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MPA CASE STUDY 5

Shifting spatial distribution
of marine species

Throughout the Mediterranean Sea, species are moving in response to climate change. Subtropical spe-
cies normally occur mostly in the south-eastern region, where water temperature is higher than average,
while cold-adapted species generally occupy the northern regions. Higher temperatures are shifting the
geographical distributions of many species, often moving them further north or to greater depths.

In areas such as the Gulf of Lion and the northern Adriatic Sea, the coldest areas of the Mediterranean
coast, these shifts might make species more vulnerable to climate variations. Some species might not be
able to adapt to changing conditions and could experience population declines as a result. The combina-
tion of these potential effects with the arrival of invasive species, changes in natural communities or the
potential loss of particularly endangered or endemic species poses new challenges for MPA managers.

For example, in Miramare MPA (Adriatic Sea, Italy), long-term monitoring data have revealed substantial
regressions in the area covered by the Adriatic endemic brown alga Fucus virsoides and the appearance
of other species such as the seagrass Cymodocea nodosa and the brown algae Cystoseira spp. New
warm-water fish species such as the Mediterranean rainbow wrasse Coris julis, barracudas Sphyraena
spp., and the dusky spinefoot Siganus luridus have also recently been observed for the first time in the
area (Piron et al., 2007; Poloniato et al., 2010).
In order to reveal the changes and range shifts in marine species, many Mediterranean MPAs have joined
the broad-scale survey at Mediterranean level conducted by CIESM scientists and other collaborators
under the CIESM Tropical Signals Programme. The monitoring results are expected to improve our un-
derstanding of how the changing distribution of species will affect the balance of native communities and
what new opportunities might be created.

Main routes of species range expansion [Mediterranean natives (orange), Atlantic migrants (green), and
Red Sea migrants (red)] and MPAs participating in the Tropical Signals Programme.

N km 11
0 200 400 7
8
9
6 3
4 13
2
10

14
12
5
11
Italy: Monaco:
1. Miramare 8. Spélugues Tunisia:
2. Torre Guaceto France: 12. Zembra
3. Punta Campanella 9. Port Cros et Zembretta
4. Regno di Nettuno-Ischia Spain: Turkey:
5. Isole Pelagie 10. Tabarca 13. Gökçeada
6. Asinara Island Cyprus: Malta:
7. Porto no 11. Cavo Greco 14. Dwejra

38 COLLECTION