Assessment Rationale:

Trechus jorgensis is an endemic cave adapted species from a single island, S. Jorge (Azores, Portugal). It has a very small extent of occurrence (EOO = 4 km²) and  reduced area of occupancy (AOO = 4 km²). The species is very rare and only known from a single subpopulation in the the volcanic pit of Algar das Bocas do Fogo. The area surrounding the cave is heavily impacted by human activities and used as a damp area. We suggest as future measures of conservation the regular monitoring of the species (every ten years) and the creation of a fence surrounding the top of the pit. The species is assessed as Critically Endangered (CR).

Geographic Range:

Trechus jorgensis is an endemic cave adapted species known from a single island, S. Jorge (Azores, Portugal) (Borges et al. 2010), and occurring in a single cave, the volcanic pit of Algar das Bocas do Fogo (Pereira et al. 2016). The extent of occurrence (EOO) is 4 km² and the maximum estimated area of occupancy (AOO) is 4 km².

Population:

The species is very rare and only known from a single population. The area surrounding the cave is heavily impacted by human activities and used as a damp area.

Habitat and Ecology

This species occurs in a 50 m deep volcanic pit (Algar das Bocas do Fogo, S. Jorge island), whose internal vault is in penumbra (not complete darkness). The surrounding area consists of exotic plantations of Pittosporum undulatum (Oromi and Borges 1991; Borges et al. 2004; Amorim 2005). It is a cavernicolous (i.e. a troglobitic species) predator and/or saprophagous species.

Major Threat(s):

The main current threats to this species are the loss of habitat quality, as the volcanic pit has been used as a dump site, as well as the destruction of the surrounding habitat with invasive plants. However, there are several future potential threats: climatic changes (see Ferreira et al. 2016) that can change the conditions inside the volcanic pit; change in the road infraestructure around the cave; potential human recreational activities with radical cave visitation; reforestation of the area with exotic trees with unknown impact and geological events (volcanic activity and earthquakes).

Conservation Actions

The species is protected by regional law (RAA 2012), however the cave where it occurs is not protected. Further research is needed into its ecology and life history in order to find extant specimens. It is necessary a monitoring plan for the invertebrate community in the habitat in order to contribute to the conservation of this species. We suggest as future measure of conservation the creation of a fence surrounding the top of the pit. A habitat management plan is needed and anticipated to be developed during the coming years.