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Studies on materials for traps for spiny lobsters
(Elsever, 1985) Meenakumari, B.; Rajan, K.V.M.
Studies were conducted along the south-west coast of India in order to identify suitable aterials and preservative treatn1ents for the fabrication of spiny-lobster traps. Traps were fabricated in different designs using different materials, such as bamboo splinters, coconut leaf stalk fibres, wood, pqlyethylefie twines, Polystrap binding tape, mild steel rod, welded mesh, chicken wire netting and galvanised iron wire. As measures of preservation, the traps fabricated of iron materials were pll!stic-coated or painted with anti-corrosive paints, and bamboo traps were treated with ASCU (arsenic-copper chrome composition) or creosote. To assess the perfoimance of different materials and to recommend suitable materials and protective coatings, t4e traps were subjected to experi mental fishing using an indigenous trap as a control. The results show that bamboo traps are weak and fragile and wooden traps are un:wie"idy and so are not favoured. Metal traps made of mild steel rods and welded mesh covered by complete plastic coating were found to perform efficiently and last longer.
Seasonal Changes of the Major Fouling Organisms in Cochin Harbour
(Ocean Research, 1998) NAlR, N. U.; MEENAKUMARI, B
Biofouling census in Cochin Harbour, the rank correlation coefficients between the members of the fouling community and their dependence on environmental perturbations are reported. The affinity/ coexistance between major taxa of foulers is examined by cluster analysis through coefficient of correlation . Maximum correlation is observed between polyzoans and tube-dwelling worms. Modiolus sp.. barnacles and oysters ranked next in their order of coexistence-. The higher fouling biomass observed is attributed to the profusion of species. their fastcr growth and attainment of sexual maturity at an early date in the tropics.
Catching efficiency of gill nets and trammel nets for penaeid prawns
(ELSEVIER, 2003) Thomas, S.N.; Edwin, L.; George, V.C.
Fishing experiments were carried out with gill nets and trammel nets off Cochin, India, from June to August 1991 to determine the relative catching efficiency of these nets to penaeid prawns. A fleet of nets consisting of two sets of gill nets of polyamide (PA) monofilament and PA multifilament; and one set of PA multifilament trammel nets, each of four units of mesh sizes 34.0, 38.0, 40.0 and 50.0 mm was used. The relative efficiency of gill nets and trammel nets with regard to material and mesh size was compared. PA monofilament was 1.5 times more efficient than PA multifilament as a gill net material. Of the four mesh sizes used, 38.0 mm gave higher catch rates than the other mesh sizes for the exploitation of Penaeus indicus of the 100-160 mm length group. Trammel nets caught on average two times more prawns than monofilament gill nets.
Resistance of preservative treated rubber wood (Hevea brasiliensis) to marine borers
(Springer, 2004) Edwin, L.; Pillai, A.G.G.
Abstract The susceptibility of rubber (Hevea brasilien- sis) wood to marine borer attack limits its use for marine purposes. In the present study three types of biocides viz. copper creosote, arsenical creosote and a dual preserva- tive treatment with copper- chrome- arsenic and creosote were selected for comparing their relative efficacy in preventing biodeterioration. The treated panels were ex- posed at the test site in Cochin harbour. The extent of internal damage through marine borer attack was assessed through visual observations, X-ray photographs and me- chanical strength testing. The untreated test panels were destroyed within six months whereas it was found that preservative treatment prevented biodeterioration under marine conditions. This was confirmed by radiographic studies and comparison of compressive stress at maxi- mum force. The service life of this cheaply and easily available timber can be increased to meet the growing demand of timber in the small-scale fisheries sector.
Assessment of biodetrioration or rubber wood exposed to field conditions
(ELSEVIER, 2006) Edwin, L.; Ashraf, P.M.
Rubber wood (Hevea braslliensis) can be used commercially for the construction of fishing boats, which are subjected to biodegration in the water, and on land both with and without soil contact. In order to obtain data on the natural durability of this wood, the extent of biodeterioration was assessed through visual observation, changes in the specific gravity of the wood and loss in the compressive strenght of wood panel after 90 and 150 days in field tests. Changes in wood chemistry due to biodeterioration under field conditions wre also characterized through Fourier transform infrared (FTIR)spectroscopy. Test samples in soil burial tests (graveyard tests) wre more severely damaged than panels exposed to atmospheric weathering or immersed in sea water below the low tide mark. Strength losses in panels exposed to the marine and atmospheric conditions were not commensurate with the weight losses.
Studies on the seasonal changes of phosphorus in the marine environments off Cochin
(Elsevier, 2006) Ashraf, P.M.; Edwin, L.; Meenakumari, B.
Studies were conducted to evaluate the changes of phosphorus in marine water and sediments of seven stations in the coastal areas off Cochin. Samples were collected on a monthly basis from January 2001 to December 2001. Results revealed higher levels of P in marine water samples collected during October–December 2001. The marine water P ranged from 0 to 0.38 ppm throughout the year. Speciation of P in marine sediment revealed that the Al bound P was maximum compared to Fe, Ca and organic bound P. Loosely bound and aluminium bound P was maximum during October–December especially in 10 and 20 m depth stations off Narakkal. Fe bound P was found to be least in June and September and highest during January–April. Low levels of Ca bound P were detected in samples collected during January–March and inorganic P was maximum in June and September. Organic bound P was maximum in 10 m depth stations and also during June and September. Phosphate fractions varied with locations and exhibited seasonal fluctuations.
Reinforcing aluminium with cerium oxide: a new and effective technique to prevent corrosion in marine environments
(Elsevier, 2007) Ashraf, P.M.; Shibli, S.M.A.
Cerium oxide (CeO2) is one of the potential choices to be explored for the protection of aluminium from corrosion. However, usage of cerium ions for surface modification of aluminium would not yield any potential effect in aggressive marine environments. Metal matrix composites of aluminium can have all the merits of aluminium such as density, strength, ductility and cost. In the present study, corrosion of aluminium in saline environment was significantly suppressed by means of reinforcing the aluminium with cerium oxide. The presence of cerium oxide in the matrix did not facilitate the formation of Al2O3 which would cause potential re-shift after few days due to the onset of pitting. The present results strongly lay emphasis on the potential scope of use of CeO2 for protection of aluminium in marine environments.
Occurance of live octocorals in the trawling grounds of veraval coast of gujarat, Arabian sea
(Central Fisheries Research Institute of Turkey, 2008) Bhagirathan, U.; Panda, S.K.; Madhu, V.R.; Meenakumari, B.
The present paper communicates the first record of live octocorals in the sub-tidal region of Veraval. The four genera identified are Litophyton sp., Studeriotes sp., Juncella juncea (Pallas) and Subergorgia suberosa (Pallas). The presence of octocorals in the trawling ground with depth of 15-20 m justifies the need to carry out further studies on the impact of bottom trawling on the coral reef ecosystem.
Development of CeO2 and TiO2- incorporated aluminium metal-composite matrix with high resistance to corrosion and biofouling
(Springer, 2008) Ashraf, P.M.; Shibli, S.M.A.
Cerium oxide (CeO2) is a potential corrosion inhibitor for aluminium, and titanium oxide (TiO2) is an efficient anti-fouling agent in the marine environment. The present study explored the possibility of incorporating CeO2 and TiO2 in aluminium to prepare a metal matrix composite that could have high corrosion and biofouling resistance under marine conditions. Such incorporation of CeO2 and TiO2 in pure aluminium offered high resistance to corrosion and biogrowth under marine conditions as evidenced during different tests. The specimens exhibited more anodic and stable open circuit potential throughout the period of the study. The optimum concentration of CeO2 and TiO2 was found to be 0.2 and 0.1%, respectively. The present results lay emphasis on the potential scope of the use of CeO2- and TiO2-incorporated aluminium in marine environments.
An appraisal of trawl fishery of Kerala
(Asian Fisheries Society Mannila, 2009) Hassan, F.; Sathidas, R.
Trawl fishery of Kerala contributes about 35-50% of the annual landings of the state. The ever increasing international demand for shrimps and cuttlefishes further induced acute competition, higher investment and continuous up gradation of trawlers. The technical specifications, capital investment, catch composition and revenue for single and multiday units has drastic differences. The present study aims to highlight the trawl landings of Kerala state and comparative efficiency of these units operating at Cochin Fisheries Harbour. The data was systematically collected during 2005-2006 in a pre-designed schedule covering all seasons. The secondary data was obtained from various publications of State Fisheries Department and CMFRI.The craft and gear specifications of these units indicate the increasing trend of capital intensity in an already overcapitalized sector. The study indicates that the shift towards multi-day units will further increase due to better catch and returns. Although the multi-day trawlers are economically efficient, the wastes and discards generated from these units are not advisable forthe long-term sustainable development of our open access marine fisheries. Regulations in termsof number of units, unit operations or quota system for trawlers appear to be imminent for theefficient management of marine fishery resources of the state.
Fish production and energy requirement during demersal and aimed midwater trawling by intermediate range freezer trawler
(Asian Fisheries Society, 2009) Boopendranath, M.R.; George, V.C.; Hameed, M.S.
This paper deals with the fish production and relative energy consumption in demersal and midwater trawling based on data derived from cruises of Intermediate range freezer trawler that operated in Indian waters during 1993-94. The trawler has length overall of 62.2 m, gross registered tonnage of 1898 and installed engine power of 2400 hp. Operations were conducted between 14° and 22° N lat., off west cost of India, within a depth range of 31 and 125 m, using 47.5 m four-seam bottom trawl rigged with bobbin gear and 70.0 m mid-water trawl. The present investigations have shown that significant improvements in landings were obtained during aimed midwater trawling, off west coast of India. The mean daily landings rose from an average of 5.66 t, during bottom trawling to 22.84 t, during midwater trawling, realising over 300% improvement in the landings that manifested in a significant reduction in the consumption of fuel per unit volume of fish landed by midwater trawling. Overall fuel consumption per kg fish landed by bottom trawling and midwater trawling worked to be 1.34 and 0.33 kg, showing a four-fold difference. The difference in daily fuel expenditure per unit volume of fish between bottom and aimed mid-water trawling was found to be highly significant statistically. As there is intense concentration of effort in the bottom trawl fisheries, it could be advantageous from the resource management perspective and also from the energy conservation point of view, to encourage diversification to midwater trawling, in a controlled manner without compromising on sustainability of resources. Stern trawler does not require any large-scale modifications in structure or deck layout, for undertaking midwater trawling. However, the vessel must be large enough, highly manoeuvrable and sufficiently powered to tow a large mouthed midwater trawl at speeds exceeding 4.5 knots; should be equipped with acoustic fish detection (sonar and echosounder) and trawl monitoring systems; and in addition, must have provision for handling and preserving large volume landings.
Remote sensing and fisheries : An introduction
(OXFORD University Press, 2011) Stuart, V.; Platt, T.; Sathyendranath, S.; Pravin, P.
The SAFARI Project (Societal Applications in Fisheries and Aquaculture using Remotely-sensed Imagery) was initiated in 2007 with funding from the Canadian Space Agency (CSA) for international coordination. SAFARI aims to accelerate the assimilation of earth observation into fisheries research and management on a global scale, one of the tasks of the intergovernmental Group on Earth Observations (GEO).
First estimate of the length–weight relationship of diaphus watasei jordan and starks, 1904 caught off the southwest coast of india
(Asian Fisheries Society, 2011) Vipin, P.M.; Pradeep, K.; Ravi, R.; Fernandez, T.J.; Ramesan, M.P.; Madhu, V.R.; Boopendranath, M.R.
The length-weight relationship of the myctophid fish species, Diaphus watasei, caught from waters off the southwest coast of India in the depth range of 300-400 m was estimated as male W=0.0026 L3.39 and females W= 0.0063 L3.06. The length–weight relation between the males and the females were found to be significantly different.
Estimation of Drift Gillnet Selectivity for Carangoides ferdau and Caranx papuensis in Kanyakumari Coast of South India
(Asian Fisheries Society, 2011) Balasubramanian, A.; Meenakumari, B.; Erzine, K.; Boopendranath, M.R.; Pravin, P.
Size selectivity parameters of drift gillnet for Carangoides ferdau and Caranx papuensis were estimated from catches obtained from the nets of 13.5, 14, 14.5 and 15 cm stretched mesh sizes operated in the Kanyakumari coast of South India from September 2002 to April 2004. In this study, maximum likelihood procedure was followed and a proprietary software GILLNET (Constat, Denmark) was used to fit selection curves viz., normal location, normal scale, log-normal, gamma and bi-normal. Of them, bi-normal model was found as best-fit for both the catch data. The fishing power influenced the selectivity of the gear in the case of C. ferdau while there was no influence in the other species C. papuensis. There was no significant difference between better-fit and best-fit models in both catch data. Modal length increased with mesh size. Shape and size of the selectivity curves were uniform in size. The mesh size 14.5 cm performed better than modeled by capturing larger size group of fishes with narrow selection range. Entangling and gilling appeared as common capture pattern in both the species. Over dispersion was found in the best-fit bi-normal model which also indicated the lack of fit and suggested for multi-nomial fitting of data.
Remotely sensed chlorophyll: a putative trophic link for explaining variability in Indian oil sardine stocks
(Elsevier, 2012) George, G.; Meenakumari, B.; Raman, M.; Kumar, S.; Vethamony, P.; Babu, M.T.; Verlecar, X.
The landing of Indian oil sardine, Sardinella longiceps Valenciennes, 1847 along the southwest coast of India is highly variable. A few physical parameters and processes correlated with sardine landing could not establish a flawless connection, and explain the phenomena of inter-annual variability.Earlier researchers indicated that the probable appearance and disappearance of sardine is an active movement in search of food and congenial conditions. But, no specific study has been carried out to explain the variability of sardine catch based on chlorophyll availability on a synoptic scale. An attempt is made in this study to correlate variability in chlorophyll-a with sardine landings along thewaters of southwest coast of India. We have estimated monthly averaged surface phytoplankton biomass along the waters of southwest coast of India from the shorelineupto 200 m isobath for ten years from SeaWiFS ocean colour data. This estimation is compared with the biological calendar of Indian oil sardine. The average chlorophyll-a for the bloom initiation month (1998-2006) matches very well with oil sardine landings. The results imply that the concentration of chlorophyll during the, bloom initiation month can be used to assess the quantum of fish that recruit into the population. Finer scale spatial variations in the chlorophyll along the coastal waters help in deciphering the migratory pattern of sardine during their active breeding phase. This study shows that 39% of interannual variability in fish landings is related to availability of chlorophyll-a during the bloom initiation month.
Phytoplankton community characteristics in the coastal waters of the southeastern Arabian Sea
(The Chinese Society of Oceanography and Springer-Verlag Berlin Heidelberg, 2014) Minu, P.; Shahu, S.S.; Ashraf, P.M.; Meenakumari, B.
Remote sensing applications are important in the fisheries sector and efforts were on to improve the predictions of potential fishing zones using ocean color. The present study was aimed to investigate the phytoplankton dynamics and their absorption properties in the coastal waters of the southeastern Arabian Sea in different seasons during the year 2010 to 2011. The region exhibited 73 genera of phytoplankton from 19 orders and 41 families. The numerical abundance of phytoplankton varied from 14.235×103 to 55.075×106 cells/L. Centric diatoms dominated in the region and the largest family identified was Thalassiosiraceae with main genera as Skeletonema spp., Planktionella spp. and Thalassiosira spp. Annual variations in abundance of phytoplankton showed a typical one-peak cycle, with the highest recorded during premonsoon season and the lowest during monsoon season. The species diversity index of phytoplankton exhibited low diversity during monsoon season. Phytoplankton with pigments Chlorophyll a, Chlorophyll b, Chlorophyll c, peridinin, diadinoxanthin, fucoxanthin, β-carotene and phycoerythrobilin dominated in these waters. The knowledge on phytoplankton dynamics in coastal waters of the southeastern Arabian Sea forms a key parameter in bio-optical models of pigments and productivity and for the interpretation of remotely sensed ocean color data.
Effect of optically active substances and atmospheric correction schemes on remote-sensing reflectance at a coastal site off Kochi
(Taylor & Francis Group, 2014) Minu, P.; Lotliker, A.A.; Shaju, S.S.; Santhoshkumar, B.; Ashraf, M.P.; Meenakumari, B.
The present study focused on understanding the variability of optically active substances (OASs) and their effect on spectral remote-sensing reflectance (Rrs). Furthermore, the effect of atmospheric correction schemes on the retrieval of chlorophyll-a (chl-a) from satellite data was also analysed. The OASs considered here are chl-a, coloured dissolved organic matter (CDOM), and total suspended matter (TSM). Satellite data from the Moderate Resolution Imaging Spectroradiometer (MODIS) on the Aqua satellite was used for this study. The two atmospheric correction schemes considered were: multi-scattering with two-band model selection NIR correction (hereon referred as ‘A1’) and Management Unit of the North Sea Mathematical Models (MUMM) correction and MUMM NIR calculation (hereafter referred as ‘A2’). The default MODIS bio-optical algorithm (OC3M) was used for the retrieval of chl-a. Analysis of OASs showed that chl-a was the major light-absorbing component, with highly variable distribution (0.006–25.85 mg m–3). Absorption due to CDOM at 440 nm (aCDOM440) varied from 0.002 to 0.31 m–1 whereas TSM varied from 0.005 to 33.44 mg l–1. The highest concentration of chl-a was observed from August to November (i.e. end of the southwest monsoon and beginning of the northeast monsoon), which was attributed to coastal upwelling. The average value of aCDOM440 was found to be lower than the global mean. A significant negative relationship between aCDOM440 and salinity during the southwest monsoon indicated that much of the CDOM during this season was derived from river discharge. Spectral Rrs was found to be strongly linked to the variability in chl-a concentration, indicating that chl-a was the major light-absorbing component. Satellite-derived spectral Rrs was in good agreement with that in situ when chl-a concentration was lower than 5 mg m–3. The validation of chl-a, derived from in situ Rrs, showed moderate performance (correlation coefficient, R2 = 0.64; log10(RMSE) = 0.434; absolute percentage difference (APD) = 43.6% and relative percentage difference (RPD) = 42.33%). However the accuracy of the algorithm was still within acceptable limits. The statistical analysis for atmospheric correction schemes showed improved mean ratio of measured to estimated chl-a (‘r’ = 1.6), log10(RMSE) (0.49), APD (25.46%), and RPD (17.57%) in the case of A1 as compared with A2, whereas in the case of A2, R2 (0.56), slope (0.26), and intercept (0.27) were better as compared with A1. The two atmospheric correction schemes did not show any significant statistical difference. However the default atmospheric correction scheme (A1) was found to be performing comparatively better probably due to the fact that the concentration of TSM and CDOM was much lower to overcome the impact of chl-a.
Dolphin Wall Net (DWN) e An innovative management measure devised by ring seine fishermen of Kerala-India to reducing or eliminating marine mammalefishery interactions
(Elsevier, 2014) Prajith, K.K.; Das, P.H.D.; Edwin, D.
One of the major problems associated with the operation of ring seines in Kerala coast is the attack of dolphins. In order to overcome this problem without harming marine cetaceans, fishermen developed aspecial type of net forms an outer protective wall to the ring seines. This paper discusses the structural and operational details of this net. This initiative of traditional fishermen to conserve marine cetaceans is documented in this communication.
Decomposition study of in vivo phytoplankton absorption spectra aimed at identifying the pigments and the phytoplankton group in complex case 2 coastal waters of the Arabian Sea
(Faculty of Oceanography and Geography, University of Gdansk/Springer, 2015) Shaju, S.S.; Minu, P.; Srikanth, A.S.; Ashraf, P.M.; Vijayan, A.K.; Meenakumari, B.
Phytoplankton modify the optical properties of the seawater by altering the subsurface light field. Information on the accessory pigments present in the phytoplankton helps to differentiate major phytoplankton classes or taxonomic groups. The variability in the absorption spectra of phytoplankton and particulate matter of case 2 coastal waters of the Southeastern Arabian Sea were studied from June 2010 to November 2011. The phytoplankton specific absorption coefficient, at 440 nm and 675 nm, a*ph (440) and a*ph (675) varied from 0.018 to 0.32 m2 mg-1 and from 0.0005 to 0.16 m2 mg-1, respectively. The 4th derivative spectra computed for each in vivo absorption spectrum showed that the amplitude of maxima obtained is proportional to the concentration of the chromoprotein which absorbed that wavelength. Regression of pigment concentration against the 4th derivative spectral coefficient showed that the measurements of particulate absorption could provide quantitative information on chlorophyll a and other accessory pigment concentrations. Fucoxanthin and diadinoxanthin, the carotenoid pigments found in the diatoms were identified from the derivatives peaks. The study demonstrates the utility of using the 4th derivative analysis as a tool to identify the dominating phytoplankton group and its pigment composition.
Development of graphene-nanometre-sized cerium oxide-incorporated aluminium and its electrochemical evaluation
(Springer, 2015) Ashraf, P.M.; Thomas, S.N.; Edwin, L.
Graphene–nanometre-sized cerium oxide-incorporated aluminium was prepared and its electrochemical and surface morphological characteristics were studied. The atomic force micrographs and scanning electron micrographs evaluation highlighted that the grapheme and nanometre-sized cerium oxide in aluminium had decreased the surface roughness and improved the surface morphological characteristics. The graphene: nanometresized cerium oxide (ratios 1:2 or 2:1) with lesser amounts of particle in the matrix showed excellent corrosion resistance in the marine environment as evidenced by linear polarization, electrochemical impedance and weight loss studies. Introduction of graphene in the aluminium matrix showed a barrier separation between the outermost layer and inner layer, increased roughness and increased corrosion. The material is found to be a potential candidate for use in marine environment.

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