Lantra hired the agency after a competitive pitch involving Mistral, IAS Smarts and HROC.
Trimedia senior consultant Stuart Humphreys said: 'It is seen as a fairly low-paid, low-skilled area of the workforce, but there are a number of interesting jobs, such as environmental technicians.'
The agency will promote a UK roadshow in spring.
Lantra is partly publicly funded. There are 230,000 businesses and one million workers in the environment and land-based sector.