Assessment Rationale:

Macarorchestia martini is a cave-adapted species from a single island, Terceira (Azores, Portugal). It has a very small Extent of Occurrence (EOO = 4 km²) and Area of Occupancy (AOO = 4 km²). The species is rare and only known from a single subpopulation in the coastal lava tube of Gruta das Agulhas. The area surrounding the cave is heavily impacted by human activities. Further research is needed into its population, ecology and life history; and a habitat management plan is needed and one is anticipated to be developed during the coming years. We also suggest the regular monitoring of the species (every ten years), and restricting access to the cave. The species is assessed as Critically Endangered (CR) based on the single location and current and future possible cave degradation. 

Geographic Range:

Macarorchestia martini is an endemic, cave-adapted species known from a single island, Terceira (Azores, Portugal) (Borges et al. 2010), and occurring in a single cave, the coastal lava tube of Gruta das Agulhas. The Extent of Occurrence (EOO) is 4 km² and the estimated Area of Occupancy (AOO) is 4 km².

Population:

The species is rare and only known from a single subpopulation on Terceira island. The area surrounding the cave is heavily impacted by human disturbance.

Current Population Trend: Decreasing 

Habitat and Ecology

) There is limited information regarding this species' ecology and life-history. Gruta das Agulhas is a 250 m long lava tube on the seashore, opening some 5 m above sea level. The above-ground area is disturbed by urbanisation and agricultural fields. Specimens of this species were found at some distance from the entrance but where dim light was still available, in high humidity but without permanent water. This species has reduced eyes, but few other adaptations to cave life (Stock 1989). It is mentioned as trogloxene, or even a driftwood specialist in Wildish (2014).

Systems: Terrestrial

Major Threat(s):

The main current threats to this species are the loss of habitat quality due to the impact of agricultural and domestic pollution and recreational cave visitation. However, there are several future potential threats: climatic changes (see Ferreira et al. 2016) are expected to cause habitat changes in lower elevations in Azores, that can change the conditions inside the cave; changes in the road infrastructure around the cave; and expanding urban development in the coastal area. The current increase in tourism in Azores is promoting the increase in cave visitation and uncontrolled recreational activities, with expected disturbance caused by cave visitation. 

Conservation Actions

The species is protected by regional law (RAA 2012), however, the cave where it occurs is not protected. Land-use changes are one of the main current and future threats, and conservation measures should be extended beyond the cave. Further research is needed into its population, ecology and life history; and a monitoring plan for the invertebrate community is necessary in order to contribute to the conservation of this species. This should include additional surveys to confirm the troglobiont status of this species (see e.g. Wildish 2014). Future conservation work should include the consideration of the restriction of visits to the cave. A habitat management plan is needed and one is anticipated to be developed during the coming years.