My research interest is closely related with the aquatic environment.
1. Nematode diversity
and ecology: their role within the context of ecosystem
functional dynamics:
Nematodes are arguably the most diverse and most numerous invertebrates of which
we know very little. Though some studies have been done on marine nematode taxonomy,
diversity and ecology, nematodes from most aquatic habitats, especially freshwater
forms, are largely unknown in every aspect. Also, only few researchers work on
their use as indicators of environmental change.
I am interested in studying the diversity of nematodes in both freshwater
as well as marine environments, in the context of understanding their ecology,
i.e.
how they interact with their physico-chemical and biological environment
and what the roles of their diversity is in ecological functioning. I have
worked
most of the last decade on the diversity of nematodes primarily in freshwater
bodies and more recently in marine habitats, and would like to extend my
research into what the impact (if any) of different levels of nematode
diversity is on
ecological functioning in benthic communities.
For example, one of the main problems in studying the feeding and food habits
of nematodes has been associated with their small size. Recent developments
in molecular techniques should provide us unparalleled opportunities to explore
this aspect of nematode ecology. It is my interest to understand the role
of
nematodes and their interaction with their environment.
In general I am interested in the largely ignored ecology of nematodes within
the context of the functioning of biodiversity in ecosystem functioning.
The ecology of nematodes in the context of understanding the role of diversity
that
provides insight into ecosystem functioning and resilience is not only important
but is also the key in developing holistic concepts and approaches to conserve
biodiversity. Managing biodiversity in aquatic environments without understanding
its role in these habitats will be difficult to sale for all involved parties,
i.e. the public, funding agencies and policy makers.
Current activities:A) Establishing an image capturing system and generating rDNA sequences: Our center is part of the team that is primarily responsible for the construction of the nematode branch of the Tree of Life (a collaborative NSF-funded project). The primary goal of the project is to collect morphological data and to sequence the diagnostic regions of the rDNA from 1000 species of nematodes, and use this data to understand the phylogenetic position of Nematoda vis-à-vis other animal phyla and determine hitherto unresolved deep branches within the Nematoda itself. My role has been to establish and manage image capturing system for the documentation and dissemination of morphological data in the form of digitized multi-focal video clips, and to adopt and refine methodology to be able to sequence the rDNA from individual worms. The data we generated so far is made openly web-accessible through a relational and dedicated database, Nematol.
B) Diversity and ecology of nematodes at Plum Island Estuary Long Term Ecological Research Site (LTER), Massachusetts. This research is aimed at inventorying nematode diversity at the LTER Site to lay the foundation for our own ecological research on the feeding ecology of free-living nematodes and to augment other extensive ongoing ecological studies with regard to understanding benthic food webs and energy transfer. We are currently attempting preliminarily to morphologically identify, and sequence diagnostic regions of rDNA from individual nematodes and their gut content (prokaryotes and eukaryotes) to establish an association between these organisms and their food sources.
2. The use of nematode community dynamics as an indicator of environmental
change:
Comparative comprehensive studies of relatively undisturbed habitats
and areas intensively exploited by humans as well as experimentally
manipulated
sites should
give a clear picture of what natural and impacted nematode communities
are like. This may be useful in defining the tolerable level
of human interference
beyond
the natural level of variation in aquatic habitats in general
and marine or freshwater environments in particular. Comprehensive
comparative
studies,
hopefully, will
lead to the recognition of nematode communities that may serve
as indicators of environmental change caused by humans. Study
of community
dynamics in
either manipulated experimental sites or in naturally dynamic
sites should provide us
some idea about factors associated with change in their communities.
I would like to explore further into the use of nematodes as
indicators of change
especially with the utilization of molecular techniques. Recent
developments in molecular
techniques have expanded our abilities to detect change in the
form of a community fingerprint. Though not tested for nematodes,
undoubtedly
this
is the future.
I have been active for the last few years in a similar research
focused on terrestrial forms and would like to work further in
the development
of methods
and using
these methods for speedy evaluation of community level change.
Current activities:
Nematode diversity in the Gulf of Maine, and the use of nematode communities to monitor environmental impact of open ocean aquaculture. We are currently studying nematode diversity at an open ocean aquaculture experimental site in the Gulf of Maine for two reasons. The first is to document the diversity per se using both morphological and molecular techniques, and the second is an attempt to use nematode community dynamics as an environmental monitoring tool.
3. Development of molecular tools for ecological studies:
Too little effort has been directed towards long-term, spatially distributed
investigations that allow us to draw synthetic conclusions about controls
on the abundance, distribution, and importance of nematodes to ecosystem
function.
One of the main hindrances in using nematodes as indicators of habitat degradation
and pollution or unwise exploitation of the environment by humans (my above-mentioned
interest) is the humongous amount of time and expertise required for their
identification. An objective, transferable, faster and easier way of defining
a taxon (species?)
would address a critical and rate-limiting step in nematology. The applicability
of a well-tested method can be far-reaching. In part this is a result of
unavailable technology – e.g., only recently have many molecular techniques
become sufficiently refined to be applied to free-living nematodes. Employment
of
molecular techniques in defining taxon in nematodes will have a huge advantage
both in
ecological, biodiversity and other more applied studies. It is now time to
apply a balanced approach to important questions about the roles of nematodes
in ecological
systems. Such an approach should include the refining of traditional and
the development of emerging molecular based approaches, such that they can
be applicable
to nematology and used in situ or with samples direct from the field. In
this way we can hope to gain a fundamental understanding of the role of nematodes
in a broad range of ecosystems and of their response to disturbance. I have
been active in this area for the last few years. I would like to continue
working
in this line in the future too especially on nematodes from aquatic environments.
4. Ecology of fishes:
Despite investigations of various aspects of fish populations of same speices
in different habitats, the reason why populations of the same (Cichlid) fish
species grow to different size in different lakes (for instance between Lakes
Chamo and Ziway, Ethiopia) remains a mystery. A close look into the ecological
dynamics of different environments could be the key and I believe this holistic
approach of understanding needs to be looked into. Integrated and holistic
evaluation of various ecological factors, which has never been considered
hitherto, is a
line of idea I would like to pursue in understanding the underlying causes
of such differences. My research experience comes from tropical environments.
I
have worked on the feeding ecology and biology of tropical fish, Oreochromis
niloticus, for some time and I am interested to continue in this line of
research