Occurrence of a multi-species diatom bloom dominated by Proboscia alata (Brightwell) Sandstorm along the southwest coast of India

• Published in: Oceanological and hydrobiological studies Vol. 42; no. 1; pp. 40 - 45
• Main Authors: Cicily, Lathika, Padmakumar, K. B., Asha Devi, C. R., Sanjeevan, V. N.
• Format: Journal Article
• Language: English
• Published: Heidelberg SP Versita 01-03-2013; Versita; Walter de Gruyter GmbH
• Subjects: Algae; Bacteriosira; Blooms; Cell density; Cells; Chaetoceros; Chlorophyll; Chlorophyll a; Coastal waters; Coasts; Communication; Coscinodiscus; Density; Diatom; Diatoms; Discoloration; Domoic acid; Earth and Environmental Science; Earth science; Earth Sciences; Food chains; Harmful Algal Blooms; Leptocylindrus danicus; Marine; Marine & Freshwater Sciences; Neurotoxins; Nitrates; Nitrogen dioxide; Nutrient concentrations; Oceanography; Original Research Paper; Phosphates; Phytoplankton; Plankton; Proboscia; Proboscia alata; Pseudo-nitzschia; Pseudo-nitzschia multiseries; Pseudo-nitzschia spp; Quantitative analysis; Rhizosolenia; Salinity; Sea surface; Shellfish; southwest coast of India; Thalassiosira; Toxicity; Toxins; Water quality; Wind; Zooplankton; India; ISW, India; Diatom; Harmful Algal Blooms; southwest coast of India; spp; Zooplankton
• ISSN: 1730-413X; 1897-3191; 1897-3191
• DOI: 10.2478/s13545-013-0055-1

The present communication reports on the occurrence of a multi-species diatom bloom in the upwelled waters along the southwest coast of India. During the late summer monsoon season (September 2009) a multi-species diatom bloom with a pale green discoloration of the sea surface was observed in the coastal waters of southwest coast of India. The bloom spread over an area of approximately 15 km
2
along the coastal waters off Kannur (Lat. 11°59.471 N, Long. 75°03.446 E). Total diatom cell density of the bloom area was 16 × 10
4
cells l
−1
.
Proboscia
(
=Rhizosolenia
)
alata
(Brightwell) Sandstrom constituted 90% of the total phytoplankton population. Other phytoplankton groups that contributed to the bloom population included
Chaetoceros
spp.,
Pseudo-nitzschia
spp.,
Rhizosolenia
spp.,
Coscinodiscus
sp.,
Leptocylindrus danicus, Thalassiosira
sp., and
Bacteriosira
sp. Among these
Pseudo-nitzschia multiseries
, a toxic species with the ability to produce potent neurotoxin domoic acid, was observed with a cell density of 4 × 10
3
cells l
−1
. Surface chlorophyll
a
concentration of the bloom region was 14.1 μg l
−1
. Nutrient concentrations of the bloom area were 0.01 μmol l
−1
for NO
2
-N, 0.1 μmol l
−1
for NO
3
-N, 0.83 μmol l
−1
for PO
4
-P and 11.44 μmol l
−1
for SiO
4
.