Technical Reports
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Item Assessment of the Relationship Between Freshwater Inflow and Biological Indicators in Lavaca Bay(2020-12) Montagna, Paul A.; Cockett, Patricia Malamalama; Kurr, Elaine M.; Trungale, JoeItem Benthic monitoring of the Mollie Beattie Coastal Habitat community in relation to opening Packery Channel(2009-08) Montagna, Paul A.; Palmer, Terence A.Packery Channel was a natural channel that linked Corpus Christi Bay with the Gulf of Mexico, but has been closed since 1912. Construction to reopen the channel began in October 2003 and Packery Channel was reopened on 21 July 2005 by storm surge produced by Hurricane Emily. Official construction was completed in October 2006. A before versus after, control versus impact (BACI) design was implemented to assess the effects of reopening Packery Channel on water quality and estuarine macrofauna in Mollie Beattie Coastal Habitat Community (MBCHC), Corpus Christi Bay. Two deep (approximately 1 m below mean sea level) and two shallow (approximately 0.2 m below mean sea level) stations were sampled monthly for physical and biological characteristics at both control and impact sites between November and March from 2003 through 2009. There was little initial impact on the macrofaunal community composition, abundance, biomass, or N1 diversity caused by opening Packery Channel between July and December 2005. There was more difference in community composition between deep and shallow stations than between either before and after, or control and impact sites. Salinity was reduced at MBCHC and fluctuated in a diurnal pattern after the opening of Packery Channel, which is related to increased tidal exchange with the Gulf of Mexico. Packery Channel may have affected the salinity of MBCHC by introducing a diurnal fluctuation when water levels are high and by possibly decreasing the magnitude of long-term salinity fluctuations in MBCHC. The same salinity changes were not observed at reference site. Flow decreases along a gradient moving up Packery Channel away from the Gulf of Mexico, which indicates that tidal flows spill into MBCHC. Macrofauna diversity and biomass significantly decreased in the deep MBCHC site, but not in the reference site since Packery Channel opened. Macrofauna abundance increased in the deep MBCHC relative to the reference site in the second two-year period after the channel opened. Overall, the channel opening did not coincide with any changes in macrofauna abundance or diversity of the shallow MBCHC. Biomass did decrease in the shallow MBCHC after the opening of Packery Channel, but biomass is still greater than in the shallow reference site. The small change in hydrography in MBCHC has had little initial impact on macrobenthic communities, probably because MBCHC was already functioning as marine in terms of salinity.Item Benthic Monitoring Project for The Mollie Beattie Coastal Habitat Community(2007-09) Montagna, Paul A.; Palmer, Terence A.Item Benthic Monitoring Project for The Mollie Beattie Coastal Habitat Community(2008-10) Montagna, Paul A.; Palmer, Terence A.Item Boundary Map Report - Habitat Management Plan of Corpus Christi Bay(2009-08) Brenner, Jorge; Montagna, Paul A.; Nance, Thomas; Palmer, Terence A.Item Chapter 5. Secondary and Tertiary Productivity Methods and Literature Update(2011-04) Montagna, Paul A.; Blomberg, Brittany; Arismendez, Sandra A.; Nanez-James, S.; Palmer, Terence A.; Scholz, DamonItem Characterization of Benthic Habitats in Proximity to The Lower Colorado River, Texas(2006-12) Montagna, Paul A.; Kalke, Richard; Palmer, Terence A.; Gossmann, AprilFreshwater inflow from the lower Colorado River supports a diverse ecological community in Matagorda Bay, East Matagorda Bay, and Oyster Lake. The region is part of the larger Lavaca-Colorado Estuary, which includes the adjacent Lavaca River and Lavaca Bay. The Lavaca-Colorado Estuary has been the subject of long-term benthic and water quality studies since 1988, but only six stations (two in Lavaca Bay and four in Matagorda Bay) have been sampled. The purpose of the current study is to sample over broader spatial scales in Matagorda Bay to determine how well the long-term stations characterize the spatial variability of benthic communities directly influenced by the Colorado River. Samples were collected from 18 stations to measure benthic community structure, hydrographic characteristics (depth, salinity, temperature, nutrients, and chlorophyll), and sediment characteristics (grain size, carbon and nitrogen content). Adjacent to the Colorado River, water quality and water column depth had higher correlations with macrobenthic community structure than sediment characteristics, but sediments were important overall. At a 40 % similarity level, macrobenthic communities were divided into five groups based on distance from the freshwater source, distance to the Gulf of Mexico, and bottom depth. Benthic communities in sheltered shallow habitats (< 0.5 m) were not represented by the current long-term stations, however all other community groups were represented. Apart from areas close to the Gulf Intracoastal Waterway and within 5 km of the Colorado River mouth, water quality in Matagorda Bay was well-characterized by the six long-term stations in low inflow conditions.Item Colorado River Flow Relationships to Bay Health: Benthic Indicators - 2007(2008-05) Montagna, Paul A.Item Colorado River Flow Relationships to Bay Health: Benthic Indicators – 2008(2009-04) Montagna, Paul A.Item Conceptual Model of Effects of Reduced Freshwater Inflow in the Anahuac National Wildlife Refuge(2017-06) Montagna, Paul A.; Morgan, ElaniItem Congo River Canyon Crossing Project, Benthic Analyses(2007-05) Montagna, Paul A.; Hyde, Larry J.Item Cruise Report for Deepwater Sediment Sampling Cruise M/V IRISH: Leg 1, 29 May to 10 June 2014, to Assess Potential Benthic Impacts from the Deepwater Horizon (DWH) Oil Spill(2015-08) Cooksey, Cynthia; Baguley, Jeffrey G.; Montagna, Paul A.To meet the objectives of the Deep Benthic Work Plan Addendum, a cruise was conducted to assess potential effects of the Deepwater Horizon (DWH) oil spill on deep-sea (>200 m) sediments and resident benthic fauna. Leg 1 of the cruise was conducted on the M/V IRISH, 29 May – 10 June 2014, under the auspices of the DWH/Natural Resource Damage Assessment (NRDA) Deepwater Benthic Communities Technical Working Group. A related deep-sea benthic sampling effort, M/V IRISH: Leg 2, was conducted June 14 – 28, 2014 and will be reported elsewhere. Only Leg 1 information is included in this document. A total of 2452 physical samples were collected from 56 deep-sea stations for the analysis of various biotic and abiotic environmental variables. Stations were included at near-field sites where DWH-related oil was measured at elevated levels during prior Response efforts, that were in paths of possible oil exposure based on subsurface trajectory-model predictions, and that serve as anticipated reference sites. At each station, a multi-corer (12 core system) was used to collect sediment samples for analysis of macrofauna, meiofauna, hydrocarbons, metals, and other basic sediment properties (total carbon, total organic carbon, total inorganic carbon, total nitrogen, grain size). Additional samples for sediment toxicity testing were collected at 12 of the 56 stations. A CTD with a dissolved-oxygen (DO) sensor also was deployed to obtain water-column profiles of salinity, temperature, DO, pH, and depth. The present cruise report provides a summary of sampling activities. Conclusions about the potential spatial extent of oil exposure, persistence of oil exposure over time, or resulting biological impacts based on these samples cannot be drawn until ongoing sample analyses are completed.Item Deepwater Horizon Oil Spill: Assessment of Potential Impacts on the Deep Soft-Bottom Benthos - Interim Data Summary Report(2013-02) Montagna, Paul A.; Baguley, Jeffrey G.; Cooksey, Cynthia; Hyland, Jeffrey L.A study was initiated in May 2011, under the direction of the Deepwater Horizon (DWH) Natural Resource Damage Assessment (NRDA) Deepwater Benthic Communities Technical Working Group (NRDA Deep Benthic TWG), to assess potential impacts of the DWH oil spill on sediments and resident benthic fauna in deepwater (> 200 meters) areas of the Gulf. Key objectives of the study were to complete the analysis of samples from 65 priority stations sampled in September-October 2010 on two DWH Response cruises (Gyre and Ocean Veritas) and from 38 long-term monitoring sites (including a subset of 35 of the original 65) sampled on a follow-up NRDA cruise in May-June 2011. The present progress report provides a brief summary of results from the initial processing of samples from fall 2010 priority sites (plus three additional historical sites). Data on key macrofaunal, meiofaunal, and abiotic environmental variables are presented for each of these samples and additional maps are included to depict spatial patterns in these variables throughout the study region. The near-field zone within about 3 km of the wellhead, where many of the stations showed evidence of impaired benthic condition (e.g. low taxa richness, high nematode/harpacticoid-copepod ratios), also is an area that contained some of the highest concentrations of total petroleum hydrocarbons (TPH), total polycyclic aromatic hydrocarbons (total PAHs), and barium in sediments (as possible indicators of DWH discharges). There were similar co-occurrences at other sites outside this zone, especially to the southwest of the wellhead out to about 15 km. However, there also were exceptions to this pattern, for example at several farther-field sites in deeper-slope and canyon locations where there was low benthic species richness but no evidence of exposure to DWH discharges. Such cases are consistent with historical patterns of benthic distributions in relation to natural controlling factors such as depth, position within canyons, and availability of organic matter derived from surface-water primary production.Item Determining Optimal Pumped Flows to Nueces Delta(2016-07) Montagna, Paul A.; Adams, Leslie; Chaloupka, Crystal; Del Rosario, Elizabeth; Kalke, Richard D.; Turner, Evan L.Item Ecological and Socio-Economic Impacts of Watershed Development on Coastal and Marine Areas(2010-11) Montagna, Paul A.; Kim, Hae-Cheol; Palmer, Terence A.; Pollack, Jennifer BeseresLarge water development projects in Korea could have effects on coastal resources. Like all other countries in the World, water is an important resource to Korea, and water needs will grow as the population grows. It is useful to review what is known about the importance of freshwater inflow to estuaries so that coastal resources can be managed wisely. Fresh water is important in diluting marine water in estuaries, which are the most productive environments on Earth. Fresh water also delivers nutrients and sediments to the coast. Estuaries are characterized by salinity and nutrient gradients, which are important in regulating many biological processes. As water is diverted for human consumption, it is common for many environmental problems to appear. While many countries have water quality programs, few are dealing with water quantity alterations. The first step is to define marine resources to protect, and the water quality conditions those resources need to thrive. The second step is to determine the flow regimes needed to maintain the desired water quality conditions. Finally, many regions are using adaptive management programs to manage freshwater resources. These programs set goals to protect ecosystem resources, identify indicators, and monitor the indicators over time to ensure that the goals are appropriate and resources are protected. By conducting in situ monitoring and research, scientists can more accurately determine the ecological and socio-economical impacts of changing freshwater inflows. In turn, stakeholders and managers can make well-informed decisions to successfully manage freshwater inflows to their local coasts.Item Effect of Climatic Variability on Freshwater Inflow, Benthic Communities, and Secondary Production in Texas Lagoonal Estuaries(2010-05) Kim, Hae-Cheol; Montagna, Paul A.This is the final report for a 2-year project (TWDB contract numbers 07-483-0672 and 08-483-0791) with the objective to complete implementation of an ecological model to predict system-wide secondary production for two trophic groups of benthic organisms in response to different freshwater inflow regimes that result from the climatic ecotone along the Texas coast. The bioenergetic model was calibrated using an 11-year dataset (from 1988 to 1999) and validated with a 20-year data from (1988 to 2008) from four estuaries in South Texas: Lavaca-Colorado (LC), Guadalupe (GE), Nueces (NE) and Laguna Madre Estuaries (LM). The estuaries lie in a climatic gradient where LC and GE receive more rainfall than NE, and NE receives more rainfall than LM. Consequently inflow decreases along the gradient and salinity increases. In addition there is year-to-year variation in rain and inflow that results in wet and dry years. Therefore, this combination of the climatic gradient and temporal variability can be used to identify the effects of inflow on estuarine productivity. Among Texas estuaries, increased salinity (and thus decreased inflow) benefited deposit feeders, while suspension feeders were harmed, but the net overall effect is a decrease in functional diversity when salinity is increased. Within estuaries, the benthic community of secondary bays is harmed by reduced inflow, whereas, the community in primary bays appears to benefit in biomass increase by reduced inflow. This is because lower salinity regimes are required to support food production for suspension feeders, and there are more polyhaline deposit feeding species. Freshwater inflow is important in to maintain productivity and functional diversity; and required to maintain functional, healthy estuarine ecosystems.Item Effect of Climatic Variability on Freshwater Inflow, Benthic Communities, and Secondary Production in Texas Lagoonal Estuaries: FY 2007(2008) Kim, Hae-Cheol; Montagna, Paul A.This is the final report for a 2-year project (TWDB contract numbers 07-483-0672 and 08-483-0791) with the objective to complete implementation of an ecological model to predict system-wide secondary production for two trophic groups of benthic organisms in response to different freshwater inflow regimes that result from the climatic ecotone along the Texas coast. The bioenergetic model was calibrated using an 11-year dataset (from 1988 to 1999) and validated with a 20-year data from (1988 to 2008) from four estuaries in South Texas: Lavaca-Colorado (LC), Guadalupe (GE), Nueces (NE) and Laguna Madre Estuaries (LM). The estuaries lie in a climatic gradient where LC and GE receive more rainfall than NE, and NE receives more rainfall than LM. Consequently inflow decreases along the gradient and salinity increases. In addition there is year-to-year variation in rain and inflow that results in wet and dry years. Therefore, this combination of the climatic gradient and temporal variability can be used to identify the effects of inflow on estuarine productivity. Among Texas estuaries, increased salinity (and thus decreased inflow) benefited deposit feeders, while suspension feeders were harmed, but the net overall effect is a decrease in functional diversity when salinity is increased. Within estuaries, the benthic community of secondary bays is harmed by reduced inflow, whereas, the community in primary bays appears to benefit in biomass increase by reduced inflow. This is because lower salinity regimes are required to support food production for suspension feeders, and there are more polyhaline deposit feeding species. Freshwater inflow is important in to maintain productivity and functional diversity; and required to maintain functional, healthy estuarine ecosystems.Item Effect of Freshwater Inflow on Habitat Suitability Change in Texas Bays(2016-11) Turner, Evan L.; Savage, Kelley; Trungale, Joe; Palmer, Terence A.; Montagna, Paul A.Freshwater inflow is critically important for foundational estuarine invertebrate species such as the Eastern Oyster, Crassostrea virginica. This empirical study tests the viability of the proactive management strategy of the release of supplementary freshwater inflow into two Texas bays to increase oyster health. An oyster habitat suitability index was created through regression analyses to test the effect of altered inflows. We demonstrate the inflow requirement to lower salinities from base marine (35 PSU) conditions to polyhaline (25 PSU) conditions is possible within human release activities if directed in Tres Palacios Bay and Caranacahua Bay, Texas. Even small inflow supplements such as 1,500 acre-ft of additional freshwater added during the summer months can enhance oyster health. This health improvement is due to lowering the risk of the oyster parasite Perkinsus marinus (Dermo) prevalance by decreasing salinities to between 20 and 25 PSU.Item Effect of Freshwater Inflow on Macrobenthos Productivity in Minor Bay and River-Dominated Estuaries – Synthesis(2008-05) Montagna, Paul A.; Palmer, Terence A.; Pollack, Jennifer BeseresItem Effect of Freshwater Inflow on Macrobenthos Productivity in the Guadalupe Estuary 2008-2009(2009-11) Montagna, Paul A.; Palmer, Terence A.