Biomass and distribution pattern of the fish eggs and larvae of European Sprat, Sprattus sprattus in the Marmara Sea, Tu rkiye

European Sprat, Sprattus sprattus (Linnaeus, ۱۷۵۸) has a great geographical distribution in a worldwide and has a great ecological importance with regards to position in the foodweb. S. sprattus is known as one the best representetive of small pelagic fish species in the Black Sea and the Sea of Marmara. In recent years, the raw material demand stemmed from feed production has tended towards over Sprat than Anchovy due to offered more people consumption against feed production. Thus, the fishing effort has become threat over stocks and correspondingly over food wed. Beside, a massive mucilage event realised February ۲۰۲۱ and August ۲۰۲۱, and covered nearly all surface waters of Marmara Sea. Scientific information on early life characteristics was insufficient for Sprat stocks in the Marmara Sea. The ichthyoplankton studies reveals good robust data for determining stock size, spawning time and spawning areas, and related environmental characteristics required by species. Hence, we tried to reveal mean fish egg and larvae biomass and it’s spatial and temporal variations in the Marmara Sea. For this purpose, three ichthyoplankton survey were realised in December ۲۰۲۱, January ۲۰۲۲ and March ۲۰۲۲ from the ۳۲ equally-located stations which covering the entire Marmara Sea. Sprat eggs and larvae were collected vertical plankton tows with WP-۲ type plankton net, which equipped with ۳۰۰ μm meshnet. Between all winter spawners in this study, Sprat was the most abundant fish species for both fish eggs and larvae, with a ۹۰.۱% and ۶۱.۹% of total biomass, respectively. The mean Sprat biomass in a unit area (n/۱۰ m۲) was found as ۷۱۳.۸ n/۱۰ m۲, whereas the mean Sprat prelarvae biomass detected as ۴۳.۵ n/۱۰ m۲ and postlarvae was ۱۶.۹ n/۱۰ m۲. A ۸۰.۳% of the total fish eggs with a mean of ۱۷۱۹.۹ n/۱۰ m۲ and a ۷۳.۶% of the total larvae abundance with a ۱۳۳.۶ n/۱۰ m۲ were seen in February. Three main spawning grounds were detected as a Karacabey Floodplain area, Bu yu kçekmece shores and Tekirdag shores, and larval shifting observed from northern part to southwestern part.

کلیدواژه ها:

Shrimp ، Trout ، Pishi ، Anchovy ، Sardine ، Sensory quality