Environmental Influences on the Spatio-Temporal Distribution of European Hake (Merluccius merluccius) in Izmir Bay, Aegean Sea

Ege Denizi, İzmir Körfezi"nde bakalyaro Merluccius merluccius L. 1758, bolluğunun zaman-mekansal dağılımı üzerinde abiyotik çevresel faktörler, derinlik ve yanısıra balıkçılık baskısının etkisi, tepki-bağımlı değişken olarak birim av gücü (CPUE) ile birlikte Genelleştirilmiş Katkı Modeli (GAM) kullanılarak analiz edilmiş, ilişkileri açığa çıkarmakta yazılım tabanlı Coğrafi Bilgi Sistemi (CBS) kullanılmıştır. Veri İzmir Körfezi'nde geleneksel dip trol ağı kullanılarak 2007-2009 yılları arasında aylık olarak elde edilmiştir. Bakalyaro, İzmir Körfezi"nde zamansal olarak; yaz boyunca ve sonbaharın başlarında (özellikle Eylül ayında), mekansal olarak; Uzunada Adası'nın kuzeyindeki bölgede ve adanın doğu kıyısı ile körfezin merkezi arasında en bol miktardadır. GAM sonucuna göre; yüksek değerdeki bakalyaro bolluğu >50 m derinlik ile birlikte 14,5-19°C arasındaki deniz tabanı sıcaklık ve >38,55 deniz tabanı tuzluluk değerlerine sahip sularda tespit edilmiştir. Buna ek olarak, balıkçılık baskısının etkisi dip trol avcılığının izin verildiği bölgede açık bir şekilde belirgindir. Türlerin zaman-mekansal dağılımındaki değişikliklerin iyi bilinmesi, bu önemli kaynakların yönetiminin geliştirilmesine imkan sağlayacaktır.

Ege Denizi, İzmir Körfezi'nde Bakalyaro (Merluccius merluccius) Zaman-Mekansal Dağılımı Üzerine Çevresel Etkiler

In Izmir Bay, Aegean Sea, the influence of abiotic environmental factors besides depth and fishing pressure on the spatio-temporal distribution of European hake, Merluccius merluccius L. 1758, abundance were analysed using a Generalized Additive Model (GAM), with the Catch Per Unit Effort (CPUE) as the response-dependent variable and a Geographic Information System (GIS) software-based approach to display relationships. Data were collected on a monthly basis from 2007-2009 using a conventional bottom trawl net in Izmir Bay. European hake is mostly abundant in Izmir Bay during summer and early autumn temporally (particularly during September) and spatially, in the region to the north of Uzunada Island and between the east coast of the island and the centre of the bay. GAM models also demonstrated that higher European hake abundances were located in waters of >50 m in depth with Sea Bottom Temperature (SBT) values ranging from 14.5-19 °C and Sea Bottom Salinity (SBS) values >38.55. In addition to this, the effects of fishing pressure were clearly evident throughout the area where bottom trawling is permitted. A better knowledge of the changes in spatio-temporal distribution of the species will allow the improved management of this important resource.

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Abella, A., Serena, F. and Ria, M., 2005. Distributional response to variations in abundance over spatial and temporal scales for juveniles of European hake (Merluccius merluccius) in the Western Mediterranean Sea. Fisheries Research, 71(3): 295-310. doi: 10.1016/j.fishres.2004.08.036
Anonymous, 2006. The Commercial Fish Catching Regulations in Seas and Inland Waters in 2006-2008 Fishing Period: Circular No. 37 / 1 (in Turkish). Ministry of Agriculture and Rural Affairs, General Directorate of Conservation and Inspection, Ankara, Turkey.
Austin, M. 2007. Species distribution models and ecological theory: A critical assessment and some possible new approaches. Ecological Modelling, 200: 1-19. doi: 10.1016/j.ecolmodel.2006.07.005
Aydın, C., Tokaç, A. and Tosunoğlu, Z., 2007. Selectivity of sorting grid with horizontal bar for hake (Merluccius barbatus) annularis). Ege Journal of Fisheries Aquatic Science, 24: 39-43. red sea (Diplodus and bream
Bjİrnstad, O.N. and Grenfell, B.T., 2001. Noisy clockwork: Time series analysis of population fluctuations in animals. 10.1126/science.1062226 638-643. doi:
Cantoni, E. and Hastie, T., 2002. Degrees-of-freedom tests for smoothing splines. Biometrika, 89 (2): 251-263. doi: 10.1093/biomet/89.2.251
Chambers, J.M. and Hastie, T.J. (Ed.), 1992. Statistical Models in S. Pacific Grove, CA: Wadsworth and Brooks/Cole.
Craven, P. and Wahba, G., 1979. Smoothing noisy data with spline functions: estimating the correct degree of smoothing by the method of generalized cross- validation. Numerische Mathematik, 31: 377-403. doi: 10.1007/BF01404567
Çoker, T., 2003. The morphology and ecology of the pelagic eggs and larvae of Teleost fishes in Izmir Bay (in Turkish). PhD Thesis, Ege University, Institute of Natural and Applied Sciences, Izmir, Turkey.
Dalamas, D., and Megalofonou, P., 2012. Discovering where bluefin tuna, Thunnus thynnus, might go: using environmental and fishery data to map potential tuna habitat in the eastern Mediterranean Sea. Scientia Marina, 10.3989/scimar.03679.26A 691-704. doi:
Erzini, K., Goncalves, J.M.S., Bentes, L., Lino, P.G., and Ribeiro, J., 2001. The hake deepwater semi-pelagic ("pedra-bola") longline fishery in the Algarve (southern Portugal). Fisheries Research, 51: 327-336. doi: 10.1016/S0165-7836(01)00256-9
Guisan, A., Edwards, J., Thomas, C.; and Hastie, T., 2002. Generalized linear and generalized additive models in studies of species distributions: setting the scene. Ecological 10.1016/S0304-3800(02)00204-1 157: 89-100. doi:
Gurbet, R., Akyol, O., and Yalçın, E., 2013. Exploitation and mortality rates of European hake (Merluccius merluccius) in the Aegean Sea (Izmir Bay, Turkey). Journal of Applied Ichthyology, 29: 56-572. doi: 10.1111/jai.12082
Hastie, T., and Tibshirani, R., 1987. Generalized additive models: some applications. Journal of American Statistical 10.1080/01621459.1987.10478440 82: 371-386. doi:
Hastie T. and Tibshirani, R., 1990. Generalized additive models. Chapman and Hall, London.
Hilborn, R., and Walters, C.J., 1992. Quantitative Fisheries Stock Assessment Chapman and Hall, London. Katsanevakis, S., Maravelias, C.D., Damalas, D., Karageorgis, A.P., Anagnostou, C., Tsitsika, E.V., and Papaconstantinou, distribution and habitat use of commercial demersal species in the eastern Mediterranean Sea. Fisheries Oceanography, 18(6): 439-457. doi: 10.1111/j.1365- 2419.2009.00523.x 2009. Spatiotemporal
Koubbi, P., Loots, C., Cotonnec, G., Harlay, X., Grioche, A., Vaz, S., Martin, C., Walkey, M., and Carpentier, A., 2006. Spatial patterns and GIS habitat modelling of Solea solea, Pleuronectes flesus and Limanda limanda fish larvae in the eastern English Channel during the spring. Scientia Marina, 70S2: 147-157. doi: dx.doi.org/10.3989/scimar.2006.70s2147 Laevastu, T. and Hayes, M.L., 1982. Fisheries
Oceanography and Ecology, Fishing News Books Ltd, Great Britain.
Maravelias, C.D., and Papaconstantinou, C., 2003. Size- related habitat use, aggregation patterns and abundance of anglerfish (Lophius budegassa) in the Mediterranean Sea determined by generalized additive modelling. Journal of the Marine Biological Association of the U.K., 83: 1171-1178. doi: 10.1017/S0025315403008440h
Maravelias, C.D., Tsitsika E.V. and Papakonstantinou, C., 2007b. Environmental influences on the spatial distribution merluccius) and red mullet (Mullus barbatus) in the Mediterranean. Ecological Research, 22: 678-685. doi: 10.1007/s11284-006-0309-0
Özbilgin, H.; Tosunoğlu, Z.; Aydın, C., Kaykaç, H. and Tokaç, A., 2005. Selectivity of standard, narrow and square mesh panel trawl codends for hake (Merluccius merluccius) and poor cod (Trisopterus minutus capelanus). Turkish Journal of Veterinary and Animal Sciences, 29: 967-973.
Perry, R.I., and Ommer, R.E., 2003. Scale issues in marine human ecosystems Oceanography, 12: 513-522. doi: 10.1046/j.1365- 2419.2003.00254.x interactions. Fisheries
Planque, B., Bellier E., and Lazure, P., 2007. Modelling potential spawning habitat of sardine Sardina pilchardus and anchovy Engraulis encrasicolus in the Bay of Biscay. Fisheries Oceanography, 16: 16-30. doi: 10.1111/j.1365-2419.2006.00411.x
Planque, B., Loots, C., Petitgas, P., Lindstrom, U. and Vaz, S., 2011. Understanding what controls the spatial distribution of fish populations using a multi-model approach. Fisheries Oceanography, 20: 1-17. doi: 10.1111/j.1365-2419.2010.00546.x
R Development Core Team, 2010: R. A Language and Environment for Statistical Computing. Vienna, Austria: R Foundation for Statistical Computing. http://www.R-project.org
Sayin, E., Pazi I., and Eronat, C., 2006. Investigation of water masses in Izmir Bay, western Turkey, Turkish Journal of Earth Sciences, 15: 343-372. Stergiou, K.I., Machias, A., Kapantagakis, A., 2003. Can we define target species in Mediterranean trawl fisheries? Fisheries Research, 59: 431-435. doi: 10.1016/S0165-7836(02)00016-4
Swartzman, G., Huang, C., and Kaluzny, S., 1992. Spatial analysis of Bering Sea groundfish survey data using generalized additive models. Canadian Journal of Fisheries and Aquatic Sciences, 49: 1366-1378.
TUIK, 2013. Fishery Statistics 2013. Turkish Statistical Institute. ISSN: 1013-6177. Publ. No. 4349, Ankara, pp. 61.
Uçkun, D., Toğulga, M., and Taşkavak, E., 2000. A preliminary study on the growth of the common hake (Merluccius merluccius L.,1758) in Izmir Bay, Aegean Sea. Acta Adriatica, 41: 25-34.
Uçkun, D., Taşkavak, E., and Toğulga, M., 2006. A preliminary study on otolith-total length relationship of the common hake (Merluccius merluccius L., 1758) in Izmir Bay, Aegean Sea. Pakistan Journal of Biological 10.3923/pjbs.2006.1720.1725 1720-1725. doi:
Wood, S.N., 2000. Modelling and smoothing parameter estimation with multiple quadratic penalties. Journal of the Royal Statistical Society: Series B, 62: 413- 428. doi: 10.1111/1467-9868.00240
Wood, S.N., 2006. Generalized Additive Models: An Introduction with R. CRC Press, London.
Zheng, X., Pierce, G.J., Reid, D.G., and Jolliffe, I.T., 2002. Does the North Atlantic current affect spatial distribution of whiting? Testing environmental hypotheses using statistical and GIS techniques. ICES Journal of Marine Science, 59: 239-253. doi: 10.1006/jmsc.2001.1131
Zuur, A.F., Ieno, E.N., and Smith, G.M., 2007. Analysing Ecological Data. Springer-Verlag Statistics for Biology and Health series, New York.