Chattonella marina which blooms regularly along

the Calicut coast bloomed for the first time in

the coastal region along Vypin, Cochin in September

2003. The bloom extended to a distance of about 1km

from the coastline covering a distance of 3km from

Puthuvypin to Malipuram

Jugnu, R

Kripa, V

CMFRI Digital Repository

C M Y K12 Marine Fisheries Information Service T&E Ser., No. 195, 2008The clupeid Albula vulpes and the sailfish Istiophorusoccurred in the period prior to the bloom, the formerduring the first instance of Chattonella marina bloomand the latter during both the blooms.Taxonomic diversity studies indicated a changein the community structure of commercial finfishes,crustaceans and molluscs due to the bloom ofC.marina. Though the species numbers did not varybetween the bloom and the non bloom period, thetaxonomic distinctness differed indicating a changein the community structure. Funnel plots indicated thedeviation in taxonomic distinctness during the bloomperiod from the theoretical mean for the region.Significant variations were observed in the bloommonth of September 02 and more in the post bloommonth of October 02. The effect of the bloom on thefishery appeared to be temporary reviving soon afterthe subsidence of the bloom. However, the economiclosses were high in the year in which the bloom wasprolonged since the fishermen abstained from fishingdue to the absence of fish shoals and low fishabundance.Subsequent to this, mass mortality of greenmussels of the region was also observed. Besidesfishes and mussels, the mole crab Emerita sp. wasalso found to be severely affected and these werefound washed ashore all along the Kappad beach on4/9/02. At Chombala, the shells of the bivalve Mactraviolacea with decayed meat was found washedashore in large numbers on 13/9/02.A report on the mass mortality of farmed shrimp due to the blooming ofChattonella marina along Vypin coastR. Jugnu and V. KripaCentral Marine Fisheries Research Institute, KochiChattonella marina which blooms regularly alongthe Calicut coast bloomed for the first time inthe coastal region along Vypin, Cochin in September2003. The bloom extended to a distance of about 1kmfrom the coastline covering a distance of 3km fromPuthuvypin to Malipuram. The greenish browncoloured bloom was noticed in the second week ofAugust in the coastal waters and adjacent farms ofthe area. Bloom subsided in the coastal waters onthe third day itself, but in nearby fish ponds it remainedin the bloom condition till the end of the month.Sampling was done on alternate days, from the daythe bloom was observed at sea (19/9/03) till the endof the following month until the normal flora wasrestored.The phytoplankton collected from the sea wasdominated by C.marina on the 1st and 3rd day afterwhich the diatom Coscinodiscus sp. becamedominant. Count of C.marina on 1st day was 2,40,000cells l-1 which decreased to 17000 cells l-1 on the 3rdday and was absent in the subsequent samplings.Coscinodiscus sp. present at 98 cells l-1 on the 1stday, increased to a density of 137 cells l-1 by 23rd day.A higher density was noted in the farm whencompared to that of sea. The density which was4,68,000 cells  l-1, on the 1st day decreased to 40,000cells l-1 by the 3rd day. On the 5th day, it again increasedto 2,00,000 cells l-1 but there were isolated patches inthe ponds which received bright sunlight where C.marina had concentrated in very high numbers. Bythe 7th day, Peridinium sp. had become dominantwhose density increased to 1400 cells l-1 by the 23rdday of the bloom.Temperature seems to play an important role inretaining the bloom condition. The results of theanalysis of physicochemical and biologicalparameters measured at the two sites is given inTable. Chl a, b, c and carotenoids values were higherat sea in the 1st, 3rd and 5th day and varied between55.9 and 73.7 mg m-3 for Chl a, 0 and 23.81 mg/m3for Chl b and between 5.89 and 21.58 mg m-3 for chl cand between 0 and 1.244 mg m-3 for carotenoids. Onthe 7th, 9th and 23rd day Chl a varied between 1.1 to7.89 mg m-3. Chl b at the site varied between 0.6113and 6.13, Chl c between 0.36 and 0.381 andcarotenoids between 0.019 and 0.14 mg m-3. In thefarm site pigment values were comparatively higherthroughout the bloom period. It varied between 14and 48 for Chl a between 0 - 44.4 for Chl b, 3.6 - 16.5for Chl c and 0.07 - 1 mg.m-3 for carotenoids.Comparatively higher Chl a was recorded on the 3rdand 23 rd day of the bloom. High Chl b and c of 44.4and 16.5 mg.m-3 was obtained in the 9th day ofsampling. Chl b and carotenoids were lower of14.37and 1.01 mg.m-3  on this day. Day 1 Day 3 Day 6 Day 8 Day 10 Day 23Sea Farm Sea Farm Sea Farm Sea Farm Sea Farm Sea FarmAT (o C) 27 34 29 30 30 31.2 31.2 30.2 28.2 29.3 32 26SST (o C) 29 33 29 30 27.3 35 26.2 30.3 29 30.3 29 30Salinity (ppt) 30 26 30 26 35 25 31 27 33 26 34 26Dissolved oxygen (mg/l) 2.06 2.61 2.12 2.4 2.28 2.06 3.68 4.73 4.12 3.36 4.38 3.88pH 8.3 8.3 7.96 7.9 7.7 7.5 7.7 7.7 7.8 7.5 8.1 7.6Ammonia (µmol l –1) 0.05 1.56 0.00 1.42 2.57 0.50 0.51 0.78 0.32 1.38 0.24 0.65Nitrate (µmol l –1) 4.48 71.84 0.05 0.15 0.45 0.08 0.84 2.74 0.37 2.24 0.48 2.45Nitrite (µmol l –1) 0.10 0.16 0.08 0.06 0.08 0.09 0.08 0.07 0.11 0.07 0.09 0.11Phosphate (µmol l –1) 0.53 1.44 1.77 2.03 1.55 2.32 0.58 3.52 0.52 2.39 0.82 2.56N:P 8.7 51.1 0.1 0.8 2.0 0.3 2.4 1.1 1.5 1.5 1.0 1.3TSS 2.5 4 10.5 48.1 11.3 12.6 10.5 5.2 6.6 16.2 8.5 10.2BOD 0.5 5.1 1.8 12.3 1.9 5.5 1.3 8.4 2.1 5.8 2.5 2.5Chl a  (mg/m3) 55.94 24.67 64.8 5.4 73.7 13.98 1.1 17.38 2.73 14.34 7.89 40.4Chl b (mg/m3) 0 4.66 23.81 0 0 1.4 0.613 1.88 6.13 44.4 1.36 0.82 Chl c (mg/m3) 9.33 4.98 21.58 4.33 5.89 4.88 0.358 3.62 3.81 16.55 1.41 13.1Carotenoids (mg/m3) 0 0.584 1.244  0.99 1.065 0.069 0.0193 0.44 0.115 1.013 0.142 0.92Table. Environmental parameters, cell density and diversity indices during the bloom of Chattonella marina at NarakkalEnvironmental variationsThe air temperature showed a general increasingtrend from a low value of 27oC on the 1st day to 32oCon the 23rd day except a decrease from 31.2 to 28.2oC on the 8th day of bloom. The SST stayed at a valueof 29oC except a lower value of 27.3 and 26.2 oC onthe 5th and 7th day of the bloom. Compared to sea,the AT and SST in the adjacent farm was higher. Thetemperature decreased steadily from a high value of34 oC in the initial to 26oC in the last phase and SSTdecreased from 33 to 30 oC except a high value of35oC on the 5th day.  Salinity varied between 30 and35 ppt in the sea and between 25 and 27 ppt in thefarm. Dissolved oxygen content was found to increasesampling which varied between 0.05 to 0.84 for nitrateand 0.09 to 0.1 µmol l –1 for nitrite. Ammonia valuesshowed a depletion in the first day and increased to2.57 µmol l –1 on the 5th day and thereafter againstarted decreasing. Phosphate which was low initiallyincreased to values between 1.55, 1.77 and thereafterdecreased to values below 0.8 µmol l –1. In the farm,the nitrate content of the water was very high, 71.84µmol l –1 on the 1st day. It sharply declined to 0.15 and0.082 µmol l –1 in the subsequent samplings andslightly increased thereafter. Phosphate valuesshowed an increasing trend from 1.44 in the beginningto values between 2.03 and 3.52 µmol l –1 in thesubsequent samplings. Ammonia values showedsteadily from a value of 2.06 during the bloom to 4.38mg l-1 when the algae was absent from thephytoplankton community. In the farm, dissolvedoxygen value was low in the initial phase and variedbetween 2.06 to 2.61 mg l-1 and between 3.36 to 4.73in the last phase.The nutrient content was higher in the farm sitewhen compared to that of the sea. Nitrate and nitritevalues were high at sea on the 1st day with values of4.48 and 0.101 µmol l–1  respectively. Comparativelylower values were obtained in the subsequentA report on the mass mortality  of Chattonella marina along Vypin coast14 Marine Fisheries Information Service T&E Ser., No. 195, 2008frequent fall and rise at the site. It was higher on the1st  and 3rd day with values of 1.56 and 1.42 µmol l –1and varied between 0.5 and 1.38 in the subsequentones. Nitrite which was slighltly high with a value of0.157 µmol l –1 in the first sampling showed lowervalues in the subsequent samplings.ImpactsHeavy mortality of shrimps and fishes werenoticed in the shrimp ponds at Narakkal and nearbyvillages like Valappu, Elakkunnapuzha andNayarambalam where there was a direct intake ofwater from the sea. Though C. marina remained inthe bloom condition only for a short period of aboutthree days in the sea, the algae that had entered thecoastal farms during tidal exchange and remained inthe ponds for a longer period which led to massmortality of fishes and prawns in these ponds. Thefishes which were killed were mainly Chanos chanos,Mugil cephalus and Etroplus maculatus. Farmersfaced heavy financial losses as fishes of all sizegroups from 100 to 600 mm were killed due to thebloom. Heavy mortality (>90%) of peaneid shrimpslike Penaeus monodon and P. indicus and nonpenaeid shrimps like Metapenaues dobsoni and M.affinis were observed. An unusual catch of catfisheswere obtained by fishermen during the bloom period.Catfishes which appeared in large numbers seemedto be in a disoriented condition and so could be easilycaught. The fish and water samples were analysedfor paralytic and diarrhetic shell fish poisoning at CIFT.The mouse bioassay showed the presence of a lipidsoluble toxin.M.K. Anil, Jasmine S., Rani Mary George, Jose Kingsly, Raju B., Udayakumr A. and Suresh .K.K.Vizhinjam Research Centre of Central Marine Fisheries Research Institute, VizhinjamUnusual landings of shrimps, trichiurids, ballistids andornamental fishes along Vizhinjam coastHeavy landings of shrimps and fin fishes wererecorded from Vizhinjam, Trivandrum during 22ndto 24th June with peak landings on 24th June 2007. Amud bank like phenomenon was observed in the area.Water was very turbid and wave action wasconsiderably reduced in the near shore waters. Signsof upwelling such as low surface water temperatureand dissolved oxygen were also observed. Surfaceseawater temperature ranged from 23-24°C and thesurface dissolved oxygen was 3.02 ml/litre comparedto normal values of 27-27.5 °C and 3.8-4.5 ml/litrerespectively. Salinity of seawater was 31 ppt. AboutA good catch of Fenneropenaeus indicus Trichiurus lepturus landings

A report on the mass mortality of farmed shrimp due to the blooming of Chattonella marina along Vypin coast

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