Translator: Omotola Awoyemi Reviewer: Denise RQ
(French) Thank you.
Connectivity, what does this word make you think about?
According to the Spanish language dictionary
connectivity is the capacity to connect or to make connections.
Surely, you are thinking of connectivity,
the social connectivity type just like taking a selfie,
or Twitter, and all that stuff on the social webs.
But I am not talking about that type of things.
I'm a biologist.
So, social connectivity is not my thing.
I will talk about population connectivity in fishes.
Population connectivity develops
due to migration and dispersal
of individuals of the same species
among multiple habitats.
For example, storks migrate very, very long distances
and are capable of connecting the north of Europe to Morocco.
Plants or animals that can't move as much,
with a much reduced mobility,
can use tricks like the wind or the sea currents
- in the case of marine animals, obviously -
that help them transport their seeds or eggs.
Connectivity, in fact, can be represented in this type of diagram.
It looks like a web where each point represents
the places where they are connected with each other
and the lines the migration routes,
these movements, this migration patterns the animals follow.
But, OK, what is connectivity really used for?
Connectivity is a phenomenon that helps preserve biodiversity,
and helps populations increase their resistance and resilience,
that is, their capacity to adapt in case of environmental change
- like for example, climatic change,
one of the most famous ones that impacts humans as well.
But there are many dangers, many factors
that can affect the good functioning of this connectivity.
And humans play an important role in this as well.
That is a very beautiful slide, as you can see,
several points that represent individuals
belonging to the same, well-connected population.
Let's add a divide, called population fragmentation
that is going to segregate this sole population
into two or more smaller populations.
The problem is that if the newly created population isn't big enough,
the integration flow of new genes, of new genetic information will be restricted.
And this type of situations
leads to endogamy or consanguinity.
It's exactly what happened in the past to the House of Habsburg,
who refused to mix outside their royal family
and sought to maintain the power through inbreeding,
with one of their last representatives, Charles II of Spain,
this poor man who, due to all subsequent consanguinity issues he had,
couldn't leave any offspring, that's it.
It seems like the new King of Spain has changed that.
In the case of terrestrial habitats, we can see that this type of fragmentation
can occur, for example, when a new route is built,
a route that divides two habitats, and the animals, or whatever there is there,
can't pass from one habitat to the other.
So one thing that we can do to improve, to restore this connectivity,
is to create, for example, ecoducts,
bridges where there are no walkways,
no bicycles, and above all no cars,
except land, plants, and trees
that link back these two divided spaces
and contribute towards a healthy connectivity.
Marine habitats face similar issues
that can hinder connectivity as well.
For example, environmental and marine pollution,
the presence of very large infrastructures,
and clearly, overfishing.
I am going to talk a little more about this topic
because I obviously know a little more about fishing than the rest of the issues.
For example, we have fishes that migrate,
- they can migrate on a small or a large scale -
and use a different way to connect themselves
called larval dispersal.
That is, just after the reproduction,
those fishes are small larvae.
This beautiful fish it's not more than a millimeter long,
and it's going to spend weeks or months,
free in the water column floating in the sea,
transported by marine currents,
until it finds a place where it feels at ease,
and where it will settle, grow, and reproduce,
thus contributing with new genetic information to its population
and increasing the quality of the population connectivity.
What does this tell us?
It tells us that in the end--
the latest studies in the field show that in fact,
these populations can stay connected - these population of fishes -
on a very, very large scale.
For example, on the scale of the whole Mediterranean region,
or even on a larger scale.
And what does that imply?
It implies that, for example,
if we are going to fish off the coast of Spain,
what we do, overfishing or not,
isn't going to not only impact the marine resources off the Spanish coast,
but the resources of the rest of the Mediterranean region as well.
And this is vital and must be taken into consideration.
Why is it so important?
Knowing the scale and the patterns of this connectivity will help us
to protect a little all such connections
and maybe implement nets of protected marine areas, for example,
to protect this connectivity that is so important.
And it's so important
because marine resources are very important for humans.
We are very dependent on that.
It's food for many people in the Mediterranean,
in the whole world.
So now, a very important thing that is to be taken into account,
is that it's high time we connect as well
we, scientists, politicians, with the greater public,
in order to talk and improve the information quality,
and to manage most adequate and efficiently
our common marine resources.
Thank you very much.
(Applause)