal Arctic and North Pacific Oceans via submarine groundwater discharge (SGD), by use of naturally occurring radium isotopes as groundwater tracers, combined with methane concentration measurements of coastal groundwater. Our findings indicate the flux of methane through this process is much greater...
Article
We quantified groundwater discharge and associated nutrient fluxes to Monterey Bay, California, during the wet and dry seasons using excess (224)Ra as a tracer. Bioassay incubation experiments were conducted to document the response of bloom-forming phytoplankton to submarine groundwater discharge (SGD) input. Our data indicate that the high nutrie...
Article
Full-text available
Methane emissions in the Arctic are important, and may be contributing to global warming. While methane emission rates from Arctic lakes are well documented, methods are needed to quantify the relative contribution of active layer groundwater to the overall lake methane budget. Here we report measurements of natural tracers of soil/groundwater, rad...
Conference Paper
Northern Monterey Bay, California is subject to recurrent algal blooms of dinoflagellates and diatoms, which can persist for over a month. The area of Monterey Bay where the algae persist has been termed "the incubator". While physical conditions contribute to the formation and retention of blooms in the incubator, the source of constituents needed...
Presentation
Methane release from sea and soils in permafrost regions of the Arctic is exacerbated by global warming. This may result in a positive feedback effect, as methane is a powerful greenhouse gas. Accordingly, it is important to gain a good understanding of the methane cycle and the sources and sinks of methane into (out of) the atmosphere. Large quant...
Conference Paper
Intense dinoflagellate blooms occur frequently in Monterey Bay, California. Blooms occur primarily during August through November and can persist for > 1 month. Maximum bloom frequency and mean intensity are in a shallow (< 25 m depth) area of the northeastern bay. This coastal area has been referred to as an ``extreme bloom incubator''. The highes...

Network

Cited By

Projects

Projects (5)
Project
Explore the geoarchaeology of the Boca Inlet Mound Complex
Project
This project seeks to bring to light new and innovative ways to improve scientific literacy while critically evaluating pedagogy.
Project
This projects seeks to understand the sources, fate, and implications of plastic in the marine environment.