The trophic and fishery impact of invasive Nemipterus randalli (Russell, 1986) in the northeastern Mediterranean Sea

Akgün, Yağmur
The Eastern Mediterranean Sea is one of the most invaded marine ecosystems under the impact of Lessepsian species which migrated from the Red Sea to the Mediterranean Sea after the construction of the Suez Canal. The impacts of Lessepsian species on the indigenous fish and fisheries can be both positive and negative. This study aimed to delineate the commonly seen Lessepsian species Randall’s threadfin bream (Nemipterus randalli)’s impact on the food web and fishery dynamics besides current ecosystem health in Mersin, Levantine Sea using one of the most widely adopted marine food-web model, Ecopath with Ecosim. Synthetic ecological indicators were used to assess the ecosystem status of the study area. The model included thirteen functional groups that were related to N. randalli either by prey-predator interaction or competition. The model was parameterized using data collected by monthly bottom trawl samplings in 2019 and literature data. N. randalli's stomach contents were analyzed. Scenarios were applied to compare N. randalli's impacts on other species and fishery. The findings highlighted that N. randalli's increasing population in the Eastern Mediterranean Sea negatively affected the commercially exploited native fish species: red mullet, surmullet, common pandora, and axillary seabream. Ecosystem of the study area showed common characteristics with other Eastern Mediterranean regions; however, it differed in ecosystem structure and functioning due to geographical differences. Considering the plans to expand further and deepen the Suez Canal in the near future, the increase in Lessepsian species necessitates the implementation of tailored conservation methods for the Eastern Mediterranean Sea. Targeted fisheries exploitation and incentives of marketing of N. randalli are alternative management strategies that can be recommended in the Eastern Mediterranean Sea to reduce the negative effects of the species.


The distribution of man-made and naturally produced halocarbons in a double layer flow strait system
Fogelqvist, E; Tanhua, T; Basturk, O; Salihoglu, I (1996-08-01)
The Bosphorus Strait, which connects the Black Sea and Mediterranean Sea via the Marmara Sea, is characterised by two distinct water masses. The upper layer consists of low density Black Sea water (sigma-t 10-11) flowing southward, and it is underlain by high density water (sigma-t > 28) of Mediterranean origin flowing northward. The sharp density gradient between the two layers is due to the difference in salinities. Here we report measurements on a suite of low molecular weight halocarbons together with b...
Gürkan, Yaprak; Yüksek, Ahsen; Tolun, Leyla; Tuğrul, Süleyman (2016-09-16)
In 7 different region which represent most used harbors, ports and fishing shelters in the Sea of Marmara and Black Sea in Turkey coasts. Ecological Quality Status was assesed by sampling soft -bottom macrozoobenthos from 22 stations in 2014.
What is the Impact of Lessepsian Species on Eastern Mediterranean Fisheries?
Lefkaditou, Evgenia; Abdelaty, Mohamed; Bariche, Michel; Corsini-Foka, Mariolina; Dimech, Mark; Economidis, Panagiotis; Gücü, Ali Cemal; Kalogirou, Stefanos; Konnaris, Kostas; Lahouf, Imad; Madi, Abdalnaser; Majdalani, Samir; Mahmoud, Hatem Hanafy; Michailidis, Nikolas; El Mokdad, Dahej; Nader, Manal; Qamheyih, Mohamed; Orsi-Relini, Lidia; Pagiatas, Giorgos; (2011-10-29)
The migration of Lessepsian species, which was the result of the opening of the Suez Canal in 1869 and further facilitated by human activities and environmental conditions, seems to play a key role for fisheries particularly in the Levant basin. However, there is still lack of accurate data for most of the Lessepsian species in order to evaluate their positive or negative effect to the fisheries catches and local fish stocks. The Project "Scientific and Institutional Cooperation to Support Responsible Fishe...
Spatial analysis of commercially important Lessepsian fish invasion in the Mediterranean Sea
Fach Salihoğlu, Bettina Andrea; Ureten, Mehmet Alp (2021-08-01)
The Mediterranean Sea is home to numerous invasive species that migrated through the Suez Canal, some of which have already established thriving populations. These Lessepsian species account for 2/3 of all alien species recorded in the sea today and impact native species and the equilibrium of the marine ecosystem. One example is Threadfin bream (Nemipterus randalli), a benthic fish with a pelagic larval stage, which was first detected in 2005 off the coast of Israel and has been a particular successful inv...
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...
Citation Formats
Y. Akgün, “The trophic and fishery impact of invasive Nemipterus randalli (Russell, 1986) in the northeastern Mediterranean Sea,” M.S. - Master of Science, Middle East Technical University, 2022.