Effect of humic acids on mercury toxicity to marine algae

Humic acids extracted from the sediment of Cochin inshore areas exhibited impairment of mercury toxicity to marine algae maintained in Walne's medium under laboratory conditions. Cultures of marine micro alga /50chrysis galbana contaminated with sublethal concentration of 10 ppb of inorganic mercury and 10 ppm humic acids registered 18%, 21 % and 37% increase in oxygen production for two, four and six hours incubation in light respectively, when compared to the controls. Similarly the daily growth rate of seaweed Ulva lactuca registered 26% increase over the control when the seaweed was maintained in medium containing 30 ppb Hg and 30 ppm humic acids

Sediment analysis

Air dry soil should be ground to pass through a 0.5 mm sieve. A 2.5 g soil sample is suspended in 50 ml of NaHCO3 solution of pH 8.5 along with 1 teaspoon of carbon black. Fine suspension is shaken for a period of 30 minutes. The solution is filtered through a Whatman No.40 or other suitable filter paper. A 5 ml aliquot of clear filtrate is pipetted in to 25 ml vol. flask. A volume of 5ml acid molybdate is added and the flask is allowed to stand for the generation of CO2. After that add 10 ml distilled water, then 1 ml stannous chloride (working solution), by immediate shaking and make up the volume to 25 ml and mix thoroughly. Prepare a blank as above and read the intensity of colour developed, at 660 nm, after 10 minutes and within 20 minutes

Pond based grow out system of gracilaria verrucosa

Gracilaria verrucosa was successfully cultivated in a pond based aquaculture system at Narakkal. Kerala. India. Daily growth rate of seaweed was found to be maximum (19.22%) during 60 days of introduction. The growth. pigment constituents and the yield of agar were influenced by the environmental parameters. Agar yield and photosynthetic pigments declined in the initial period up to 50 days due to acclimatization of the plants lo new environment which was collected from Chennai, India and introduced in the pond at 'Narakkal. After 60 days, the algae started establishing in the bottom of the pond and an initial harvest of 230.25 kg was harvested after 90 days of culture period. Further regular harvest was made at every 10 days interval yielding 1015 kg of Gverrucosa during the culture period. The agar content ranged between 7-14.8% and bottom sample exhibited better yield of. agar than the plants cultured in the floating raft

Manual of Analytical Methods for Seawater and Sediment

This "Manual of Analytical Methods for Seawater and Sediment" is a comprehensive laboratory manual prepared for the NATP project " Impact of Dams on river run-off into Sea and Changes in the Nutrient and Productivity Profile of Coastal waters" functioning at Kochi, Mangalore, Visakhapatnam and Veraval Centres with an intention to obtain a relatively comparable results by employing uniform methodology in collection, processing and analyses of sample

Trends in heavy metal concentrations in sediment, finfishes and shellfishes in inshore waters of Cochin, southwest coast of India

Profile of Cadmium, Zinc, Copper and Lead in sediment and tissues from four species of finfishes and shellfishes from estuarine and inshore regions of Cochin were analysed from the monthly data, collected for ten years since 1990. Annual mean levels of Zinc in Nemipterus japonicus registered a gradual decreasing trend towards 1998 with a peak (35 ppm) during 1992. Similar trend was also observed in Metapenaeus dobsoni and Suneffa scripfa. However, an increasing trend was noticed in Ofolithus ruber, registering a peak (9 ppm) during 1995. Lead concentrations were higher in M. dobsoni followed by N. japonicus with an increasing trend. On the other hand, Cadmium and Copper levels showed a decreasing trend with peak levels in Nemipterus (Cd 0.58 ppm, Cu 10.43 ppm) and M. dobsoni (Cd 1.16, Cu 8.87 ppm) than the molluscs and the croaker species. Levels of these four metals in sediment were higher in inshore regions than in the estuarine areas. Copper, Lead and Cadmium content in sediments of estuarine as well as the inshore regions showed an increasing trend over the ten years period. However, the levels of Zinc showed no significant variation in the inshore areas and a marked decreasing trend in the estuarine regions. The profile of metals in tissues and sediment samples were correlated in relation to the state of health of these resources and ecosystem in the light of increasing port and anthropogenic activities

Studies on the infestation of an isopod crustacean, Cirolana fluviatilis in some parts of the Cochin backwaters, Kerala

In July 1994 reports appeared in the media about the large scale occurrence of a tiny 'antlike fish killer' in the Kumbalangi-Perumpadappu area of the Cochin backwaters causing threat to the aquatic living resources.The CMFRI initiated an investigation on the problems. The isopod C.Jluviatilis is a commonly occurring organism in the Cochin backwaters and elsewhere. It is a voracious carnivore which if present in very large numbers can cause a threat to the living resources in the estuarine water area. Population explosion of this isopod has now taken place in the Kumbalangi - Perumpadappu area. The reason for the unprecedented population explosion of this isopod in the Kumbalangi- Perumpadappu area is the recent changes taken place in the ecosystem there

Oil slick in the inshore waters to the north of Cochin Port Channel

The oil samples resembles that of Gulf crude oil and was not seen in Fort Cochin area south of the fairway channel, the oil slick might have caused extensive damage to the intertidal organisms including bivalve spat populations attached to the granite wall constructed to check sea erosion. Strict enforcement of preventive measures is recommended against such oil spillage

Experiments on broodstock development and spawning of Epinephelus tauvina (Forskal)

The present paper reports on broodstock development and spawning of the greasy grouper Epinephelus tauvina in indoor 5 ton capacity FRP tanks in recirculating sea water system, under controlled conditions. The broodstock was developed in the culture system by rearing the wild fingerlings, caught in the size range 90 to 200mm. After attaining maturity, the fishes were fed with supplementary diet for developing them into mature females. Simultaneously, a few were administered the male hormone methyltestosterone (MT) for sex inversion to males. Mature spermiating males were developed by this technique. A mature female fish weighing 3.85 kg and a single spermiating male weighing 3.25 kg have spawned spontaneously in the same indoor tank consecutively for two days from 29-10-1998 to 30-10-1998 and also from 20-12-’98 to 23-12-’98, producing approximately 2,50,000 eggs in each spawning. On both the occasions, the same hormonally sex inverted male has spermiated. Fertilization rate was over 90%. Eggs measured 0.920 mm with a single oil globule. The eggs hatched out at 23 hours. Hatching rate observed in the first spawning was 60% and in the second instance, 45%. Newly hatched larvae measured 1.74mm. After 68 hours the larval mouth has opened and feeding has started

Database on trace metal levels in the Indian marine ecosystem: decadal trends of lead and cadmium in sediment off Cochin

The Fishery Environment Management Division (FEMD) of Central Marine Fisheries Research Institute (CMFRI), Kochi, has been documenting the real-time data on total concentration of metals viz., Pb, Cd, Cu, and Zn since 1994, in sediments off Cochin and since 2002, data on Pb, Cd, Ni, Hg, Cu, Cr, Zn, Mn and Fe, in sediments from different regions of the Indian coast. Database on these vital parameters determining the sediment quality with respect to environmental toxicity is available in the FEM Division of CMFRI since 199

Not Available

Not AvailableHumic acids extracted from the sediment of Cochin inshore areas exhibited impairment of mercury toxicity to marine algae maintained in Walne's medium under laboratory conditions. Cultures of marine micro alga /50chrysis galbana contaminated with sublethal concentration of 10 ppb of inorganic mercury and 10 ppm humic acids registered 18%, 21 % and 37% increase in oxygen production for two, four and six hours incubation in light respectively, when compared to the controls. Similarly the daily growth rate of seaweed Ulva lactuca registered 26% increase over the control when the seaweed was maintained in medium containing 30 ppb Hg and 30 ppm humic acids.Not Availabl