A new conceptual model describes the inlet migration and inlet transition phases of development of the Nauset Beach–Pleasant Bay barrier beach system. The model uses historical cartographic resources to inform geomorphological analysis of sedimentary processes, inlet migration, and new inlet formation for the purpose of estimating future system configurations and conditions. Using this model, we place the natural evolution of the system in context and observe that an anthropogenic alteration of the mainland shore, a stone revetment, likely contributed to the system's transition to a single inlet system.

Benthic habitat maps are an important part of ecosystem-based management as they document biotic and abiotic resources. Integrating multiple ecosystem and environmental components is challenging, and the ability to do this is highly dependent on the methodology employed. The US Coastal and Marine Ecological Classification Standard (CMECS) uses a standardized set of classifications in a hierarchal structure to create benthic habitat maps. This study used acoustic surveys and benthic samples from Pleasant Bay, Cape Cod, MA, to develop benthic habitat maps and test relationships between biotic and abiotic variables. The collected data comprise a critical baseline record of biological and physical characteristics and will inform future management decisions as well as guide future studies of coastal resources in Pleasant Bay.

This paper discusses the utility of using seismic-reflection profiling and sediment cores in addition to bottom grab samples and acoustic data to develop shallow-water benthic habitat maps. Currently, the classification system used herein does not provide for the incorporation of stratigraphic data, but we believe that the utility of these maps would improve if such data were included. We conducted vessel-based seafloor-mapping surveys using a phase-measuring sidescan sonar in very shallow waters (mean depth = 3.2 m) covering an area >6.7 km² in Pleasant Bay in 2014. We collected a total of 192 bottom grab samples to document macro-invertebrates and sediment characteristics. We conducted seismic-reflection profiling surveys to document stratigraphy and determine optimal locations for multiple sediment cores during the 2014 field season; we collected both Kullenberg and Livingstone cores. The seismic-reflection data, though conducted at the reconnaissance scale, proved useful to place the seafloor acoustic data in context. The acoustic and benthic habitat data and mapping products become more valuable when an understanding of the underlying stratigraphy is used as context for the benthic habitat maps. Sediment coring and analysis can provide insights into past and current basin evolution, which can further aid marine natural resource managers. However, we believe that stratigraphic data should be incorporated into standard benthic habitat mapping protocols. These multi-modal datasets provide a better understanding of these habitats for the multidisciplinary teams that typically produce and use these maps as well as coastal managers.

Pleasant Bay, MA, is a coastal lagoon system featuring diverse habitats that support a variety of commercially, recreationally, and ecologically important marine species. In response to ecosystem changes noted by natural resource managers, we conducted an inventory of commercially and recreationally important shellfish and finfish in the bay from 2014 to 2017, the first such survey to be conducted since 1966. Fish and macroinvertebrate community composition and seasonal patterns of abundance during this study were broadly similar to those observed during other recent studies along the eastern shore of Cape Cod. This comprehensive inventory indicated that Pleasant Bay is home to a diverse and changing assemblage of marine species, some of which utilize the bay as spawning or nursery habitat. Long-term monitoring is necessary to place our observations in the broader contexts of short-term variability and long-term change.

Due to seal bounties throughout New England in the 19^th and 20^th centuries, Phoca vitulina vitulina (Harbor Seal) and Halichoerus grypus atlantica (Gray Seal) were nearly extirpated from the east coast of the US. The 2 species are now recovering and are repopulating southern New England haul-outs. To begin to develop an understanding of their current distribution and aspects of their diet inside Pleasant Bay and Chatham Harbor, we conducted monthly aerial surveys in 2014 and 2015 and collected scat monthly from January 2016 through March 2017. Although both species were observed to be hauling out, little temporal overlap of Harbor and Gray Seals was detected. While a variety of prey species were detected in the scat samples analyzed, Ammodytes spp. (sand lance) occurred most frequently in the diet of both seal species.

Pleasant Bay, MA, is a 8741-ha (21,600-acre) coastal lagoon with extensive eelgrass, shellfish, and salt marsh habitats and is subject to predictable variations in inlet formation resulting in shifting tides and access to the ocean. Here we describe methods to link data from independent surveys (benthic habitat assessment and fishery-independent trawl/dredge sampling) to create linkages across the ecosystem in order to guide future monitoring and management efforts.. The integration of water parameters, grain size, and surficial benthic analysis to create habitat categories allowed us to explain 45% of microinvertebrate distribution. Microinvertebrate communities had significant correlations to fish and macroinvertebrate communities, strengthening the usefulness of microinvertebrate surveys. Habitat categories containing Zostera marina (Common Eeelgrass) had higher species diversity and abundances of fishes and macroinvertebrates than other habitats. The links between habitat, communities of microinvertebrates, macroinvertebrates, and fish indicate a connected ecosystem.

Along the shoreline of a coastal lagoon with fringing salt marsh, we used the basinward edge of marsh vegetation, or marshline, as a shoreline indicator. We quantified uncertainties associated with the delineation of this indicator from aerial photographs. Where both could be delineated, we compared the marshline to the most widely used proxy-based shoreline indicator, the high water line (HWL). The marshline was shown to better represent change than the HWL along fringing marsh shorelines in this study. The visual cues used to delineate the marshline on aerial photographs were more objective, repeatable, and reliable than the visual cues associated with the HWL. In addition, several sources of uncertainty in calculating rates of shoreline change are eliminated, or significantly reduced, when using the marshline. Uncertainties associated with the timing of aerial photographs regarding tidal stage, seasonality, storm impact, as well as the misinterpretation of the shoreline indicator are all either negligible or of minimal influence when calculating uncertainty for the marshline. We calculated rates of shoreline change along a 40-km stretch of lagoon shoreline with fringing marsh. Less than 9.8 km of coast was outside the range of uncertainty using the HWL as compared to 22.5 km using the marshline for the same segments of shoreline for the same temporal period.