*4.2. Place-Based Solutions*

Using this framework, we located coral reefs vulnerable to local and global human stressors and linked them to areas on land where limiting sources of human-derived nutrients could prevent increases in benthic algae and promote chances of coral recovery from bleaching. Under the high coastal development scenario, most of the total nutrient increase (>2000 kg) occurs to the east and center of the *ahupua'a*, where flushing and mixing from waves is limited by the reef crests of Makua and Pu'ukahua reefs. Some of these areas that contribute high levels of human-nutrients lie upstream from the protected reef fish nursery at Makua. Coral reefs in Ha'ena may appear less susceptible ¯ to nutrient inputs from coastal development because they benefit from dilution and mixing from high freshwater and wave power. However, we showed that the back-reef of Makua is vulnerable to algae blooms (habitat area loss: 8.2%; shift in fish biomass composition, marked in pink in Figure 8A) and coral bleaching (habitat area loss: 13%, coral percent cover loss: 0–9%, fish biomass loss: −3.3%; marked in yellow in Figure 8A) due to the nearness of human-derived nutrient sources, limited mixing due to shallow depths and low wave power, and abundant corals and algae. Under the high coastal development scenario at Ka'up¯ ulehu, most of the nutrient increase (>8000 kg) occurs to the north of ¯ the *ahupua'a*, downstream from the proposed development. On the other hand, coral reefs appear more vulnerable to nutrient inputs from more coastal development, combined with higher levels of background nitrogen in the groundwater and limited dilution and mixing from low rainfall and wave power (habitat area loss: 14%, fish biomass loss: 0.6%; marked in pink in Figure 8B). Additionally, Ka'up¯ ulehu's plentiful coral cover is prone to coral bleaching (habitat area loss: 13%, coral cover loss ¯ 0–13%, fish biomass loss: −1.5%; in yellow in Figure 8B).

**Figure 8.** Coral reef areas vulnerable to local and global human stressors (i.e., nutrients and bleaching), coral reef areas with high fish recovery potential and priority land areas for management. Coral reef areas vulnerable to local and global human stressors (i.e., nutrients and bleaching), coral reef areas with high fish recovery potential and priority land areas, where local management actions can target wastewater and fertilizer practices at (**A**) Ha'ena and ( ¯ **B**) Ka'up¯ ulehu. Projected high coastal ¯ development land use/cover and marine closure/fishing rest areas are also shown.

Although the extent to which nutrient levels interact with elevated SST to affect the outcome of bleaching events remains poorly understood, it is increasingly recognized that water quality plays a complex role in the fate of nearshore coral reefs under climate change [60–62]. This seems to be the case since excess nutrients have been shown to impact coral reefs by promoting benthic algae growth and reducing coral's ability to recover from bleaching impacts [63,64]. When combining the effects of future coastal development and climate change on coral reefs, the impact worsens at both sites. Coral reefs vulnerable to both (coral reef areas marked in red in Figure 8A,B) do not overlap at Ka'up¯ ulehu (habitat ¯ area loss: 20.8%, fish biomass loss: −1.6%), while the shallow back-reef of Makua at Ha'ena is vulnerable ¯ to both stressors due to limited wave mixing (habitat area loss: 21.1%, fish biomass loss: −3.3%).

Given that climate change and coastal development occur simultaneously, these results suggest that adopting local management can benefit both places. Land-based management can improve the benthic habitat conditions by preventing increases in benthic algae, which promotes coral recovery from bleaching within & outside the marine closures (habitat gain: 8% at both sites). Therefore, to promote coral reef resilience to climate change, the Ha'ena community may benefit from upgrading cesspools ¯ in the priority areas we identified, located upstream from Makua (located in pink zone in Figure 8A). Based on our findings, the Ka'up¯ ulehu community could focus on minimizing phosphorus inputs ¯ from the wastewater injection well by increasing the nutrient removal through treatment (located in the pink zone below the injection well in Figure 8B) to reduce the vulnerability of coral reefs located downstream. In addition, the community could help foster resilience of their coral reefs by ensuring that environmentally sound practices are continued when fertilizing the golf course, particularly in the land areas located upstream from Uluweuweu bay and Kahuwai bay (located in pink zone in Figure 8B). This may also help to protect the water quality of a culturally important groundwater spring (*Wai a Kane ¯* ) that was identified by the Ka'up¯ ulehu community in Kahuwai bay (Figure ¯ 3B). While marine-based management increases the herbivore population within the reserves, which can supplement adjacent reef through spillover (fish biomass gain within the marine closure boundaries: +13% at Ha'ena and +2.6% at Ka' ¯ up¯ ulehu). Overall, this research supports the communities' concerns ¯ and provides evidence that more coastal development can potentially negatively impact culturally important fisheries at both sites.

#### *4.3. Application and Transferability*

Ridge-to-reef management that integrates LEK has been widely advocated because it can improve social-ecological resilience. Watershed units have commonly defined the ecological systems in traditional management systems, which have been found in the Pacific north west, Asia, Africa and Oceania [65]. Among the richest set of ridge-to-reef, social-ecological system approaches to natural resources management is found in Oceania [8,65]. Examples include the *tambak* in Indonesia [66], the *puava* in the Solomon Islands, the *tabinau* in Yap, the *vanua* in Fiji [67] and the *moku* in Hawai'i [27]. Through this research, we show that place-based solutions that integrate land and sea processes are critical for addressing local environmental threats. We demonstrate that culturally grounded and inclusive research can guide management actions with multiple benefits such as improved groundwater and coastal water quality and foster the resilience of coral reefs, which are important food production systems for local communities. The lessons learned from this process highlight the critical aspects of collaboration necessary to develop scientific tools that can inform these practical and appropriate management actions. Managing ICCAs requires taking into account interests at all levels, evaluating trade-offs and finding win-win solutions [23].

There is a strong need for planning tools that can prioritize local management actions at relevant spatial scales for decision makers, which are simple to interpret and implement [68,69]. These decision support tools can easily be updated as more data becomes available, or model components of the framework can be substituted or added based on management objectives. For example, in another application, we substituted the groundwater models with the open source Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) spatially-explicit Sediment Delivery Ratio Model (SDR version 3.2) [70] to model the impact of sediment runoff on coral reefs in Fiji [71]. To support Fijian communities currently working with government, NGOs and the private sector to design and implement Integrated Coastal Management plans [72], we applied the modified land-sea modeling framework with scenario planning in Kubulau District (Fiji), where logging and commercial agriculture expansion competes with forest conservation and potentially fisheries livelihoods, to identify where forest conservation or restoration actions could benefit coral reefs [71]. In addition to fostering collaboration, this approach offers a flexible, transferable, data-driven, place-based model that is spatially-explicit and relies on increasingly available free remote sensing imagery and bathymetry data (i.e., Worldview III, GEBCO).

#### **5. Conclusions**

These research findings suggest that different environmental conditions make place-based solutions essential [23], because one-size-fits-all kinds of management ignore issues of place and scale [26]. Rodgers et al. [73] provided the first quantitative statewide evidence that watershed and adjacent coral reef health are significantly interconnected in Hawai'i, with the exception of ridge-to-reef systems on the windward side due to exposure to high rainfall and wave power, implying that reefs in these locales are less vulnerable to land-based activities. Consistent with Rodgers et al. [73], our impact assessment showed that Ka'up¯ ulehu is vulnerable to local land-use change, as well as climate change ¯ impacts. Our findings also revealed that coral reefs on the windward side are vulnerable to local land-use change at the local-scale, especially back-reef systems, like Makua back-reef. In addition, our results show that managing local human drivers can foster coral reef resilience to global human drivers. Although the marine closures can promote reef recovery, they are not always able to offset the impacts from coastal development and other land-based activities on coral reefs, especially beyond their boundaries. Due to the risk that coastal development can undermine local marine conservation efforts, it is essential to manage upstream land-use change.

Therefore, local-scale and place-based solutions are particularly important in Hawai'i, where locally sourced food is socially and culturally important and food systems are vulnerable to coastal development and climate change impacts [18,33]. Our research provides place-based case studies of the interaction of researchers, community members, resource managers and policy makers to inform future planning. ICCAs, such as Ha'ena and Ka' ¯ up¯ ulehu, can help redefine co-management and the ¯ role of local communities and institutions throughout Hawai'i. Although this management approach may be more suited for communities with strong ancestral ties to the place, as larger and more heterogeneous communities, such as Maunalua Bay on East O'ahu, will require early onset and more efforts to build consensus [74] and necessitate creative strategies to engage the various members [75]. However, this type of research can help coordinate and facilitate reaching agreements across different community groups by testing policies prior to implementation and bridging gaps between managers and communities by visualizing synergies and trade-offs on maps.

**Author Contributions:** Conceptualization, J.M.S.D., K.B.W., S.D.J., M.B.-V., L.L.B., K.B., T.T.; Methodology, J.M.S.D., K.B.W., S.D.J.; Software, J.L.T.; Validation, J.M.S.D. and K.B.W.; Formal Analysis, J.M.S.D.; Investigation, K.B.W., S.D.J., M.B.-V., K.B., T.T.; Resources, J.M.S.D., J.L.T.; Data Curation, J.M.S.D.; Writing—Original Draft Preparation, J.M.S.D. and K.B.W.; Writing—Review & Editing, K.B.W., S.D.J., M.B.-V., L.L.B., K.A.S., K.B., P.G., J.L.T., T.T.; Visualization, J.M.S.D. & J.L.T.; Supervision, K.W., S.D.J., T.T.; Project Administration, K.B.W.; Funding Acquisition, K.B.W., S.D.J., M.B.-V., K.B., T.T.; J.M.S.D., J.L.T., K.A.S. revised the illustrations to reflect the specificity of each place.

**Funding:** This research was funded by the NSF Coastal SEES project number 1325874 and the APC was funded by Hawai'i Community Foundation.

**Acknowledgments:** Many thanks to a collaborating artist, Sophie Eugène, for the illustrations and the Integration and Application Network, University of Maryland Center for Environmental Science (ian.umces.edu/symbols/) for the marine symbols. The authors are very grateful for Robert Whittier from the Hawai'i Department of Health for embarking on this collaborative research that allowed us to produce a story that goes beyond the sum of its parts. The authors would like to acknowledge the Principal Investigators (Alan M. Friedlander, Heather McMillen), the research collaborators (Greg Guannel, Natalie Kurashima, Lisa Mandle, Robert Toonen, Anders Knudby, Jonatha Giddens, Cheryl Geslani) and data providers (Tracy Wiegner, Chad Wiggins, & Eric Conklin) on this research project. Finally, we are grateful to our community members, key landowner partners, Kamahameha schools in Ka'up¯ ulehu and, Limahuli Gardens and Preserve in H ¯ a'ena, who inspired this research and made this ¯ project possible.

**Conflicts of Interest:** The authors declare no competing interests as defined by *Sustainability*, or other interests that might be perceived to influence the results and/or discussion reported in this paper. The founding sponsors had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript and in the decision to publish the results.
