Download Surveillance of Algal Blooms along the Kerala coast

Surveillance of Algal Blooms along the Kerala coast
Introduction
Planktonic microalgae form the major primary producers in any aquatic
ecosystem and serve as the key synthesizers of primary organic matter. These microalgae
can proliferate into enormous concentrations of upto millions of cells per litre when
sufficient light and nutrients are available. Such sudden increase of microalgal cells are
referred to as blooms (Fogg, 2002). Most blooms are extremely beneficial to the marine
ecosystem as a primary source of food for the larvae of commercially important marine
organisms. Of the many thousands of species of microalgae those that produce specific
toxins hardly exceed a hundred. These occur in both salt and freshwaters and whilst most
are planktonic and some are benthic. International Council for the Exploration of the Seas
(ICES, 1984), defines algal blooms as “Those, which are noticeable, particularly to
general public, directly or indirectly through their effects, such as visible discoloration of
the water, foam production, fish or invertebrate mortality or toxicity to humans”.
Blooms of autotrophic algae and some heterotrophic protists are very frequent in
coastal and oceanic waters around the world. Aggregation of these organisms can
discolour water with biomass or foam and deplete oxygen levels through excessive
respiration or decomposition. The main constraint in the study of these blooms is the lack
of sufficient and reliable historical and time series data. Fish kills and human illness
caused by toxic dinoflagellates date back several hundred years (Richardson, 1997).
Harmful phytoplankton might contain neurotoxins and when they get concentrated in
filter feeding bivalves can pose a serious public health hazard. Phytoplankton blooms are
natural phenomena that play an important role in relation to carbon, energy flow and
geochemical cycling in marine systems. About 200 species of phytoplankton have been
identified as causing harmful blooms (Hallegraeff, 2002).
Definition of the problem
Increasing frequency, intensity and spreading of toxic and non-toxic
phytoplankton blooms occurring in the sea have been characterized as a global epidemic.
Some species recur in the same geographic regions each year, while others are episodic,
leading to the unexpected deaths of local fish, shellfish, mammals and birds. Potential
threat to fishery resources is the cumulative effect of these toxic species on other
microflora and fauna and commercial fish species. There is an increased discussion on
the potential role of aquaculture and mariculture in HAB development. Cultured shellfish
and finfish populations produce huge amounts of faeces, pseudofaeces and other
excretory products rich in N and P, important to algal growth. This would lead to the
proliferation of algal cells and finally by its devastating effects, vanish the industry in a
short time span. The specific reason for the rapid proliferation of harmful species is still
debated. Reasons for the increasing interest in HABs include not only public safety
concerns associated with protecting human health, but also adverse effects on living
resources of many coastal systems, economic losses attributed to reduced tourism,
recreation or seafood related industries.
Harmful algal bloom occurrences worldwide have prompted the testing and use of
methods to control and mitigate their detrimental effects (Padilla et al., 2010). The most
remarkable comment in connection to planktonic microalgal blooms is not why they
occur but rather what mechanisms control the species which occur at a given time and
place (Richardson, 1997). Marine environment provides many different niches that can
be exploited by different microalgal species and each species has its own specific
combination of necessities to the external environment, such as light, micro and macronutrients. Hence, it may be possible to identify a ‘fingerprint’ of each bloom producing
species describing its external requirements. So, matching the environmental condition at
any given time to the ‘fingerprints’ of microalgal species potentially occurring in an area
would provide a basis for predictive models pertaining to the probable development of
algal blooms. The ‘fingerprint’ or the available data of the biological and physicochemical variables recorded during the bloom of Coscinodiscus asteromphalus var.
centralis Ehrenberg, observed in the southwest coast of India, was prepared earlier
(Sanilkumar et al., 2009). It is assumed that this ‘fingerprint’ definitely would help the
upcoming bloom events and can correlate with this particular data.
To find out and study the areas where the Harmful Algal Blooms (HABs) are
recurring seasonally, its appropriate monitoring, investigations relating to the distribution,
species composition and environmental conditions are the need of the hour.
Objectives
1. Investigations of algal blooms in the coastal areas and estuaries along
the Kerala coast
2. Studying the dynamics of bloom formation and crash
3. Qualitative and quantitative analysis of marine flora, especially
diatoms and dinoflagellates.
4. Organizing public awareness campaigns regarding the harmful algal
blooms (if necessary)
Status of R&D on the subject
International Status
Extensive fish kills were very often reported from the eastern Gulf of Mexico due to
the toxic blooms (TABs) of dinoflagellate Karenia brevis (Flaherty and Landsberg,
2011). Marine raphidophycean alga, Chattonella spp. (C. antiqua, C.marina and C.
ovata), have been implicated in major fish kills in the various parts of the world and are
regarded as the most noxious HAB species in Japan and China (Wang et al., 2011).
Increasing intensity and spreading of toxic and non-toxic blooms, as well as global
transport of non-indigenous marine species, their taxonomy, ecology, genetics and
bioactive compounds of toxic algae have been studied extensively by various institutions
and scientists (Haigh (1991), Honjo (1992), Rensel (1995), Bernier (1996), Berger
(1997), Fog (2002), Smayda (2002) Stielow and Ballantine (2003), Hajdu et al., (2005).
A number of international programmes are in operation to investigate the various aspects
of HABs. More researchers are in the field for surveying their local waters for the
causative organisms. Many algal groups produce fatty acids that can damage the
epithelial tissues of gills of fishes. Thus intensive and multifaceted studies on these
blooms are now going on at the international level. International Oceanographic
Commission (IOC) has been giving top priority and coordinates several works related to
HABs. A series of workshops have been conducted by IOC-HAB since 1987. IOC, ICES,
SCOR, EU and APEC are the agencies focusing specifically on HABs and their impacts.
National status
Algal blooms are quite common in Indian waters. Periodic blooms of species such
as Noctiluca scintillans, Trichodesmium erythraeum and Rhizosolenia sp have been
reported earlier. Many events of harmful blooms from coastal waters of Tamil Nadu,
Karnataka, Maharashtra and Kerala were reported by Bhat and Matondkar (2004).
Trichodesmium and Noctiluca blooms were the most frequently observed in the Indian
waters (Nair et al.,1992; Naqvi et al., 1998; Sarangi et al., 2004; Sahayak et al., 2005;
Mohanty et al., 2007;Padmakumar et al., 2008). Blooms of Coscinodiscus asteromphalus
var. centralis (Sanilkumar et al., 2009a) and Protoperidinium sp. (Sanilkumar et al.,
2009b) have also been reported in recent past.
Anticipated output from the project, its utility/applicability
References on various harmful algal species, its effect on other flora and
fauna and growth kinetics of Algal Blooms are the expected outputs of the
project.
Finding out the relationship between hydrological variables and growth
characteristics will have a bearing in developing strategies for application to
certain coastal algal blooms.
The qualitative and quantitative analyses bring an idea about the microalgal
distribution along the Kerala coast.
Work Plan and Summary
Surveillance and selection of stations:
Estuarine and coastal stations for regular monitoring (seasonal samplings)
have been identified on the basis of the past records of occurrence of algal blooms. A
total of eight stations are now recognized, viz., (1) Vaadi (80 52’ 01N & 760 34’ 26E), (2)
Kavanad (80 55’ 55N & 760 33’ 37E), (3) Azheekode (100 11’ 02N 760 09’ 22E), (4)
Balathuruthu (110 07’ 50N & 750 49’ 57E), (5) Kodikkal (110 28’ 43N & 750 36’ 10E),
(6) Mahe (110 42’ 18N & 750 32’ 36E)., (7) Thaikadappuram (120 12 39N & 750 07 33E)
and (8) Bekalam (120 12’ 39”N & 750 07’ 33”E). Stations 1, 3, 5 and 8 are coastal areas
and rest is estuaries. More stations may be fixed on appropriate circumstances.
Sociological research tools like, semi-structured interviews and historical time line would
be employed to obtain traditional knowledge about the phenomenon of algal blooming
i.e., the history of previous incidence, the pattern, occurrence and crashing, its direct and
indirect effects on the local people and environment etc. from the veteran fisher folk of
the locality. Public awareness campaign would be conducted in those areas, about HAB
and its effects on the environment. Efforts will be made to create a good rapport with the
local residents or their cooperative societies by continuous dialogue and interactions.
Monitoring and Sampling:
Water samples will be collected from each station to delineate the spatial and
temporal variations in the distribution and occurrence of HABs. Data on the physicochemical characteristics of the area before, during and after the bloom will be collected.
(This is often possible by periodic monitoring in hotspots). Water, sediment and affected
animals will be collected. Regular collections (seasonal) during the off bloom season and
the bloom season will be carried out.
a. Analysis of the samples collected:
Samples are to be analysed systematically in a predestined time frame and
the results made available without delay. Along with the analysis of the physicochemical factors responsible for blooming, if possible, analysis of trace metals and
dissolved organic material will also be done.
b. Culturing of the Harmful Algal spp:
Growth kinetics as well as the biochemical changes of HABs can be
understood by culturing harmful algae using the standard methods. Laboratory studies
using algal culture and in situ studies at selected coastal stations through hired boats
will also be carried out.
Organization of work elements
1. Algal blooms will be monitored during its incidence and factors such as
incident light, nitrogen level, silicate, phosphate, salinity, total bacteria,
dissolved oxygen and species composition, will be analysed.
2. Harmful Algal species will be isolated and cultured. The cultures will be
maintained in the laboratory as well as in large culture system outdoor.
Work summary
Year 1
Year 2
Year 3
Year 4
Year 5
Mode of work
Monitoring & surveillance
Identification & enumeration
of toxic and HAB species
Sample Analysis
Laboratory work
Data analysis
Finalization of report
Technical Components.
Field Data collection:
Area where field work is proposed (Latitude)
Kollam-Kasargod (8 – 120 N Lat)
i. Four estuaries and four coastal stations
ii. Regular monitoring (seasonal) of near-shore and estuarine waters
using hired boats.