18 research outputs found
Chattonella marina blooms and its impact on the coastal fishery resources along north Kerala coast
In north Kerala region, a widespread and high density
bloom of Chattonella marina occurred in the first
week of September 2002. The bloom showed a
discontinuous distribution and extended over a
distance of about 50 kilometers along the coast, from
Konadu near Calicut to Mahe near Thalassery
A report on the mass mortality of farmed shrimp due to the blooming of Chattonella marina along Vypin coast
Chattonella marina which blooms regularly along
the Calicut coast bloomed for the first time in
the coastal region along Vypin, Cochin in September
2003. The bloom extended to a distance of about 1km
from the coastline covering a distance of 3km from
Puthuvypin to Malipuram
Studies on the prevalence of algal blooms along Kerala coast, India
61 species of marine phytoplankton belonging to 32 genera were recorded from Chombala in north
Kerala during the period from October 2001 to September 2002 (first year) and 76 species of 33
genera during the period from October 2002 to September 2003 (second year). From Vizhinjam,
along south Kerala, 91 species of 30 genera and 90 species of35 genera were recorded in the sea
in the first and second years respectively whereas in the adjacent bay 88 and 95 species belonging
to 28 genera were recorded.
2. Diatoms and dinoflagellates, the two most diverse phytoplankton groups were rich in species diversity
and density at both the sites, with the diatom species contributing the maximum to phytoplankton
community structure. Blue green algae, mainly Trichodesmium sp was recorded from Chombala
(12.5%) and Vizhinjam bay (8.3%) but was more frequent (25%) from Vizhinjam sea. A
rapidophyte Chat/onella marina was recorded only from Chombala. Diatoms formed 83.5 % of
the community at Chombala, while at Vizhinjam they formed 70.9"10, the reduction in
contribution mainly due to the dominance of dinoflagellates; the diversity being controlled by the
two genera Ceratium and Peridinium.
3. The annual average phytoplankton diversity index at Chombala was 1.88, of which the diversity of
diatom and dinoflagellate were 1.81 and 0.29 respectively.
4. The diatom community at Chombala consisted of 10 families, of which members of the families
Coscinodiscaceae (32.7%), Fragilaroideae(19.3%) and Biddulphiae (16.4%) were dominant
Among the 7 families of dinoflagellates recorded at Chombala, Gymoodinaceae (24.3%),
Peridinaceae (13.3%) and Ceratiaceae (13%) dominated the phytoplankton community structure.
5. The annual average phytoplankton diversity at Vizhinjam bay and sea were 2.13 and 2.09 respectively,
of which the diversity indices of diatom and dinoflagellate in the sea were 1.85 and 1.15 and in
the bay 1.5 and 0.98 respectively.
6. The diatom community at Vizhinjam sea consisted of 9 families of which members of Chaetocerae
(28.4%), Fragilaroideap. (19"10), Biddulphiae (16.8%) and Coscinodiscacea (16.6%) were
dominant. Among dinoflagellates, the families Dinophysiaceae (26.3%), Ceratiaceae (23.7%),
Peridinaceae (36.1 %) dominated the phytoplankton community structure. At Vizbinjam bay, of
the 9 families, members of Chaetocerae (21.6%), Fragilaroideat.(21.2%), Biddulphiae (17.3%)
and Coscinodiscaceae. (16.3%) were dominant and among dinoflagellates, the families
Peridinaceae (37.1 %), Dinophysiaceae (35.4%), Ceratiaceae (17 .9"10), dominated the
phytoplankton community structure.
7. In the family Dinophysiaceae, the family in which DSP toxicity is shown by most of its members, two
species were common Prorocellhlm micans was present in 6 and Dillophysis caudata in 15 out of
the 24 sampled months at Vizhinjam
Prevalence of non toxic and harmful algal blooms along Kerala coast
The oceans are home to thousands of microscopic
algae which constitute the base of the marine
food web. These phytoplankton are essential for the
production of biomass at all levels of the food web
and thus play an important role in oceanтАЩs ecology
On occurrence of certain biotoxins along the Kerala Coast
Occurrence of algal blooms has been reported from the coastal
regions of Kerala. A study was conducted to collect detailed
information on location and seasonality of the incidence of PSP and
DSP toxins in-the bivalves of (his region for providing advance warning
to avoid shellfish poisoning. A database on the hydrographic
parameters in relation to algal blooms and toxic blooms at selected
stations, which are sites of frequent blooms in the past years, was
prepared
Mortality of farmed pearl oyster Pinctada fucata (Gould, 1850) due to the blooming of Noctiluca scintillans and Cochlodinium sp. at Kollam Bay, Kerala
Blooming of the dinoflagellates Noctiluca scintillans was observed at Kollam Bay, Kerala during September
2003 (bloom-1) and Cochlodinium sp. in September 2004 (bloom-2) with cell densities of 9.8 x 104 and
1.4 x 105 cells l-1 respectively. These caused 27% and 100% mortality of the farmed pearl oyster Pinctada
fucata in the raft farms of Central Marine Fisheries Research Institute moored in the Bay. The mortality of
the pearl oysters can be attributed to the high dissolved ammonia 14.9 ╬╝mol l-1 during bloom-1 and high
dissolved ammonia (14.7 ╬╝mol l-1) and total suspended solids (154.8 mg l-1) during bloom-2. These
instances of harmful algal blooms (HAB) indicate that precautionary management protocols should be
developed to relocate the farm stock to overcome such natural causes to prevent economic loss to farmers
Not Available
Not AvailableIn north Kerala region, a widespread and high density
bloom of Chattonella marina occurred in the first
week of September 2002. The bloom showed a
discontinuous distribution and extended over a
distance of about 50 kilometers along the coast, from
Konadu near Calicut to Mahe near Thalassery.Not Availabl
Not Available
Not AvailableThe oceans are home to thousands of microscopic
algae which constitute the base of the marine
food web. These phytoplankton are essential for the
production of biomass at all levels of the food web
and thus play an important role in oceanтАЩs ecology.Not Availabl
Studies on the prevalence of algal blooms along Kerala coast, India
Algal blooms are naturally occurring phenomena in the aquatic environment. These blooms cause mass mortalities of wild and farmed fish and shellfish, human intoxications which sometimes result in death, alteration of marine trophic structure through adverse effects on larvae and other life history stages of commercially important species and death of marine animals. Occurrences of harmful algal blooms and associated mortality have been reported along the coastal waters of India since the early period of the last century. The present study was taken up to study the dynamics of major phytoplankton blooms, which occur along the Kerala coast. The results of quantitative and qualitative analysis of phytoplankton in the coastal waters of Vizhinjam and Chombala, their species diversity and community structure is presented and the major algal blooms recorded along the coast of Kerala during the study period is described and their occurrence is related to the hydrographic and meteorological variations. There is a clear evident from these works in the Indian region that the fishes avoid areas where these harmful algae bloom, either due to the toxicity or due to some irritant property of the chemicals secreted by the algae. Taxonomic diversity studies indicated a change in the community structure of commercial finfishes, crustaceans and molluscs due to the bloom of C.marina and funnel plots indicated the deviation in taxonomic distinctness during the bloom period from theoretical mean for the region