# Nearshore Benthic Mapping in the Great Lakes:
## 5 Conclusions  
The approach described in this study, in which airborne and satellite data were evaluated for the classification of benthic substrate and biotic components reveals the potential strengths and weaknesses of those datasets for use in basin-wide mapping. Furthermore, it shows how these different approaches can be complementary, revealing levels of certainty when used in tandem or if fused or integrated more directly. This integrative aspect is important as regional initiatives such as the Great Lakes Water Quality Agreement strive to find ways to better protect and restore aquatic resources, in which monitoring and adaptive management are key objectives, setting the stage for critical regional activities and policies [4]. For example, the products generated from this study could be used to better understand the benthic substrate and associated habitat prior to shoreline protection project implementation (pre- and post-placement of shoreline protection structures) funded by the Great Lakes Restoration Initiative. Future steps should include not only evaluating the portability of the approach developed in this study to other areas in the Great Lakes, but also further integrating additional data types, such as vessel-based measurements, at larger spatial extents. Scaling analytical efforts up will increase the class diversity and complexity as well as require bringing even more disparate data types together, a challenging endeavor. Yet, no single data type or platform can accomplish the goal of basin-wide nearshore benthic mapping, and given the high variability of the nearshore environment within the Great Lakes, a multi-sensor data integration approach is warranted. A large piece of the regional puzzle will include the integration of airborne and satellite data, and many of the previous hurdles surrounding their use continue to improve--higher spatial, spectral, and temporal resolutions, better data quality, enhanced water column correction techniques, more advanced analytical methods, such as machine learning, as well as free, open data policies. Coastal and nearshore mapping programs and initiatives including the USACE NCMP, Seabed 2030, and Lakebed  
Figure 24: Shoreline changes and destruction of infrastructure illustrated in the central part of the study area as a result of lake level changes between 1960 and 2020: (**a**) 1960 topographic map obtained from the U.S. Geological Survey [57] showing homes and roads along the shoreline with the superimposed 2020 shoreline (digitized from RGB aerial imagery collected by the JALBTCX in 2020), (**b**) Tier 1 substrate classification result using airborne data inputs from 17 July 2018, highlighting remnants of various infrastructure found offshore (1973 structures digitized from historic topographic maps, [58]) and classified as anthropogenic substrate (in red), (**c**) airborne fusion image from 17 July 2018 also illustrating offshore benthic environment, and (**d**) 1973 photograph showing destruction of a home impacted by the shoreline erosion [59]. 2030, to name only a few of the efforts underway, are working to increase the temporal and spatial resolution of available data. It will be important to scale the benthic mapping work accordingly to take advantage of these new data streams and create meaningful, accurate, and reliable benthic data products that support the coastal and natural resources management professionals. The nexus of these technical improvements, along with a flexible classification system that meets management needs while being widely applicable (e.g., CMECS), and cross-jurisdictional partnerships for leveraging data, expertise, and resources will ultimately help overcome the challenges associated with basin-wide nearshore benthic mapping. Conceptualization, M.K.R. and B.S.K. ; methodology, M.K.R., B.S.K., S.E.B. and E.J.T. ; software, M.K.R., B.S.K. and J.H.H. ; validation, M.K.R., B.S.K., S.E.B. and E.J.T. ; formal analysis, M.K.R. and B.S.K. ; investigation, M.K.R., B.S.K. and J.H.H. ; resources, M.K.R., B.S.K., S.E.B. and E.J.T.