214 



Fishery Bulletin 90(1). 1992 



over the Aegean Sea in July- August when they fre- 

 quently reach gale force (Carapiperis 1962) would 

 probably deepen the mixed layer, and hence entrain 

 nutrient-rich water from below the thermocline. Mullin 

 et al. (1985) have shown that microzooplankton biomass 

 and chlorophyll a levels can be doubled after wind- 

 related events. In addition, an increase in the frequency 

 and intensity of etesians winds may also result in an 

 intensification of upwelling in the northern, northeast- 

 em, and eastern part of the Aegean Sea (Metaxas 1973, 

 Theocharis et al. 1988). Hence, periods dominated by 

 higher-than-average frequency of etesians in July- 

 August may be associated with favorable feeding con- 

 ditions for anchovy larvae which may be subject to 

 lesser mortalities through starvation and predation, the 

 main factors affecting larval mortality in Mediterra- 

 nean anchovy (Azov-Black Sea: see Dekhnik and Rass 

 1988 for a review; Adriatic Sea: see S. Regner 1985 

 for a review; western Mediterranean: Palomera and 

 Lleonart 1989). 



Other factors may also affect variability in the an- 

 chovy abundance. For example, climatically-mediated 

 long-term changes in production and plankton species 

 composition in the eastern Mediterranean, changes in 

 larval dispersion due to changing patterns of currents, 

 as well as other factors, intrinsic or extrinsic, may 

 affect the egg/larval/postlarval/juvenile phases. It has 

 been maintained that in periods of increased air pres- 

 sure gradient over the eastern Mediterranean, the 

 water exchange between its basins intensifies (Pucher- 

 Petkovic et al. 1971, Vucetic 1981). As a result, the 

 salinity, nutrient content, temperature, and primary 

 productivity of the Adriatic Sea and of the eastern 

 Mediterranean basin rise, and the species composition 

 of the phytoplankton community changes. These 

 changes were accompanied by changes in the total 

 biomass of small pelagic fish (sardine, anchovy, horse 

 mackerel, etc). Such climate-plankton-small pelagic fish 

 interactions in the eastern Mediterranean involve time 

 lags of 2-3 years (Pucher-Petkovic et al. 1971). Last- 

 ly, cycles in anchovy catches may also be the result of 

 social-economic factors (Stergiou 1991) and/or a change 

 in the anchovy availability to purse seiners (changes 

 in the distribution and/or density of schools as a 

 response to changes in atmospheric and/or marine 

 climatic patterns) rather than to changes in the abun- 

 dance of anchovy itself. 



Incorporation into management schemes of these 

 cycles in abundance (e.g., Taylor and Prochaska 1984) 

 is particularly important for anchovy and other small 

 pelagic fish which are prone to collapse under intense 

 fishing pressure and poor recruitment. 



Acknowledgments 



The author wishes to thank two anonymous reviewers 

 for their constructive criticisms. 



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