Mapping of marine habitats of the island of Molat


Employees and associates of the Association Sunce at the invitation of the WWF Adria Association, and with the logistical support of the diving center Draulik Milna, in the period from 28.5.-3.6.2021. conducted field research as part of the service “Preparation of the Scientific and Technical Baseline for the Establishment of the FRA / NTZ in the Molat Island Aquatorium” which includes research and mapping of marine habitats for the area of ​​the island of Molat in order to preserve angel shark.

The conducted mapping is a necessary precondition for future monitoring of the condition and adoption of measures for the management of habitat types and species (such as seagrass Posidonia oceanica) as well as the protection of endangered species (such as angel shark Squatina squatina).

Slika 1. Posidonia meadows

Two species of angel sharks were recorded in the Adriatic Sea, the angel shark or monkfish (S. squatina) and smoothback angel shark (S. oculata), a less common species. Angel sharks were once hunted with a specialized bottom trawls, in croatian language called „sklatare“, and were important target species throughout the Adriatic. However, after the 1960s, their catch dropped drastically.

On the east coast of the Adriatic Sea, the area around the island of Molat has been identified as a potential hotspot for S. squatina, based on catches of this species in recent years.

Slika 2. Diver pulling a buoy along the meadow border

Habitat and species mapping was conducted according to the protocols that the Association Sunce has been applying in field research for years. Divers dive in pairs, along the line transect, maintaining a diving buoy directly above them, to which a waterproof tank is attached, in which the GPS device is located.
During the dive, they record data on the type of habitat, its condition, the presence of invasive and endangered species. Since the goal was to make a map of as large area as possible, underwater scooters were also used in the research.

Data on the distribution of the upper edge of marine habitats were collected using a drone. During this habitat mapping, special attention was paid to sandy areas within meadows with the aim of finding the angel shark. Also, due to the activity of this species, shallow sandy bays were explored during the night.

Although we were unable to find and record this endangered and mysterious species, we recorded several species of cartilaginous fish species and mosaic habitats suitable for their reproduction and development. This research will be the baseline for the establishment of measures to preserve the angel sharks and the present areas of the ecological network important for the preservation of posidonia meadows, reefs and sea caves.

Slika 3. Diver using a undewater scooter