Homa dalyanı (İzmir Körfezi, Ege Denizi)'nde sekonder prodüktivitenin araştırılması

Bu çalışmada İzmir Körfezi (Ege Denizi)’nde yer alan Homa Dalyanı’nda zooplankton biyomasından yararlanılarak sekonder prodüktivite araştırılmıştır. Primer ve sekonder prodüktiviteyi kontrol eden faktörlerin ortaya konulmasıyla, dalyanda balık verimliliğini kontrol eden faktörler de belirlenmiş olacaktır. Bu da dalyandaki balık üretiminin kontrolü anlamına gelmektedir. Bu amaçla Ekim 1998 - Eylül 1999 tarihleri arasında dalyandan alınan zooplankton örnekleri incelenmiş; ayrıca sıcaklık, tuzluluk, çözünmüş oksijen ve pH ölçülmüştür. Yapılan çalışmalar sonucunda sekonder prodüktivitenin yıl boyunca gösterdiği değişim elde edilmiştir. Sonbahar aylarında veriler ortalama bir değer etrafında salınırken, yaz aylarında önemli bir artış görülmüştür. Sekonder üretim değerleri yıl boyunca ortalama 1000 μgC/m3gün civarında iken yaz aylarında bu değer 7000 μgC/m3gün’e kadar artış göstermiştir. Buna göre, mesozooplankton ve makrozooplankton üretiminin yıllık balık veriminin %20’si olduğu açığa çıkmıştır. Bu sonuçlar, beklenen zooplankton üretiminin çok altında olup, fitoplankton ve mikrozooplankton üretiminin bağıl önemini göstermektedir.

Investigation on the secondary productivity in Homa Fisheries lagoon (Izmir Bay, Aegean Sea)

Investigation on the secondary productivity in Homa Fisheries Lagoon (Izmir Bay, Aegean Sea). In this study, secondary productivity in Homa Fisheries Lagoon (Izmir Bay) has been evaluated using zooplankton biomass measurements. Identifying the factors that control the primary and secondary productivity will also reveal the factors on fish productivity; leading to the control of the fish production in the fisheries. Therefore, the zooplankton samples were taken periodically from the lagoon between October 1998 and September 1999. Temperature, salinity, dissolved oxygen and pH were also measured. At the end of these studies, the variation of the secondary productivity during a year was obtained. It was observed that the secondary productivity oscillates around an average in autumn, but there is a significant increase in summer. The secondary productivity is about 1000 μgC/m3day along the year, but it reaches 7000 μgC/m3day in summer months. Thus, it is revealed that the productivity of mesozooplankton and macrozooplankton was 20% of the annual fish production. These results are much less than the expected zooplankton productivity and show the relative importance of the phytoplankton and microzooplankton productivity.

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