ELHS does not support the connectivity hypothesis between either side of the
Sicilian Channel, even though as much as 20% exchange rate of particles between
both coastlines is possible (Patti et al. 2018).
Permanent hydrographic patterns create conditions that pelagic fish species
recognize and, in doing so, adopt a homing behavior for reproduction and ontogenic
development. Brochier et al. (2009) analyzed the environmental cues for sardine and
anchovy on the basis of retention or dispersion constraints that may determine a
homing behavior in small pelagic stocks of major eastern boundary current, such as
the Canary and Humbold upwelling systems. They concluded that rather than natal
homing, the reproduction is tuned with an environmental homing as it can be specific
temperature or salinity gradients. This is the case of the Atlantic tuna, which migrates
to diverse spawning grounds in the Mediterranean (among which the Balearic Sea is
foremost, Reglero et al. 2013) looking for specific conditions that are provided by
intermediate waters resulting from the mixing of newly inflowing surface and older
resident Atlantic water (Alemany et al. 2010; Balbin et al. 2013). In the Alboran Sea,
blackspot seabream (Pagellus bogaraveo) is likely an example illustrating these
processes. Blackspotted seabream reproductive stock is fished by Spanish and
Moroccan artisanal fleets in the Strait of Gibraltar (Gil 2012; Burgos et al. 2013).
The recapture of juvenile tagged outside this region indicates migration of juveniles
toward the Strait of Gibraltar, the main concentration site of adult specimens in the
region (Gil 2012), and suggests environmental homing behavior.
ELHS are at the mercy of hydrodynamics which has consequences on their
survival or mortality depending on the course of advection, the duration of egg
and larval drift, and the availability of feeding resources while flowing. Hydrography
may be a connective driver of different sub-populations geographically distant
forming part of a determined population resource by enhancing the exchange
among individuals, thereby, influencing population dynamics and the genetic structuring of populations.
12.5.2 Pelagic Larval Duration and Dispersal
The most abundant and appreciated fish species from both sides of the Strait of
Gibraltar belong to the sardine and anchovy species’ complexes. They have welldefined spawning and nursery grounds on both sides of the Strait (Baldo et al. 2006).
The importance of the AJ is paramount to understand the manner in which it
influences the biological traits of species. Its fluctuations of intensity and direction
have a consequence on the recruitment of Alboran Sea anchovy via the modulation
of larval advection from spawning and nursery grounds (Ruiz et al. 2013; Catalan
et al. 2013). Drifting can import ELHS from remote spawning grounds into other
regions whereby new imports can be fundamental to the maintenance of stock. Such
is the case of the sardine spawning grounds off the Gulf of Manfredonia in the
Adriatic Sea which receives imported ELHS that contribute substantially to the
maintenance of the stock (Sciascia et al. 2018).
474
J. Garcia-Lafuente et al.
Sicilian Channel, even though as much as 20% exchange rate of particles between
both coastlines is possible (Patti et al. 2018).
Permanent hydrographic patterns create conditions that pelagic fish species
recognize and, in doing so, adopt a homing behavior for reproduction and ontogenic
development. Brochier et al. (2009) analyzed the environmental cues for sardine and
anchovy on the basis of retention or dispersion constraints that may determine a
homing behavior in small pelagic stocks of major eastern boundary current, such as
the Canary and Humbold upwelling systems. They concluded that rather than natal
homing, the reproduction is tuned with an environmental homing as it can be specific
temperature or salinity gradients. This is the case of the Atlantic tuna, which migrates
to diverse spawning grounds in the Mediterranean (among which the Balearic Sea is
foremost, Reglero et al. 2013) looking for specific conditions that are provided by
intermediate waters resulting from the mixing of newly inflowing surface and older
resident Atlantic water (Alemany et al. 2010; Balbin et al. 2013). In the Alboran Sea,
blackspot seabream (Pagellus bogaraveo) is likely an example illustrating these
processes. Blackspotted seabream reproductive stock is fished by Spanish and
Moroccan artisanal fleets in the Strait of Gibraltar (Gil 2012; Burgos et al. 2013).
The recapture of juvenile tagged outside this region indicates migration of juveniles
toward the Strait of Gibraltar, the main concentration site of adult specimens in the
region (Gil 2012), and suggests environmental homing behavior.
ELHS are at the mercy of hydrodynamics which has consequences on their
survival or mortality depending on the course of advection, the duration of egg
and larval drift, and the availability of feeding resources while flowing. Hydrography
may be a connective driver of different sub-populations geographically distant
forming part of a determined population resource by enhancing the exchange
among individuals, thereby, influencing population dynamics and the genetic structuring of populations.
12.5.2 Pelagic Larval Duration and Dispersal
The most abundant and appreciated fish species from both sides of the Strait of
Gibraltar belong to the sardine and anchovy species’ complexes. They have welldefined spawning and nursery grounds on both sides of the Strait (Baldo et al. 2006).
The importance of the AJ is paramount to understand the manner in which it
influences the biological traits of species. Its fluctuations of intensity and direction
have a consequence on the recruitment of Alboran Sea anchovy via the modulation
of larval advection from spawning and nursery grounds (Ruiz et al. 2013; Catalan
et al. 2013). Drifting can import ELHS from remote spawning grounds into other
regions whereby new imports can be fundamental to the maintenance of stock. Such
is the case of the sardine spawning grounds off the Gulf of Manfredonia in the
Adriatic Sea which receives imported ELHS that contribute substantially to the
maintenance of the stock (Sciascia et al. 2018).
474
J. Garcia-Lafuente et al.