Predicting the Size Selectivity Based on the Striped Red Mullet Morphology (Mullus surmuletus) in Bottom Trawl Fisheries

Öz

DOI: 10.26650/ASE201817

The striped red mullet (Mullus surmuletus) is a commercially important demersal species caught by mixed trawl fishing in the Mediterranean Sea. Although it is not among the target species of bottom trawl operations, the striped red mullet is an important species due to its high commercial value in trawl catch composition. The primary target is to catch adult individuals while allowing the immature and juvenile fish to escape for sustainable fisheries using selective fishing gears. Various selectivity studies regarding trawl codends aimed at improving selectivity have been carried out in the past two decades. However, the selectivity sea trials generally require a great deal of work, time, and labor on the deck and are also expensive. Therefore, instead of experimental-based selectivity studies, simulation-based studies (i.e., the FISHSELECT methodology) were recently started to predict the size selectivity of species in bottom trawl fisheries. In this study, sampled individuals of the striped red mullet were used in morphological measurements, fall-through experiments, and simulation phases. Diamond mesh sizes of 40, 44, and 50 mm and a square mesh size of 40 mm of bottom trawl codends were simulated, and the L50 values were calculated as 9.87, 10.75, 12.19, and 12.3 cm for the aforementioned mesh sizes, respectively. Design guides were then created for various mesh sizes and opening angles. The study results were compared with those of previous studies on the red mullet (M. barbatus) that were conducted using the FISHSELECT methodology, and the selectivity results of these two species were found to be similar.

Anahtar Kelimeler

• FISHSELECT,striped red mullet,Mullus surmuletus,selectivity,bottom trawl

References

1. Akaike, H. (1974). A new look at the statistical model identification. IEEE Transactions on Automatic Control, 19(6), 716-723.
2. Ateş, C., Bök, T., Alicli, T.Z., Kahraman, A.E., Göktürk, D., Ulutürk, T., (2010). Selectivity of diamond and square mesh beam trawl codends for European hake and striped red mullet in the Sea of Marmara, Turkey. Journal Animal and Veterinary Advances, 9(2), 436-440.
3. FAO, (2011). Review of the State of World Marine Fishery Resources. FAO Fisheriesand Aquaculture Technical Paper No. 569, Rome.
4. FAO, (2014). Global Capture Production for Species, FAO FishStats, Available from: http://www.fao.org/fishery/species/3207/en (accessed 21.11.2017)
5. Frandsen, R.P., Herrmann, B., Madsen, N. (2010). A simulation-based attempt to quantify the morphological component of size selection of Nephrops norvegicus in trawl codends. Fisheries Research, 101(3), 156-167.
6. Herrmann, B., Krag, L.A., Frandsen, R.P., Madsen, N., Lundgren, B. and Stæhr, K.J. (2009). Prediction of selectivity from morphological conditions: Methodology and a case study on cod (Gadus morhua). Fisheries Research, 97(1), 59-71.
7. Herrmann, B., Sistiaga, M.B., Nielsen, K.N., Larsen, R.B. (2012). Understanding the size selectivity of redfish (Sebastes spp.) in North Atlantic trawl codends. Journal of Northwest Atlantic Fishery Science, 44, 1-13.
8. Herrmann, B., Sistiaga, M., Larsen, R.B., Nielsen, K.N. (2013). Size selectivity of redfish (Sebastes spp.) in the Northeast Atlantic using grid-based selection systems for trawls. Aquatic Living Resources, 26(2), 109-120.

9. İlhan, D.U., Akalın, S., Özaydın, O., Tosunoğlu, Z., Gurbet, R. (2009). İzmir Körfezi’nde Tekir Balığı’nın (Mullus surmuletus L., 1758)
10. Büyüme ve Üremesi. Ege University Journal of Fisheries & Aquatic Sciences, 26, 1-5.
11. Krag, L.A., Herrmann, B., Madsen, N., Frandsen, R.P. (2011). Size selection of haddock (Melanogrammus aeglefinus) in square mesh codends: A study based on assessment of decisive morphology for mesh penetration. Fisheries Research, 110(2), 225-235.
12. Krag, L.A., Herrmann, B., Iversen, S.A., Engås, A., Nordrum, S., Krafft, B. A. (2014). Size selection of Antarctic krill (Euphausia superba) in trawls. PLoS One, 9(8), e102168.
13. Ordines, F., Massutí, E., Guijarro, B., Mas, R. (2006). Diamond vs. square mesh codend in a multi-species trawl fishery of the western Mediterranean: effects on catch composition, yield, size selectivity and discards. Aquatic Living Resources, 19(4), 329-338.
14. Sistiaga, M., Herrmann, B., Nielsen, K.N. and Larsen, R.B. (2011). Understanding limits to cod and haddock separation using size selectivity in a multispecies trawl fishery: an application of FISHSELECT. Canadian Journal of Fisheries and Aquatic Sciences, 68(5), 927.
15. Tokaç, A., Herrmann, B., Gökçe, G., Krag, L.A., Nezhad, D.S., Lök, A., Kaykaç, H., Aydın, C., Ulaş, A., (2016). Understanding the size selectivity of red mullet (Mullus barbatus) in Mediterranean trawl codends: A study based on fish morphology. Fisheries Research, 174, 81-93.
16. TUİK (Turkish Statistical Institute), (2016). Quantity of caught sea fish report. Available from http://www.tuik.gov.tr/PreTablo.do?alt_id=1005 (accessed 23.11.2017)