On the occurrence of Acanthaster planci (the crown-of-thorns) at Minicoy Atoll.

The predation of coral-polyps by the multi-armed star fish Acanthaster planci is identified during the last two decades as a major biological factor that causes large scale death to reef corals at several parts of the Indo-Pacific. During a recent visit by a team of scientists from Central Marine Fisheries Research Institute,the presence of this star fish in the lagoon of Minicoy Atoll was noticed in November, 1979.Many control measures of star fishes have been practised elsewhere in the Pacific. However, hand-picking of the adults with the aid of pointed spears and killing them with formalin or ammonia solution is the most eifective.Careful search among the corals is required, since the crown-of-thorns hide under the crevices during day time

Hydrography and Circulation in the Vicinity of a Power Plant

131-135Physical aspects of the hydrographic survey conducted in the vicinity of the Tarapur Atomic Power Plant are presented. No spatial variation in temperatures has been noticed in the intake and discharge canal regions. The sediment load in the sea water varies inversely with the distance from the coast. Flow patterns more or less parallel to the coast with strong onshore components have been observed

Studies on mixing of the waters of different salinity gradients using Richardsons number and the suspended sediment distribution in the Beypore estuary, south west coast of India

29-34<span style="font-size:14.0pt;line-height: 115%;font-family:" times="" new="" roman";mso-fareast-font-family:"times="" roman";="" color:black;mso-ansi-language:en-in;mso-fareast-language:en-in;mso-bidi-language:="" hi"="" lang="EN-IN">The study was conducted up to 15 km upstream in the Beypore estuary of the Chaliyar river in Calicut. The study area was divided into four sections (5 km interval) with two transverse stations on either side of each section. The logarithmic values of Richardsons number (log RL) shows high variation at river mouth section of the estuary (section-I) and at about 10km upstream (section-II) during the postrnonsoon period. During the premonsoon period there was no noticeable variation in log RL values at section-I and section- II and the estuary was found to be well mixed. During the monsoon period the stratification was higher and the variation in log RL was high from flood to ebb tide. The lower part of the estuary is a turbidity maximum zone, especially during premonsoon season. During the postmonsoon period the concentration of suspended matter was not high compared to premonsoon and monsoon period. There was a high surface value during ebb tide in monsoon period.</span

Studies on sediment transport along Kerala coast, south west coast of India

11-15Longshore sediment transport characteristics of the Kerala coast have been examined to delineate various physical processes affecting the different coastal environments. Monthly averages of the daily LEO (Littoral Environmental Observation) data for one year made at each station have been used for this study. Monthly longshore sediment transport rates showed high variability in the sediment transport mechanism

Flushing characteristics of Amba river estuary, west coast of India

212-215Tide dominated Amba river estuary was studied to evaluate its flushing characteristics. Although, spring tidal range of 3.4 m was observed at 40 km inland, the seawater component here at high tide was < 1%. The wet weather flushing time of 22 tidal cycles for neap, 6 to 7 tidal cycles for spring and dry weather flushing time of 45 tidal cycles for neap, 6 to 7 tidal cycles for spring based on modified tidal prism method indicated that the load retained in the estuary after infinite number of tidal cycles was 17 times and 33 times for neap during wet and dry weather conditions and 2 times the load introduced per tidal cycle for spring during both the weather conditions. The flushing times calculated by the classical tidal prism method were shorter than those obtained by the modified tidal prism method

Residual fluxes of water, salt and suspended sediment in the Beypore estuary

157-162The monthly trends of the residual fluxes of salt and water and the transportation of suspended sediments in the Beypore estuarine system were examined. At the river mouth the water flux was directed seaward during the postmonsoon and monsoon season. During the premonsoon period the transport was upstream and the net transport was higher during May. Maximum flux of the suspended sediment was obtained during July (1220.97 mg/cm2/s) at the river mouth. High negative fluxes are obtained during premonsoon period with the highest value occurring during May (-381.31 mg/cm2/s) at river mouth. During the study period the annual sediment input and the net sediment transported towards the sea were estimated to be 8.8 x 104 tons per year and 5.7x104 tons/year respectively so that the annual entrapment of sediment was 3.1x104tons per year

Not Available

Not AvailableThe predation of coral-polyps by the multi-armed star fish Acanthaster planci is identified during the last two decades as a major biological factor that causes large scale death to reef corals at several parts of the Indo-Pacific. During a recent visit by a team of scientists from Central Marine Fisheries Research Institute,the presence of this star fish in the lagoon of Minicoy Atoll was noticed in November, 1979.Many control measures of star fishes have been practised elsewhere in the Pacific. However, hand-picking of the adults with the aid of pointed spears and killing them with formalin or ammonia solution is the most eifective.Careful search among the corals is required, since the crown-of-thorns hide under the crevices during day time.Not Availabl