Intervencion C1-MH- 012

The Mediterranean monk seal colony of Cabo Blanco could be considered, at last, “closed”

Since 20 years ago, Cabo Blanco seals have been monitored continuous and intensely. Throughout this time, the knowledge we have of the colony is higher than of any other Mediterranean monk seal population.

We think that for the first time we are looking at a population of this species that can be considered “closed” from a demographic and geographic perspective, understanding the meaning of this term in a wide sense and not strictly technique.

Let’s get deeper into this statement

From the technical and demographic point of view, it is correct to say that this population is closed, because it seems clear that there are no migratory movements from or to other populations of this species. Therefore, only the births inside the breeding caves and the deaths at any moment of their vital cycle are the ins and outs of individuals of the population.

On the other hand, we can consider this population closed, related to how well monitored it is. This is so, because we are able to identify almost all seals of the colony and the main demographic parameters of the population are being studied on high level of accuracy and reliability.

From a geographic perspective something similar happens.

For the first time, the maximum area with presence and activity of seals is known. The breeding caves localized and monitored, and analyzed the rest of the caves of the nearby littoral. In short, we know where do seals go and their movement patterns.

All said it is delimited to an area of around 80 km north and south of the breeding caves and 25 nautical miles inside. Unfortunately, it is a very small area, surrounded by a huge empty space of seals! In fact, further from those limits, we found nothing on the coast prospected. It seems obvious that there are no more seals until getting to Madeira archipelago or to the Mediterranean populations.

Consider the Mediterranean monk seal colony of Cabo Blanco as a closed population has very important implications. On one side, it eases the monitoring of the conservation status of the colony throughout time and helps to understand better the data. On the other, it allows to focus on the measures and conservation efforts on a very delimited and known geographical area.

Now more than ever we have the knowledge and the technical tools to improve the situation of the species!

But now more than ever, we are aware as well of the fragility of the Cabo Blanco population and the small of the area they occupy.