Where Does River Runoff Matter for Coastal Marine Conservation?

Abstract

Excess sediment and nutrient runoff from land-based human activities are considered serious threats to coastal and marine ecosystems by most conservation practitioners, resource managers, fishers, and other "downstream" resource users. Deleterious consequences of coastal runoff, including eutrophication and hypoxia, have been observed worldwide. Literature on integrated coastal management offers numerous methods to address land-based activities that generate runoff, but many of these approaches are time-and resource-intensive. Often, high-level conservation managers have few tools to aid in decisions about whether land-based threats that generate runoff are of sufficient concern to warrant further investment in planning and management interventions. To address this decision-making process, we present a decision tree that uses geophysical and ecological characteristics to sort any marine coastal ecosystem into a category of high, moderate, low, or minimal risk from the land-based threats of nutrient and sediment runoff. By identifying situations where runoff could influence biodiversity or ecosystem services, the decision tree assists managers in making informed, and standardized decisions about when and where to invest further efforts in integrated land-sea planning. We ground-truth the decision tree by evaluating it in five very different regions and conclude the tree classifies regions similarly to the existing literature that is available, but based on less information. Recognizing that the decision tree only encompasses environmental variables, we also discuss approaches for interpreting the decision tree's outputs in local social and economic contexts. The tree provides a tool for conservation managers to decide whether the scope of their work should include land-sea planning.

Chlorophyll Estimation of Lake Water and Coastal Water Using Landsat-8 and Sentinel-2a Satellite

“…In the recent decade, the increased pollutant load degraded the water quality of case-2 water mainly rivers, lakes and coastal oceans (Carpenter et al, 1998;Kändler et al, 2017;Zhang et al, 2018;Bhagowati and Ahamad, 2018). Land-based activities adjacent to the coastal and inland water bodies directly affect the water quality and aquatic ecosystem through numerous point sources (i.e., wastewater effluent, runoff from waste storages, stormwater outfalls) and non-pint sources of pollution (i.e., atmospheric deposition, agricultural runoff, deforestation and land conversion) (Fredston-Hermann et al 2016;Kandler et al 2017). Riverine transport is the primary mechanism for the direct impact of the terrestrial-human activities on the nearshore coastal waters and estuaries (Fredston-Hermann et al 2016).…”

“…Excess sediment and nutrient transport from anthropogenic sources (e.g., agriculture, industries and sewage disposal) in case-2 water often lead to increased turbidity and reduced light * S.Yadav availability, which in turn negatively impacts the biogenic species in the aquatic environment such as fishes and corals in freshwater and coastal water (Silva et al, 2016;Fredston-Hermann et al, 2016;Lintern et al, 2017). Nutrient load to inland waters (Le et al, 2009;Yadav et al, 2017) and coastal zones (Cloern and Jassby, 2010) lead to eutrophication including harmful algal bloom.…”

Ecosystem‐based management of coral reefs under climate change

“…However, many people rely on reefs for food and livelihoods and multi‐use of reefs requires careful consideration of the identification and understanding of trade‐offs among conflicting management and conservation objectives. This also requires a detailed understanding of the multiple stakeholders involved in direct use of and those involved in distal activities that could be impacting reefs, for example, in the case of land‐based pollution (Fredston‐Hermann et al., ) and logging (Hamilton et al., ). The type of management and conservation measures in place needs to take into account a combination of the changing environmental and human impacts as well as their potentially changing benefits.…”

“…and livelihoods and multi-use of reefs requires careful consideration of the identification and understanding of trade-offs among conflicting management and conservation objectives. This also requires a detailed understanding of the multiple stakeholders involved in direct use of and those involved in distal activities that could be impacting reefs, for example, in the case of land-based pollution(Fredston-Hermann et al, 2016) and logging(Hamilton et al, 2017).The type of management and conservation measures in place needs to take into account a combination of the changing environmental and human impacts as well as their potentially changing benefits.Marine protected areas or no-take marine reserves are the most common form of reef management, focusing predominantly on reducing local anthropogenic pressures(Agardy, di Sciara, & Christie, 2011;Mellin, Aaron MacNeil, Cheal, Emslie, & Julian Caley, 2016).…”

Place‐based management can reduce human impacts on coral reefs in a changing climate

“…, Fredston‐Hermann et al. ). Anthropogenic impacts depend on local conditions, including land‐use change, topography and bathymetry, geology, and habitat.…”