Environmental Sciences & Sustainability Faculty Research

Environmental Sciences & Sustainability Faculty Research

Catch up with research from the environmental sciences & sustainability department at Merrimack College.

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Dr. Cynthia Carlson

Managing urban storm water is challenging under the best of situations, and due to projected increases in intensity of rainfall events, is exacerbated by climate change. Institutional and individual aspects of urban storm water management and the implications for low-impact development (LID) are presented. The paper frames storm water as a public good provision issue in order to build on existing knowledge about that kind of social dilemma. This topic is then examined in more detail through stakeholder interviews conducted in Somerville, Massachusetts, United States. Interviews were completed at a variety of management levels, from household to regional planning level, and are related back to the theory of public good provision. Finally, synthesis of theory and practice results in specific recommendations for urban storm water management, based on revising the storm water institutional framework, showcasing redevelopment opportunities, and facilitating education and awareness through local NGOs.

Dr. Bryan Bannon

The farmhouse lingers, though averse to square With the new city street it has to wear A number in. But what about the brook That held the house as in an elbow-crook? I ask as one who knew the brook, its strength And impulse, having dipped a finger length And made it leap my knuckle, having tossed A flower to try its currents where they crossed. The meadow grass could be cemented down From growing under pavements of a town; The apple trees be sent to hearth-stone flame. Is water wood to serve a brook the same? How else dispose of an immortal force No longer needed? Staunch it at its source With cinder loads dumped down? The brook was thrown Deep in a sewer dungeon understone In fetid darkness still to live and run–And all for nothing it had ever done Except forget to go in fear perhaps. No one would know except for ancient maps That such a brook ran water. But I wonder If from its being kept forever under, The thoughts may not have risen that so keep This new-built city from both work and sleep.

Dr. April Bowling

Children in low-income, urban public schools are at a greater risk of poor physical activity (PA) and academic outcomes. The purpose of this study was to examine whether the use of a novel exerlearning application, Active Science (AS), in third-grade physical education (PE) classes improved PA levels, student attitudes toward science, and third-grade science curriculum content knowledge.

Dr. Michael Corcoran

This cluster-randomized trial was designed to determine the efficacy of a 6-month exercise-nutritional supplement program (ENP) on physical function and nutritional status for older adults and the feasibility of implementing this program in a senior living setting. Twenty senior-living facilities were randomized to either a 3 day per week group-based ENP led by a trained facility staff member or a health education program (SAP). Participants (N = 121) completed a short physical performance battery, 400-m walk, handgrip strength test, and mini-nutrition assessment. 25-hydroxyvitamin D [25(OH)D], insulin-like growth-factor 1 (IGF-1), and activity level were also measured. The ENP did not significantly improve physical function or nutritional status compared with the SAP. Compared with baseline, participants in the ENP engaged in 39 min less physical activity per week at 6 months. Several facility characteristics hindered implementation of the ENP. This study highlights the complexity of implementing an evidence-based program in a field setting.

Dr. Ellen Fitzpatrick

This paper explores the efficacy of a development model designed to enhance social capital where social capital is seen as a catalyst to increased economic opportunities. The study covers smallholder livestock producers in Malawi and the Philippines. The key question examined in this paper is whether communities that received this specific development intervention significantly increased their access to social capital over time and whether this social capital is positively correlated with net farm income and improved livelihoods. We draw data from two case studies: Heifer International’s Malawi Smallholder Dairy Development Project (MSDD1) and the Philippine Raising Income of Families through Sustainable Agri-Business Project (RICSA). The examination of these two cases increases our understanding of how implementation and contextual variables may influence changes in social capital and livelihoods. The study applies social network analysis (SNA) to understand the connection between asset-based/human capacity interventions and social capital.

Dr. Mariko Frame

Two major trends are currently challenging the sustainability of human civilization: extreme inequality and the ecological crisis. This book argues that these are intrinsically linked by further exploring the complex relationships between global ecological crises, neoliberal globalization, orthodox development policies, and imperialism. Drawn from extensive theoretical, historical, policy, and empirical research, as well as fieldwork in Africa and Asia, this book examines the crucial characteristics of the capitalist world-system and how it enables and drives ecological imperialism. Neoliberal globalization has allowed for capital’s unfettered access to and exploitation of Nature across the planet, and neoliberal development policies have reinforced a contemporary form of ecological imperialism where the environments of the Global South are enclosed and exploited, and local communities are dispossessed of their land and livelihoods.

Simultaneously, resources from the Global South are funneled to the Global North in the form of consumer goods and ecologically unequal exchange, while the profits from those resources are siphoned away to transnational corporations, financiers, and government elites. This work traces the historical development of free market policies, while also paying special attention to the role of Northern international financial institutions, emerging economies (the semi-periphery), and the often-hidden role of international finance in ecological imperialism. This volume will be of keen interest to scholars and students of political economy, critical development studies, environmental sociology, and political ecology.

Dr. R. David MacLaren

The present study examined the effects of environmentally realistic exposure to atrazine (ATZ) on the behavior of sailfin mollies, Poecilia latipinna. ATZ is one of the most commonly used pesticides in the US and a known endocrine disrupting chemical (EDC). The behavior of sailfin mollies is well documented in the scientific literature. Moreover, they are ecologically important indicators of environmental health, widely distributed among the mangroves along the Gulf Coast of the Southeastern US where significant amounts of ATZ are introduced via runoff and storm water drainage from coastal households, businesses, and farms. Four sets of experiments designed to assess ATZ’s impact on various aspects of male and female reproductive behavior, aggression, anxiety, and boldness were conducted following 12 weeks of exposure to 1 or 15 ppb water-borne ATZ, along with a no-exposure control group.

Results indicated that the behavior of ATZ-exposed individuals differed from those of controls: ATZ exposure affected which stimulus fish (a male vs. a female) subject females preferred to associate with while also affecting female strength of preference for males of larger body size and their sexual receptivity to conspecific males in general. ATZ-exposed males also showed reduced overall responsiveness to conspecific stimuli and directed significantly less aggression toward their mirror image compared with controls. Finally, ATZ exposure affected multiple aspects of male and female behavior that are often used as proxies for boldness and anxiety. Overall, ATZ exposure resulted in alterations across a variety of behaviors attributed to sexual receptivity, mate choice and motivation to mate, aggression, as well as boldness and anxiety. These ATZ-induced behavioral changes may adversely affect the long-term health of natural populations exposed to similar, environmentally realistic concentrations and add to a growing body of empirical data demonstrating substantial fitness consequences of exposure to sublethal concentrations of this known EDC.

Dr. William McDowell

Impacts of invasive species on ecosystems are often context dependent, making empirical assessments difficult when climatic baselines are shifting and extreme events are becoming more common. We documented a mass mortality event of the Asian clam, Corbicula fluminea, an abundant invasive clam, which has replaced native mussels as the dominant filter-feeding bivalve in the southeastern United States. During an extremely hot and dry period in the summer of 2012, over 99% of Corbicula died in our 10-km study reach of the Broad River, Georgia. Because Corbicula were the only filter-feeding organism in the ecosystem with substantial bio- mass, their death led to the nearly complete cessation of ecosystem services provided by filter-feeding bivalves.

We estimate that following the mass mortality event, turnover time within the sampling reach (reach volume/total filtration) rose from approximately 5 h to over 1200 h. In addition to the loss of filtering capacity, concentrations of total dissolved phosphorus (TDP) and soluble reactive phosphorus (SRP) were also higher in areas where die-off was occurring than in an upstream area without mortality. Mass balance calcu- lations and a manipulative mesocosm experiment predicted TDP and SRP concentrations much higher than our observed values, suggesting that rapid biotic or abiotic uptake of phosphorus may have occurred. Our study demonstrates that climate change can increase the temporal variability of populations of aquatic organisms that provide key ecosystem functions, and highlights that even pulsed, short-lived events can markedly affect systems of reduced diversity.

Dr. Azam Noori

Recent years have seen significant increases in the use of silver nanoparticles (AgNPs) in areas such as medicine and agriculture. AgNPs released into environment can be accumulated by plants, potentially affecting environmental and human health. In addition, the accumulation of silver in plant tissues can negatively affect plant vascular tissues and membrane transporters that are responsible for the transport of water and essential nutrients. In this study, Lycopersicon esculentum plants were exposed to 10, 20, or 30 mg/L of silver in bulk (Ag0), nanoparticle (AgNPs), or ionic (AgNO3) form for 7 days in Hoagland media. Tissues were then harvested and subjected to elemental, molecular, and microscopic evaluation. The highest and lowest concentration of silver was detected in roots of plants exposed to 10–30 mg/L AgNO3 (432–471 μg/g dw) or AgNPs (40–47 μg/g dw), respectively. Particulate silver was detected in plants exposed to 20 nm AgNPs. The highest (52,700–58,400 particles/g) and lowest (6200–13,700 particles/g) concentrations of particles were detected in roots and leaves, respectively.

The membrane transporters H+-ATPase, potassium transporter, and sulfate transporter were upregulated by 23.50%, 52.09%, and 7.6% upon exposure to all forms of silver as compared to the control group. Exposure to all forms of silver resulted in larger xylem cells (70 ± 1.1 μm in AgNP-exposed plants) than the control group (46 μm ± 0.6). Collectively, the data suggest that exposure to AgNPs resulted in the translocation and accumulation of both ionic and particulate forms of silver in tomato plants, affected the structure of vascular tissues, and significantly impacted the expression of membrane transporters. These changes subsequently affect the electrochemical potential of plant cells, the balance of water and nutrient dynamics, and plant growth; all of which have implications for sustainable agriculture and ultimately human health. These results also improve our understanding of the fate and effects of nanomaterials in food crops.