Urban Wetlands and Mental Health?

The Wildfowl and Wetlands Trust (WWT) suggest that, creating more wetlands, would improve the mental health of the poorest in UK cities. The wetlands needn't even be large. They could be created around ponds and streams (https://www.theguardian.com/environment/2022/jul/06/urban-wetlands-could-improve-wellbeing-deprived-uk-areas-report). I like wetlands, which are currently the most rapidly disappearing environments. New wetlands might reduce flooding risk in some locations. They will also attract some species of mammals, birds, amphibia and fish. Wetlands also encourage flowers and some showy insects, like dragonflies. It is now claimed that, giving urban folk the opportunity to walk in such areas on a weekly basis, could improve mental health and reduce costs to the NHS. There are, however, a few issues we need to consider. People tend to 'release' alien aquarium plants and out-of-favour, pet terrapins into urban wetlands. Established wetlands (like bogs) are carbon sinks, reducing the release of the 'greenhouse gas', carbon dioxide. Some pools of stagnant water, however, can release methane (a rather more potent 'greenhouse gas'). Some wetlands might also serve as locations, where mosquito larvae can grow and develop. Combining wetland creation with global heating, might consequently reintroduce malaria, into parts of Britain. I (like the WWT) actually favour the creation of more small urban wetlands. The potential pros and cons of particular developments should, however, be carefully considered. We also need established networks of folk to care for locations and to monitor what is going on!