Managing Watersheds for Coral Reefs and Public Health: A Vibrant Oceans Initiative Whitepaper

ABSTRACT
The health and integrity of coral reef ecosystems are in decline worldwide due to an increasing suite of human activities, which threaten biodiversity and human wellbeing. One of the major drivers of coral reef ecosystem decline is poor water quality from human activities on land. Land-based pollutants from human activities travel downstream via watersheds - through groundwater flow and land areas drained by streams – and are funnelled into coastal environments. There is now ample evidence of the linkages between human activities in watersheds and elevated levels of pollutants in water discharged to coastal marine ecosystems. There is also a growing understanding of the myriad and often interacting impacts these pollutants have on coral reef ecosystems and the critical services they provide for associated dependent communities. This white paper reviews the linkages between land-based runoff and coral reef ecosystems, with four specific objectives to: (1) review how sediments, nutrients, chemicals, and pathogens affect corals and reef-associated organisms at a variety of life stages; (2) assess how these processes impact associated dependent human populations; (3) identify existing knowledge needs; and (4) provide science-based management options. Improving the management of upstream human activities within watersheds has great potential to alleviate the severe local threats of poor water quality on coral reef ecosystems and preserve the critical functions and services they provide (e.g., tourism, fisheries, and coastal protection). Improving water quality can reduce coral disease risk and increase vital biological functions needed for corals to grow (e.g., reproduction), which also improves the resilience of corals to global impacts such as climate change. Yet, despite the breadth of research demonstrating critical land-sea linkages for coral reef ecosystem health, there are few standout examples of successful improvements to coral reef ecosystem condition that can be directly linked to upstream management action. This is largely because investments in both interventions and monitoring often need to be large in scale and sustained over long (i.e., decadal) periods to detect measurable downstream impacts. There are also a variety of human health impacts resulting directly from poor water quality flowing within watersheds onto coastal environments. The direct impacts to human health from declining water quality include: (1) enhanced transmission of diseases (e.g., gastrointestinal and upper respiratory diseases); (2) reduced food availability and nutritional deficit from decline of fisheries associated with coral reef habitat; and (3) food poisoning from consumption of seafood contaminated with pollutants and pathogens. Poor water quality is consequently a major contributor to global disease burdens and conservatively estimated to cost 12 billion USD in economic losses annually, a cost disproportionately borne by the poorest countries (Alhamlan et al. 2015). The overlapping drivers of coral reef and human health from watershed alteration provides an opportunity to create strategic management interventions within watersheds that will address the goals of both the conservation and public health sectors and enhance human and ecosystem health outcomes. This paper presents innovative solutions that incentivize the large-scale, sustained action required to both improve water quality in watersheds and prevent water quality impacts on coral reef ecosystems. The solutions use holistic approaches to integrated watershed management that bridge social and ecological systems and provide important co-benefits to human wellbeing. Focusing on the combined economic, human health and wellbeing impacts across linked watersheds and reef areas can motivate action and leverage investment that result in co-benefits across multiple sectors. Designing appropriate solutions, therefore, requires taking a multi-sector, systems approach, that accounts for both social and ecological systems, with collaboration required across environmental, agricultural, public health, and water, sanitation and hygiene (WASH) sectors, and across the land-sea interface. Having a wide range of informed stakeholders sharing resources and taking an integrated approach will assist in buffering risks and create more effective and proactive governance. We provide several recommendations of key actions to promote successful outcomes for nature and people from improved watershed management: -Undertake risk assessments to identify main sources of land-based impacts to coral reef ecosystems, and consider where these risks overlap with risks to public health, especially in the context of future climate change scenarios. -Ensure engagement of the full range of actors, landowners, and beneficiaries within watershed boundaries and provide platforms for transparent, participatory planning, and decision-making. -Develop guidance materials to integrate coral reef ecosystem health into integrated watershed management, public health, and WASH planning. -Engage and/or establish multi-sector management authorities (e.g., watershed commissions) with the mandate and resources to coordinate action across marine resource users/managers, logging, mining, agricultural, public health, and WASH sectors. -Undertake policy gap analysis to improve implementation of existing policies and identify opportunities to strengthen best-practice management guidelines for land use including logging, mining, food production, and wastewater treatment to properly account for downstream human and ecosystem health impacts. -Conduct research and synthesis to improve the quantity and quality of data available on thresholds and indicators of water quality and impacts on coral reef ecosystems, and make the information easily accessible (i.e., through an open-source water quality database) to support monitoring and assessment programs. -Develop/enhance sustainable and innovative financing mechanisms, through impact investment and private sector engagement, business case studies and integrated resource mobilization strategies, to provide the resources required to implement phased, integrated watershed management interventions across nested scales. -Advocate for integrated watershed management in places where pollution is likely to undermine other conservation interventions being implemented (e.g., within marine protected areas). -Document the process of developing and implementing integrated watershed management strategies in order to create communication materials for the broader conservation, WASH and public health communities on lessons learned.