Puerto Vallarta, Mexico - It's a big year for water! The theme of this year's World Biodiversity Day, celebrated annually on May 22, is ‘water and biodiversity,' which has been chosen to coincide with the designation of 2013 as the International Year of Water Co-operation.

Water is required to support biodiversity. Without sufficient water, stresses on species increase global biodiversity losses. In turn, biodiversity is critical to the maintenance of both the quality and quantity of water supplies and plays a vital but often under-acknowledged role in the water cycle.

The water cycle is influenced heavily by ecosystems and the life associated with them. Forests, grasslands, soils, wetlands all influence water. Vegetated land cover regulates water movement across land and water infiltration into soils. Wetlands in particular have particularly visible hydrological functions such as the ability to store water, thereby helping us to regulate floods.

World Biodiversity Day provides a key opportunity for the community to raise the profile of freshwater biodiversity and highlight both the importance of it and the threats it faces.

In this spirit, and to commemorate the day, Puerto Vallarta's protected ecological area, the El Salado Estuary, will host a photo exhibition featuring images taken by the participants of the "Banderas Bay and its Natural Resources" photo contest, as well as pictures taken by those who participated in Petr Myska's nature photography course held earlier this month.

Frank McCann's photographs of the inhabitants of Estero El Salado will also be on display, along with a collection of arthropod photos taken by Dr. Fabio Cupul of the Centro Universitario de la Costa.

The exhibition and photo contest awards ceremony, scheduled to take place at gate number 4 of the Estero El Salado from 10 am to 4 pm, is free and open to the public.