Estimates of the types and number of recreational users visiting an estuary are critical data for quantifying the value of recreation and how that value might change with variations in water quality or other management decisions. However, estimates of recreational use are minimal and conventional intercept surveys methods are often infeasible for widespread application to estuaries. Therefore, a practical observational sampling approach was developed to quantify the recreational use of an estuary without the use of surveys. Designed to be simple and fast to allow for replication, the methods involved the use of periodic instantaneous car counts multiplied by extrapolation factors derived from all-day counts. This simple sampling approach can be used to estimate visitation to diverse types of access points on an estuary in a single day as well as across multiple days. Evaluation of this method showed that when periodic counts were taken within a preferred time window (from 11am-4:30pm), the estimates were within 44 percent of actual daily visitation. These methods were applied to the Three Bays estuary system on Cape Cod, USA. The estimated combined use across all its public access sites is similar to the use at a mid-sized coastal beach, demonstrating the value of estuarine systems. Further, this study is the first to quantify the variety and magnitude of recreational uses at several different types of access points throughout the estuary using observational methods. This work can be transferred to the many small coastal access points used for recreation across New England and beyond.

We introduce and validate the use of commercially available human mobility datasets based on cell phone locations to estimate visitation to natural areas. By combining this data with on-the-ground observations of visitation to water recreation areas in New England, we fit a model to estimate daily visitation for four months to more than 500 sites. The results show the potential for this new big data source of human mobility to overcome limitations in traditional methods of estimating visitation and to provide consistent information at policy-relevant scales. However, the data providers' opaque and rapidly developing methods for processing locational information required a calibration and validation against data collected by traditional means to confidently reproduce the desired estimates of visitation. We found that with this calibration, the high-resolution information in both space and time provided by cell phone location-derived data creates opportunities for developing next-generation models of human interactions with the natural environment.

We introduce and validate the use of commercially-available datasets of human mobility based on cell phone locational data to estimate visitation to natural areas. By combining this data with on-the-ground observations of visitation to water recreation areas in New England, we fit a model to estimate daily visitation for four months to over 500 sites. The results show the potential for this new big data source of human mobility to overcome limitations in traditional methods of estimating visitation and to provide consistent information at policy-relevant scales. The high-resolution information in both space and time provided by cell phone location derived data creates opportunities for developing next-generation models of human interactions with the natural environment. However, the opaque and rapidly developing methods for processing locational information by the data providers required a calibration and validation against data collected by traditional means to confidently reproduce the desired estimates of visitation.

Howarth et al., 2000;Woodward et al., 2012). In coastal waters, cultural eutrophication can lead to a suite of adverse outcomes including the degradation of seagrass beds and shellfish habitats, decreased water clarity, and more (Bricker et al., 1999;Driscoll et al., 2003).Similar to non-point source water quality management efforts elsewhere, Cape Cod, Massachusetts, USA ("the Cape") faces a number of challenges in dealing with nutrient pollution (Boesch, 2002). These challenges include the diffuse nature of the nitrogen inputs, a relatively low density (for the northeastern U.S.) of residential and commercial development which makes sewering more expensive, and a complex set of stakeholders and decision makers with sometimes conflicting interests and values (Perry et al., 2020).

Water recreation is valuable to people and its value can be affected by changes in water quality. This paper presents the results of a primary data collection effort using a revealed preference survey to elicit coastal New England, USA residents’ values for water recreation and water quality. We combined the survey responses with a comprehensive dataset of coastal attributes, including in-water and remotely sensed water quality metrics for the coast of New England. The results provide an updated willingness-to-pay for a coastal recreation trip of $26-$28 (USD). Using a travel cost model framework, we found water clarity and the bacterial conditions of coastal waters to be practical water quality inputs to economic analysis, available at appropriate scales and meaningful to people and their behavior. Changes in clarity and bacterial conditions affected trip values, with a $4-$5 change for a meter in clarity and $0.13 for a one-unit change, respectively. We demonstrate their utility and the large potential value of improving water quality through welfare analysis scenarios for Narragansett Bay, Rhode Island, and Cape Cod, Massachusetts, USA. The paper discusses generalizable lessons for improving the policy relevance and applicability of water quality valuation studies in the U.S. and worldwide through improved water quality data collection and aggregation combined with application of scalable analysis tools for valuation.