Sighting data of Mustelus mustelus in the Canary Islands

These data were generated to investigate the distribution and population
structure of Mustelus mustelus across the Canarian archipelago. This shark
is widely found in the eastern Atlantic Ocean and catalogued as
'Vulnerable'  by the IUCN European assessment. Data on
the distribution and population structure of this species across the
islands of the Canarian archipelago, located along an east to west
gradient in the north-eastern Atlantic, were collected by taking advantage
of 'Local Ecological Knowledge', in terms of sightings in
coastal waters. This source of qualitalitve and quantitative data
(sightings) demonstrated that adults of M. mustelus has a significantly
larger presence in the eastern and central, than in the western of the
archipelago. Adult smooth-hound sharks were significantly more observed in
sandy and sandy-rocky bottoms, with idividuals seen throughout the entire
year, whereas juveniles aggregate on very shallow waters in spring and
summer. Such aggregations requiere a special management strategy, as they
pley a key role in critical life stages; these sites should be protected
from human perturbations. We also suggest a temporal fishing ban between
April and October, when individuals tend to concentrate on earshore
waters. Because of the large differences in presence of this shark among
the Canarian Islands, management of the species should be adapted to th
specific peculiarities of each island, rather than adopting a management
policy at the entire archipelago-scale. Overall, this study sets the basis
for further investigation to promote conservation of this vulnerable shark
in the study region.