SEE PEER REVIEW

INTRO:

Climate change is one of the most important topics to be discussed in our days. Studying the influence of climate chage in aquatic system is really relevant, because the organisms in this ecosystem are very sensitive to the temperature changes.  The introduction is well written, considering the limits of words stabilished. 

MERITS:

The monitoring of environmental changes in the Bhimtal lake can contribute with understanding the effects of climate change in the studied habitat and elsewhere. This data is relevant for conservation planning, strategies, and could be also used as a stimulation of the environmental conscience.  

CRITIQUE:

The weakness of this manuscript is the lack of information about the expectations of the study. Since they have the data from the abiotic caracteristics from the lake, they should have some hypotheses about the productivity in the lake.  This would allow a better discussion about the findings. 

DISCUSSION:

The results of this project has many implications, and they really should publish it. Collecting data together with the monitoring of this data, are really important tools to understand how our environment is changing with time, and how can we contribute with knowledge and information. 

- - -
INTRO:

Global climate change is recognized as an ecological threat on ecosystem productivity of aquatic ecosystem. Climate can be considered the major factor determining the distribution of species at a continental scale. Climate changes are recognized as important environmental regulatory factors to assess the ecosystem productivity in relation to changing pattern of abiotic and biotic characteristics in aquatic system of lake.The catchment basin of lake is posing a numbers of ecological stresses due to climatic variations, invasive land use pattern, degraded forest zones and changed agriculture pattern. The water surface area is decreasing due to massive infestation of aquatic macrophytes and water depth level showed a decreasing trend due to increased siltation along with sedimentation load.The lake ecosystem productivity mainly depends on species richness, abundance and biomass of phytoplankton, zooplankton, benthos and fish species. A total of 5 groups of phytoplankton, 3 groups of zooplankton, 11 groups of benthos and 14 fish species were recorded in Bhimtal lake. 

MERITS:

The present study focused on long and short term effect of climate change on ecosystem productivity of Bhimtal lake. The comparative meteorological data of last fifteen years of catchment basin of Bhimtal lake revealed that air temperature has been increased 1.5 to 2.1^oC and 0.2 to 0.8^oC in summer and winter seasons respectively, relative humidity decreased 4 to 6% annually and rainfall pattern changed erratically in rainy season. The surface water temperature of lake showed an increasing pattern as 0.8 to 2.6 oC, pH value decreased 0.5 to 0.2 in winter and increased 0.4 to 0.6 in summer and dissolved oxygen level showed a decreasing trend as 0.4- 0.7 mg/l in winter. The present research study focused on correlation matrix among different climatic variables, physico-chemical characteristics with population of phytoplankton, zooplankton, benthos and fishes of Bhimtal lake.

CRITIQUE:

Studies should have been done on a wider range of time frame (3 to 4 decades or more). Data generated is focused on species rather than community or a ecological niche. The data should have been simulated in a model to develop a future trend of impact of climate change on the lake so that mitigation strategies can be developed. Other abiotic, biotic factors and biological invasion is missing. What is the overall impact of climate change on invasive and non-invasive species is also missing

DISCUSSION:

Most climate change studies to date have focused on individuals or species populations, rather than the higher levels of organization (i.e. communities, food webs, ecosystems). It is  essential  that an understanding of the connections between these different levels, which are all ultimately based on individuals, can help to develop a more coherent theoretical framework based on metabolic scaling, foraging theory and ecological stoichiometry, to predict the ecological consequences of climate change. The different components of climate change (e.g. temperature, hydrology and atmospheric composition) not only affect multiple levels of biological organization, but they may also interact with the many other stressors to which fresh waters are exposed, and future research needs to address these potentially important synergies.

- - -
INTRO:

It would appear that there is some useful information from this study, in terms of the putative impact of climate change on Himalayan aquatic ecosystems.

MERITS:

as per my comment above.  There apprears to have been some good data collected as part of this work, but there is a bit more work to do in restructuring and rewriting the abstract.

CRITIQUE:

The abstract needs to be organised a bit clearer and to include hypotheses/objectives, then methods, then a clearer description of analyses and findings of change over the 15 year period for which climate data was available.  Were climate data only available for that timeframe though? I'd have thought a longer data series would have been obtainable to allow climate shifts at the study site to be characterised.  The study needs to hypothesize what the particular climate shifts would mean for the various measured aquatic ecosystem variables, then to test if the hypotheses held or not.  Descriptions of change from winter to summer are only valid if data are being examined over the timeframe of putative climate shifts.

DISCUSSION:

as per my comments above.