An assessment model for the fate and environmental effects of offshore drilling mud discharges

The benthic boundary layer transport (bblt) model was developed to assess potential impact zones from drilling mud discharges from offshore oil and gas drilling. The model focuses on the drift, dispersion and concentration levels of the suspended fraction of the drilling mud fines in the benthic boundary layer with the assumption of a spatially homogeneous environment. The current version of the model includes a wave boundary layer, a breakup module for drilling mud flocs, a dose–response module for scallops, and a graphical user interface (GUI). The GUI was written in Java which makes the code largely platform independent. Simulations of suspended barite concentration near Sable Island on the Scotian Shelf during drilling in the fall of 1999 reproduce the very low concentrations (generally less than 1 μg L⁻¹) observed during the Environmental Effects Monitoring program. However, the simulations also exhibited concentrations in excess of the no-effects concentration for scallops (100 μg L⁻¹) prior to the sampling program. The model estimates that the potential impact on scallops in the vicinity of the drilling is a few days of lost growth over scales of a few kilometers.     

GIS Investigation of the relationship of sex and season on the population distribution of common bottlenose dolphins (Tursiops truncatus) in Charleston,South Carolina

ABSTRACT

The Charleston Estuarine System Stock (CESS) of common bottlenose dolphins (Tursiops truncatus) has been the focus of population monitoring for the past 20 years. Photo-id studies have determined abundance and survival estimates for this population, which exhibits high site fidelity in this area. However, fine-scale distribution, utilization patterns, and the driving forces behind these patterns are lacking. Using historical photo-id data and a novel application of geographic information system (GIS) analysis, the present study identified core use areas within Charleston Harbor, as well as patterns specific to sexes and seasons. Photo-id data of 319 dolphins sighted 11 times or more during 2004–2009 were analyzed. Heat maps were developed to examine spatial distributions using kernel density estimates (KDE) and were compared between sexes and seasons. Multiple high-density core use areas were identified for this population, with the most noteworthy near the mouth of the harbor toward the Atlantic Ocean. Fine-scale distribution varied across sexes, as well as seasons. Some areas were identified as more specifically inhabited by one sex, while other areas overlapped between sexes. Females were more tightly concentrated within their distribution while males were more dispersed. Although population distribution varied across seasons, sex distributions remained.     

Wildfire-Migration Dynamics: Lessons from Colorado's Fourmile Canyon Fire

The number of people living in wildfire-prone wildland–urban interface (WUI) communities is on the rise. However, no prior study has investigated wildfire-induced residential relocation from WUI areas after a major fire event. To provide insight into the association between sociodemographic and sociopsychological characteristics and wildfire-related intention to move, we use data from a survey of WUI residents in Boulder and Larimer counties, Colorado. The data were collected 2 months after the devastating Fourmile Canyon fire destroyed 169 homes and burned more than 6,000 acres of public and private land. Although this study is working with a small migrant sample, logistic regression models demonstrate that survey respondents intending to move in relation to wildfire incidence do not differ sociodemographically from their nonmigrant counterparts. They do, however, show significantly higher levels of risk perception. Investigating destination choices shows a preference for short-distance moves.     

Practicing community geography in times of crisis

Community geography emphasizes the centrality of community engagement to socially transformative research. This introduction to a special issue of GeoJournal on community geography outlines how this growing subfield provides a model for collaborative action with the crises of our time, from white supremacy through climate change. As the co-editors of this special issue, we summarize the contents of these 14 articles, grouping them by the shared themes of power, institutional partnerships, pedagogy, and methods.

     

Community Recovery Following the Deepwater Horizon Oil Spill: Toward a Theory of Cultural Resilience

Culture plays an important role in communities’ abilities to adapt to environmental change and crises. The emerging field of resilience thinking has made several efforts to better integrate social and cultural factors into the systems-level approach to understanding social–ecological resilience. However, attempts to integrate culture into structural models often fail to account for the agentic processes that influence recovery at the individual and community levels, overshadowing the potential for agency and variation in community response. Using empirical data on the 2010 BP oil spill’s impact on a small, natural-resource-dependent community, we propose an alternative approach emphasizing culture’s ability to operate as a resource that contributes to social, or community, resilience. We refer to this more explicit articulation of culture’s role in resilience as cultural resilience. Our findings reveal that not all cultural resources that define resilience in reference to certain disasters provided successful mitigation, adaptation, or recovery from the BP spill.     

Closing the Gap Between Researchers and Policymakers: Lessons from the History of Fisheries Management in the United States

Increases in sea surface temperature have led to distributional changes in many commercially exploited fish species. These changes have already led to conflict over mackerel fisheries, arising from demand for fair resource apportionment and desire to manage the fishery sustainably. In order to develop adaptable management strategies for complex ocean fishery systems, policymakers and researchers must move beyond a reactive producer–consumer relationship to develop proactive, supportive collaborations. The history of U.S. national fisheries management is presented as an example of this transition. Building cooperative capacity over the last two centuries has lead to a more systematic understanding of the oceans, and has led to success in reducing the number of overfished stocks. Similar development of cooperation between policymakers and researchers on an international scale may be the surest way to develop management strategies adaptable enough to withstand challenges posed by future climate change.     

Knowledge gaps in our perceptual model of Great Britain's hydrology

There is a no lack of significant open questions in the field of hydrology. How will hydrological connectivity between freshwater bodies be altered by future human alterations to the hydrological cycle? Where does water go when it rains? Or what is the future space–time variability of flood and drought events? However, the answers to these questions will vary with location due to the specific and often poorly understood local boundary conditions and system properties that control the functional behaviour of a catchment or any other hydrologic control volume. We suggest that an open, shared and evolving perceptual model of a region's hydrology is critical to tailor our science questions, as it would be for any other study domain from the plot to the continental scale. In this opinion piece, we begin to discuss the elements of and point out some knowledge gaps in the perceptual model of the terrestrial water cycle of Great Britain. We discuss six major knowledge gaps and propose four key ways to reduce them. While the specific knowledge gaps in our perceptual model do not necessarily transfer to other places, we believe that the development of such perceptual models should be at the core of the debate for all hydrologic communities, and we encourage others to have a similar debate for their hydrologic domain.