Skip Navigation


ICES Journal of Marine Science: Journal du Conseil Advance Access originally published online on March 29, 2007
ICES Journal of Marine Science: Journal du Conseil 2007 64(3):531-536; doi:10.1093/icesjms/fsm026
This Article
Right arrow Abstract Freely available
Right arrow FREE Full Text (PDF) Freely available
Right arrow All Versions of this Article:
64/3/531    most recent
fsm026v1
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrowRequest Permissions
Google Scholar
Right arrow Articles by Ceyhan, T.
Right arrow Articles by Juanes, F.
Right arrow Search for Related Content
PubMed
Right arrow Articles by Ceyhan, T.
Right arrow Articles by Juanes, F.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

© 2007 International Council for the Exploration of the Sea. Published by Oxford Journals. All rights reserved. For Permissions, please email: journals.permissions@oxfordjournals.org

Age, growth, and reproductive season of bluefish (Pomatomus saltatrix) in the Marmara region, Turkey

Tevfik Ceyhan1, Okan Akyol1, Adnan Ayaz2 and Francis Juanes3,

1 Ege University, Faculty of Fisheries, 35100 Bornova, Izmir, Turkey
2 Çanakkale Onsekiz Mart University Faculty of Fisheries, Terzioglu Campus, 17100 Çanakkale, Turkey
3 Department of Natural Resources Conservation, University of Massachusetts, Amherst, MA 01003, USA

Correspondence to F. Juanes: tel: +1 413 545-2758; fax: +1 413 545-4358; e-mail: juanes{at}forwild.umass.edu

Ceyhan, T., Akyol, O., Ayaz, A., and Juanes, F. 2007. Age, growth, and reproductive season of bluefish (Pomatomus saltatrix) in the Marmara region, Turkey. – ICES Journal of Marine Science, 64: 531–536.

Bluefish (Pomatomus saltatrix) are distributed widely along the Turkish coasts, and are regularly captured, especially in the Sea of Marmara during their spawning migration to the Black Sea from the Mediterranean in spring and during their return migration south in early autumn. Age, growth, and reproductive season are reported. The ages of 1114 bluefish were determined from otoliths. The age groups ranged from 0 to III, and mean fork lengths (and weights) were 14.4 ± 0.12 cm (38.2 ± 1.02 g), 19.5 ± 0.06 cm (93.7 ± 0.86 g), 27.5 ± 0.48 cm (238.5 ± 11.3 g), and 33.3 ± 0.50 cm (431.9 ± 17.08 g) for each age group, respectively. The von Bertalanffy growth parameters were L{infty} = 51 cm, K = 0.228, and t0 = –1.26 y. The reproductive period, evaluated from gonadosomatic indices, began in early spring and extended until August.

Keywords: age, bluefish, growth, Pomatomus saltatrix, reproduction, Sea of Marmara, Turkey

Received 12 October 2006; accepted 8 February 2007; advance access publication 29 March 2007.


   Introduction
Top
 Introduction
Material and methods
 Results
 Discussion
 References
 
Bluefish (Pomatomus saltatrix) are migratory pelagic predators that are distributed over continental shelves and in estuaries of temperate waters throughout most of the world, with the exception of the northern and mid-Pacific Ocean (Briggs, 1960; Wilk, 1977; Juanes et al., 1996). Directed fisheries for the species have developed over its entire global range, but in many cases basic biological information is lacking (Juanes et al., 1996), likely impacting the effectiveness of fisheries management. This lack of information is especially critical along the Turkish coast in the eastern Mediterranean, the Sea of Marmara, and the Black Sea, where there are historically important fisheries (Ivanov and Beverton, 1985; Kocatas et al., 1993).

Bluefish are found all along the Turkish coast; migrating via the Aegean Sea northwards from the Mediterranean in spring and returning south in early autumn. They are the target of an important artisanal fishery, which includes handlines, encircling nets, and gillnets in all Turkish seas, otter trawlers in the Black Sea, and purse-seiners in the Sea of Marmara. Total catches averaged 25 000 t in 2002 (DIE, 2002), representing 36% of global commercial catches of the species (FAO, 2000). The maximum recorded catch was 32 184 t in 1982. Data on the recreational catch are lacking, so the declared values are clearly under-reported.

Fragmentary information exists on bluefish ecology and fisheries in Turkey (Devejiyan, 1915; Turgan, 1959a; Üner, 1961; Aksiray, 1987), only one study investigating bluefish age and growth in the Marmara region (Turgan, 1959a). Basic biological information is therefore needed to underpin sustainable management of the species in the area. The main objectives of the study were to analyse age, growth, and sex composition data and to identify the reproductive season of bluefish in the Marmara region, Turkey.


   Material and methods
Top
 Introduction
 Material and methods
Results
 Discussion
 References
 
The Marmara region includes three seas: the Sea of Marmara, the western Black Sea, and the northern Aegean Sea (Figure 1). Bluefish from the Marmara region were sampled monthly between January 2003 and December 2004. Samples were collected from commercial coastal fisheries, i.e. encircling nets (46–64 mm stretched mesh), gillnets (64 mm stretched mesh), and from purse-seiners (24 mm stretched mesh) returning to the Istanbul fish market.


Figure 1
View larger version (10K):
[in this window]
[in a new window]
[Download PowerPoint slide]
  		Figure 1. Sampling area.

 
Bluefish were measured [fork length (FL), to the nearest millimetre], weighed (total weight, to the nearest gramme), and the maturity was assessed according to Gunderson's (1993) scale: stage I, immature; stage II, resting; stage III, developing; stage IV, ripe; and stage V, spent. Maturity stages were assigned based on morphological characteristics and the estimated age-at-maturity of females by plotting percentage maturity by age. The gonadosomatic index (GSI) of mature fish was calculated as GSI = G x 100W–1, where G is the gonad wet weight and W the somatic wet weight of gutted fish.

We used otoliths for age determination because they yield much better between-reader agreement (92%) than scales (67%) or vertebrae (33%) (Barger, 1990; Sipe and Chittenden, 2002). Age determination protocol followed that of Metin and Kinacigil (2001). Sagittal otoliths were removed, wiped clean, and stored dry in U-plates. The age of 1114 sagittal otoliths was determined by two readers, otoliths being placed in glycerol and examined under reflected light using a binocular microscope. The opaque otoliths belonging to older fish were embedded in polyester, and two or three thin sections (0.1 mm) were cut along a transerve plane through the focus of the otolith using a Buehler isomet low-speed saw. On whole or sectioned otoliths, an opaque zone (mark) preceded by a translucent (hyaline) zone was assumed to be an age mark (Figure 2), as assumed in other age studies of bluefish (Salerno et al., 2001; Sipe and Chittenden, 2002).


Figure 2
View larger version (93K):
[in this window]
[in a new window]
[Download PowerPoint slide]
  		Figure 2. Examples of bluefish otoliths for age groups (A) 0, (B) I, (C) II, and (D) III.

 
Non-seasonal growth parameters (L{infty}, K, and t0) were estimated with the von Bertalanffy growth formula (VBGF) in the (FAO-ICLARM Stock Assessment Tools) (FISAT) computer program (Gayanilo et al., 1994) using individual lengths-at-age. The von Bertalanffy growth equation for length, Lt = L{infty}[1 – e–K(t–t0)], where L{infty} is the asymptotic length, K the growth curve parameter, and t0 the theoretical age when fish length would have been zero, was applied.


   Results
Top
 Introduction
 Material and methods
 Results
Discussion
 References
 
In all, 1114 bluefish, 543 females, 394 males, and 177 of unknown sex, were sampled during surveys in the Marmara region. Fork lengths ranged from 9 to 35 cm. Females dominated all age groups, and we detected significant differences in F:M ratios [({chi}2(calc) = 4.5 < {chi}2(3;0.05) = 7.81), p < 0.05; Table 1].


View this table:
[in this window]
[in a new window]

  		Table 1. Age and sex composition of bluefish in the Marmara region.

 
Age groups ranged between 0 and III, and mean FLs (and mean wet weight) were 14.4 ± 0.12 cm (38.2 ± 1.02 g), 19.5 ± 0.06 cm (93.7 ± 0.86 g), 27.5 ± 0.48 cm (238.5 ± 11.3 g), and 33.3 ± 0.50 cm (431.9 ± 17.08 g), respectively.

The estimated von Bertalanffy growth parameters for both sexes combined were L{infty} = 51 cm, K = 0.228, and t0=–1.26. The von Bertalanffy growth equation for length was Lt = 51[1 – e–0.228(t+1.26)] (Figure 3). We also estimated growth parameters for males, females, and unknown sex (immature) separately (Table 2), and found significant differences between the growth curves for each sex [F* = 26.2 > F(0.05;2.936) = 2.99]. There were statistical differences between the observed (obs) and calculated (calc) mean lengths in all age groups except age I females and all age II fish (Table 3).


Figure 3
View larger version (5K):
[in this window]
[in a new window]
[Download PowerPoint slide]
  		Figure 3. Von Bertalanffy growth curve for bluefish, sexes combined. FL is fork length.

 


View this table:
[in this window]
[in a new window]

  		Table 2. Von Bertalanffy growth parameters for males, females, unknown sex, and all samples combined.

 


View this table:
[in this window]
[in a new window]

  		Table 3. Observed and calculated mean lengths (FL, cm) of bluefish of each age group for females, males, and sexes combined.

 
GSI values for bluefish increased in the Marmara region in early spring, and peaked in July (Figure 4), which is also when we found mature bluefish with ripe gonads. Overall 81% of age I females were immature, and 62% of age II fish had ripening gonads. The scarcity of mature fish in our sample precluded us from estimating length-at-maturity using statistical methods, but from our results we can estimate that 50% maturity of females would occur by age II at a minimum size of 25.4 cm FL (Figure 5).


Figure 4
View larger version (23K):
[in this window]
[in a new window]
[Download PowerPoint slide]
  		Figure 4. Gonadosomatic index (GSI) of mature bluefish in the Marmara region (numerals are sample sizes).

 


Figure 5
View larger version (5K):
[in this window]
[in a new window]
[Download PowerPoint slide]
  		Figure 5. Percentage maturity by age group for bluefish in the Marmara region.

 

   Discussion
Top
 Introduction
 Material and methods
 Results
 Discussion
References
 
To our knowledge, this is the first study of bluefish age and growth in the Marmara region, including the western Black Sea. Our observed maximum FL of 34.2 cm is much lower than the 68 cm (3.71 kg) reported by Türgan (1959a) for the Black Sea and lower still than maximum lengths from bluefish collected from research surveys off the Northeast coast of the US (88 cm), and for bluefish landed by recreational fishers (96 – 120 cm) in the US (Salerno et al., 2001). In addition, Lucena and O'Brien (2001) documented a maximum length of bluefish of 67.2 cm in purse-seine samples from southern Brazil.

Juanes et al. (1996) compared age–length relationships from global P. saltatrix populations. Three groupings were apparent. The fast growth group included northeastern North America (Hamer, 1959; Wilk, 1977) and Northwest African populations (Champagnat, 1983). The moderate growth group included the Black Sea (Turgan, 1959b; Kolarov, 1964) and eastern South America populations (Krug and Haimovici, 1989). The slow growth group included the South African (van der Elst, 1976), Mediterranean (Kedidi, 1975), and Australian (Bade, 1977) populations. The intermediate Black Sea populations exhibited assymptotic lengths between 50 and 60 cm based on the data from bluefish in the Sea of Marmara (Turgan, 1959b) and the Bulgarian coast (Kolarov, 1964). Our results (L{infty} = 51 cm) support previous estimates for bluefish in the area of an intermediate asymptotic length (Table 4). Our estimates of the other von Bertalanffy parameters (K and t0) are also within the range of those of other populations (Table 4). Juanes et al. (1996) also suggested that these various growth groups were related to size-at-maturity: faster growing populations have larger sizes at maturity. The results of our study also agree with this life history trade-off, because Marmara region bluefish mature at a size of ~25 cm. Life history theory (Charnov and Berrigan, 1991) would also predict a negative relationship between the Brody growth coefficient (K) and the maximum asymptotic length. Such a relationship exists with both global (Juanes et al., 1996) and US (Salerno et al., 2001) bluefish von Bertallanfy parameters. The values for Marmara region bluefish obtained here are consistent with the relationships above, but L{infty} for the growth coefficient is on the small side. This may be explained in part by the relatively small maximum recorded length of the bluefish sampled here (Gallucci and Quinn, 1979).


View this table:
[in this window]
[in a new window]

  		Table 4. Von Bertalanffy growth parameters for bluefish obtained in various locations.

 
The absence of larger, older fish in our samples suggests heavy fishing pressure on bluefish in the Marmara region, a conclusion strengthened when it is considered that the combination of fishing gear used to collect our samples would minimize bias attributable to gear selectivity (Lucena and O'Brien, 2001). In another recent study on bluefish in the Marmara region, Akyol and Ceyhan (in press) reported a maximum length of 45.3 cm (just one fish) and a mean length of 16.9 ± 0.01 cm (range 8.4– 45.3 cm), similar to the range reported here. In contrast, in a much earlier study, Türgan (1959b) reported a maximum length of 68 cm and a mean length of 28.5 cm (range 5–68 cm). These size differences are not surprising because there has been a decrease in the mean length of fish caught by purse-seines and gillnets between 1959 and 2004. Fishing mortality (F = 0.60) has been much higher than natural mortality (M = 0.36), exemplifying heavy fishing pressure, particularly on juveniles (Akyol and Ceyhan, in press). The minimum landing size (MLS) for bluefish is just 14 cm in the Turkish Fishery Regulation Circular (TFRC), well below the likely size-at-maturity and perhaps therefore contributing to growth-overfishing and the absence of larger fish in the exploited population.

According to our GSI values, the reproductive season extends from early spring through late summer, peaking in July. We did not collect any bluefish in August, by when they would have completed their spawning migration to the Black Sea (Turgan 1959a, b; Gordina and Klimova, 1996). Gordina and Klimova (1996) showed that bluefish spawn in the Black Sea, on the Ukrainian and Bulgarian coasts, in water temperatures of 20–26°C from late July to late September. This may explain why we only found mature fish in late July in our samples; the population was likely on its spawning migration through the Sea of Marmara towards the Black Sea (Borcea, 1929, 1933; Turgan, 1959 a, b; Ivanov and Beverton, 1985), where it is likely that most spawning takes place (Gordina and Klimova, 1996) and inshore juvenile recruitment has been observed (Borcea, 1933; Oven, 1957; Porumb, 1968, 1971). Sabates and Martin (1993) also reported bluefish spawning in the Northwest Mediterranean from July to September at peak temperatures of 25ºC. In July, water temperatures ranged from 20 to 26ºC in the Marmara region, so such temperatures are obviously warm enough for spawning to take place along the Black Sea coasts of the Marmara region.

In conclusion, bluefish represent an important fishery in the Marmara region. The resource may not be sustainable, however, if minimum harvest sizes remain as they are now because of the potential for growth-overfishing. Further investigations are necessary to quantify the impact of the existing regulations on the population dynamics and recruitment patterns of bluefish in the region.


   Acknowledgements
 
We thank The Ministry of Agriculture, Generale Directory of Agricultural Researches, for their financial support (project TAGEM/HAYSÜD/2002/09/02/03), and Naciye Erdogan from Istanbul fish market, fishery cooperatives, and fishers in the Marmara region for their help in providing samples. FJ was supported by a fellowship from the National Center for Ecological Analysis and Synthesis, a Center funded by NSF (Grant #DEB-0553768), the University of California, Santa Barbara, and the State of California. We thank Jay Burnett and Flavia Lucena for their insightful comments which led to a much improved manuscript.


   References
Top
 Introduction
 Material and methods
 Results
 Discussion
 References
 

    Aksiray F. (1987) Pomatomidae. Türkiye Deniz Baliklari ve Tayin Anahtari (Istanbul Üniversity Rektörlügü Yayinlari, 3490, Turkish)370–372.

    Akyol O. and Ceyhan T. Exploitation and mortalities of bluefish (Pomatomus saltatrix L.) in the Sea of Marmara. (Turkish Journal of Applied Biological Sciences, Turkey) (in press).

    Bade T. M. (1977) The biology of tailor (Pomatomus saltatrix) from the east coast of Australia. University of Queensland MSc thesis.

    Barger L. E. (1990) Age and growth of bluefish Pomatomus saltatrix from the northern Gulf of Mexico and US South Atlantic coast. Fishery Bulletin US 88: pp. 805–809.

    Borcea I. (1929) Observations sur les poissons migrateurs dans les eaux Roumaines de la Mer Noire. Annales Scientifiques de 1'Universite de Jassy 15:656–750.

    Borcea I. (1933) Nouvelles observations sur les migrations et sur la periode de ponte des especes de poissons migrateurs de la Mer Noire. Annales Scientifiques de 1'Universite de Jassy 17:503–564.

    Briggs J. C. (1960) Fishes of world-wide (circumtropical) distribution. Copeia 1960:3171–180.[CrossRef]

    Champagnat C. (1983) Peche, biologie et dynamique du tassergal (Pomatomus saltatrix Linnaeus, 1766) sur les cotes Senegalo-Mauritaniennes. Travaux et Documents du L'ORSTOM (Office de la Recherche Scientifique et Technique Outre Mer). 168:279.

    Charnov E. L. and Berrigan D. (1991) Evolution of life history parameters in animals with indeterminate growth, particularly fish. Evolutionary Ecology 5:63–68.[CrossRef][Web of Science]

    Devejiyan K. (1915) Balik ve balikçilik. Duyun-i Umumiye-i Osmaniye Varidat-i Muhassasa Idare-I Merkeziye Matbaasi. , Turkish24–28.

    DIE. (2002) Su Ürünleri Istatistikleri 2002. (Ankara, Turkish) T.C. Basbakanlik Devlet Istatistik Enst. Yayin No. 2883.

    FAO. (2000) Fishstat Plus: Universal Software for Fishery Statistical Time Series, version. 2.3. , Rome FAO Fisheries Department, Data and Statistics Unit.

    Gallucci V. F. and Quinn T. (1979) Reparameterizing, fitting and testing a simple growth model. Transactions of the American Fisheries Society 108:14–25.[CrossRef]

    Gayanilo F. C., Sparre P., Pauly D. (1994) The FAO–ICLARM Stock Assessment Tools (FISAT) User's Guide. FAO Computerized Information Series 6:186.

    Gordina A. D. and Klimova T. N. (1996) On bluefish (Pomatomus saltatrix L.) spawning in the Black Sea. Marine and Freshwater Research 47:315–318.[CrossRef][Web of Science]

    Gunderson D. R. (1993) Surveys of Fisheries Resources. (John Wiley, New York)248.

    Hamer P. E. (1959) Age and growth of the bluefish (Pomatomus saltatrix Linnaeus) of the New York Bight. Rutgers University MSc thesis.

    Ivanov L. and Beverton R. J. H. (1985) The fisheries resources of the Mediterranean. 2. Black Sea. 60:135 Studies and Reviews of the General Fisheries Council for the Mediterranean/FAO.

    Juanes F., Hare J. A., Miskiewicz A. G. (1996) Comparing early life history strategies of Pomatomus saltatrix: a global approach. Marine and Freshwater Research 47:365–379.[CrossRef][Web of Science]

    Kedidi M. S. (1975) Contribution a l'étude morphologique et biologique de Pomatomus saltatrix (Linnaeus, 1758) poisson teleosteen du golfe de Tunis. , Tunis in French DEA de Biologie marine et d'Oceanographie.

    Kocatas A., Koray T., Kaya M., Kara O. F. (1993) Fisheries and environment studies in the Black Sea system. 64:87–143 3. A review of the fishery resources and their environments in the Sea of Marmara. Studies and Reviews of the General Fisheries Council for the Mediterranean/FAO.

    Kolarov P. (1964) Size and age composition of bluefish (Pomatomus saltatrix) of the Bulgarian Black Sea coast. Bulletin de l'Institut de Pisciculture et de Pecherie de Varna 4:207–220.

    Krug L. C. and Haimovici M. (1989) Age and growth of enchova Pomatomus saltatrix in southern Brazil. Atlantica 11:47–61.[Medline]

    Lucena F. M. and O'Brien C. M. (2001) Effects of the gear selectivity and different calculation methods on estimating growth parameters of bluefish. Pomatomus saltatrix (Pomatomidae, Pisces) 99:432–442 from southern BrazilFishery Bulletin US.

    Metin G. and Kinacigil H. T. (2001) Otolitten yas tayininde kesit alma teknigi. E.Ü. Su Ürünleri Dergisi , in Turkish 18:271–277.

    Oven L. S. (1957) On the drifting approach of fingerling bluefish (Pomatomus saltatrix) (Linnaeus) to the shores of the Black Sea in the Karadag region (1947–1954). Proceedings of Karadag Biological Station, Academy of Science of the Ukraine , in Russian 14:155–157.

    Porumb I. I. (1968) The role of young Pomatomus saltatrix in the trophic chain of the Black Sea. Rapports du Commission International du Mer Mediterranee 19:303–305.

    Porumb I. I. (1971) Contribution a la connaissance de la biologie de Pomatomus saltator, Linne 1758, de la Mer Noire: nutrition des jeunes dans les eaux du littoral Roumain et l'influence de la nutrition sur la croissance. Institutul Roman de Cercetari Marine. , in French 2:75–99.

    Sabates A. and Martin P. (1993) Spawning and distribution of bluefish Pomatomus saltatrix (L.) in the northwestern Mediterranean. Journal of Fish Biology 43:109–118.[CrossRef][Web of Science]

    Salerno D. J., Burnett J., Ibara R. M. (2001) Age, growth, maturity and spatial distribution of bluefish, Pomatomus saltatrix (Linnaeus), off the Northeast coast of the US, 1985–96. Journal of Northwest Atlantic Fishery Science 29:31–39.

    Sipe A. M. and Chittenden M. E. (2002) A comparison of calcified structures for aging bluefish in the Chesapeake Bay region. Transactions of the American Fisheries Society 131:783–790.[CrossRef]

    Türgan G. (1959a) Pomatomus saltatrix L. (lüfer baliklari)'in biyolojisi hakkinda. Hidrobiologi Mecmuasi, I.Ü. , in Turkish144–180 Fen Fak. Hidrobiologi Aras. Enst. Cilt V (1–4).

    Türgan G. (1959b) Recherches preliminaires sur la biologie des Temnodon saltator (tassergal) qui font leur migration par les detroits des Dardanelles et du Bosphore. International Commission for the Scientific Exploration of the Mediterranean Sea 15:409–420.

    Üner S. (1961) Lüfer. Balik ve Balikçilik Dergisi, Cilt IX (9–10). , in Turkish18–22.

    Van der Elst R. (1976) Gamefish of the east coast of southern Africa. 1. The biology of the elf, Pomatomus saltatrix (Linnaeus), in the coastal waters of Natal. Investigational Report Oceanographic Research Institute , South Africa 44:59.

    Wilk S. J. (1977) Biological and fisheries data on bluefish, Pomatomus saltatrix (Linnaeus). US National Marine Fisheries Service Northeast Fisheries Science Center 11:56 Sandy Hook Laboratory Technical Series Report.


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?



This Article
Right arrow Abstract Freely available
Right arrow FREE Full Text (PDF) Freely available
Right arrow All Versions of this Article:
64/3/531    most recent
fsm026v1
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrowRequest Permissions
Google Scholar
Right arrow Articles by Ceyhan, T.
Right arrow Articles by Juanes, F.
Right arrow Search for Related Content
PubMed
Right arrow Articles by Ceyhan, T.
Right arrow Articles by Juanes, F.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?