**5. Conclusions**

In this paper, we have used a stratification approach to examine di fferent types of change by analysing land cover types. Ancillary data and local expert knowledge were necessary to expose long-term trends and formulate explanations in a region that surrounds and includes a national park that has, until now, been largely devoid of significant direct anthropogenic impact. Whereas the reasons for such changes could generally be explained with detailed field-based data sets, such information does not exist at the requisite spatial and temporal scales. Remote sensing datasets, e.g., Landsat imagery, provided the only feasible method to enumerate the trends in LULC in the spatially extensive study area. Areal reduction in threatened and endangered ecosystems (e.g., mangroves and estuarine wetlands) occurred within Cape Palmerston National Park and its surroundings. We found a decreasing trend in the vegetation extent of estuarine wetlands, saltmarsh grass, and grazing areas. Significant declining values were observed in open forest, fringing mangroves, estuarine wetlands, and saltmarsh grass, albeit on localized scales, with a mosaic of ensemble change across the study site. The occurrence of a severe tropical cyclone immediately preceding capture of the 2017 Landsat image was likely the main agen<sup>t</sup> in the declining trend for shoreline and stream vegetation. Long-term grazing pressure contributed to vegetation degradation and loss of resilience on a landscape scale. SLATS maps confirm that many sites in the sub-catchment were cleared of woody vegetation and converted to pasture during our time period. To maintain ecosystem services and encourage habitat–fishery linkages, effective monitoring action is crucial to understand recovery and set in place adaptive managemen<sup>t</sup> approaches. Historical occurrence of mangrove dieback in the region, coupled with the recent calls for the increased monitoring of northern Australian mangrove ecosystems due to dieback connections to climate change, could be extended to Great Barrier Reef catchments. Future studies by the authors will create virtual constellation synergies by integrating optical land imaging systems with similar characteristics, e.g., Landsat and Sentinel-2, firstly to assess post-cyclone recovery and secondly to explore ecosystem variability forced by climate controls in Great Barrier Reef catchments. Our research contributes to the body of knowledge on coastal ecosystem dynamics to enable planning to achieve more e ffective conservation outcomes.

**Supplementary Materials:** The following are available online at http://www.mdpi.com/2072-4292/12/1/197/s1, Table S1: Accuracy assessment of Landsat image captured in 2004, Rocky Dam Creek/Cape Palmerston National Park, Table S2: Accuracy assessment of Landsat image captured in 2017, Rocky Dam Creek/Cape Palmerston National Park, Table S3: Thematic Change Summary Matrix 2004–2017 with number of pixels in each land class per zone Rocky Dam Creek/Cape Palmerston National Park, Table S4: Thematic Change Summary Matrix 2004–2017 with percentage of land classes occurring in each zone Rocky Dam Creek/Cape Palmerston National Park.

**Author Contributions:** Conceptualization, S.P.; formal analysis, D.C.; methodology, D.C.; resources, H.P.; supervision, S.P. and H.P.; writing—original draft, D.C.; writing—review and editing, S.P. and H.P. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research received no external funding.

**Acknowledgments:** Technical support was gratefully received from Steve Bryant of Mackay State High School (Mackay, QLD 4740, Australia).

**Conflicts of Interest:** The authors declare no conflict of interest.
