rivers

Integrated Water Plan for Puerto Rico, December 2006

"Plan Integral de Agua" December, 2006.

Abstract: 
Water is a natural resource important for life, growth and development of cities and towns. It's "Not just the most basic of necessities it's also the basis of sustainable development." The spatial and temporal distributions varies in such a way that its in abudnant in some regions and times while is is vary limited in others. While it is considers a renewable resource it is no less correct that improper management can lead to a reduced quantity and quality of available water. It's also the case that contamination can also render the resource unusable. For these reasons the availability, quality, and management of water resources represents a grand challenge for Puerto Rico and most of the world. El agua es un recurso natural de vital importancia para la vida, crecimiento y desarrollo de los pueblos. Es “[n]o sólo la más básica de las necesidades, sino también el núcleo del desarrollo sostenible”1. Su distribución espacial y temporal varía de forma que, mientras es abundante en unas regiones o épocas, en otras es muy limitado. A pesar de que se considera un recurso renovable no es menos cierto que su manejo inapropiado, puede tener el efecto de reducir la cantidad disponible y utilizable del recurso. De igual forma, la contaminación irreversible del recurso puede convertirlo en uno agotable. Es por ello que la disponibilidad, calidad y manejo adecuado del recurso representa un gran desafío para Puerto Rico y la mayor parte del mundo.

Factors Influencing Tropical Island Freshwater Fishes: Species, Status, and Management Implications in Puerto Rico

Neal JW, Lilyestrom CG, Kwak TJ (2009) Factors influencing tropical island freshwater fishes: species, status, and management implications in Puerto Rico. Fisheries 37:546-554

Abstract: 
Anthropogenic effects including river regulation, watershed development, contamination, and fish introductions have substantially affected the majority of freshwater habitats in Europe and North America. This pattern of resource development and degradation is widespread in the tropics, and often little is known about the resources before they are lost. This article describes the freshwater resources of Puerto Rico and identifies factors that threaten conservation of native fishes. The fishes found in freshwater habitats of Puerto Rico represent a moderately diverse assemblage composed of 14 orders, 29 families, and 82 species. There are fewer than 10 species of native peripherally-freshwater fish that require a link to marine systems. Introductions of nonindigenous species have greatly expanded fish diversity in freshwater systems, and native estuarine and marine species (18 families) also commonly enter lowland rivers and brackish lagoons. Environmental alterations, including land use and development, stream channelization, pollution, and the impoundment of rivers, combined with nonnative species introductions threaten the health and sustainability of aquatic resources in Puerto Rico. Six principal areas for attention that are important influences on the current and future status of the freshwater fish resources of Puerto Rico are identified and discussed.

A Model for Predicting Daily Peak Visitation and Implications for Recreation Management and Water Quality: Evidence from Two Rivers in Puerto Rico

Santiago LE, Gonzalez-Caban A, Loomis J (2008). “A model for
predicting daily peak visitation and implication for recreation
management and water quality: evidence from two rivers in Puerto
Rico”. Environ. Manage., 41: 904-914.

Abstract: 
Visitor use surveys and water quality data indicates that high visitor use levels of two rivers in Puerto Rico does not appear to adversely affect several water quality parameters. Optimum visitor use to maximize visitor defined satisfaction is a more constraining limit on visitor use than water quality. Our multiple regression analysis suggests that visitor use of about 150 visitors per day yields the highest level of visitor reported satisfaction, a level that does not appear to affect turbidity of the river. This high level of visitor use may be related to the gregarious nature of Puerto Ricans and their tolerance for crowding on this densely populated island. The daily peak visitation model indicates that regulating the number of parking spaces may be the most effective way to keep visitor use within the social carrying capacity.

Effects of land use change on northeastern Puerto Rican rivers

Clark, J. 1997. Effects of land use change on northeastern
Puerto Rican rivers. Phd Dissertation, Johns
Hopkins University, Baltimore, Maryland, 187
pages.

Abstract: 
The 500 year period considered in this study is sufficiently long that river change may be produced by natural changes in the external controls of river geometry. These controls include changes in the base level and changes in the climate which, like land use, change the supply of sediment to the rivers.

Does the river continuum concept apply on a tropical island? Longitudinal variation in a Puerto Rican stream

Greathouse,Effie A.; Pringle, Catherine M. 2006. Does the river continuum concept apply on a tropical island? Longitudinal variation in a Puerto Rican stream.. Can. J. Fish. Aquat. Sci. 63: 134-152.

Abstract: 
We examined whether a tropical stream in Puerto Rico matched predictions of the river continuum concept (RCC) for macroinvertebrate functional feeding groups (FFGs). Sampling sites for macroinvertebrates, basal resources, and fishes ranged from headwaters to within 2.5 km of the fourth-order estuary. In a comparison with a model temperate system in which RCC predictions generally held, we used catchment area as a measure of stream size to examine truncated RCC predictions (i.e., cut off to correspond to the largest stream size sampled in Puerto Rico). Despite dominance of generalist freshwater shrimps, which use more than one feeding mode, RCC predictions held for scrapers, shredders, and predators. Collector–filterers showed a trend opposite to that predicted by the RCC, but patterns in basal resources suggest that this is consistent with the central RCC theme: longitudinal distributions of FFGs follow longitudinal patterns in basal resources. Alternatively, the filterer pattern may be explained by fish predation affecting distributions of filter-feeding shrimp. Our results indicate that the RCC generally applies to running waters on tropical islands. However, additional theoretical and field studies across a broad array of stream types should examine whether the RCC needs to be refined to reflect the potential influence of top-down trophic controls on FFG distributions.

A SURVEY OF METHODS FOR SETTING MINIMUM INSTREAM FLOW STANDARDS IN THE CARIBBEAN BASIN

SCATENA, F. N. 2004. A SURVEY OF METHODS FOR SETTING MINIMUM INSTREAM FLOW STANDARDS IN THE CARIBBEAN BASIN.. River Res. Applic. 20: 127-135.

Abstract: 
To evaluate the current status of instream flow practices in streams that drain into the Caribbean Basin, a voluntary survey of practising water resource managers was conducted. Responses were received from 70% of the potential continental countries, 100% of the islands in the Greater Antilles, and 56% of all the Caribbean island nations. Respondents identified ‘effluent discharges’, ‘downstream water quality’ and ‘existing extraction permits’ to be the most common sources of instream flow conflicts. In 75% of the countries, some type of ‘formal procedures’ exist for reviewing permit applications for freshwater extraction. In 82% of the countries, effluent discharge permits state the amount of effluent that can be discharged into a water body while only 69% require that surface water extraction permits explicitly state the quantity of water that can be extracted. In setting instream flow requirements, record low flow is used over 83% of the time. Freshwater fish were identified as the most important aquatic organism but no country ‘always’ considers the ecology or habitat requirements of aquatic species in their instream flow determinations and nearly 70% of the respondents indicated that multivariate, ecological-based methods are ‘never’ used in their country. Survey responses also indicate there is a notable lack of public involvement during the issuing of water permits. Moreover, over 80% of the countries do not provide public announcements or hearings during the permit process. In summary, this survey indicates that while there is a widespread recognition of the need for instream flows, there is a general lack of regionally based information and public involvement regarding stream flow determination.
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