4.3.3. Management and Policy

Ecosystem function and services of artificial waterbodies likely depends on the managemen<sup>t</sup> they receive after construction as well, just as managemen<sup>t</sup> matters in natural waterbodies. In reservoirs, the ability of an artificial aquatic system to provide ecosystem services may depend more heavily on ongoing policy and managemen<sup>t</sup> than on the specifics of the initial design [135,136]. In ditches, managemen<sup>t</sup> strategies, including dredging, mowing, chemical weeding, burning, and regulation of water depth, can have significant impacts on ditch biodiversity and water quality [137,138]. However, ongoing managemen<sup>t</sup> and maintenance, like initial design, often does not include these

potential outcomes in its considerations, instead opting to continue to focus on relatively few, highly human-oriented goals [126]. Such decisions about ongoing managemen<sup>t</sup> and policy, however, can, at least, in theory, be revised to reflect changing goals.

In complex landscapes, achieving a portfolio of ecosystem services often requires both structural changes and ongoing active managemen<sup>t</sup> of artificial aquatic systems. Ditches and canals draining ranchlands in the watershed of Lake Okeechobee were not traditionally managed for water quality or conservation purposes, even though they house large native animals and other species of interest [139]. Establishment of Total Maximum Daily Loads for phosphorus in the lake and its tributaries [140,141] prompted creative responses including regional collaborations among various governmen<sup>t</sup> agencies, nonprofit conservation organizations, a local scientific research station, and ranchers to raise and actively manage water levels to flood ditched wetlands. This strategy removed phosphorous more cost-effectively than did constructed storm water treatment areas [142], while also increasing wetland vegetated area and vertebrate abundance [143]. Multi-stakeholder managemen<sup>t</sup> of artificial aquatic systems with ecologically oriented goals could prove a cost-effective way to increase ecosystem services at a similarly regional scale in other locations, perhaps as a complementary tool to traditional restoration.

Accidental waters, which often receive little to no managemen<sup>t</sup> attention, can provide comparable but non-overlapping ecosystem services to both deliberate and more natural waterbodies. Abandoned features, especially within broader abandoned landscapes and even in the hearts of cities, can provide habitat for urban-avoiders and other organisms that survive best away from humans and human intervention [26]. Abandoned areas can contain accidental artificial waterbodies sustaining both human and nonhuman life, and functioning as little pockets of biodiversity [27]. Accidental urban wetlands can also mitigate nutrient pollution flowing from cities to downstream in natural waterbodies [27]. Two European species of damselfly were believed extinct for decades, until rediscovered, separately, in former industrial and mining areas "not usually explored by biologists". Other neglected artificial habitats in our midst could hold similar surprises. Notably, conservation interventions "focused on returning habitats to a 'natural' state" intended to boost one of those damselfly populations actually backfired [144]. These observations sugges<sup>t</sup> that active intervention, for non-ecological and even ecological goals, can limit the ecological value of artificial aquatic systems.
