some of the

multi-day units ventured into deeper waters

(60-80 m) and obtained good catches of reef

cods (Fig: 1) along with threadfin breams and

cuttle fishes. Encouraged by this, more number

of multi-day units were put into operation in

September of the following year (1995) and got

still better catches of reef cods

Kemparaju, S

Mahadevaswamy, H S

SampathKumar, G

Zacharia, P U

CMFRI Digital Repository

lurdEniRd MARINE FISHERIES INFORMATION SERVICE APRIL, MAY 1997 , . . T T ^ T E C H N I C A L A N D h J l o i c l l E X T E N S I O N S E R I E S •^FV CENTRAL MARINE FISHERIES STT^^FTF^TFT RESEARCH INSTITUTE tF%r^, 'JTRrf COCHIN, INDIA INDIAN COUNCIL OF AGRICULTURAL RESEARCH HIGH ABUNDANCE OF LARGE SIZED ROCK CODS {EPINEPHELUS SPP.) OFF KARNATAKA COAST DURING THE POSTMONSOON MONTH OF SEPTEMBER* Introduction Mechanised trawl fishery along the Mangalore and Malpe coasts resumes in September every year after a ban of 3 months on mechanised fishing during monsoon. Till 1994, trawling operation during September-October was of less intensity and mostly carried out by few single-day units in the inshore waters. Multi-day units usually start their operation by mid October or early November. However, during September 1994, some of the multi-day units ventured into deeper waters (60-80 m) and obtained good catches of reef cods (Fig: 1) along with threadfin breams and cuttle fishes. Encouraged by this, more number of multi-day units were put into operation in September of the following year (1995) and got still better catches of reef cods. This large scale landing of rock cods was again observed during September 1996 also. Due to this phenomenal occurrence of the high value rock cods in sizeable quantities during the post- monsoon month of September for the last three years, a study of the fishery was carried out; the details of which are presented here. Fig. 1. Heap of rock cods ready for transportation. Fishery Catch and effort During September 1994, an estimated 142 tonnes of rock cods were landed at Mangalore and Malpe at a catch rate of 183 kg/unit (Fig. 2). In September of the following year, a sharp increase in the number of units operated (from 774 to 2,304) was observed. The landing of large size rock cods was 534 t and it formed 13.5% of the multi-day trawl catch. The catch in September alone constituted 40% of the annual reef cod catch. This heavy landing lasted only upto the 3rd week of September and thereafter the catch started to decline and from October onward the rock cod catch consisted exclusively of juveniles of the spinycheek grouper, Epinephelus diacanthus. Landings of reef cods during September 1996 were estimated at 584.4 tonnes forming 18.26% of the trawl catch at a catch rate of 300 kg/unit. There was a marginal fall in the number of units operated as well as actual fishing hours as compared to the correponding month of previous year. Nevertheless, the landing of rock cods registered an increase of 50.7 tonnes (Table 1). Apart from rock cods, dominant groups present in multi-day fleet catch were cuttlefishes and threadfin TABLE 1. Details of catch, effort and catch rate of rock cods at Mangalore and Malpe during September and the biological characteristics of dominant species Particulars No. of units operated Trawling hours Total trawl catch (t) Catch of rock cods (t) % In total catch % in annual catch Catch rate (kg/unit) Dominant species Length range (cm) Mean size (cm) Mean weight (g) Length-weight relationship September 1994 774 18,110 899 141.9 15.79 14 183.3 E. diacanthui ----September 1995 2,304 94,529 3,950.211 533.671 13.51 40 231.6 September 1996 1,945 80,332 3,199.6 584.4 18.26 -300.5 E. diacanthus E. diacanthus 25-48 32.4 476 -22-44 32.96 457 a = 0.018015 b = 2.660619 * Prepared by: P.U. Zacharla, H.S. Mahadevaswamy, S. Kemparaju and G. Sampathkumar, Mangalore Research Centre of CMFRI, Mangalore - 575 001 10 700 CATCH (TONNES) CATCH RATE (KQ/UNIT) 350 Ssptember 94 September 96 September 96 I S CATCH E 3 CATCH RATE Fig. 2. Catch and catch rate of rock cods during September of last three years at Mangalore-Malpe. Species and length composition The rock cod catch during September 1995 £ind 1996 consisted of five species namely, Eptnephehis diacanthus (82.65%), E. epistictus (7.71%), E. malabaricus (4.6%), E. latifasciatus (3.21%) and E. chlorostigma (1.9%). The size range of E. diacanthus was 25-46 cm and the modal size group was 30-34 cm (Fig. 4). During October 1995 the catch consisted of small sized E. diacanthus in the length range of 20-32 cm with modal size at 24-26 cm. In September 1996 the length of E. diacanthus ranged from 22 to 44 cm with the mean length at 33 cm. The average weight of each specimen during Septem-ber 1995 and 1996 was more or less the same (Table 1). The length range of E. malabaricus was 60-64 cm. breams (Fig. 3). Crustaceans were caught only in less quantities. Depth of operations and craft and gear employed During September 1994 trawling along Karnataka coast was carried out in depths ranging from 60 to 80 m. Fishing was mainly of four day/night duration. In the following year (1995), fishing was extended to still deeper waters and in September 1996 trawling was carried out between 72 and 108 m depth. The area of operation was north of Mangalore upto Karwar. The details of the craft and gear employed by multi-day fleet are given elsewhere (Zacharia et al 1996, Mar. Fish. Injor. Sew., T &E Sen, No. 143). Priacanthus 2.7 Cephalopoda 40.9 MIsc.flshes 5.3 1 hreadfIn breams 25 LIzardflsh Crtasfaceans 0.12 Rock cods 18.3 Fig. 3. Percentage occurrence of different groups In the mutlj-day trawl catch at Mangadore-Malpe during September 1996. 25 20 15 10 Percentage frequency 1 B 8*pt.95 I § • 8*pt.9e I I fm m 23 25 27 29 31 33 36 37 39 41 43 46 Total length (cm) Fig. 4. l.ength frequency distribution of E. diacanthus at Mangalore in September 1996. Price structure and marketing The small sized fishes were sold in local market and others were sent to neighbouring states. The price per kg/of fish varied between Rs. 8 and 20 at the Icinding centres. Remarks The exploratory handline operations carried out by R.V. Varuna between 8°N and 14°N of the southwest coast yielded good quantities of perches abundant with the species of Eptnephehis, Lutjanus and Lethrinus indicating good perch grounds (Silas, 1969, Bull, CMFRI, No. 12). Exploratory trawl surveys during 1992-'95 by Indo-Danish Fisheries Project, IDFP (1995) indicated high concetration of reef cods along Karnataka coast between 50-125 m depth associated with areas of coral and rocky bottom. 11 10' 20' 30' 40' 50' 7 4 ' 10' 20' 30' 40' 50' 75° INDO-DANISH FISHERIES PROJECT TAORI KARNATAKA STATE Fig. 5. Map showing the distribution pattern of rock cods along the Karnataka coast (Reproduced from Fishery Charts - Konkan coast published by IDFP, Tadrl, Karnataka). Considerable quantities of the juveniles of the spinycheek grouper, Epinphehis diacanthus used to land every year during October-March (Zacharia et al 1995, Mar. Fish. Infor. Sew., T & E Sen, No. 139). The multi-day units recently ventured into deeper waters during September and landed large quantities of rock cods, threadfin breams and cuttlefishes making the trawling operation in this month very profitable. The catch and effort data for the past four years indicate the rise in the number of multi-day units in September every year. The effort increased from 274 fishing hours in 1993 to 80,332 hours in 1996. The average rock cod catch for the entire Karnataka state during 1985-'89 period was 311.6 tonnes whereas the catch from Mangalore-Malpe alone now stands at 1,344 tonnes (1995/ •96). Reef cods are shoaling fishes found near the bottom. IDFP reports (1995) show that highest concentration was in August-October and maximum catch rate of 35 kg/hr was during August. The areas of high abundance are between Ankola-Tadri and Coondapur-Mangalore (Fig. 5). The study indicated that many areas in deeper waters along the Karnataka coast are also rich in cephalopod, threadfinbream and lizardfish resources which can be exploited by the traditionally used trawl boats with provisions like steel wire rops and fish finding equipments and high opening nets. IDFP 1995. Fishery Charts - Konkan coast. Published by Indo-Danish Fisheries Project, Tadrl, elaborated by Dept. of Fisheries, Govt, of Karnataka and sponsored by DANIDA. 12 

High abundance of large sized rock cods (Epinephelus spp.)  off

Karnataka coast during the postmonsoon month of September

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High abundance of large sized rock cods (Epinephelus spp.) off Karnataka coast during the postmonsoon month of September

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