Wetland Observation: data gathering in the Kazhuveli Lake


Wetland Observation – Kazhuveli Lake, Saturday, November 26th 2016.

Our senior biologist Dr Bubesh Guptha led a group of 24 students (7th and 8th standards (13-14 years old) and 2 teachers from Vandipallayam school to observe the Kazhuveli lake.

Bubesh gave a small introduction about biodiversity and importance of wetlands, which are a critical habitat of wetland birds.

This is an annual programme for the school group, who started the observation last year, so part of the task this time was to notice any differences and try to understand how the ecology of the Kazhuveli is changing over time.

The students gathered data about:

  • what living things can be observed there (birds, fish, plants etc)
  • what is the depth of the lake
  • salinity levels and what this means
  • human impact
  • any other ecological observations

Their finding were as follows:

Last year:

  • Depth:  6-7 ft
  • Wetland bird count: high (15-20000 counted in seasonal census)
  • Salinity: low
  • Human disturbance: average

This year:

  • Depth:  2-3 ft
  • Wetland bird count: very low ( < 500 counted in seasonal census)
  • Salinity: high
  • Human disturbance: high

One good sign that the students noticed is that there were many young fish, snails, prawns and crabs in the lake.

Bubesh explained how the lack of rainfall this year has affected the wetlands in many different ways.

When the rains do not come, the lake depth is much reduced, making it far easier for humans to fish in the lake. This increase in human disturbance and the human competition for fish keeps the birds away.

With the lack of rain, salinity increases as the water flow is reversed, entering the lake from the sea, rather than flowing out to the sea as is normal for this time of year.

The students also noticed an increase in the amount of plastic rubbish thrown into the lake. They resolved to write to the Forest Department to ask them to put a noticeboard reminding people that their rubbish is harmful to wildlife.