Recent increases in global urea usage, including its incorporation in slow-release fertilizers commonly used in lawn care in Florida, have the potential to alter the form and amount of nitrogen ...inputs to coastal waters. This shift may, in turn, impact phytoplankton community diversity and nutrient cycling processes. An autonomous water quality monitoring and sampling platform containing meteorological and water quality instrumentation, including urea and phycocyanin sensors, was deployed between June and November of 2009 in Sarasota Bay, Florida. This shallow, lagoonal bay is characterized by extensive and growing urban and suburban development and limited tidal exchange and freshwater inputs. During the monitoring period, three high-biomass (up to 40 µg chlorophyll-a·L−1) phytoplankton blooms dominated by picocyanobacteria or picoeukaryotes were observed. Each bloom was preceded by elevated (up to 20 μM) urea concentrations. The geolocation of these three parameters suggests that “finger canals” lining the shore of Sarasota Bay were the source of urea pulses and there is a direct link between localized urea inputs and downstream picoplankton blooms. Furthermore, high frequency sampling is required to detect the response of plankton communities to pulsed events.
Coastal monitoring has become reliant upon automated sensors for data acquisition. Such a technical commitment comes with a cost; particularly, the generation of large, high-dimensional data streams ...(‘Big Data’) that personnel must search through to identify data structures. Nature-inspired computation, inclusive of artificial neural networks (ANNs), affords the unearthing of complex, recurring patterns within sizable data volumes. In 2009, select meteorological and hydrological data were acquired via autonomous instruments in Sarasota Bay, Florida (USA). ANNs estimated continuous chlorophyll (CHL) a concentrations from abiotic predictors, with correlations between measured:modeled concentrations >0.90 and model efficiencies ranging from 0.80 to 0.90. Salinity and water temperature were the principal influences for modeled CHL within the Bay; concentrations steadily increased at temperatures >28° C and were greatest at salinities <36 (maximizing at ca. 35.3). Categorical ANNs modeled CHL classes of 6.1 and 11 μg CHL L−1 (representative of local and state-imposed constraint thresholds, respectively), with an accuracy of ca. 83% and class precision ranging from 0.79 to 0.91. The occurrence likelihood of concentrations > 6.1 μg CHL L−1 maximized at a salinity of ca. 36.3 and a temperature of ca. 29.5 °C. A 10th-order Chebyshev bivariate polynomial equation was fit (adj. r2 = 0.99, p < 0.001) to a three-dimensional response surface portraying modeled CHL concentrations, conditional to the temperature–salinity interaction. The TREPAN algorithm queried a continuous ANN to extract a decision tree for delineation of CHL classes; turbidity, temperature, and salinity (and to lesser degrees, wind speed, wind/current direction, irradiance, and urea-nitrogen) were key variables for quantitative rules in tree formalisms. Taken together, computations enabled knowledge provision for and quantifiable representations of the non-linear relationships between environmental variables and CHL a.
•Neural networks modeled chlorophyll a in a high-dimensional estuarine database.•Pedagogical knowledge extraction defined environmental influences upon chlorophyll.•Salinity and temperature were the principal influences for modeled concentrations.•Decision trees delineated chlorophyll concentrations relevant to management use.•Application of nature-inspired computation for coastal data synthesis was discussed.
The objectives of the present study were to develop methods for conducting chronic toxicity tests with juvenile mussels under flow‐through conditions and to determine the chronic toxicity of copper ...and ammonia to juvenile mussels using these methods. In two feeding tests, two‐month‐old fatmucket (Lampsilis siliquoidea) and rainbow mussel (Villosa iris) were fed various live algae or nonviable algal mixture for 28 d. The algal mixture was the best food resulting in high survival (≥90%) and growth. Multiple copper and ammonia toxicity tests were conducted for 28 d starting with two‐month‐old mussels. Six toxicity tests using the algal mixture were successfully completed with a control survival of 88 to 100%. Among copper tests with rainbow mussel, fatmucket, and oyster mussel (Epioblasma capsaeformis), chronic value (ChV, geometric mean of the no‐observed‐effect concentration and the lowest‐observed‐effect concentration) ranged from 8.5 to 9.8 μg Cu/L for survival and from 4.6 to 8.5 μg Cu/L for growth. Among ammonia tests with rainbow mussel, fatmucket, and wavy‐rayed lampmussel (L. fasciola), the ChV ranged from 0.37 to 1.2 mg total ammonia N/L for survival and from 0.37 to 0.67 mg N/L for growth. These ChVs were below the U.S. Environmental Protection Agency 1996 chronic water quality criterion (WQC) for copper (15 μg/L; hardness 170 mg/L) and 1999 WQC for total ammonia (1.26 mg N/L; pH 8.2 and 20°C). Results indicate that toxicity tests with two‐month‐old mussels can be conducted for 28 d with >80% control survival; growth was frequently a more sensitive endpoint compared to survival; and the 1996 chronic WQC for copper and the 1999 chronic WQC for total ammonia might not be adequately protective of the mussel species tested. However, a recently revised 2007 chronic WQC for copper based on the biotic ligand model may be more protective in the water tested.
The effects of Bourbon reforms on mission architecture of the northern frontier of New Spain have not been examined in the surprisingly limited historiography of the San Antonio, Texas missions. The ...few existing architectural studies overlook major structural and developmental changes at the missions. Using the construction history of Mission San Francisco de la Espada, I argue that most of these changes are the result of the application of the Bourbon-revised mission administrative method, the método nuevo, made possible by the Patronato Real Universal of 1753 that gave the King of Spain temporal control over the Catholic Church within the Spanish Empire. In Texas, the método nuevo instituted new mission structural goals intended to improve mission defenses, reduce the cost and complexity of mission structures, move the missions toward secularization, and provide housing for salaried vecinos who replaced some of the declining Native American population. The number of houses at Espada was doubled in the 1780s, in contrast to the standard historical narrative that the missions deteriorated and failed in the last quarter of the eighteenth century. Episodes of construction at Espada indicate that projects designed and directed by the maestros were only those requiring arches, vaults, or domes. Most of the structures built were simple trabeated buildings, an ancient and still ongoing tradition where inexpensive housing may be needed in the Americas, the coastal areas of the Mediterranean, and elsewhere. These structures were designed and their construction directed by the Franciscans or their mayordomos as part of the application of the método nuevo. The recognition of these and other episodes of redesign and construction at Espada give us a new understanding of the effects of Bourbon reforms on the architecture of the San Antonio missions and their changes to the mission goals and intents on the northern frontier.
An artificial neural network (ANN)-based technology – a ‘Grey-Box’, originating the iterative selection, depiction, and quantitation of environmental relationships for modeling microalgal abundance, ...as chlorophyll (CHL) a, was developed and evaluated. Due to their robust capability for reproducing the complexities underlying chaotic, non-linear systems, ANNs have become popular for the modeling of ecosystem structure and function. However, ANNs exhibit a holistic deficiency in declarative knowledge structure (i.e. a ‘black-box’). The architecture of the Grey-Box provided the benefit of the ANN modeling structure, while deconvolving the interaction of prediction potentials among environmental variables upon CHL a. The influences of (pairs of) predictors upon the variance and magnitude of CHL a were depicted via pedagogical knowledge extraction (multi-dimensional response surfaces). This afforded derivation of mathematical equations for iterative predictive outcomes of CHL a and together with an algorithmic expression across iterations, corrected for the lack of declarative knowledge within conventional ANNs. Importantly, the Grey-Box ‘bridged the gap’ between ‘white-box’ parametric models and black-box ANNs in terms of performance and mathematical transparency. Grey-Box formulations are relevant to ecological niche modeling, identification of biotic response(s) to stress/disturbance thresholds, and qualitative/quantitative derivation of biota-environmental relationships for incorporation within stand-alone mechanistic models projecting ecological structure.
► A neural network-based Grey-Box model was demonstrated. ► Via response surfaces, the Grey-Box depicted the influences of predictor variables. ► The Grey Box provided multivariate equations for iterative predictive outcomes. ► The Grey-Box is intended to fuel a greater acceptance for ‘black box’ ANNs.
CDOM transport from the Bahamas Banks OTIS, Daniel B; CARDER, Kendall L; ENGLISH, David C ...
Coral reefs,
04/2004, Volume:
23, Issue:
1
Journal Article
Peer reviewed
The transport of colored dissolved organic matter (CDOM) between shallow banks and deep basins in the Bahamas was the focus of this study. Hydrographic and CDOM absorption measurements made on the ...Bahamas Banks and in Exuma Sound during the spring of 1999 and 2000 showed that values of salinity and CDOM absorption at 440 nm were higher on the banks (37.18 psu, 0.06 m super(-1)), compared to Exuma Sound (37.04 psu, 0.03 m super(-1)). Spatial patterns of CDOM absorption in Exuma Sound revealed that plumes of CDOM-rich water flow into Exuma Sound from the surrounding banks. These patterns were determined using Sea-viewing Wide Field-of-view Sensor (SeaWiFS) data processed using a Moderate Resolution Imaging Spectroradiometer (MODIS) algorithm to derive CDOM absorption estimates. These data, along with time-series data collected in a channel between the banks and sound, suggest that bank water rich in CDOM and salinity leaves the banks during ebb tide, whereas sound water, with lower levels of CDOM and salinity, extends onto the banks during flood tide. Because CDOM absorbs ultraviolet radiation, a causal factor of reef organism bleaching, we discuss the meaning of our findings in terms of susceptibility to coral bleaching in the Exuma region.
When the Villa de San Fernando de Bexar was founded next to the Presidio de San Antonio de Bexar in 1731, Juan Antonio Perez de Almazan prepared a clear narrative for laying out the plaza and ...streets, distributing town lots to the new residents, and surveying the lands of the villa. However, a comparison of this proposal with maps of San Antonio made thirty years later demonstrates that no trace Perez de Almazan's intentions can be seen in th actual plan of the villa. Here, Ivey examines the difference between the narrative and subsequent survey and the later actual plan of the town. Moreover, the available evidence demonstrates that islanders, for whom the new villa was to be established, elected to lay out their own plaza and principal lots within the already existing plan of the settlement rather than undertaking the laboritorous process of tearing down the old structures and building an entirely new town based on Almazan's plan. This means that the central area of modern San Antonio does not reflect of 1731, which was based on orders of the viceroy and the provisions of the Laws of the Indies, but rather on a modified version of the town plan that grew up around the presidio after it was moved to its final location in 1722.
Presidio San Antonio de Béxar was one of the four presidios established to halt French aggression into Northern New Spain from Louisiana between 1690 and 1722. Today, the presidio is in the heart of ...modern-day San Antonio, Texas. While the urban built environment setting today has impacted the remains of the presidio, one original structure still stands. In addition, compliance archaeological investigations in a restricted urban area have identified remains of three civilian residences in the former presidial town adjacent to the presidio as well as a portion of the original irrigation ditch, the acequia madre. Hampered by a shortage of colonial historical research to connect archaeological remains and occupants through deed transactions, there is still much useful information to be gleaned from the archaeological remains. One contribution from the archaeological studies is the refinement of several broadly defined ceramic types such as Puebla Blue-on-White and lead-glazed coarse earthenwares into chronologically distinct variants.
We present a new approach that incorporates two models to estimate the underwater light field from remote sensing of ocean color. The first employs a series of analytical, semi-analytical, and ...empirical algorithms to retrieve the spectrum of inherent optical properties (IOPs), including the absorption and the backscatter coefficients, from the spectrum of remote sensing reflectance. The second model computes the profile of photosynthetically available radiation E^sub 0,PAR^(z) for a vertically homogeneous water column using the information of the retrieved IOPs and the ambient optical environment. This computation is based on an improved look-up table technology that possesses high accuracy, comparable with the full solution of the radiative transfer equation, and meets the computational requirement of remote sensing application. This new approach was validated by in situ measurements and an extensive model-to-model comparison with a wide range of IOPs. We successfully mapped the compensation depth by applying this new approach to process the SeaWiFS imagery. This research suggests that E^sub 0,PAR^(z) can be obtained routinely from ocean-color data and may have significant implications for the estimation of global heat and carbon budget.PUBLICATION ABSTRACT
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