Study

Reversing introduced species effects: experimental removal of introduced fish leads to rapid recovery of a declining frog

  • Published source details Vredenburg V.T. (2004) Reversing introduced species effects: experimental removal of introduced fish leads to rapid recovery of a declining frog. Proceedings of the National Academy of Sciences of the USA, 101, 7646-7650.

Actions

This study is summarised as evidence for the following.

Action Category

Remove or control fish by catching

Action Link
Amphibian Conservation
  1. Remove or control fish by catching

    A replicated, controlled, before-and-after study in 1996–2005 of 21 lakes in California, USA (Vredenburg 2004) found that mountain yellow-legged frogs Rana muscosa increased following fish removal. One year after removal, numbers had increased for frogs (0.1 to 1.0/10 m) and tadpoles (0.1 to 8.1). Following removal, numbers were significantly greater than in lakes with fish (frogs: 0.1; tadpoles: 0.1/10 m). Within three years there was no significant difference between numbers within removal lakes and fishless control lakes (frogs: 7 vs 5; tadpoles: 10 vs 30/10 m). Trout Oncorhynchus mykiss, Salvelinus fontinalis were eliminated from three, and greatly reduced in two, removal lakes. Fish were removed by gill-netting starting in 1997–2001. Frog visual encounter surveys along shorelines and snorkelling surveys were undertaken in trout removal lakes (n = 5), fish-containing lakes (n = 8) and fishless lakes (n = 8) each two weeks in 1997–2001 and 2–3 times in 2002–2003.

     

Output references
What Works 2021 cover

What Works in Conservation

What Works in Conservation provides expert assessments of the effectiveness of actions, based on summarised evidence, in synopses. Subjects covered so far include amphibians, birds, mammals, forests, peatland and control of freshwater invasive species. More are in progress.

More about What Works in Conservation

Download free PDF or purchase
The Conservation Evidence Journal

The Conservation Evidence Journal

An online, free to publish in, open-access journal publishing results from research and projects that test the effectiveness of conservation actions.

Read the latest volume: Volume 18

Go to the CE Journal

Discover more on our blog

Our blog contains the latest news and updates from the Conservation Evidence team, the Conservation Evidence Journal, and our global partners in evidence-based conservation.


Who uses Conservation Evidence?

Meet some of the evidence champions

Endangered Landscape Programme Red List Champion - Arc Kent Wildlife Trust The Rufford Foundation Save the Frogs - Ghana Bern wood Supporting Conservation Leaders National Biodiversity Network Sustainability Dashboard Frog Life The international journey of Conservation - Oryx British trust for ornithology Cool Farm Alliance UNEP AWFA Butterfly Conservation People trust for endangered species Vincet Wildlife Trust