Immediate effect of bottom trawling on the physicochemical parameters in the inshore waters (Cochin -Munambum) of Kerala


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Authors

  • Joice V Thomas School of Industrial Fisheries, Cochin University of science and Technology, Cochin-628 016, India
  • P Premlal School of Industrial Fisheries, Cochin University of science and Technology, Cochin-628 016, India
  • C Sreedevi School of Industrial Fisheries, Cochin University of science and Technology, Cochin-628 016, India
  • B Madhusoodana Kurup School of Industrial Fisheries, Cochin University of science and Technology, Cochin-628 016, India

Abstract

The immediate effect of bottom trawling on physico-chemical parameters of the sea bottom was studied during December 2000 to June 2001 along Cochin -Munambum area (Long.76º10’ 94" to 75º 56’00" and Lat. 9058’ to 10010’), in
the south west coast of India at depth ranging from 0-50m. Trawling operations were carried out at selected depth zones viz. 0-10,11-20,21-30,31-40 and 41-50 m using a commercial trawler of size 45 OAL. Temperature, salinity, dissolved
oxygen, turbidity, pH and nutrients were determined before and after trawling. Perceptible variations could be observed in turbidity, dissolved oxygen and nutrients in the bottom water samples after trawling when compared to the same collected before trawling. While turbidity and nutrients showed an
increase, dissolved oxygen decreased in the bottom waters immediately after trawling and this was due to the churning action of trawl nets on sea bottom. Highest turbidity of 88 NTU was observed in July, while nitrites and inorganic
phosphates registered highest values of 3.27 and 8.32 micromoles per litre respectively in July in samples collected after trawling. Variations in respect of temperature, salinity and pH due to bottom trawling were insignificant

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Author Biographies

  • Joice V Thomas, School of Industrial Fisheries, Cochin University of science and Technology, Cochin-628 016, India
    School of Industrial Fisheries, Cochin University of science and Technology,
    Cochin-628 016, India
  • P Premlal, School of Industrial Fisheries, Cochin University of science and Technology, Cochin-628 016, India
    School of Industrial Fisheries, Cochin University of science and Technology,
    Cochin-628 016, India
  • C Sreedevi, School of Industrial Fisheries, Cochin University of science and Technology, Cochin-628 016, India
    School of Industrial Fisheries, Cochin University of science and Technology,
    Cochin-628 016, India
  • B Madhusoodana Kurup, School of Industrial Fisheries, Cochin University of science and Technology, Cochin-628 016, India
    School of Industrial Fisheries, Cochin University of science and Technology,
    Cochin-628 016, India

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Issue

Vol. 51 No. 3 (2004)

Section

Articles

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The copyright of the articles published in Indian Journal of Fisheries vests with the Indian Council of Agricultural Research, who has the right to enter into any agreement with any organization in India or abroad engaged in reprography, photocopying, storage and dissemination of information contained in these journals. The Council has no objection in using the material, provided the information is being utilized for academic purpose but not for commercial use. Due credit line should be given to the ICAR where information will be utilized.

How to Cite

Thomas, J. V., Premlal, P., Sreedevi, C., & Kurup, B. M. (2011). Immediate effect of bottom trawling on the physicochemical parameters in the inshore waters (Cochin -Munambum) of Kerala. Indian Journal of Fisheries, 51(3), 277-286. https://epubs.icar.org.in/index.php/IJF/article/view/7202