Hake, Merluccius merluccius L., in the northeastern Mediterranean Sea: a case of disappearance

Hake was not an important commercial fish in the northeastern Levant until the 1990s when a sudden increase in landings was experienced. However, following a series of profitable years, landings declined sharply. The rapid development of the trawl fleet played a role in the decline; however such an episodic event cannot be explained within the fisheries context alone. In this study the results of sparse historical trawl surveys were evaluated together with oceanographic data, and the impact of hydrographical changes on the appearance/disappearance of hake in the Levant was considered. The formation and movement of different water masses in the area seem to have primary importance for the species. The winter occurrence of modified Atlantic water that temporarily intrudes in the region may favour hake. Parallel with the increase in hake, an increase in clupeid species not common in the area was also observed. The change in the hydrography of the region, which was probably linked to the cold period that prevailed at the same time, temporarily led to an additional late summer pulse in the production cycle. The consequent increase in clupeids along with the changes in the hydrology favoured the advent of clupeid-eating hake in the NE Levant. The growth pattern result of the modal shift in monthly length-frequency distributions also showed that the species underwent a rapid growth phase in winter, which was most likely associated with intense feeding.


The Comb Jelly Mnemiopsis Leidyi in the Black Sea
Kıdeyş, Ahmet Erkan (Kluwer Academic Publishers, 2002-01-01)
Following its transportation in ballast waters, the western Atlantic ctenophore Mnemiopsis leidyi caused a striking damage to the ecosystem of the Black Sea in the early 1990s. The concentration of food Zooplankton and simultaneously catches of anchovy and other pelagic fishes sharply decreased during the peak levels of the ctenophore. There have been many studies on the distribution and physiology of this ctenophore in its new environment due to its substantial impact on the marine ecosystem. Later in mid ...
Current distribution of the small pelagic fish populations in the North Eastern Levantine Sea in relation to environmental conditions and predicting the impacts of temperature rise on their future distributions
Sakınan, Serdar; Gücü, Ali Cemal; Department of Marine Biology and Fisheries (2014)
Stocks of traditionally targeted fish species are in decline in the north eastern Levant Sea due to overfishing during recent decades, while catch statistics show a simultaneous increase in landings of commercially less valuable small pelagic species. Moreover, the number of species in the eastern Mediterranean is increasing due to Lessepsian migration and the response of native species to the continuous migration of lessepsian species is in question. Additionally, warming associated with climate change is ...
Evaluation of the demersal fish assemblages of the northeastern levant sea
Ok, Meltem; Gücü, Ali Cemal; Department of Marine Biology and Fisheries (2012)
Ecosystem-level changes have taken place in the Mediterranean Sea over the last decades due to both anthropogenic interferences and natural perturbations. Compared to the western Mediterranean Sea, influences of these factors especially on flora and fauna characteristics are much more dramatic and intense in the eastern part, particularly in the northeastern Levant Sea where the study area is located. In this study, life history traits of some core species (both native and immigrant) occupying the continent...
Impact of a new invasive ctenophore (Mnemiopsis leidyi) on the zooplankton community of the Southern Caspian sea
Roohi, Abolghasem; Yasin, Zulfigar; Kıdeyş, Ahmet Erkan; Hwai, Aileen Tan Shau; Khanari, Ali Ganjian; Eker-Develi, Elif (2008-12-01)
The invasive ctenophore Mnemiopsis leidyi (Agassiz), which was transported from the Black Sea into the Caspian Sea at the end of the 1990s, has negatively affected the ecosystem of the Caspian Sea. Zooplankton abundance, biomass and species composition were evaluated on the Iranian coast of the Caspian Sea during 2001-2006. A total of 18 merozooplankton (13 species composed of larvae of benthic animals) and holozooplankton (four Copepoda and one Cladocera) species were identified. The total number of zoopla...
The annual cycle of Synechococcus (cyanobacteria) in the northern Levantine Basin shelf waters (Eastern Mediterranean)
Uysal, Zahit (2006-09-01)
Abundance of picoplanktonic chroococcoid marine cyanobacteria Synechococcus was monitored weekly over the year 1998 in shallow coastal waters of the northern Levantine Basin. The ambient physical, chemical and biological variables (temperature, salinity, Secchi disk depth, total suspended sediment, nitrate, phosphate, Chl a and phytoplankton) were also measured. Synechococcus was found to be more abundant during summer and early autumn and less during winter and early spring. At the surface and 15 m depth, ...
Citation Formats
A. C. Gücü, “Hake, Merluccius merluccius L., in the northeastern Mediterranean Sea: a case of disappearance,” JOURNAL OF APPLIED ICHTHYOLOGY, pp. 1001–1012, 2011, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/31224.