UCC ecology students study conservation issues in the Ria Formosa National Park, Algarve, Portugal.

Field work is the cornerstone of all our degree programmes in the School of Biological, Earth and Environmental Sciences (BEES) in University College Cork (Ireland). Every April for the last 17 years we have taken our third year ecology, zoology and plant science students to the Algarve in Portugal to experience the local habitats and ecosystems and to learn the various survey techniques that help us to understand them. The field course lasts seven days and includes work in terrestrial and aquatic sites from the coast to the Monchique Mountains. One of the highlights of the trip is the annual survey of the local fiddler crab (Uca tangeri) population in the Ria Formosa National Park. These amazing invertebrates inhabit many of the sheltered intertidal muddy foreshores in this region and they play an important part in maintaining the structure and function of these tidal areas. Unfortunately their continued existence in this unique environment is threatened by the rapid regional development that has taken place here over the last thirty years. Tourism has resulted in a chain of holiday related construction from Faro to Lagos and this has impacted on other coastal activities. One of the knock on effect of large numbers of tourists is an increase in demand for local seafood, especially small benthic clams that feature in dishes such as "cataplana" . These are supplied locally by a combination of licensed shellfish farming on intertidal plots and unlicensed, opportunistic clam diggers who take part in so called recreational fishing. Both activities will cause local disturbance and anecdotal evidence, accumulated over the years by our students' studies, would suggest that the relentless digging and trampling that accompanies the fishing and farming activities is taking its toll on the shy and sensitive fiddler crab. In addition to the impact caused by clam harvesting, the crabs themselves are exploited by fishermen who catch the males and remove their large white signal claw to sell as a local delicacy. It is difficult to estimate the scale of this now illegal activity, but our studies have demonstrated a significant imbalance in the sex ratio for the last ten years or so. The extent of the anthropogenic impact on the Algarvian fiddler crabs is not known but an extensive survey is urgently needed so that we can ascertain the current status of this keystone species.