Seasonal changes in the abundance and biomass of zooplankton from shallow mudflat river-estuarine system in Persian Gulf

Abstract

The present study was designed to investigate the seasonal changes in the abundance and biomass of zooplankton and their relationships with water quality parameters in mudflat shallow estuary, Helleh River, Persian Gulf (Iran). The zooplankton consisted of Acartia sp., Euterpina sp., Oithona spp., Oncaea sp., Paracalanus sp., Corycaeus sp., Labidocera sp., Macrosetella sp., Microsetella sp., Temora sp., copepod copepodid, copepod nauplii, Barnacle, Polychaeta, Conchoecia sp. (Ostracoda), Hyperid, Decapoda (zoea and megalopa), Actinula, Echinopluteus, Mollusca, Tintinnopsis sp., Ctenophora (Boliopsis sp.), Protozoa (Discorbis sp.), cumacea (Diastylis sp.), Cnidaria (Siphonophora and Phialidium), Nematoda (Pratylenchus spp.), Urocordata (Oikopleura spp.), fish eggs and fish larvae. The maximum biomass was estimated at estuary mouth in all seasons, the highest values in autumn (97.8-255.6 mg/m3) and the lowest in winter (5.5-68.2 mg/m3). The seasonal abundance (density) of zooplankton was 21237±2419, 45739±6053, 5242±648, and 12905±1867 ind./m3 in summer, autumn, winter and spring, respectively. There was a significant correlation (P<0.01) between zooplankton abundance as well as biomass with salinity, dissolved oxygen and chlorophyll a. Based on PCA (Principal Component Analysis), the most important factors in mudflat shallow river–estuarine system that could describe most changes of biomass and abundance of zooplankton were salinity, chlorophyll a, temperature and pH, respectively.

Seasonal variations in abundance and diversity of copepods in Mond River estuary, Bushehr, Persian Gulf

“…They are main grazers of microzooplankton and phytoplankton and they play the role of prey for zooplanktivorous fishes and 449 invertebrates (Benfield 2013). A similar situation has been reported in other estuaries (Primo et al 2009;Hwang et al 2010;Xuelu et al 2011;Farhadian and Pouladi 2014). Also, copepods nauplii as a wide variety of species were observed in Mond River estuary, which occurred in appreciable amounts.…”

Seasonal dynamics of zooplankton in a northern Chile bay exposed to upwelling conditions

“…Seasonal differences in plankton composition and biomass have been described from a variety of marine environments. In high latitudes like the Barents Sea this is mainly related to water mass circulation and bottom topography (Araskkevich et al 2002) and in a tropical estuarine system in the Persian Gulf the observed changes were mainly related to salinity, chlorophyll a, temperature and pH differences (Farhadian & Pouladi 2014). Other examples of changes in plankton composition and abundance along coastal settings ).…”

Sinking particles in the photic zone: relations with biogeochemical properties in different sectors of the Cananéia-Iguape Estuarine-Lagoon Complex (CIELC)-Brazil

“…These ratios (measured in the photic zone during the sediment trap exposure) are useful to check the contribution level of the zooplankton ecosystem (via grazing) to carbon sinking. Significant correlations between zooplankton abundance and Chla concentration have been observed in estuarine waters (Lopes et al, 1998;Farhadian and Pouladi, 2014). The Valo Grande water column showed PhaeP concentrations higher than Chla and no increased percentages of POM and PhaeP from the water column to V-Trap collectors (Figure 17).…”