Linking Soil Loss to Sediment Delivery in Two Estuaries in Puerto Rico

Enhanced soil loss from the watershed is a major environmental issue. Increased soil loss from a watershed can potentially increase sediment delivery and loading to aquatic ecosystems such as rivers and estuaries. An increase in sediment delivery and loading to freshwater and transitional marine ecosystems can impact water quality and supply specifically by: (1) reducing water clarity, (2) transporting nutrient and pollutant laden sediments and (3) reducing the storage capacity of reservoirs. To address these broader environmental impacts of increased sediment delivery and loading to aquatic ecosystems it is imperative that potential source areas of sediments available for transport are identified in the watershed. It is also important that sediment source areas are linked to sediment transport and delivery to aquatic ecosystems. This study attempted to establish a link between soil loss from watersheds and sediment delivery in two estuaries on the island of Puerto Rico. The two estuarine systems used in this investigation were the Rio Espiritu Santo (RES) riverine-estuarine system and the Jobos Bay (JB) Estuary. Soil loss from both study watersheds was estimated using RUSLE. Sediment cores and surface grab samples were collected from both estuaries. In addition, soil samples were collected from the two watersheds. Gamma analyses were performed in order to measure activity concentrations of 137Cs and excess 210Pb in sediment cores, surface and soil samples. 137Cs inventories were computed for each core collected from both watersheds. Also, grain-size and LOI were performed on the sediments to describe the sedimentological characteristics of collected sediment cores, surface samples and soil samples. A conceptual framework was developed and implemented for linking sediment production, availability (supply), transport and delivery to study estuaries. Results from the RUSLE model indicated that soil loss within both watersheds were low with patchy instances of erosional hotspots. These results did not provide any information on sediment supply or insights into the hydrologic connectivity of the study watersheds. 137Cs inventories computed from the RES watershed indicated that sediment cores located further upstream had the highest inventories. With reference to the JB Estuary, statistical analysis showed that location had an effect on distribution of Cs in surface samples within the bay. Sedimentological characteristics varied between cores. The implementation of the conceptual model in both study watersheds allowed for the identification of potential source areas of sediments that were available for transport and delivery to adjacent aquatic systems. This investigation revealed that to link soil loss to sediment delivery it is essential that key processes and variables (rainfall, soils, LULC and geomorphology) must be included in the analysis. This conceptual model may be a valuable tool for monitoring and managing soil loss within the watershed and consequently, addressing problems of increased sediment delivery to aquatic and transitional marine ecosystems such as estuaries

Communicating land loss for coastal Louisiana with visuals: Issue Urgency and Issue Importance

This study explores the influence of visual imagery on individuals\u27 perception of complex scientific information on coastal land loss. It investigates how mass media channels use visual frames to convey an environmental issue\u27s outcomes and how these frames might influence perceptions of issue urgency and issue importance. The primary message frames explored in this study were gain/loss frames and temporal context. A content analysis was conducted to collect online images of coastal land loss in Louisiana and the potential message frames used to communicate this issue\u27s outcomes to the public were identified for each image and coded. Focus group discussions were then used to evaluate the effectiveness of these message frames. Results suggest that visual cues can shape public understanding of coastal change and its risk to coastal communities. Particularly, images that refer to future environmental conditions (temporal context) are more likely to convey the urgency and importance of an issue. Images that emphasize environmental and economic losses may be more engaging to an audience, however these types of images may also reduce motivation to mitigate losses. Willingness to support environmental solutions appears to be a result of public\u27s ability to visualize short-term goals and successes. Best practices for coastal managers to produce and deliver environmental imagery are discussed

Estimating soil loss from two coastal watersheds in Puerto Rico with RUSLE.

The loss of topsoil from the landscape increases sediment loading to adjacent aquatic systems, which may be transported further downstream. Increased sediment loading to downstream ecosystems such as estuaries can negatively impact these environments. This research compares the sediment loss from two watersheds [Jobos Bay (JB) and Rio Espiritu Santo (RES) watersheds] on the island of Puerto Rico. The revised universal soil loss equation (RUSLE) was applied to both watersheds. Results from this study suggested that potential soil loss from both watersheds is relatively low. There is some indication that the RES watershed may have a higher soil loss potential when compared to the JB watershed

The Sustainability of Ecotourism Activities: Develo pment of an Accessible, Applicable, and Efficient Tool for Asse ssment in the Caribbean Region

Tourism is one of the fastest growing industries in the world. Ecotourism is increasing in popularity as nations and visitors seek to minimise their impact on the natural environment. The Caribbean, like much of the developing world, lacks monitoring and governmental management of their growing ecotourism industry due to both personnel and resource scarcity. This study aimed to develop a tool for effective management of the Caribbean ecotourism industry. This tool is based on sustainability indicators and includes all onsite activities necessary to facilitate the business of ecotourism. Sustainability indicators were selected via the responses from a community survey, environmental checklist, screening and scoping exercise and semi-structured interviews. A reductionist approach was used to ensure that the indicators met the requirements of both World Tourism Organisation (WTO) and Organisation of Economic Development (OECD). The data were then evaluated for five different scenarios representing demographic and social changes and translated into target plots for efficient assessment purposes. Results from this analysis indicate that sustainability of ecotourism activities in the Caribbean region can be assessed across fifteen indicators among the three core pillars of sustainability: environmental, societal and economic. Sensitivity analysis showed that the assessment tool responded to social and demographic changes and that evaluation of average impact differentials across each core pillar of sustainability could be used to plan for possible future detrimental impacts