Monitoring during the project:

For the project, the current monitoring systems involve the use of a Remotely Operated Vehicle (ROV), followed by a specialized scientific analysis of the various videos and images. Additionally, another monitoring method includes the participation of multiple divers equipped with scientific gear, who use cameras for recording and capturing images, which are subsequently used for a comprehensive study of biodiversity. Combining both monitoring systems, scientifics are able to obtain physicochemical parameters as well as biomass, biodiversity, CO2 capture and other biological parameters. All of this allows us to determine if the restoration actions are being useful to recover the environment, since we are implementing them in a degraded area (Port of Estartit), as well as in a natural area (Cala Calella) of the MPA site, providing us with important data for comparing both of them.

Moreover, a first monitoring approach is essential in order to obtain the bathymetry of the site. Having the cartography of the area is crucial, since part of the project is to deploy an artificial reef on this area. Also, by obtaining the physicochemical parameters, we are able to determine where the restoration activities are going to take place, and moreover, the different  requirements of the preseeding species.

Also, there has been established a positive control site (still liable to authorisations and permits). There’s some options about where to put this control along the MPA: Cala Calella, Falaguer zone, Cala Formatge and the Morisca. At the moment, we are working on the authorisations for the first option.

Cala Calella:

Is a small rocky cove in the municipality of Torroella de Montgrí (Baix Empordà), located on the coast of the Massís del Montgrí, between the tip of the Salines and La Trona, within the Montgrí Natural Park, the Medes Islands and the Baix Ter. It is accessed by the circular path that joins the towns of l’Estartit and l’Escala, about 30 minutes on foot from the port of l’Estartit, in a northerly direction and 10 minutes by boat. At the bottom of the cove there is a small rocky beach. Near the cove there is the Pou de la Calella, a 55 meter deep chasm caused by the erosion of the limestone rocks that form the Massís. Cala Calella is then the perfect place to install our control positive regeneration devices, so that we can obtain data from a healthy environment and compare the effectiveness of the restoration actions between two completely different habitats. Moretheless, this positive control allows us to study the negative impact of degraded environments, specially in the species recruitment and colonization, by the monitoring of preseeding flagship species both in port and at the cala.

Threats and impact

Tourism
(recreational activities at sea):

The Medes Islands Marine Protected Area (MPA) attracts the highest number of dives among all Mediterranean MPAs and hosts a significant volume of visitors. It experiences the greatest absolute and relative number of dives compared to any other Marine Protected Area in the Mediterranean, resulting in considerable pressure from tourism. This influx of visitors significantly impacts the sessile communities, such as coralligenous, sea fan communities, caves, red coral, calcareous algae, bryozoans, through intentional or unintentional erosion. Additionally, the feeding habits of fish, often influenced by human interaction, undergo alterations due to the high level of tourism. The cumulative effect of frequent visitation, compounded by the anchoring of boats on delicate seabeds like coralligenous formations and Posidonia beds, along with recent incidents of fish and coral poaching, necessitates a thorough quantification of its impact (Ros, J., & Gili, J. M., 2016). In the maritime area of the Natural Park, various activities are conducted, such as scuba diving, snorkeling, water sports, including sailing, windsurfing, and kitesurfing.

Fishing: Due to its previous overfishing, in 1983 was created the Fishing Reserve on the Medes Islands MPA. Nowadays, fish communities such as groupers and sparids, can be found within this area. Additionally, artisanal fishing is permitted.

Pollution: The Medes Islands face threats including constant boat traffic, pollution, dumping of garbage, improper anchoring impacting Posidonia oceanica meadows despite the presence of an anchoring buoy system, and illegal poaching of red coral, Corallium rubrum. These activities, prohibited within the protected area, pose significant risks to its integrity, exacerbated by the area’s popularity (Ros, J., & Gili, J. M., 2016).

Negative effects

Some submarine areas of the Medes Islands are being overwhelmed by the direct and indirect effects of massive numbers of visitors. They have been literally trampled, and the most emblematic benthic communities and species (coralligenous, sea fan communities, caves, red coral, calcareous algae, bryozoans) show clear signs of degradation. For the most visited areas, it has been estimated that damage caused to the violescent sea-whip (P. clavata), a very slow growing cnidarian, by voluntary uprooting or by involuntary “trampling” could eliminate their populations in one or two decades. The permanent boat-traffic, dumped garbage, pollution, the anchoring effect on the prairie of P.  oceanica—a  system  of  anchoring  buoys  has  been  in  place  for  some  years, though it has been inadequately used—, the underwater poaching and illegal collecting of red coral, C. rubrum―although collecting this species is not legal inside the preserved area and, in any case, its size is clearly smaller than allowed elsewhere―are also threats to the integrity of this protected area that is suffering the effects of its fame