International Conference on Advances in Biotechnology and Pharmaceutical Sciences (ICABPS'2011) Bangkok Dec., 2011

Human effect on the brown trout, Salmo trutta,

populations in some streams of Upper Coruh

River, Turkey

Ayhan Yildirim, Murat Arslan, Edward J. Peters and Namık Mevlüt ARAS

Abstract- Objectives of this investigation were to determine the In this study, we investigated some population parameters such as effect of human activities and some habitat characteristics on brown total mortality, age, length frequency distribution, Proportional trout ( Salmo trutta) living in three streams of upper of Coruh River. Stock Density (PSD), relative weight (Wr) to determine the effect of Instantaneous rate of total mortality (Z) of Salmo trutta for Anuri, human activities and habitat characteristics on brown trout, living in Kan and Cenker streams were as 0.9559/year, 0.9619/year and the Anuri, Kan and Cenker Streams of Upper the Coruh River, 0.7395/year, respectively. Highest mortality rates corresponded to Turkey. highest fishing pressure. Age distributions were ages1-6 for the Anuri stream and 1-7 for the Cenker and Kan streams. Dominant age II. STUDY AREA classes were ages 1 (49.49%) for Anuri, 1 (33.24 %) for Cenker and 2 (35.76%) for Kan. Longest lengths for Anuri, Kan and Cenker This study was carried out in the Anuri, Kan and Cenker Streams, streams were as 29.9 cm, 26.1 cm and 34.4 cm and dominant length three important tributaries of the Upper Çoruh River in northeast classes were 9 cm (14.02%), 8 cm (18.1%) and 13 cm (9.26%), Turkey. The streams all originate on Kaçkar Mountains (Fig. 1). The respectively. Values of Proportional Stock Density (PSD) for Anuri, water, all streams, is used for agricultural irrigation near the stream. Kan and Cenker streams were as 6.33, 4.8 and 11.24, respectively. In summer, most of water is taken for agricultural affairs by a Largest and oldest fish were found in streams with the lowest fishing channel to villages’ people, so flow decreases. Water continues to pressure. flow, in upstream sections, but flow decrease to isolated pools that are favorable for trout down the channel. Some physical and Key Words: Salmo trutta, PSD, mortality, Coruh River, human chemical parameters of three streams also were given at Table 1. effect.

I INTRODUCTION

The brown trout, Salmo trutta L., which is distributed naturally across Europe including Turkish freshwaters [1], was introduced successfully into at least 24 countries outside Europe in less than 90 years (1852-1938) and status of brown trout changed from that of a European species to that of a global species [2]. This species is exploited wherever it is distributed and as a renewable resource, it has some importance like sport fishing, commercial fishing and aquaculture interest at international level [3].

Brown trout has an importance as sport fishing at international level [3], [4]. Most trout populations in lakes and streams are subjects to some angling exploitation, which accounts for a significant mortality of the oldest age groups. Angling exploitation has reduced the mean age, the age diversity and number of trout exceeding the minimum size in exploited sections [6]. Effects of angling exploitation on brown trout populations are assessed by comparing fished sections with close ones unfished for at least 20 years, in mountain streams of Asturias. Both the fish size and age Fig. 1. Map of study area. structure significantly differ among sections in the expected direction according to their exploitation status. The main effects are While woody plants are rare in Cenker and Kan Stream, they are a significant decrease in age structure complexity, life span, and abundant in Anuri stream basin. Moreover, in comparison to Cenker percent individuals above Stream there are more pools and riffles here. Altitudes and along from upstream to downstream are as 2500-1255 m and 25 km for Age-distribution of brown trout varies generally from 4 to 12 Anuri stream, 2600-1200 m and 35 km for Kan stream, 2700-1147 m years old [37,8,9,10,11,12,13,14,1516,17,18,19] although few and 20 km for Cenker stream. Slope of from the streams from studies have 16-19 age classes [20,21]. Maximum longevity and age highest to lowest is Cenker, Kan and Anuri stream. A country road in fish are affected by their genetics, food intake, water temperature, follows very close to the Anuri stream, to serve villages, along its floodplain and fishing activities [4,6,22,23,25] bed. Along Kan stream, a highway from Erzurum to Rize, enables anyone to reach the stream easily. Reaching the Cenker Stream is Ayhan Yildirim and Murat Arslan are from University of Ataturk, Ispir Hamza Polat Vocational School 25900 Ispir Erzurum Turkey. more difficult, since no roads run the length of the stream. The width Edward J. Peters is from University of Nebraska-Lincoln, School of of Anuri stream is greater than Kan and Cenker Stream. All the Natural Resources 12 Plant Industry Building, Lincoln, NE, 68583-0814, streams are characterized by large seasonal fluctuations in discharge, USA level and temperature of water, and food supply. The streams are Namık Mevlüt ARAS, is from University of Ataturk, Faculty of covered with ice in winter, so sampling could not be done during Agricultural, Fisheries Department, 25270 Erzurum, Turkey December, January, and February in the Anuri and Cenker, during

259 International Conference on Advances in Biotechnology and Pharmaceutical Sciences (ICABPS'2011) Bangkok Dec., 2011

December in Kan. In spring and early summer (May-July) some determined by using the z test between Anuri and Cenker, Anuri and torrents occur because of the rain and melting snow. This also results Kan, then Cenker and Kan. If there was a statistical significant in a short period of high turbidity that occurred each spring. Brown among the streams, it was indicated to be a,b,c etc. After values of trout is the only fish species present in the streams. Wr were applied logarithmic transformation, relative weight condition and factor were tested using two-way analyses of variance. Table 1. Some physical and chemical characteristics of three streams All tests statistical significance were based on p=0.05. Statistica for of Upper Coruh River, Turkey. windows was used for calculating. STREAMS Parameters Anuri Cenker IV. RESULTS Kan Stream Stream Stream 400 25’ N, 400 22’ N, 400 31’ N, The length-frequency distributions were analyzed to determine GPS 400 44’ E 400 28’ E 400 02’ E differences among the three streams. The most frequently occurring Maximum altitude for Anuri, Kan and Cenker streams were 10 cm (13.7%), 8 cm 2500 2700 2700 (m) (13.6%) and 11 cm (9.7%) cm, respectively, while maximum lengths Flow (m3 s-1) 0.5-3 0.3-5 0.3-2 for these streams were 30.9 cm, 27.3 cm and 35.5 cm, respectively Wide (m) 2.5-5 2-8 2-4.5 (Table 2). Deep (cm) 10-70 20-100 10-60 Rock and Rock and Table 2. Age-frequency distribution for brown trout from three Streambed cover boulder boulder boulder streams of the Upper Coruh River, Turkey. (a, b, c indicates Annual mean water statistically significant differences among stream for comparison if 9.3 9.3 9.9 temperature (oC) N percent by age groups). Annual mean dissolved oxygen (mg 9.7 9.8 9.8 Age Anuri Stream Kan Stream Cenker Stream -1 N N N l ) Classes %N %N %N Annual mean pH 7.8 7.7 7.7 63 24 Number of village 0 6.59 a 48 9.43 a 3.37 a and total human 5, 252 6, 1520 4, 427 474 237 1 49.58 ab 180 35.36 a 33.24 b population 194 152 2 20.29 a 182 35.76 ab 21.32 b 122 120 3 12.76 a 41 8.06 a 16.83 a III. MATERIAL AND METHODS 88 145 4 9.21 a 35 6.88 b 20.34 ab Fish were caught in streams by electrofishing from November 2000 9 17 to October 2002. The sampling sites were all located at about 1800 5 0.94 ab 18 3.54 a 2.38 b m above sea level. Specimens were placed on ice and returned to the 6 13 o 6 0.63 a 4 0.79 1.82 a laboratory, where they were held in a freezer at –10 C for later 0 5 analysis. Prior to dissection, all fish were thawed, rinsed and blotted 7 - 1 0.20 0.70 dry, measured to the nearest 1 mm (total length) and weighed to the Total 956 100.00 509 100.00 713 100.00 nearest 0.01 g an electronic balance. Age was determined by reading the otolith. Otoliths were read whole, at using projecting stereomicroscope while immersed in a solution of glycerin and alcohol. Age estimates were obtained by counting the number of Stock size individuals (15 to 23) were common in all three streams. opaque bands from the nucleus to the margin [26]. Estimates of the Quality size fish (>22 cm) were uncommon in the Kan Stream, while instantaneous rate of total mortality (Z) were obtained using the age- The Anuri and Cenker streams contained more abundant numbers of based catch curve method The natural logarithm of the number of this size category. Preferred size (>29 cm) brown trout were only found in the Cenker Stream (Table 2). Proportional stock density fish in each age (Nt) was plotted against their corresponding age (t) and Z values were estimated from the descending slope, b [27]. (PSD) for Anuri, Kan and Cenker were 5.92, 6.95 and 11.25, respectively. For stock density calculations, fish were separated into length classes of 15, 23, 30, 38 and 46 cm for stock, quality, preferred, memorable Age-frequency distribution was analyzed to determine differences and trophy categories, respectively [28]. The proportional stock among the three streams. The oldest fish in Cenker and Kan stream density index (PSD) is the proportion of fish of quality size in were age group 7 while in the Anuri stream it was age group 6. relation to the number of stock size or larger individuals. The value, Dominant age classes for Anuri, Kan and Cenker Stream were expressed as a percentage, is calculated as: determined to be 1 (49.58%), 2 (35.76%) and 1 (33.24%), number >= minimum quality length respectively. The Cenker stream had the oldest fish while the Kan PSD= x100 [29]. stream had the youngest maximum age fish. The z test was number >= minimum stock length calculated for comparing differences among streams by age classes. All stream for 0 and 3 age classes were statistical significant each other (p<0.05). On 1 age class, Anuri was higher than Kan and W Cenker as statistical significantly (P<0.05). Also, Anuri and Cenker Relative Weight (Wr) was calculated follow as: Wr= x100, for three and up to age classes were lower than Cenker (Fig. 3). Ws where W is total weight (g), W (g) is length-specific standard s Instantaneous rate of total mortality (Z) from Anuri, Kan and Cenker weight. The standard weight functions are of the form W =- s streams were Z = 0.9559 and R2=0.8975, Z =0.9619 and 4.867+2.960 Log TL [28]. To determine the condition of the fish anuri Kan R2=0.9508 and Z =0.7395 and R2=0.8742, respectively. W cenker condition factor, K, was used, K= x100, where W is total TL3 weight (in g) and TL is the fish total length (in cm) [29] To compare the ratio of age and length classes among the stream were

260 International Conference on Advances in Biotechnology and Pharmaceutical Sciences (ICABPS'2011) Bangkok Dec., 2011

Table 3. Relative Weight (Wr) and Condition Factor (K) for brown Table 4. Relative Weight values for length classes of brown trout trout from different streams of Upper Coruh River . from three streams in Turkey. Length Homoge Anuri Kan Anuri Stream Kan Stream Cenker Stream classes Cenker stream Mean nous Stream Stream Length (cm) groups Conditi Groups Relative Condition Relative Condition Relative on 1-14 99.11±0.43 100.92±0.5 96.18±0.4 98.79±0.2 (cm) Weight Factor Weight Factor Weight Factor 15-22 107.69±0.8 105.55±1.2 102.69±0.6 105.23±0.4 a ( Wr ) ( K ) ( Wr ) ( K ) ( Wr ) ( K ) 23-29 110.66±4.2 102.10±5.9 99.59±2.0 103.25±1.9 b 4 69.36 0.806 86.15 1.009 87.07 1.018 30-38 90.01 90.98±5.0 91.53±3.5 ab 5 105.46 1.219 94.39 1.092 Mean 101.74±0.4 101.91±0.5 98.83±0.3 100.83±0.2 6 89.63 1.029 105.50 1.212 82.37 0.946 Homoge 7 96.65 1.103 101.13 1.154 90.17 1.030 nous a b ab groups 8 97.22 1.105 98.95 1.124 93.52 1.062 *Values of two-way analyses of variance were calculated as 9 96.98 1.097 94.72 1.072 92.50 1.047 F=12.633 and p=0.000 for stream, F=44.653, p=0.000 for length 10 96.24 1.085 103.15 1.163 95.40 1.075 classes, F=3.105, p=0.015 for stream*length classes interaction. *Difference of among means indicating same latter was statistically 11 96.61 1.085 102.59 1.153 98.06 1.101 significant (p<0.05). 12 101.67 1.138 103.21 1.155 100.27 1.122 13 104.97 1.171 102.97 1.150 98.30 1.097 Table 5. Condition factor values for total length classes of brown 14 105.71 1.177 106.30 1.183 98.65 1.098 trout from three streams in Turkey. 15 106.89 1.186 101.38 1.126 100.23 1.113 Length Anuri Kan Cenker H.Grou 1 Mean * 16 103.78 1.149 106.66 1.181 101.44 1.123 classes Stream Stream Stream ps 1.116±0.00 1.081±0.00 1-14 cm 1.138±0.06 1.112±0.003 17 108.25 1.196 109.81 1.213 98.51 1.088 5 5 18 105.78 1.166 109.73 1.209 105.58 1.164 1.190±0.00 1.165±0.01 1.133±0.00 15-22 cm 1.161±0.005 a 19 110.95 1.218 99.68 1.094 109.15 1.198 9 3 7 1.203±0.04 1.112±0.06 1.084±0.02 1.124±0.002 20 110.95 1.218 99.68 1.094 109.15 1.198 23-29 cm ab 6 5 2 1 21 112.41 1.231 99.44 1.090 103.98 1.139 0.980±0.05 30-38 cm 0.998 0.984±0.039 ab 22 109.18 1.194 105.32 1.152 101.50 1.110 6 1.138±0.00 1.143±0.00 1.101±0.00 23 112.25 1.225 115.38 1.260 102.91 1.124 Mean 1.127±0.003 4 6 4 24 107.62 1.173 88.68 0.967 101.48 1.106 H. a b ab 25 107.75 1.172 106.05 1.154 96.31 1.048 groups* 26 113.79 1.236 95.54 1.038 1 27 103.25 1.119 90.49 0.981 110.64 1.200 Values of two-way analyses of variance were calculated as F=14.661 and p=0.000 for stream, F=22.765, p=0.000 for length 28 135.04 1.462 85.71 0.929 classes, F=3.583, p=0.006 for stream*length classes interaction. 29 113.06 1.222 93.90 1.016 *Difference of among means indicating same latter was statistically 30 .6 1.001 100.65 1.087 significant (p<0.05). 31 88.58 0.956 V. DISCUSSION 32 33 In this study, we investigated the effect of human activities and some 34 habitat characteristics on brown trout in living Anuri, Kan and 35 83.728 0.900 Cenker streams of Coruh River in Turkey. Age and length-frequency distribution, Instantaneous rate of total mortality (Z), condition factor (K) and Proportional Stock Density (PSD) were compared among the streams. Values of means of condition factor and relative weight for all streams were 1.138, 1.143, 1.101 and 101.74, 101.91, 98.83, respectively. Variation of condition and relative weight values was Cenker stream generally had older fishes while Anuri and Kan similar to each other with two-way analyses of variance (Table 3 & streams have younger fishes. A maximum age class was as 6 for Fig.3). For both condition and relative weight for stream, while one Anuri and, 7 for Kan and Cenker stream. (Table 2). Age class ranges homogeneous group was Kan and Anuri, Cenker was lower than for brown trout from different studies has been reported to be 0-4[7], those statistical significant with F=12.633, p=0.000 for relative 0-5 [11,12,17] 0-6 as [8,14,17,19], 0-7 as (7,9), 0-10 as weight and F=14.661, p=0.000. For length classes, it was occurred (7,10,15,16,18 and 0-12 [13. Also, few studies have 16-19 age two homogeneous groups, which were as 1-14 cm group - 30-38 cm classes [20,21]. Maximum longevity and age in fish are affected by group and 1-14 cm, group, 14-22 cm, 23-29 cm with two-way their genetics, food intake, water temperature, floodplain and fishing analyses of variance. Also, Stream*length classes interactions were activities [24,,22,23,24]. It seems that trout Anuri, Kan and Cenker statistical significant for both condition factor and relative weight have proportionally shorter lifespan than other populations in the with two-way analyses of variance (Table 5). world. Cenker stream had mostly older fishes than Anuri and Kan streams. This may attributed to fishing that generally has used a cast nets (mesh sizes 10x10 mm, 12x12 mm) for fishing.

261 International Conference on Advances in Biotechnology and Pharmaceutical Sciences (ICABPS'2011) Bangkok Dec., 2011

Table 6. Age range and instantaneous rate of total mortality for 14 Anuri Stream Kan Stream brown trout from different locations. Anuri Stream Kan Stream 12 Cenker Stream Age Total Cenker Stream Lit. Location Ran Mortal 10 Stock Size Quality Size Preferred size ge ity 2 8 Cedar Run, in United State 0-4 0.36 2 6 Spring Creek 0-4 0.71

% Number of Fish of Number % [7] Spruce Creek 0-7 0.472 4 2 Kan Stream Anuri Stream Cenker Stream Young Woman`s Creek 0-4 0.26 2 Kettle Creek 0-4 0.722 2 0 Shaver Creek 0-8 0.36 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 Different streams in Coruh and [8] 1-6 Lenght classes (cm) Aras River, in Turkey Sqre in Sqre Osa river system, in 0.950 1-6 Norway 71 Fig. 3. Length-frequency distribution of brown trout from three 1.125 streams of the Upper Coruh River. [9] Qestre 1-6 1 5 1.925 Vestra 1-6 Instantaneous rate of total mortality (Z) for brown trout from Kan, 11 Anuri and Cenker was 0.9619, 0.9559 and 0.7395, respectively. 0.593 [10] Aspropotamos stream, in Greece 0-8 Values of Z of Kan, Anuri and Cenker were similar to estimates 31 from Sqre in Norway[9], from river Avion-Milanos in Spain (11), 1.541 River Ucero, in Spain 1-5 from Sub-Alpine reservoir in Norway (15), and from section-2 in 31

Norway (19). Instantaneous rate of total mortality is lower than that 0.907 River Avion-Milanos 1-4 found from Qestra and Vestra in Norway (9), from Aspropotamos in 61 Greece (10) from River Ucero in Spain (11), and higher than from Tees and tributaries, in England 0.56 different creek in USA (7), from Wye River in England (12), from a [27] Cow Green Reservior 0.56 tributary of Ceyhan River in Turkey (18), from section-1 in Norway 0.586 (19). Moreover, if we generally evaluate as values, our values of Z [12] Wye River, in England 0-5 11 are higher than the average of Z values of brown trout on the world. [13] Norwegian reservoir, in Norwey 1-12 [14] Aygir Lake, in Turkey 1-6 Relative weight values for brown trout in all three streams are near 0.826 or over 100 for most length groups up to 22 cm. However, Mean Wr [15] Sub-Alpine reservoir, in Norwey 1-8 71 and mean K values are significantly lower in Cerker stream fish than [16] Cenker stream, in Turkey 1-10 either Kan and Anuri fish. This is most prominent in the 23 cm and longer groups. This may be due to the higher slope of the Cenker Bellbekken, in Norwey 1-5 stream, which impresses a higher energetic cost on these fish. Fish [17] Bjoaa and Gjesa 1-7 larger than 22 cm exhibited more variable and lower Wr values than Osa and Ulvaa 1-6 A tributiary of Ceyhan River in 0.569 the smaller fish. This may be due to a lack of appropriate food for [18] 1-9 1 these size classes or just the low number of individuals in a Turkey 8 0.654 particular size class. Since there are no other fish species in these [19] Sulbalpine river Section-1, Norwey 0-6 1 streams, the larger fish may be limited by the availability of 4 0.932 appropriate size food organisms (25). Sulbalpine river Section-2 0-7 61 Anuri, upper Coruh River, in 0.955 Specially, condition factor and relative growth, up to preferred 0-6 length classes, values Cenker stream was lower than in Kan and Pres Turkey 9 ent 0.961 Anuri streams. It may be attributed following patterns. Cenker has Kan 0-7 highest slope and it supply unsuitable habitat for larger brown trout, Stud 9 y 0.739 prefer more deep and slower velocity water (30,31,32,33,34). (5) Cenker 0-7 3 -1 5 found that an annual discharge of 0.00679 m sec in a tributary 1 stream in Ontario precluded use by larger fish during winter that Authors calculated values of total mortality by using age-frequency values in the papers. overwintered in deeper pools of the main river with discharge of 2 2.24 m3 sec-1. Also, Fish consume more energy because of slope get Authors calculated values of Instantaneous rate of total mortality by increase velocity (3,25). using annual rates of survival values in the paper.

Stock size individuals were common in all three streams. Quality It may be suggested following patterns due to values of age-length size fish were uncommon in the Kan Stream, while The Anuri and frequency distribution, Z, PSD/RSD, condition factor and relative Cenker streams contained more abundant numbers of this size weight. Although Anuri, has a roadway along bed, and Kan stream, category. Preferred size brown trout were only found in the Cenker has a highway and high human population are relationally better than Stream. The PSD and RSD values match well with the apparent Cenker, They have mostly younger fish, Cenker stream, which is fishing pressure that each stream receives. The Kan Stream receives difficult to reach anywhere and a low human population and the highest fishing pressure and exhibits the highest instantaneous protected by resident people. We think that this patterns has occurred rate of total mortality. The Anuri Stream receives the next highest a result of human activities on streams. fishing pressure and exhibits a slightly lower mortality rate. The Cenker Stream receives the lowest fishing pressure and exhibits the VI. ACKNOWLEDGEMENTS lowest mortality rate. We wish to thank Dr. James Parham and Mr. Vaughn Snook for valuable comments on drafts of this manuscript. Support for this research was provided to A. Yildirim by the University of Ataturk,

262 International Conference on Advances in Biotechnology and Pharmaceutical Sciences (ICABPS'2011) Bangkok Dec., 2011

Ispir Hamza Polat Vocational School, Erzurum, Turkey, and [27] Ricker, W.E. 1975. Computation and interpretation of biological assistance in preparation of the manuscript was provided to E. J. statistics of fish populastions. Bull. Fish. Resh. Board. Peters by the Agricultural Research Division of the University of [28] Milewski C.L and M. L. Brown 1994. Proposed standard weight (Ws) Nebraska, Lincoln, Nebraska,USA. equation and length-categorization standards for stream-dwelling brown trout (Salmo trutta) Journal of Freshwater Ecology 9: 111-117. [29] Anderson, R.O. and S.J. Gutreuter 1996. Length, Weight, and References Associated Structural Indices. Pages 283-299. In Larry A. Nielson and [1] Frost, W.E. and M.E. Brown 1967. The Trout. Collins. David L. Johnson Editors. Fisheries Techniques. American Fisheries [2] Elliott J.M. 1994. Quantitative Ecology and the Brown trout. Oxford Society, Bethesda, Maryland. University press. [30] Heggenes, J. 1988a. 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