Research Information System
Biological Invasions, vol.23, no.5, pp.1-16, 2021 (SCI-Expanded)
Invasive non-native crustaceans are a
biodiversity and management concern in the Mediterranean
Sea. The Atlantic blue crab (Callinectes
sapidus) was first recorded in the Mediterranean Sea
in 1949, but may have arrived as early as in the 1930’s.
Blue crabs in the Mediterranean Sea are of concern
due to their presumed potential for negative consumptive
and competitive interactions with native fauna.
The aim of this study was to provide a first
assessment of the trophic ecology of non-native blue
crab in the Northern Aegean Sea using stable carbon
(d13C) and nitrogen isotope (d15N) analysis. We found
limited isotopic niche overlap between blue crabs and
seven native species examined at Go¨kc¸eada Island in
April, June, and August of 2017. In addition, the range
of calculated trophic positions of blue crabs at
Go¨kc¸eada Island (2.0 to 4.4), while broad, is in
general agreement with prior studies in both native and
non-native ranges. We also observe that trophic
position declined and the relative importance of
pelagic carbon sources to blue crabs increased from
April to August. However, we also found that differing
assumptions as to the number and type of food web
baselines and trophic discrimination factors led to
differing estimates of trophic position in blue crabs at
Go¨kc¸eada Island by as much as one to two trophic
levels. These methodical differences make it challenging
to directly compare results within and between
studies, and thus limit our ability to assess negative
consumptive and competitive interactions of invasive
blue crab with native coastal species in the Mediterranean
Sea