Recent changes in the spawning grounds of Black Sea anchovy, Engraulis encrasicolus

Date

2016-01-01

Author

Gücü, Ali Cemal
Ok, Meltem
Sakinan, Serdar

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

165
views

0
downloads

Towards the end of the 1980s, when the spawning grounds in the northwestern shelf (NWS) of the Black Sea were lingering with the effects of eutrophication and of an exotic invasive ctenophore, a series of basin-wide international ichthyoplankton surveys pointed out an increase in the anchovies spawning in the southern half of the Black Sea. Later, with the help of international conservation efforts, several key littoral ecosystem components within the anchovy's historical spawning grounds showed signs of recovery. However, the fate of the spawning stock anchovy in the south remained unanswered. In order to present the current situation in the southern Black Sea after two decades, an ichthyoplankton survey adopting the same methodology as previously used was undertaken during the peak spawning season of the Black Sea anchovy (BSa). The survey showed that the density of eggs was by far greater than for any of the surveys conducted previously. A wider geographical distribution of the eggs indicated an increase in the number of vagrants which had drifted away from the known spawning grounds. In contrast, the increased reproductive activity in the south signifies existence of a growing, non-migrating southern BS stock. This stock seems to utilize the coastal hydrographic features associated with the rim current facilitating escape (loophole) from gelatinous predators such as Mnemiopsis leidyi and Aurelia aurata.

Subject Keywords

The Black Sea anchovy, Spawning strategy, Spawning grounds, Gelatinous organisms, Engraulis encrasicolus

URI

https://hdl.handle.net/11511/31003

Journal

FISHERIES OCEANOGRAPHY

DOI

https://doi.org/10.1111/fog.12135

Collections

Graduate School of Marine Sciences, Article

Suggestions

OpenMETU
Core

Understanding the Impact of Environmental Variability on Anchovy Overwintering Migration in the Black Sea and its Implications for the Fishing Industry Güraslan, Ceren; Fach Salihoğlu, Bettina Andrea; Oğuz, Temel (2017-01-01) Black Sea anchovy (Engraulis encrasicolus) undertake extensive overwintering migrations every fall from nursery grounds to warmer overwintering areas located on the south-eastern coast of the Black Sea. During migration and particularly upon arrival at the Anatolian coast, they support an important fishery and valuable source of income for the regional community. Black Sea anchovy have undergone significant stock fluctuations partly related to climatic conditions, for example, migrating anchovy schools arri...
MODELING THE IMPACT OF CLIMATE VARIABILITY ON ANCHOVY OVERWINTERING MIGRATION IN THE BLACK SEA Güraslan, Ceren; Fach Salihoğlu, Bettina; Department of Oceanography (2016-10-21) Black Sea anchovy (Engraulis encrasicolus ponticus) undertake extensive (~1000km long) overwintering migration in autumn from northern spawning grounds to the overwintering areas located at the south-eastern coasts of the Black Sea. When arriving at the Anatolian coast, they support important fisheries in Turkey. Black Sea anchovy is known to experience stock variability quite frequently including stock collapses, which are believed to be closely linked with environmental conditions. Therefore, it is of imp...
DISTRIBUTION OF ANCHOVY EGGS AND LARVAE (ENGRAULIS-ENCRASICOLUS CUV) IN THE BLACK-SEA IN 1991-1992 NIERMANN, U; BINGEL, F; GORBAN, A; GORDINA, AD; Gücü, Ali Cemal; Kıdeyş, Ahmet Erkan; KONSULOV, A; RADU, G; SUBBOTIN, AA; ZAIKA, VE (1994-11-01) Two international surveys of anchovy eggs and larvae were carried out in the Black Sea at the beginning of the spawning season in June 1991 and during the main spawning period in July 1992. Horizontal tows demonstrated that the bulk of anchovy eggs acid larvae were distributed in the upper 3-m layer, but in downwelling areas eggs and larvae were found down to 70 m depth. In contrast to earlier studies, vertical hauls obtained during the present investigation contained higher egg numbers in the southern and ...
Abrupt transition of the northwestern Black Sea shelf ecosystem from a eutrophic to an alternative pristine state Oguz, Temel; Velikova, Violeta (2010-01-01) Long-term (1960-2005) ecological data were used to identify a regime shift in the northwestern Black Sea shelf and to assess whether it has recovered from its former eutrophic state. Following the collapse of fish stocks and the population explosion of the ctenophore Mnemiopsis leidyi between 1988 and 1991, anthropogenic P-PO4 loads from the River Danube dropped strongly in 1992-1993. This decline in P-PO4 levels was caused by reductions in fertilizer use and emissions from land-based point sources during t...
The diel vertical distribution of zooplankton in the southeast Black Sea Erkan, F.; Gücü, Ali Cemal; Zagorodnyaya, J. (2000-01-01) The diel changes in the vertical distribution of zooplankton in the southeast Black Sea were described in this study. The zooplankton were sampled using two different sampling methods throughout one day in October 1996 and July 1997 at the same station. The zooplankton counts, the length measurements and biomass estimates showed that the zooplankton in the southeast Black Sea is dominated by small organisms, among which Noctiluca scintillans is the dominant species. In the vertical distribution of zooplankt...

Citation Formats

A. C. Gücü, M. Ok, and S. Sakinan, “Recent changes in the spawning grounds of Black Sea anchovy, Engraulis encrasicolus,” FISHERIES OCEANOGRAPHY, pp. 67–84, 2016, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/31003.