The availability of clean water is fundamental to the survival of all living things. Humans have altered fresh water cycles in a number of ways that affect both water quality and quantity. This has led to a global water crisis where an estimated nine million people are without access to a clean and reliable source of water. Yet water is more than a basic need, more than a physical resource. As a facet of daily life for communities all over the world, water carries many different cultural values and meanings. These values and meanings, in turn, have a strong influence on how people use water and how they relate to sources and suppliers of water. My study examined the complex and global challenge of managing water by focusing on cultural values and meanings about water on a local scale. I took an ethnographic approach to understanding the relationship between cultural values and water resources in the Sierra y Huasteca region of Hidalgo state in East-Central Mexico. Through participant observation, semi-structured household interviews and key informant interviews I: 1) described how water is used, obtained and managed; 2) evaluated local concerns about water management and access; and 3) compare two different water management systems; a communally managed system and a municipally managed system. My research resulted in three major findings. These were: 1) water scarcity is the main water concern in the two communities, which people attribute to deforestation; 2) despite considerable differences between the communities the primary concerns and values of water are the same; and 3) growing concern about water and other resources may be resulting in an increased environmental consciousness among the people in the two communities. This research contributes to practical, policy, and scholarly discussions about the relationships between humans and their natural resources. Understanding local social and cultural values can help in the effort to find equitable and feasible solutions to the global water crisis.

Typescript. / Thesis (Ph. D.)--University of Hawaii at Manoa, 1990. / Includes bibliographical references (leaves 127-136) / Microfiche. / ix, 136 leaves, bound ill. 29 cm

Exploration for geothermal resources in Hawaii has required adaptation of conventional exploration techniques as well as the implementation of relatively new techniques because of the complexities introduced by the oceanic island environment / ill / maps

The modern day Mississippi River Delta Plain and the Louisiana Chenier Plain have been greatly altered through anthropogenic changes to course and hydrological conditions of the Mississippi River and local rivers, most notably by levees that have excluded the Mississippi River from the delta plain. This has slowed accretion and increased land loss destroying vast quantities of marsh, endangering many coastal communities. This masters thesis examined long-term total suspended sediment yield of four Chenier Plain rivers, total suspended sediment yield of the Mississippi River under different flow conditions, and total suspended sediment dynamics of the Atchafalaya River in relation to Atchafalaya River Delta Complex growth and Atchafalaya River Basin sedimentation. Results estimated average annual total suspended sediment yield to coastal Louisiana of 176.3 megatonnes (MT), with the Mississippi River contributing 72% and the Atchafalaya River contributing 28%. The Chenier Plain rivers contributed a negligible amount to this total, averaging annually 342,950 tonnes, with the Sabine contributing 62% to this total (213,100 tonnes), while the Calcasieu River supplied 46,850 tonnes, Mermentau River 40,200 tonnes, and Vermilion River 42,800 tonnes. The hydrograph-based approach for quantification of actual available total suspended sediment of the Mississippi River identified the rising limb of the flood pulse during Action Stage (12.1-14.6 m) and Flood Stage (14.6-16.8 m) maximized total suspended sediment with 28.9 MT supplied. Atchafalaya River Delta Complex growth rate was 2.8 km2 yr-1 (1989-2010). Both Atchafalaya River Morgan City subdelta (ARSD) and Wax Lake Outlet Subdelta (WLSD) growth rates were influenced by large floods that helped maintain positive growth rates, and tropical systems that decreased growth rates over the period. Average annual sedimentation rate in the Atchafalaya River Basin (ARB) was estimated between 30.4-79.1 mm yr-1, while total suspended sediment retention averaged 5.3 MT yr-1 (1996-2010), but interannual variation demonstrates that the ARB has reached an equilibrium and resembles a fluvially dominated system rather than lacustrine or palustrine system. Results from this study provide an exhaustive understanding of riverine sediment availability to coastal Louisiana and the impacts on coastal evolution, providing information that land managers can use to model restoration of coastal Louisiana.

Since its introduction in 1956, the use of open-system, diel dissolved oxygen curves for estimating the components of ecosystem metabolism in the lotic setting have been important in determining the current ecosystem theory of streams, both spatially among multiple systems and longitudinally within the same system, as well as identifying potentially impaired systems, especially when contrasted with streams considered unimpaired. Several factors have been identified as controls on both components of ecosystem metabolism and include light, nutrients, and stable substrates for gross primary production (GPP) and a source of organic matter (OM) for ecosystem respiration (ER). Stream size is important at mediating these factors through the presence or absence of a riparian canopy where small streams tend to have an intact canopy that can severely limit light to primary producers but provide a good source of OM for respiration. Alternatively, larger systems tend to lose canopy cover via widening of the stream and the limitation of light is relaxed while input of OM decreases. Additionally, inputs from watershed land use can affect GPP and ER in the stream via the inputs of nutrients to stimulate algal growth or organic pollution that stimulates heterotrophic activity. In the following studies, the effect of the presence or absence of a riparian canopy, watershed land use, and stochastic events such as flooding on ecosystem metabolism in coastal plain streams of southeast Louisiana are described. These systems behave similarly to previous studies and provide more evidence that the use of ecosystem metabolism as a metric for stream health is beneficial. Recommendations for future studies include the identification of more unimpaired systems while adding a temporal component, modeling systems under different hydrologic or climate change regimes, and the assessment of the impacts of stochastic events such as extreme weather events, exotic species invasions, or local extirpations of important species.

Marine spatial property rights reduce many common pool externalities that plague wild capture fisheries and incentivize productive use for aquaculture. Specifically, Territorial Use Rights for Fisheries (TURFs) are a management tool whereby individuals or groups are granted exclusive access to harvest resources within an area, and are the prevailing management of coastal fisheries in Chile. Additionally, secured spatial property rights appear inherently obligatory for aquaculture development; i.e., private leases in Virginia, where submerged grounds granted to an individual or a company for oyster production are considered a form of TURF. Although the number and extent of spatially managed areas are the highest they have ever been in both systems, the impacts of spatial property rights on fisheries and aquaculture sustainability are still not fully understood. The objective of this dissertation was to evaluate current challenges to the effective use of TURFs, deepening our understanding of their efficacy for fishery and aquaculture management. The long-term impacts of the Chilean TURFs network on harvests of benthic resources was investigated both inside and outside TURFs (Chapter 2). Although catch rates were significantly higher inside TURFs than surrounding open access areas, they appeared to be decreasing over time, and, though limited, the impact of TURFs on catches in open access areas was negative. Spatio-temporal trends in private lease use and productivity in Virginia were examined to identify challenges faced by the oyster aquaculture industry. Constraints to aquaculture expansion were investigated by evaluating whether a lack of space limits aquaculture development as well as the extent and drivers of lease non-use (Chapter 3). Limited evidence of spatial constraints was found, although results suggest additional social and regulatory limiting factors. While rates of lease use and productivity increased from 2006 to 2016, only 33% of leases were ever used for oyster production. The non-used leases were potentially held for exclusionary or speculative uses. Additionally, Virginia had the second lowest levels of total production of cultured oysters per leased acre among the states along the U.S. East and Gulf coasts, confirming significant limitations associated with the current leasing system. Production frontier models were used to quantify lease use efficiency (i.e., utilization of space given the underlying environment) for oyster production (Chapter 4). Significant amounts of inefficiency in intensive aquaculture practices suggest that production could increase by at least 64% per lease, on average (though high heterogeneity is observed between leases). Low levels of use efficiency (i.e., underutilization) imply that leaseholders tend to lease more area than needed, likely due to the low annual lease costs and the absence of enforced production requirements. The number of leases held per leaseholder increased use efficiency, whereas leases in more populated areas were less efficiently used. This research contributes to a better understanding of TURF's efficacy and challenges in Chile and in Virginia. Overall, socioeconomic and management factors appear to be limiting productivity and sustainability of TURFs in both systems, recognizing the importance of incentives, enforcement, zoning, and the potential presence of trade-offs between economic, social and biological sustainability.

Thesis (PhD)--University of South Australia, 1998

No description available.

No description available.

The papers presented in this thesis represent my contributions to the empirical study of marine biological resources. This research has adopted the same experimental approach to: (i) develop scientifically validated techniques to solve specific problems; (ii) use these techniques to detect patterns and form conceptual models about the processes that may have caused them; (iii) do manipulative field experiments to support or refute hypotheses derived from these models; (iv) use these results to develop new models and hypotheses and to test them in new experiments; and (v) recommend, where appropriate, changes to the management of the resources examined. A rigorous, empirical approach is the common feature throughout my research (in its overall direction and subject-to-subject execution) and represents one of the few attempts to adopt such an approach across the three fields in which I have worked: (1) the ecology of underwater kelp systems; (2) the biology of and fishery for a commercially exploited crab; and (3) solving by-catch problems in commercial trawl fisheries.