Which of the following is not a recognized technique for salt marsh water management?

Lavaiciding is not a recognized technique for salt marsh water management. In the context of mosquito control and wetland management, techniques are generally designed to manipulate water levels, improve habitat for natural predators, or facilitate drainage and irrigation.

Other options listed are accepted practices. Drainage system installation helps manage water levels to reduce mosquito breeding sites by efficiently removing excess water. Ditching serves a similar purpose, allowing for more controlled water flow and also helping with aeration of the marsh environment. Cattail removal can be part of an integrated management strategy, as cattails can provide habitat for mosquitoes and other insect species, so their management can help in controlling such populations.

The reason why lavaiciding is not appropriate in this context is that it typically refers to the application of sunken volcanic ash or lava material, which does not directly relate to water management strategies in salt marshes. This makes it an unsuitable choice in the context of recognized techniques for managing water in such ecosystems.