Page 32 - Bioconstructions_2018

92 Gianmarco Ingrosso et al.

in the intertidal; it can therefore be presumed that populations separated
by stretches of sea or sandy shore extending for tens of kilometres have very
limited genetic connectivity. Data from subtidal Corallinales are presently
not available.
The role of both physical (hydrodynamics, currents, waves, tide, winds)
and biological factors (PLD, larval growth and lifespan, larval behaviour,
spawning time) is crucial to explain connectivity among Sabellaria bio-
constructions in the intertidal zone, where they occur as irregular patchy
banks. Larval dispersal and potential connectivity have been modelled for
Sabellaria reefs in the English Channel, which are the largest known reefs
in Europe, and this work has revealed the crucial role played by hydrody-
namic and meteorological conditions on larval dispersion along coastal areas
(Ayata et al., 2009). To face deficiency of information about potential and
realized connectivity among Sabellaria populations in the Italian seas, the
reefs occurring along the Tyrrhenian coasts (Latium) are presently being
studied in terms of genetic connectivity and using a biophysical modelling
approach which simulates larval dispersal under hydrodynamic and meteo-
rological factors at very local spatial scales (Bonifazi, 2018).
Deep-sea connectivity among species and habitats is still poorly known
(Hila ´rio et al., 2015). The LIW and the cascading of Northern Adriatic
waters into the Ionian Sea are the main conveyor belts sustaining active
CWC growth in the Mediterranean Sea. These water masses can be possible
vectors for larval dispersal, connecting the different coral sites and provinces
of the basin (Chimienti et al., 2018b). Genetic connectivity among the dif-
ferent sites in the Mediterranean Sea and with the Atlantic Ocean has yet to
be comprehensively studied.
Connectivity among biostalactites in different caves is unknown. These
structures have been only recently described in detail and the currently avail-
able information from different geographic sites most probably does not
refer to the same engineer species. Further, the Protula species responsible
for the Otranto biostalactites is new to science (Causio et al., 2015) and is
still poorly known. No other populations of this species are known at the
present, but even the connections among close caves in the same area
(the Cape of Otranto) are unstudied and information on the production
and dispersal of larvae or propagules of any type is lacking.

3.2.2 Connectivity Models
Since wide-scale spatial and temporal sampling with a high degree of reso-
lution is often impossible, researchers tend to turn to models in order to