1.9.1 Agricultural pollution

Unknown effectiveness (limited evidence)

Create walls or barriers to exclude pollutants

1One controlled study in Mexico found that installing filters across canals to improve water quality and exclude fish increased weight gain in axolotls. Assessment: unknown effectiveness — limited evidence (effectiveness 35 %; certainty 29 %; harms 0 %).

2http://www.conservationevidence.com/actions/771

Plant riparian buffer strips

3One replicated, controlled study in the USA found that planting buffer strips along streams did not increase amphibian abundance or numbers of species. Assessment: unknown effectiveness — limited evidence (effectiveness 0 %; certainty 30 %; harms 0 %).

4http://www.conservationevidence.com/actions/819

Reduce pesticide, herbicide or fertilizer use

5One study in Taiwan found that halting pesticide use, along with habitat management, increased a population of frogs. Assessment: unknown effectiveness — limited evidence (effectiveness 71 %; certainty 26 %; harms 0 %).

6http://www.conservationevidence.com/actions/832

No evidence found (no assessment)

7We have captured no evidence for the following intervention:

• Prevent pollution from agricultural lands or sewage treatment facilities entering watercourses

1.9.2 Industrial pollution

Trade-off between benefit and harms

Add limestone to water bodies to reduce acidification

8Five before-and-after studies, including one controlled, replicated study, in the Netherlands and UK found that adding limestone to ponds resulted in establishment of one of three translocated amphibian populations, a temporary increase in breeding and metamorphosis by natterjack toads and increased egg and larval survival of frogs. One replicated, site comparison study in the UK found that habitat management that included adding limestone to ponds increased natterjack toad populations. However, two before-and-after studies, including one controlled study, in the UK found that adding limestone to ponds resulted in increased numbers of abnormal eggs, high tadpole mortality and pond abandonment. Assessment: trade-offs between benefits and harms (effectiveness 47 %; certainty 50 %; harms 50 %).

9http://www.conservationevidence.com/actions/748

No evidence found (no assessment)

10We have captured no evidence for the following intervention:

• Augment ponds with ground water to reduce acidification.