Our names are Irene and Lea. We are both fascinated by the ocean‘s complexity and therefore joined the Archipelagos Institute of Marine Conservation to get an insight into marine biology and conservation. Irene is completing a BSc. in Biology at the University of Sevilla and I (Lea) graduated from the University of Hamburg aftering completing my BSc. in Geophysics and Oceanography.

The Aegean Sea is a biodiversity hotspot. Its richness and biodiversity is constantly pressured by human impact such as tourism, introduction of invasive species and climate change. Understanding how these ecosystems are functioning now and how they respond to pressures over time is important, as it might allow us to identify future challenges which can result from changes in biodiversity. The health of an ecosystem can be indicated by abundance and presence of macroinvertebrate species as some of the species are quite sensitive to changes in water quality, for example. For this reason we are monitoring macroinvertebrates on different sites around Lipsi Island, Greece.

Macroinvertebrates include sessile and mobile species. To obtain comprehensive data, we record both sessile and mobile species during the day and mobile species at night as some macroinvertebrates are nocturnal. Before we go on a survey we prepare the necessary equipment. This includes packing snorkel gear and other items which are helpful to conduct the survey such as transect ropes and dive slates. We want to make sure that everything can be used easily once we are at the site and that the ropes do not tangle in the water. Furthermore we charge electronic devices such as an underwater camera and torches, it is important for this sort of work that weather conditions are appropriate. Since we conduct two surveys, one during daylight and one at night respectively, we require good weather conditions for at least 12 hours. Under suitable conditions we go to one of our sites around midday and set up the 50 m transect line to conduct our survey.

We then swim along the transect and identify and count the macroinvertebrate species 1 m to the right and left of the transect line. Should there be individuals that we cannot identify immediately, we record the species using the underwater camera to identify later on. After completing the survey we gather our gear and rinse it to prevent seawater causing any damage. We repeat the survey at the same site after sunset focusing on mobile species. Between surveys we process the data we gathered. We add the new information to an excel file and review the videos we took, adding the information to the file of recorded macroinvertebrates.

The project will be continued by other interns to allow for a comparison between winter and summer.