EXPERT REPORT OF PAUL MONTAGNA, Ph.D. Background Information I received a B.S. in Biology from SUNY Stony Brook (1971), an M.S. in Biology from Northeastern University (1975), a Ph.D. in Biology from the University of South Carolina (1983), and completed a postdoctoral fellowship at the Lawrence Livermore National Laboratory (1986). I was a professor at the University of Texas at Austin, Marine Science Institute from 1986 – 2006, where I was the creator and founding manager of the Mission-Aransas National Estuarine Research Reserve in 2006. In September 2006, I became the Endowed Chair for Ecosystem Studies and Modeling at the Harte Research Institute for Gulf of Mexico in Corpus Christi, Texas. I am a marine ecologist. My research focuses on coastal management, benthic processes, ecoinformatics, ecosystem modeling, environmental flows, and integrating natural science and socioeconomics. My research is related broadly to the question of: “what flow regime is necessary to maintain the ecological health of estuaries?” I have performed inflow studies in all Texas estuaries, edited a volume on freshwater inflow studies, acted as a consultant to set flow standards in Florida and Texas, worked with the U.S. State Department, Agency for International Development to develop inflow guidelines to protect the coastal zone of developing countries, and am a member of the Science Advisory Committee for Texas Environmental Flows Advisory Group. My expertise includes riverine inflows, estuarine ecology and estuary structure and function, including individual estuarine species such as blue crabs. I have authored over 100 peer reviewed publications as shown on attachment 1, which is a current curriculum vitae. I have received over 100 grants and contracts for estuarine-related research both here at Texas A&M Corpus Christi and at the University of Texas Marine Science Institute. The bulk of these publications and research grants have been concerned with estuaries with a significant number being specifically concerned with the role of freshwater inflow on estuarine health. Many of my publications and research grants are specific to the Texas coast and the Guadalupe Estuary (e.g., San Antonio Bay). This opinion report has been written at the request of Blackburn and Carter. I have been paid a fee of $10,000 for this report. My rate is $150/hour. I have not testified in a legal proceeding in the last ten years. Information Considered All the information that I depended on to form conclusions is included in the list of references at that end of the report. The research projects, professional experiences, and reports that I have authored over the years are identified in my resume and provide background information that I also considered in formulating my report. 1 Opinion 1: The physical characteristics and biological productivity of an estuary can be altered by reductions in freshwater inflows, particularly during times of drought. Initially, this report will focus upon an overview and description of an estuary. In this section, the potential impacts of the reduction of freshwater inflows upon an estuary will be set out, culminating in the opinion that the physical and chemical characteristics of an estuary can be altered by reductions in freshwater inflows, particularly during times of drought. Definition of Estuary An estuary is defined as a semi-enclosed body of water where salt water from the ocean mixes with fresh water from rivers and land. Nothing is more fundamental to the functioning of an estuary than the amount of freshwater delivery to the mixing zone (Dahms 1990, Montagna et al. 2002a). Freshwater inflow regimes vary, but inflows are usually delivered in pulses that arrive in stochastic and complex long-term cycles. The pulses of inflow regimes have four characteristics: frequency, timing, duration, and volume. Altered freshwater inflow has driven changes in coastal ecosystem hydrology, downstream transport of nutrients and sediments, and salinity regimes, and has resulted in losses of habitat, biodiversity, and productivity (Montagna and Kalke 1992, 1995, Longley 1994, Attrill et al. 1996, Mannino and Montagna 1997, Montagna et al. 2002b, Tolley et al. 2006). Maintaining the hydrological regime and natural variability of an estuary is necessary to maintain its ecological characteristics, including biodiversity. Because freshwater inflow to estuaries is a major influence on coastal ecosystems, it is important to understand the effects caused by altered freshwater inflow and to create effective management strategies for water resource development and coastal resource management. International attention has become focused on the importance of preserving freshwater flows and the need to develop and employ standards on limitations to the reduction or alteration of flows (Istanbul Water Guide 2009). The European Union (EU) has undertaken several initiatives in recent years, the most important being the European Water Framework Directive (2000/60/EC) which aims to achieve “good ecological status” for all inland and coastal waters by 2015 through the establishment of environmental objectives and ecological targets for surface waters (WFD 2000). The South African National Water Act of 1998 requires that, for any given water resource, sufficient water be set aside to provide for basic human needs and the protection and maintenance of aquatic ecosystems (Republic of South Africa 1998; Thompson 2006). The National Water Policy of India (2002) directs that minimum flow should be ensured in perennial streams for maintaining ecological and social considerations. Within the United States, states with large coastal populations (e.g., Texas, Florida, and California) were among the first to face the issue of environmental flows by passing legislation to protect coastal species and resources (Montagna et al. 2002a). This international attention indicates that water shortages, and the consequent reductions of environmental flows, are emerging global issues. 2 Climate change threatens to change precipitation and temperature patterns in vast regions of the globe. Even with no change in precipitation, increased temperature will increase evapotranspiration, thus creating water deficits in many regions. Although dewatering of estuaries at the current time is driven largely by coastal development and human demand for freshwater, current water management practices may not be adequate to cope with the impacts of climate change. Despite the uncertainty associated with global climate models, the tendency towards more widespread drought increases concomitantly for many arid and semi-arid regions of the globe, including the African Sahel and southern Africa, Central America, the Mediterranean basin, western USA, southern Asia, eastern Australia, and northeastern Brazil (Bates et al. 2008). One immediate threat of reduced precipitation is food security, which depends on irrigation. However, the greater water deficits will lead to greater dewatering of the coastal zone. If river discharge decreases, salinity of coastal ecosystems will increase and the amount of sediment and nutrient delivery will decrease, thereby altering the zonation of plant and animal species as well as the availability of freshwater for human use (Bates et al. 2008; Pollack et al. 2009). Given the unprecedented change in the water cycle caused by human and climate systems, there are clear needs to manage water resources in the coastal zone using an ecosystem- based approach to protect human health and well-being by sustaining coastal resources. Considerable scientific information is needed to manage coastal ecosystems, such as: What effect will altered freshwater inflow have on coastal resources? What are the relative magnitudes of effects driven by human activities versus climate change? The focus of management initiatives must shift to land planning efforts that conserve water, prevent polluted runoff and groundwater contamination, restore the physical integrity of aquatic ecosystems by increasing natural flow regimes, and promote and protect ecosystem services that could potentially be produced (Ruhl et al. 2003). Despite the growing consensus that the key to maintaining healthy aquatic ecosystems and the services that they provide is to preserve or restore some semblance of a natural flow regime to protect the native flora and fauna, we have continued to implement a piece-meal policy approach making such efforts exceedingly difficult (Katz 2006). The issues of what to do about environmental flows will increase in importance worldwide as developing nations further develop water resources for cities, irrigation, and industry. Creating answers to the above questions will provide policy makers and resource managers with science-based ecosystem information and an array of options to manage environmental flows and water quantities. 3 Figure 1. Habitats and geomorphological components of bar‐built estuaries (Montagna et al. 1996). Conceptual Model of Estuary Ecosystems Estuaries An estuary is a semi-enclosed coastal body of water which has a free connection with the open sea and within which sea water is measurably diluted with fresh water from land drainage (Pritchard, 1967). Most estuaries have a series of landscape subcomponents: a river (or fresh water) source, a tidal-estuarine segment, marshes (or mangroves depending on latitude), bays, and a pass (or inlet) to the sea (Figure 1). All estuaries are quite different, however, and the landscape of each subcomponent can vary, combinations