SEAFWA 2016

AUTHORS: Julia Cherry, University of Alabama

ABSTRACT: Tidal marsh resilience to sea-level rise and climate change depends on maintaining surface elevations relative to mean sea level or migrating upslope when rates of vertical adjustment are insufficient. The biophysical mechanisms regulating the capacity for vertical adjustment or horizontal migration are influenced by simultaneously changing external forcing factors, including rising concentrations of atmospheric CO2, changes in the depth or duration of flooding, alterations in sediment or freshwater delivery, nutrient enrichment, and shifts in disturbance regimes. To promote marsh resilience to these changing environmental factors, it is important to understand the interactive effects that these changes have on the biophysical processes regulating surface elevation and marsh migration. Through a combination of surface elevation change measurements and field and greenhouse experiments, I have examined some of the critical biophysical processes governing marsh responses to environmental change. Here, I will highlight some of the results of these studies, including the ways in which CO2, sea-level rise, disturbances, and/or nutrient enrichment can affect biological feedbacks to marsh surface elevations, as well as the ways in which these factors can affect the ability of marshes to transgress upslope. Collectively, the results of these efforts demonstrate that species-specific responses to changing conditions can drive marsh ecosystem responses, and they underscore the importance of examining multi-factor interactions on processes regulating marsh persistence in the landscape. Thus, the results of this research can inform management and conservation strategies aimed at improving tidal marsh resilience to sea-level rise and other environmental changes.

AUTHORS: Tim Carruthers, The Water Institute of the Gulf; Melissa Baustian, The Water Institute of the Gulf; Camille Stagg, US Geological Service; Carey Perry, Gulf South Research Corporation; Kelly Darnell, The Water Institute of the Gulf; Ann Hijuelos, The Water Institute of the Gulf

ABSTRACT: While the importance of coastal marshes in supporting commercially and recreationally important fisheries species in coastal Louisiana is well recognized, frameworks to interpret the relative importance of various emergent marsh habitats versus adjacent submerged aquatic habitats are lacking. In addition, approaches to assess the relative importance of key coastal habitats to suites of species to develop assessments of integrated ecosystem function (including fisheries) are challenging, yet this knowledge can inform decision making for sustainable management and prioritization of restoration actions.

Habitat suitability index (HSI) outputs from the 2012 Master Plan were used to develop an approach for assessing integrated ecosystem function values for broad coastal habitat classifications. Of the nineteen HSIs calculated, seven were commercially or recreationally important fisheries species; alligator, brown shrimp, crawfish, largemouth bass, oyster, spotted trout, and white shrimp. These spatial HSI data from across coastal Louisiana were synthesized and analyzed relative to the Coastwide Reference Monitoring System (CRMS) marsh habitat classification (saline, brackish, intermediate and fresh). Linkages between habitats, species and consideration of integrated ecosystem function value of each habitat were summarized and verified, where possible, with available literature.

Ongoing loss of emergent marsh in coastal Louisiana and transition to shallow open water habitat makes understanding the linkages between ecosystem functions (including fisheries), with submerged aquatic habitats, independent of associated emergent marsh habitats, increasingly important. This work provides a conceptual framework and analytical approach to assist in addressing these knowledge gaps.

AUTHORS: James Whitaker, Louisiana Department of Wildlife and Fisheries

AUTHORS: Jamie A Duberstein, Clemson University Baruch Institute

ABSTRACT: Improvements in efficiencies for cargo ships accessing the Savannah River harbor are underway, along with a variety of environmental monitoring protocols. Higher salinity water is expected to flood further up the main channel of the Savannah River as the shipping lane is deepened from -42 feet to -47 feet, potentially effecting those environmental resources being monitored; mitigation features are planned to be implemented to offset marsh losses along the main channel. Twelve freshwater and oligohaline marsh sites are being monitored for changes in aboveground and/or belowground salinity, and community composition of the marsh vegetation. Three tidal freshwater forest areas are also being monitored for growth rates and salinity conditions. Marsh monitoring began in April 2014, and forest monitoring began December 2014. Analysis results from marsh vegetation surveys of June 2014 and 2015 will be compared, and the dominant six community types described. A summary of site-specific salinity conditions will also be provided. An anticipated timeline for the Savannah Harbor Expansion Project will be presented, recognizing the inherent dynamics associated with this national infrastructure development priority.

AUTHORS: Edmond C. Mouton Jr., Ruth M. Elsey, Jeb T. Linscombe - Louisiana Department of Wildlife & Fisheries

ABSTRACT: The Louisiana Department of Wildlife and Fisheries manages the American alligator (Alligator mississippiensis) as a commercial, renewable natural resource. The Department’s sustained use program is one of the world’s most recognizable examples of a wildlife conservation success story, and has been used as a model for managing various crocodilian species throughout the world. The goals of the Department’s alligator program are to manage and conserve Louisiana’s alligators as part of the state’s wetland ecosystem, provide benefits to the species, its habitat and the other species of fish and wildlife associated with alligators. The basic philosophy was to develop a sustained use management program which, through regulated harvest, would provide long term benefits to the survival of the species, maintain its habitats, and provide significant economic benefits to the citizens of the state. Since the inception of the Department’s program in 1972, over 1 million wild alligators have been harvested, over 9 million alligator eggs have been collected from the wild, and over 5 million farm raised alligators have been sold bringing in millions of dollars of revenue to landowners, trappers and farmers. Conservative estimates have valued these resources at over one billion dollars over the years providing significant, direct economic benefit to the citizens of Louisiana. This presentation will briefly review the federal government’s oversight and approval role for management of the alligator, discusses wild, farm and nuisance alligator programs as well as research activities.

AUTHORS: Dan Tonsmere, Apalachicola Riverkeeper

ABSTRACT: The ACF River Basin drains 19,600 square miles from the foothills of the Smokey Mountains to the Northern Gulf Coast where Apalachicola Bay pours into the Eastern Gulf. This system provides 35% of the freshwater and nutrients that nourish the offshore fisheries over 250 miles out into the Gulf. That same system provides drinking water for the growing North Georgia Metropolitan Area surrounding Atlanta, irrigation for the agricultural breadbasket of the SE US in SE Alabama, SW Georgia and NW Florida, along with energy and industrial uses such as cooling towers, paper mills and beer making. At the bottom of the system, the Apalachicola River, Floodplain and Bay are renowned as having the highest bio-diversity of any River System in North America and one of the most productive estuaries in the Northern Hemisphere. Management of the water resources has been incongruent, short sighted and uncompromising for over 50 years with divergent interests locked in litigation for over 25 years. Not unlike other historic water allocation battles, upstream water use for agricultural, municipal and industrial uses are taxing the viability of ecosystem functions and services that support a downstream fishing and natural resources based economy. This presentation will provide some insight into the biology, science, and modeling concepts used to determine how the freshwater needs of an estuary can be viewed to determine impacts in attempts to resolve the long-standing water dispute.

AUTHORS: Michael G. Brasher, Ducks Unlimited Inc., Gulf Coast Joint Venture

ABSTRACT: The extent and rate of coastal wetland loss in the northern Gulf of Mexico are the highest observed throughout the conterminous U.S. In response, numerous techniques have been developed to help slow these losses and restore productive coastal wetlands. Marsh terracing is a relatively new technique and has become a common feature of coastal restoration efforts in the northern Gulf of Mexico. Marsh terraces are segmented ridges of bare soil and emergent marsh constructed from excavated subtidal substrates in shallow, open water areas. They function by reducing fetch and wave energy, which is believed to help create emergent marsh, reduce shoreline erosion, increase growth of submerged aquatic vegetation, and ultimately increase habitat quality for marsh-dependent organisms. However, the efficacy of marsh terraces in achieving their intended objectives remains uncertain, largely due to a lack of rigorous evaluations, which has led to their de-emphasis in some coastal restoration programs and projects. I conducted a literature review to ascertain and summarize current knowledge and remaining gaps in our understanding of the benefits of marsh terraces. Available information provided general support for the effectiveness of marsh terraces, although the magnitude and consistency of benefits varied greatly among objectives. Benefits were most evident for improving nekton habitat, but were more variable for improving waterbird habitat, reducing shoreline erosion, and creating emergent marsh outside the terrace footprints. Recommendations are provided for additional scientific investigations that are needed to definitively assess the benefits of marsh terraces and appropriately inform decisions about their design and application.

AUTHORS: MK La Peyre, U.S. Geological Survey, Louisiana Fish and Wildlife Cooperative Research Unit, School of Renewable Natural Resources, LSU AGCenter; ER Hillmann; KE DeMarco; JA Nyman, School of Renewable Natural Resources, LSU AgCenter; B Couvillion, U.S. Geological Survey, Wetland and Aquatic Resources Center; S Brown, Coastal Protection and Restoration Authority, Baton Rouge, LA

ABSTRACT: Across the northern coast of the Gulf of Mexico, wetlands and shallow water habitats provide valuable food and habitat for fish and wildlife. Specifically, submerged aquatic vegetation (SAV) habitat is preferentially occupied by many species as compared to adjacent habitats, as SAV beds provide cover and high quality nutrition. Predictions of changing coastal conditions in this area include increased water levels, altered salinities, and higher temperatures, potentially affecting the distribution, characteristics and relative availability of coastal habitats, including areas supporting SAV. Currently, aquatic habitat suitable to support SAV occupies approximately 7% of these coastal areas, and provides ecosystem services including food and habitat provision. Using inter and intra annual sampling of SAV and environmental variables, we examined SAV resources (presence, percent cover, species, biomass) in relation to discrete and integrated environmental data. Despite differences in mean salinities and water depths across marsh types, the overall abundance of SAV resources remained stable from 2013-2015 although spatial distribution and SAV species assemblages and biomass differed. SAV was most abundant and diverse in fresher habitats, indicating that if freshwater habitats expand, SAV resources may increase. Significant reductions in SAV resources only occurred in saline areas, suggesting that fresh through brackish SAV habitats may provide similar resources. A possible threshold for SAV resources exists related to higher salinities and associated landscape variables such as exposure and water depth. Determining how changes in coastal conditions will impact SAV provides critical data to help manage coastal habitats and understand fish and wildlife carrying capacities.

AUTHORS: R. D. Perry, S. C. Department of Natural Resources; D. E. Harrigal, S. C. Department of Natural Resources; R. M. Kaminski, Clemson University; M. R. Kneece, Clemson University; M. B. Prevost, White Oak Forestry Corporation; D. A. Shipes, S. C. Department of Natural Resources; E. P. Wiggers, Nemours Wildlife Foundation; and R. K. Williams, Williams Land Management

ABSTRACT: The landscape of the South Atlantic Coast (SAC) has ecological, environmental, aesthetic and economical values attributed to estuarine systems formed by rivers pulsing nutrients and sediments that created forested and emergent wetlands. Tidal impoundments are special wetlands existing along the SAC as relics of 17th-early 20th-century rice production. Management of these habitats is historically, culturally and economically important to SAC ecosystems and continental waterbirds. Moreover, conservation and management of former rice plantations in the SAC is unique worldwide and vital to habitat protection under the North American Waterfowl Management Plan and other landscape conservation initiatives. An intact infrastructure, consisting of embankments and water control structures, (“trunks”) is required for habitat management to allow manipulation of water levels, hydroperiods and salinity – the primary factors influencing estuarine plant communities. We describe effective practices for management of freshwater, brackish and saline wetlands promoting production of native emergent and submersed habitats used preferentially by waterfowl and other waterbirds. Typical coastal impoundment habitat management across salinity zones involve cyclic drawdown, moist-soil management, staged increases and decreases in water levels and seasonal or semi-permanent flooding with circulation. Cross- and within-seasonal water level management are critical in maximizing waterbird use and species diversity. Although high resource value is placed on SAC impoundments, threats to sustainability arise from development, pollution, incompatible recreation and, most importantly, sea-level rise. Adaptive regulatory policies, secure funding sources, additional conservation and programmatic/philosophical shifts are needed to allow coastal impoundments to persist but also migrate managed wetlands inland in response to sea-level rise.

AUTHORS: Jeff Beal, Steve Rockwood, Kent Smith - Florida Fish and Wildlife Conservation Commission

ABSTRACT: Worldwide, the hardening of waterfront properties to reduce erosion using heavily-engineered solutions (eg, seawalls, revetments) threatens coastal waterbodies such as estuaries. These structures decrease littoral habitat, contribute to water quality degradation, and are often short-term expensive fixes. In tidal areas, they restrict adaptive management in lieu of stressors such Sea Level Rise, contributing to “coastal squeeze.” Techniques are currently available as alternatives to shoreline hardening using predominantly natural products (oyster shell, rock, coquina, natural fiber fabrics, native plants). These “Living Shorelines” often provide cost-effective long-term solutions to erosion while providing nutrient uptake and habitat for fish and wildlife. When properly designed and maintained, Living Shorelines afford the dissipation of wave energy, subsequent baffling of nearshore sediments, and, in places, accretion. Numerous successful Living Shorelines projects have been implemented throughout the southeastern U.S. In some locations, fringing tidal wetlands have been installed as a key component of these projects. As a result of recent changes to state and federal permitting requirements, these types of projects are gaining in popularity and ease of implementation. Challenges remain, however, in terms of promoting these concepts to public/private interests given the long-standing historical use of hardening techniques. Given recent Living Shoreline project successes, this practice is now a well-recognized tool for developing resiliency for shorelines along estuaries.