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Ocean and coastal data management

We introduce data management concepts, including what we mean by "data" and its "management," sources of data, interoperability, and data geometry. We then discuss various components of a data management system. Finally, we summarize some existing ocean and coastal data management efforts. We make specific recommendations throughout the paper. We are generally optimistic that ocean and coastal data management is an interesting and solvable challenge that will provide great benefit to society.

Conference Paper

The California Seafloor and Coastal Mapping Program – Providing science and geospatial data for California's State Waters

The California Seafloor and Coastal Mapping Program (CSCMP) is a collaborative effort to develop comprehensive bathymetric, geologic, and habitat maps and data for California's State Waters. CSCMP began in 2007 when the California Ocean Protection Council (OPC) and the National Oceanic and Atmospheric Administration (NOAA) allocated funding for high-resolution bathymetric mapping, largely to support the California Marine Life Protection Act and to update nautical charts. Collaboration and support from the U.S. Geological Survey and other partners has led to development and dissemination of one of the world's largest seafloor-mapping datasets. CSCMP provides essential science and data for ocean and coastal management, stimulates and enables research, and raises public education and awareness of coastal and ocean issues. Specific applications include: •Delineation and designation of marine protected areas •Characterization and modeling of benthic habitats and ecosystems •Updating nautical charts •Earthquake hazard assessments •Tsunami hazard assessments •Planning offshore infrastructure •Providing baselines for monitoring change •Input to models of sediment transport, coastal erosion, and coastal flooding •Regional sediment management •Understanding coastal aquifers •Providing geospatial data for emergency response

California

Sediment deposition, erosion, and bathymetric change in San Francisco Bay, California, 1971–1990 and 1999–2020

Bathymetric change analyses document historical patterns of sediment deposition and erosion, providing valuable insight into the sediment dynamics of coastal systems, including pathways of sediment and sediment-bound contaminants. In 2014 and 2015, the Office for Coastal Management, in partnership with the National Oceanic and Atmospheric Administration (NOAA) Office of Coastal Management, provided funding for new bathymetric surveys of large portions of San Francisco Bay. A total of 93 bathymetric surveys were conducted during this 2-year period, using a combination of interferometric sidescan and multibeam sonar systems. These data, along with recent NOAA, U.S. Geological Survey (USGS), U.S. Army Corps of Engineers, and private contractor surveys collected from 1999 to 2020 (hereinafter referred to as 2010s), were used to create the most comprehensive bathymetric digital elevation models (DEMs) of San Francisco Bay since the 1980s. Comparing DEMs created from these 2010s surveys with USGS DEMs created from NOAA’s 1971–1990 (hereinafter referred to as 1980s) surveys provides information on the quantities and patterns of erosion and deposition in San Francisco Bay during the 9 to 47 years between surveys. This analysis reveals that in the areas surveyed in both the 1980s and 2010s, the bay floor lost about 34 million cubic meters of sediment since the 1980s. Results from this study can be used to assess how San Francisco Bay has responded to changes in the system, such as sea-level rise and variation in sediment supply from the Sacramento-San Joaquin Delta and local tributaries, and supports the creation of a new, system-wide sediment budget. This report provides data on the quantities and patterns of sediment volume change in San Francisco Bay for ecosystem managers that are pertinent to various sediment-related issues, including restoration of tidal marshes, exposure of legacy contaminated sediment, and strategies for the beneficial use of dredged sediment.

California

Nearshore survey and cleanup of benthic marine debris using citizen science divers along the Mediterranean coast of Israel

Information on marine debris along the Mediterranean coast of Israel, especially on the seafloor, is limited. Many recreational divers are enthusiasts of marine conservation and can thus contribute to data collection which does not require highly specialized training. The Society for the Protection of Nature in Israel together with The Israeli Diving Federation established the diver volunteer program “Sea Guard” (“Mishmar Hayam” in Hebrew), which supports marine conservation through citizen science. The divers were trained in marine ecology and survey methods to conduct independent surveys and lead underwater cleanups. For the first time, we have described the patterns of benthic debris density and composition in the nearshore environment of the southeastern part of the Mediterranean Sea. We found that benthic marine debris in the nearshore along the Israeli Mediterranean coast is primarily plastic, likely originating from the use of local beaches. Fishing, boating and domestic activities also play an important role as sources for marine debris. The currents' regime prevented the debris from accumulating on the seafloor in the nearshore environment, with the exception of several “debris traps”. Our findings will be useful for the development of programs to improve coastal waste management.

Ocean and Coastal Management

Processes influencing the transport and fate of contaminated sediments in the coastal ocean– Boston Harbor and Massachusetts Bay

Most of the major urban centers of the United States including Boston, New York, Washington, Chicago, New Orleans, Miami, Los Angeles, San Francisco, and Seattle—are on a coast (fig. 1.1). All of these cities discharge treated sewage effluent into adjacent waters. In 2000, 74 percent of the U.S. population lived within 200 kilometers (km) of the coast. Between 1980 and 2002, the population density in coastal communities increased approximately 4.5 times faster than in noncoastal areas of the U.S. (Perkins, 2004). More people generate larger volumes of wastes, increase the demands on wastewater treatment, expand the area of impervious land surfaces, and use more vehicles that contribute contaminants to street runoff. According to the National Coastal Condition Report II (U.S. Environmental Protection Agency, 2005a), on the basis of coastal habitat, water and sediment quality, benthic index, and fish tissue, the overall national coastal condition is only poor to fair and the overall coastal condition in the highly populated Northeast is poor. Scientific information helps managers to prioritize and regulate coastal-ocean uses that include recreation, commercial fishing, transportation, waste disposal, and critical habitat for marine organisms. These uses are often in conflict with each other and with environmental concerns. Developing a strategy for managing competing uses while maintaining sustainability of coastal resources requires scientific understanding of how the coastal ocean system behaves and how it responds to anthropogenic influences. This report provides a summary of a multidisciplinary research program designed to improve our understanding of the transport and fate of contaminants in Massachusetts coastal waters. Massachusetts Bay and Boston Harbor have been a focus of U.S. Geological Survey (USGS) research because they provide a diverse geographic setting for developing a scientific understanding of the geology, geochemistry, and oceanography of coastal systems in general. Scientific data from this region can also be used to inform decisions about important economic, environmental, and political issues. From the economic viewpoint, the annual value of tourism and shipping in Massachusetts and Cape Cod Bays is about $1.5 billion and $1.9 billion, respectively. Commercial and recreational fishing generates about $240 million per year in the same region (U.S. Environmental Protection Agency, 2005b). The environmental issue is the 300-year history of waste discharge from the Boston metropolitan area into the harbor. This history is punctuated by cycles of environmental degradation, public outcry, and improvements in the sewage treatment system. With each improvement, however, the continuous growth of population in greater Boston (fig. 1.2) and the resulting increase in the volume of waste exceeded the capacity of the treatment system, thereby setting the stage for a new contamination crisis. By the 1980s, the levels of contaminants in sediments of Boston Harbor were among the highest in the nation (National Oceanic and Atmospheric Administration, 1987). Fish were diseased, shellfish beds were closed, and swimming beaches were unsafe after heavy rains; in general, water quality and aesthetics were below acceptable standards. Legal and political issues have always been part of Boston Harbor’s history. The environmental conditions in the 1980s were highlighted in a 1983 legal suit brought by the city of Quincy against the Metropolitan District Commission (MDC, the state agency responsible for sewage treatment) and heads of three state agencies for discharging untreated or poorly treated sewage into the harbor (Dolin, 2004). The suit never went to trial, but through the actions of a Massachusetts Superior Court, the issue of Boston Harbor contamination remained on the political and public agenda. The judge called the harbor “unsafe, unsanitary, indecent, in violation of the law (Clean Water Act), and a danger to the health and welfare of the people” (Forman, 1984). To force the state legislature to implement a plan to improve harbor conditions, the judge threatened to place the MDC in receivership and curtail new sewage hookups for industry. Under intense lobbying by business, the legislature created the Massachusetts Water Resources Authority (MWRA) in December 1984. The independent MWRA was established to manage Boston’s waste treatment system and was given the authority to float bonds to pay for major improvements in the treatment system. In 1985, a Federal court began hearings on a suit brought by the Conservation Law Foundation, the Environmental Protection Agency (USEPA), and towns of Quincy and Winthrop against the MDC and MWRA (as heir to responsibilities of the MDC) for years of violation of the Clean Water Act. The judge ruled against the defendants and required all the parties to submit a construction plan and schedule for a new sewage treatment system. From these submissions, he developed a schedule for treatment system upgrades that would give the “citizens of this commonwealth a public assurance that Boston Harbor will be cleaned up within a defined period of time” (Dolin, 2004). The MWRA’s Boston Harbor cleanup program (Levy and Connor, 1992) has transformed the Boston sewage system. Key improvements were to (1) reduce contaminants at the industrial source; (2) remediate leaks in the sewage-collection system; (3) eliminate sewage sludge discharge to the harbor; (4) upgrade sewage treatment from primary to secondary; (5) construct a new ocean outfall 15.2 km offshore in Massachusetts Bay for discharge of treated effluent (fig. 1.3); and (6) implement improvements in the combined-sewer-overflow system. As part of the harbor cleanup program, the MWRA developed a comprehensive monitoring program (summarized in MWRA, 2004) to assess changes in the harbor and bays that specifically related to the new sewage system. Additional information about conditions and processes in the coastal system on a regional scale and over a long time period was and continues to be important in predicting and interpreting local change. Implementation of the MWRA’s program and the mission of the USGS to understand the geology of the nation’s offshore waters provided an opportunity to conduct a cooperative multidisciplinary research program. This USGS program addresses basic scientific questions as well as concerns raised by management regarding the design, implementation, and assessment of the new sewage treatment system. Already active in Boston Harbor during the late 1970s, the USGS expanded research into Massachusetts Bay with a multidisciplinary program in 1989.

Massachusetts

A synthesis of thresholds for focal species along the U.S. Atlantic and Gulf Coasts: A review of research and applications

The impacts from climate change are increasing the possibility of vulnerable coastal species and habitats crossing critical thresholds that could spur rapid and possibly irreversible changes. For species of high conservation concern, improved knowledge of quantitative thresholds could greatly improve management. To meet this need, we synthesized information pertaining to biological responses as tipping points to sea level rise (SLR) and coastal storms for 45 fish, wildlife, and plant species along the U.S. Atlantic and Gulf Coasts and Caribbean through a literature review and expert elicitation. Although these species were selected based on their ecological, economic, and cultural importance, just over half (56%, n = 25) have quantitative threshold data currently available that can be used to assess the effects of SLR and storms during some aspect of their life history. Birds, reptiles, and plants represent the best studied coastal species. Thirteen of the species (29%) are projected to lose at least 50% of their population or habitat (e.g., foraging, nesting, spawning, or resting habitat) in some areas with a 0.5 m or greater rise in sea levels by 2100. Two species (a bird and reptile) may gain habitat from projected SLR and be resilient to future impacts. Numeric thresholds were not available for the remaining 20 species we searched for. Coastal fishes, mammals, and amphibians were among the groups representing a major information gap in this field of research. In addition, quantitative threshold responses to coastal storms were scarce for all taxa. While vulnerability assessments and qualitative research related to the impacts of SLR and storms on coastal species and habitats are increasing, work that incorporates quantitative thresholds as response and impact metrics remains limited. Additional monitoring, modeling, and research that provides multiple quantitative thresholds across species' life stages and/or latitudinal gradients is ideal to support robust coastal management and decision-making across spatio-temporal scales in the face of climate change.

Ocean and Coastal Management

Oyster reef restoration in the northern Gulf of Mexico: extent, methods and outcomes

Shellfish reef restoration to support ecological services has become more common in recent decades, driven by increasing awareness of the functional decline of shellfish systems. Maximizing restoration benefits and increasing efficiency of shellfish restoration activities would greatly benefit from understanding and measurement of system responses to management activities. This project (1) compiles a database of northern Gulf of Mexico inshore artificial oyster reefs created for restoration purposes, and (2) quantitatively assesses a subset of reefs to determine project outcomes. We documented 259 artificial inshore reefs created for ecological restoration. Information on reef material, reef design and monitoring was located for 94, 43 and 20% of the reefs identified. To quantify restoration success, we used diver surveys to quantitatively sample oyster density and substrate volume of 11 created reefs across the coast (7 with rock; 4 with shell), paired with 7 historic reefs. Reefs were defined as fully successful if there were live oysters, and partially successful if there was hard substrate. Of these created reefs, 73% were fully successful, while 82% were partially successful. These data highlight that critical information related to reef design, cost, and success remain difficult to find and are generally inaccessible or lost, ultimately hindering efforts to maximize restoration success rates. Maintenance of reef creation information data, development of standard reef performance measures, and inclusion of material and reef design testing within reef creation projects would be highly beneficial in implementing adaptive management. Adaptive management protocols seek specifically to maximize short and long-term restoration success, but are critically dependent on tracking and measuring system responses to management activities.

Alabama, Florida, Louisiana, Mississippi, Texas

Gauging state-level and user group views of oyster reef restoration activities in the northern Gulf of Mexico

Successful oyster reef restoration, like many conservation challenges, requires not only biological understanding of the resource, but also stakeholder cooperation and political support. To measure perceptions of oyster reef restoration activities and priorities for future restoration along the northern Gulf of Mexico coast, a survey of 1500 individuals representing 4 user groups (oyster harvesters, shrimpers, environmental organization members, professionals), across 5 states (Texas, Louisiana, Mississippi, Alabama, Florida) was conducted in 2011. All respondents highly supported reef restoration efforts, but there was a dichotomy in preferred restoration goals with commercial fishermen more likely to support oyster reef restoration for stock enhancement, while professionals and environmental organization members were more likely to support oyster reef restoration to enhance ecosystem services. All user groups identified enforcement, funding, and appropriate site selection as basic requirements for successful reef restoration. For management of restored oyster reefs, oyster harvesters and shrimpers were less likely to support options that restricted the use of reefs, including gear restrictions and permanent closures, but did support rotating annual reef closures, while other stakeholders were willing to consider all options, including annual reef closures and sanctuary reefs. Overall, there were clear differences in management and communication preferences across user groups, but few differences across states. Understanding these key differences in stakeholder support for, and willingness to accept specific management actions is critical in moving management and restoration forward while minimizing conflict.

Ocean and Coastal Management

Are coastal managers ready for climate change? A case study from estuaries along the Pacific coast of the United States

A key challenge for coastal resource managers is to plan and implement climate change adaptation strategies inlight of uncertainties and competing management priorities. In 2014, we held six workshops across estuaries along the Pacific coast of North America with over 150 participants to evaluate resource managers' perceived level of understanding of climate change science, where they obtain information, how they use this knowledge, and their preparedness for incorporating climate change into their management decisions. We found that most resource managers understood the types of climate change impacts likely to occur in their estuaries, but often lacked the scientific information to make decisions and plan effectively. Managers stated that time, money, and staff resources were the largest obstacles in their efforts. Managers identified that they learned most of their information from peers, scientific journals, and the Internet and indicated that sea-level rise was their greatest concern. There was, however, variation in managers' levels of readiness and perceived knowledge within and among workshop locations. The workshops revealed that some regions don't have the information they need or the planning capacity to effectively integrate climate change into their management, with eight out of fifteen site comparisons showing a significant difference between their level of preparedness (F 5,26 = 6.852; p = 0.0003), and their willingness to formally plan (F 5,26 = 12.84; p = 0.000002). We found that Urban estuaries were significantly different from Mixed Use and Rural estuaries, in having access to information and feeling more prepared to conduct climate change planning and implementation (F 2,29 = 17.34; p = 0.00001). To facilitate climate change preparedness more comprehensive integration of science into management decisions is essential.

Ocean and Coastal Management

Defining oyster resource zones across coastal Louisiana for restoration and aquaculture

Eastern oysters ( Crassostrea virginica ) are a critical ecological and commercial resource in the northern Gulf of Mexico facing changing environmental conditions from river management and climate change. In Louisiana, USA, development of restored reefs, and off-bottom aquaculture would benefit from the identification of locations supportive of sustainable oyster populations ( i.e., metapopulations) and high consistent production. This study defines four oyster resource zones across coastal Louisiana based on environmental conditions known to affect oyster survival, growth, and reproduction. Daily data from 2015 to 2019 were interpolated to generate salinity and temperature profiles across Louisiana's estuaries, which were then used to classify zones based on monthly and annual salinity mean and variance. Zones were classified as supportive of (1) broodstock sanctuary reefs (i.e., support reproductive populations), (2) productive reefs during dry (salty) years, (3) productive reefs during wet (fresh) years, and (4) off-bottom aquaculture development. Of the 38,000 km 2 investigated, over 11,000 km 2 of potential oyster zone area was identified across the Louisiana coast. The Broodstock Sanctuary Zone was the smallest (∼540 km 2 ), as salinity variance limited this zone in many areas, as it is driven largely by riverine inputs across many estuaries. Located up-estuary (Dry Restoration Zone) and down-estuary (Wet Restoration Zone) of the Broodstock Sanctuary Zone, Dry and Wet Restoration Zone areas covered ∼2400 km 2 and ∼3900 km 2 , respectively. Mapped reefs in Louisiana currently exist largely within the Dry Restoration zones, suggesting a potential strategy to focus reef development in Wet Restoration zones to ensure reef network sustainability through years with high precipitation and river inflow. The off-bottom Aquaculture Zone was the largest (∼6400 km 2 ) zone identified, with much of this area located more down-estuary and off-shore. Accounting for variable water quality conditions enables the development of a network of reefs resilient to environmental variability, and more stable areas for consistent off-bottom aquaculture production. Spatial planning and identification of oyster resource zones reduces focus on individual reef success and supports management of oyster metapopulation outcomes, while identifying zones supportive of off-bottom aquaculture.

Louisiana

Spatial social value distributions for multiple user groups in a coastal national park

Managing public lands to maximize societal benefits requires spatially explicit understanding of societal valuation, and public participation geographic information systems (PPGIS) are increasingly used in coastal settings to accomplish this task. Social Values for Ecosystem Services (SolVES), a PPGIS tool that systematizes the mapping and modeling of social values and cultural ecosystem services, is promising for use in coastal settings but has seen relatively limited applications relative to other PPGIS approaches; it has also, to our knowledge, not yet been applied in a barrier island setting. In this study, we surveyed two visitor groups and residents living near Cape Lookout National Seashore (North Carolina, USA) to understand their social values in the context of the park's management needs. We developed social-value models to evaluate differences between three user groups (fall visitors, summer visitors, and residents) and to evaluate how respondents' experiences, attitudes, and recreational activities influence the locations they value and their most strongly held value types, which included aesthetic, recreation, biodiversity, future, therapeutic, and historic values. We found that accessibility, user types and the seasonality of major recreational activities, and the linear configuration of the barrier island system at Cape Lookout are important influences on the social values held by visitors and residents. The modeling results provide information relevant to management at Cape Lookout and can inform the design of future PPGIS studies in coastal and marine settings.

North Carolina

The applicability of terrestrial visitor impact management strategies to the protection of coral reefs

A dramatic expansion in nature-based tourism to tropical coastal destinations has occurred in the past 20 years. Tourism development, combined with intense recreational pressures, has irreversibly transformed and degraded many popular scenic natural environments. This paper examines the management of recreational impacts to coral reefs using Virgin Islands National Park as a case study. A review of terrestrial recreational ecology research explores the implications and potential applicability of some principal findings to the protection of coral reefs. Visitor impact management recommendations for the protection of coral reefs are offered. Managers can minimize coral reef recreational impacts by (1) restricting high-impact uses, (2) containing rather than dispersing recreational use, (3) encouraging the use of resistant environments, (4) teaching low-impact recreational practices, and (5) enforcing park rules and regulations.

Ocean and Coastal Management

A multidisciplinary coastal vulnerability assessment for local government focused on ecosystems, Santa Barbara area, California

Incorporating coastal ecosystems in climate adaptation planning is needed to maintain the well-being of both natural and human systems. Our vulnerability study uses a multidisciplinary approach to evaluate climate change vulnerability of an urbanized coastal community that could serve as a model approach for communities worldwide, particularly in similar Mediterranean climates. We synthesize projected changes in climate, coastal erosion and flooding, watershed runoff and impacts to two important coastal ecosystems, sandy beaches and coastal salt marshes. Using downscaled climate models along with other regional models, we find that temperature, extreme heat events, and sea level are expected to increase in the future, along with more intense rainfall events, despite a negligible change in annual rainfall. Consequently, more droughts are expected but the magnitude of larger flood events will increase. Associated with the continuing rise of mean sea level, extreme coastal water levels will occur with increasingly greater magnitudes and frequency. Severe flooding will occur for both natural (wetlands, beaches) and built environments (airport, harbor, freeway, and residential areas). Adaptation actions can reduce the impact of rising sea level, which will cause losses of sandy beach zones and salt marsh habitats that support the highest biodiversity in these ecosystems, including regionally rare and endangered species, with substantial impacts occurring by 2050. Providing for inland transgression of coastal habitats, effective sediment management, reduced beach grooming and removal of shoreline armoring are adaptations that would help maintain coastal ecosystems and the beneficial services they provide.

California

Conservation easements and coastal armoring: Protecting sea turtle nesting habitat through property ownership

To determine the relationship between the intent of owners of homes located near sea turtle nesting beaches in the state of Florida to engage in coastal conservation easements (CCE), the theory of planned behavior (TPB), environmental identity (EI) and relevant demographics were analyzed. As CCEs are a novel application of a proven conservation tool, a statewide survey was administered to 1274 property owners living within a mile of a protected section of sea turtle nesting habitat (e.g. state park, preserve, wildlife refuge). Multiple linear regression showed coastal property owners were more likely to engage with a CCE if they believed they had the ability and opportunity, held positive attitudes about entering into a CCE, and identified more favorably with potential CCE motivators for property owners. These motivators include receiving assistance from a conservation organization to manage their beachfront land; conserving beach habitat; obtaining annual tax deductions; and trusting the organization administering a CCE. Knowing these motivators and demographics of coastal property owners can help aid coastal land conservationists in crafting strategies to conserve sea turtle nesting beaches.

Florida

Ecological and political issues surrounding decommissioning of offshore oil facilities in the Southern California Bight

To aid legislators, resource managers, and the general public, this paper summarizes and clarifies some of the issues and options that the federal government and the state of California face in decommissioning offshore oil and gas production platforms, particularly as these relate to platform ecology. Both local marine ecology and political climate play a role in decommissioning offshore oil production platforms. Compared to the relatively supportive political climate in the Gulf of Mexico for “rigs-to-reefs” programs, conflicting social values among stakeholders in Southern California increases the need for understanding ecological impacts of various decommissioning alternatives (which range from total removal to allowing some or all of platform structure to remain in the ocean). Additional scientific needs in the decommissioning process include further assessment of platform habitat quality, estimation of regional impacts of decommissioning alternatives to marine populations, and determination of biological effects of any residual contaminants. The principal management need is a ranking of environmental priorities (e.g. species-of-interest and marine habitats). Because considerable numbers of economically important species reside near oil platforms, National Oceanic and Atmospheric Administration Fisheries should consider the consequences of decommissioning alternatives in their overall management plans. Management strategies could include designating reefed platforms as marine protected areas. The overarching conclusion from both ecological and political perspectives is that decommissioning decisions should be made on a case-by-case basis.

Ocean and Coastal Management

Southern Salish Sea Habitat Map Series data catalog

In 2010, the U.S. Environmental Protection Agency, Region 10 initiated the Puget Sound Scientific Studies and Technical Investigations Assistance Program, which was designed to support research for implementing the Puget Sound Action Agenda. The Action Agenda was created because Puget Sound was designated as one of 28 estuaries of National Significance under section 320 of the Clean Water Act, and its overall goal is to restore the environment of the Puget Sound Estuary by 2020. The Southern Salish Sea Mapping Project was funded through the Assistance Program request for proposal process which also supports a large number of coastal-zone- and ocean-management issues, and includes the recommendations of the Marine Protected Areas Work Group to the Washington State Legislature. These recommendations include a Puget Sound and coast-wide marine conservation needs assessment, gap analysis of existing Marine Protected Areas and recommendations for action. Four areas with recently acquired National Ocean Service hydrographic data are included in the Southern Salish Sea Habitat Map Series (fig. 1), each to be published individually as USGS Open File Reports at a scale of 1:40,000. The map products display seafloor geoforms, substrate, and biotopes using the Coastal and Marine Ecological Classification Standard. This data catalog contains much of the data used to prepare the SIMs in the Southern Salish Sea Habitat Map Series. Other data that were used to prepare the maps were compiled from previously published sources (for example, sediment samples and seismic reflection profiles) and are not included in this data series.

Washington

Coupling alongshore variations in wave energy to beach morphologic change using the SWAN wave model at Ocean Beach, San Francisco, CA

Coastal managers have faced increasing pressure to manage their resources wisely over the last century as a result of heightened development and changing environmental forcing. It is crucial to understand seasonal changes in beach volume and shape in order to identify areas vulnerable to accelerated erosion. Shepard (1950) was among the first to quantify seasonal beach cycles. Sonu and Van Beek (1971) and Wright et al. (1985) described commonly occurring beach states. Most studies utilize widest spaced 2-D cross shore profiles or shorelines extracted from aerial photographs (e.g. Winant et al. 1975; Aubrey, 1979, Aubrey and Ross, 1985; Larson and Kraus, 1994; Jimenez et al., 1977; Lacey and Peck, 1998; Guillen et al., 1999; Norcorss et al., 2002) to analyzed systematic changes in beach evolution. But with the exception of established field stations, such as Duck, NC (Birkemeier and Mason, 1984), ans Hazaki Oceanographical Research Station (HORS) in Japan (Katoh, 1997), there are very few beach change data sets with high temporal and spatial resolutions (e.g. Dail et al., 2000; Ruggiero et al., 2005; Yates et al., in press). Comprehensive sets of nearshore morphological data and local in situ measurements outside of these field stations are very rare and virtually non-existent high-energy coasts. Studied that have attempted to relate wave statistics to beach morphology change require some knowledge of the nearshore wave climate, and have had limited success using offshore measurement (Sonu and Van Beek, 1971; Dail et al., 2000). The primary objective of this study is to qualitatively compare spatially variable nearshore wave predictions to beach change measurements in order to understand the processes responsible for a persistent erosion 'hotspot' at Ocean Beach, San Francisco, CA. Local wave measurements are used to calibrate and validate a wave model that provides nearshore wave prediction along the beach. The model is run for thousands of binned offshore wave conditions to help isolate the effects of offshore wave direction and period on nearshore wave predictions. Alongshore varying average beach change statistics are computed at specific profile locations from topographic beach surveys and lidar data. The study area is located in the San Francisco Bight in central California. Ocean Beach is a seven kilometer long north-south trending sandy coastline located just south of the entrance to the San Francisco Bay Estuary (Figure 1). It contains an erosion hotspot in the southern part of the beach which has resulted in damage to local infrastructure and is the cause of continued concern. A wide range of field data collection and numerical modeling efforts have been focused here as part of the United States Geological Survey's (USGS) San Francisco Bight Coastal Processes Study, which began in October 2003 and represents the first comprehensive study of coastal processes at the mouth of San Francisco Bay. Ocean Beach is exposed to very strong tidal flows, with measured currents often in excess of 1 m/s at the north end of the beach. Current profiler measurements indicate that current magnitudes are greater in the northern portion of the beach, while wave energy is greater in the southern portion where erosion problems are greatest (Barnard et al., 2007). The sub-aerial beach volume fluctuates seasonally over a maximum envelope of 400,000 m 3 for the seven kilometer stretch (Barnard et al, 2007). The wave climate in the region is dominated by an abundance of low frequency energy (greater than 20 s period) and prevailing northwest incident wave angles. The application of a wave model to the region is further complicated by the presence of the Farallon Islands 40 kilometers west, and a massive ebb tidal delta at the mouth of San Francisco Bay (~150 km 2 ), which creates complicated refraction patterns as wave energy moves from offshore Ocean Beach; however the cost and threat of the energetic nearshore environment have limited the temporal and spatial resolution of these measurements. Applying numerical models to predict wave and current patterns along the beach can help supplement the filed data that exists and provide opportunities to make prediction about the impacts of changing environmental forcing.

California