biological advantages for the reproduction strategy of small pelagic species and
other coastal dwelling species.
13.3 Phytoplankton and Zooplankton Variability
of the Alboran Sea Coast
The coastal hydrodynamics in the Alboran Sea which affects the formation of
advection and upwelling processes that propitiate phytoplankton production and
enriches plankton communities has been highlighted widely. In fact, the northwestern Alboran Sea represents the most productive area in the Western Mediterranean
Sea in terms of chlorophyll-a (Chl-a), primary production and phytoplankton abundance (Rodríguez et al. 1998; García-Gorriz and Carr 2001; Ruíz et al. 2001, 2013;
Bosc et al. 2004; Mercado et al. 2008, 2012, 2014; Patti et al. 2010; Navarro et al.
2011). Consequent with the Alboran Sea’s high phytoplankton production, zooplankton biomass and production estimates of the Alboran Sea (García and Camiñas
1985; Sampaio et al. 2005; Yebra et al. 2017) have ranked among highest in the
western Mediterranean (Champalbert 1996; Siokou-Frangou et al. 2010). A quarterly monitoring project carried out in MA since 1992, ECOMALAGA, describes
the temperature/salinity time series (Fig. 13.10), as well as the mesozooplankton
abundance and chlorophyll concentration (Fig. 13.11). The data were obtained from
quarterly samplings performed principally in January–February (winter), March–
April (spring) July–August (summer), and October–November (autumn). These data
indicate that the annual maximum in temperature and minimum in salinity is
normally obtained in summer-autumn. However, the occurrence of annual cycles
departing significantly from these typical cycles is frequent (for instance, see the
periods 1994–1995 and the years 1999 and 2003; Mercado et al. 2007, 2012).
The TS time series depicts strong seasonal differences in which temperature
between winter and spring/summer periods differs by 6
C. Likewise, the salinity
profiles provide a picture of upwelling events observed, such as that of 1993, 1999,
and 2012. Such hydrographic seasonal variability shows its influence in the
mesozooplankton and chlorophyll a variability (Fig. 13.11). The upwelling events
that occurred during 1993 and 1999 showed peaks of mesozooplankton abundance
and chlorophyll a values, while that of 2012 was mainly reflected by the peaks of
chlorophyll a concentration. Nevertheless, the gap observed in 2013 was covered by
another monthly sampling project of MA (REMALA) that also showed strong
upwelling events in the winter of 2013 and summer of 2014 (see Fig. 13.10).
These data show the complex time variability patterns that feature the plankton
community in the Alboran Sea. Thus, conspicuous peaks in the abundance of
mesozooplankton are often registered (years 1993, 1998–1999), which are normally
attributable to copepods, but it does not apply in every case. It is also notable that
peaks of zooplankton often were not related to periods of elevated phytoplankton
biomass (Fig. 13.11).
498
A. García et al.
other coastal dwelling species.
13.3 Phytoplankton and Zooplankton Variability
of the Alboran Sea Coast
The coastal hydrodynamics in the Alboran Sea which affects the formation of
advection and upwelling processes that propitiate phytoplankton production and
enriches plankton communities has been highlighted widely. In fact, the northwestern Alboran Sea represents the most productive area in the Western Mediterranean
Sea in terms of chlorophyll-a (Chl-a), primary production and phytoplankton abundance (Rodríguez et al. 1998; García-Gorriz and Carr 2001; Ruíz et al. 2001, 2013;
Bosc et al. 2004; Mercado et al. 2008, 2012, 2014; Patti et al. 2010; Navarro et al.
2011). Consequent with the Alboran Sea’s high phytoplankton production, zooplankton biomass and production estimates of the Alboran Sea (García and Camiñas
1985; Sampaio et al. 2005; Yebra et al. 2017) have ranked among highest in the
western Mediterranean (Champalbert 1996; Siokou-Frangou et al. 2010). A quarterly monitoring project carried out in MA since 1992, ECOMALAGA, describes
the temperature/salinity time series (Fig. 13.10), as well as the mesozooplankton
abundance and chlorophyll concentration (Fig. 13.11). The data were obtained from
quarterly samplings performed principally in January–February (winter), March–
April (spring) July–August (summer), and October–November (autumn). These data
indicate that the annual maximum in temperature and minimum in salinity is
normally obtained in summer-autumn. However, the occurrence of annual cycles
departing significantly from these typical cycles is frequent (for instance, see the
periods 1994–1995 and the years 1999 and 2003; Mercado et al. 2007, 2012).
The TS time series depicts strong seasonal differences in which temperature
between winter and spring/summer periods differs by 6
C. Likewise, the salinity
profiles provide a picture of upwelling events observed, such as that of 1993, 1999,
and 2012. Such hydrographic seasonal variability shows its influence in the
mesozooplankton and chlorophyll a variability (Fig. 13.11). The upwelling events
that occurred during 1993 and 1999 showed peaks of mesozooplankton abundance
and chlorophyll a values, while that of 2012 was mainly reflected by the peaks of
chlorophyll a concentration. Nevertheless, the gap observed in 2013 was covered by
another monthly sampling project of MA (REMALA) that also showed strong
upwelling events in the winter of 2013 and summer of 2014 (see Fig. 13.10).
These data show the complex time variability patterns that feature the plankton
community in the Alboran Sea. Thus, conspicuous peaks in the abundance of
mesozooplankton are often registered (years 1993, 1998–1999), which are normally
attributable to copepods, but it does not apply in every case. It is also notable that
peaks of zooplankton often were not related to periods of elevated phytoplankton
biomass (Fig. 13.11).
498
A. García et al.