17 research outputs found
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-тАЩ98 to 23-12-тАЩ98,
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