Sunday, December 22, 2019

Biodiversity Walk Training Workshop

The objective of this workshop is to train people on how to conduct biodiversity walks. It is a two day workshop, the first session was on the 16th of November, 2019 and the second session  on the 15th of December, 2019. 

Often in urban areas, people are lost and detached from the biodiversity  around them. This is a collaborative effort by BIOME and ATREE to break this notion as part of CItizen-Science project funded by Oracle.

Session 1

The day started by gathering at Jakkur Lake on 16th November 2019 at 7:00 am. An interested group of 16 gathered around for this journey. Dr. R. Ganesan, a Botany Researcher at ATREE conducted this walk and session. After a short introduction, Dr.R. Ganesan spotted the tree right next to us (a fig tree) and asked the question, 'how did this come into existence?'

The group came up with a lot of answers, which not only included the trees and plants around but the whole system of nature (including insects, birds and animals). We learnt about different species of trees, explored their anatomy and understood their behaviour.

'One of the best ways to learn about biodiversity is just by observing', R Ganesan says.

After two hours of walking around and exploring the biodiversity at Jakkur Lake, we headed back to ATREE which was followed by breakfast. We then gathered around in the auditorium to explore more about this journey. We learnt about various forms of trees and its surroundings.

After this, we were divided into 4 groups to explore the biodiversity around ATREE. After half an hour, we gathered in the same place to exchange our learnings. We realised that even a small patch of land filled with nature has so much to learn and explore. It is very much necessary for many more to understand its value.

The next session is held next month. Meanwhile the task/challenge is to have a small biodiversity walk, record them and share it with others: the beauty of nature.

Session -2   December 15th, 2019 

The second session started with a walk at Jakkur lake at 7.30am. The walk was on Spiders and insects.  Vena Kapoor, a spider expert from the Nature Conservation Foundation led this walk and session. Plan was to spot a spider or a web and observe its behaviour, pattern of the web, its habitat such as - on ground,  on the tree bark, under the leaves, in the leaf litter or between shrubs or on the wall and then name it. 

Spiders belong to the class Arachnida, order Araneae. They are not insects.  One of the differences between spiders and insects is, Spiders have eight legs whereas insects have 6 legs. Spiders can be blind, or have 2,4,6 or 8 eyes. Over 50,000 species of spiders have been identified.

There are mainly two kinds of spiders, one which builds its web to catch its prey and the other which do not build webs but actively hunt to catch its prey. All spiders produce silk. They use it for different purposes to build web,, to protect the egg sacs, as retreat etc

Spider which build web can be seen on the web or away from the web but they are always connected to their web.  Few of the spiders which we saw were 

Orchard orb weaver - This is a web building spider. The web is in the shape of a wheel or orb.  They are found in shrubs and build the web at an angle. Usually one can spot the spider sitting at the center of the web which is called the hub. When a prey gets trapped in the web they inject venom which has enzymes to liquify inside parts of the prey.  The spider then sucks the liquid of the insect leaving the exoskeleton intact. 

Tent web Spider - The web of a tent spider is more complex than the orb weaver.  It looks like a tent, has scaffoldings and a platform at the bottom. This helps to entangle the prey betten and an effective defence against predation.
Tent web       Egg sack

Cross Spider, Signature spider : They have their tipical signature  - the zig zag pattern which is called the stabilimentum.  They are called cross spider as they sit in the shape of ‘X’.

Cross Spider           Sheet web spider

Sheet web spider - Found on the ground level.  This also has a tunnel where the spider is found.

Comb footed spider - have a random shaped web which crisscross.

Social family spider - These build thick webs which are sticky then other spider webs. A  group of related individuals live together to hunt large prey and repair the web. Sometimes they bring up young once. There is ongoing research on to understand their behaviour better.
Social spider web

Candy striped Jumping Spider - Do not build webs. They jump to catch their prey.  They stalk their prey like cats. They have the best eyesight amongst spiders. The egg sacs are under leaves and they build web around it to protect it. 

Candy striped jumping spider
Common two tail spider - In the pic below she is sitting on her egg sac.  The white fuzzy layer is silk protecting the egg sac. These are found on the bark of the tree, a great example for camouflage. The two long tails are the spinnerets. She has six eyes.

Two tailed spider protecting the egg sac                Two tailed spider
Spider’s retreat

Green Lynx spider - hunting spider - Do not build webs. They are called sit and wait predators. Are usually found on hairy flowers/plants.  They sit and wait and feed on the insects which come to the flower . Below is a picture where the spider is sitting in the flower of Bixa tree.

Green Lynx spider

Tunnel wolf web spider - They are hunting spiders and also builds web. 

Tunnel wolf spider

Few of the other spiders we came across were
  • Daddy long legs spider - found on walls and homes.
  • Debri orb weaver spider - 
  • Ant mimicking Spiders - Get access to ants nests also mimics the feremons and escapes the ants predators
  • Thorny Orb weaver- has thorns on its abdomen. 

We also got to see some insects such as
  • Hoverfly
  • Handmaid's moth
  • Weevil
  • Weaver Ants

After a couple of hours of walking at the lake we headed to ATREE. After breakfast Vena shared more information about spiders. 

Later the participants presented and talked about the walk they conducted. They shared their learning and takeaways from it.

All participants who conducted a walk and  participated on both the days were given a certificate for participating in the workshop. 

Friday, December 6, 2019

Dead Zone Project at Jakkur Lake

Biome is working on a Bangalore Sustainability Forum (BSF) funded project to identify and revive dead zones in Jakkur lake. Dead zones are low oxygen areas in oceans and lakes that occur due to eutrophication (presence of excess nutrients such as phosphorus and nitrogen). It often negatively impacts aquatic life, since most plants and organisms require oxygen to survive.

A way to identify a dead zone is to measure dissolved oxygen (DO). DO levels of 4mg/L and above generally indicate a healthy aquatic life and DO levels less than 4mg/L indicate poor water quality and is considered detrimental to aquatic life. To test DO levels we will be using a YSI Pro20 Dissolved Oxygen handheld meter. The cost of the meter was approximately Rs 70,000 and it was purchased from Xylem Analytics, a dealer for YSI instruments in India. A picture of the DO sensor is shown below in Image 1.

Image 1: YSI Pro20 Dissolved Oxygen Handheld Meter

We started the project in August 2019 and monitored the DO in the lake on a regular basis. We identified three dead zone areas: two near the wetland and the other in the kalyani. We will be trying different methods such as aerators and floating wetlands to revive one of the dead zones.

This is an ongoing project, which will be updated once the project is completed. 

Tuesday, September 24, 2019

Algae and Algal Blooms

What are Algae?

Algae (one alga, but several algae) are type of plant-like living thing that can make food from sunlight by photosynthesis. Algae are unicellular or multicellular organisms.  They are mostly found in rivers, lakes and sometimes in seas too. Algae are very important because much of the Earth’s oxygen is generated by algae.

Algae can be classified into 7 major types

- Euglenophyta (Euglenoids)
- Chrysophyta (Golden-brown algae and Diatoms)
- Pyrrophyta (Fire algae)
- Chlorophyta (Green algae)
- Rhodophyta (Red algae)
- Paeophyta (Brown algae)
- Xanthophyta (Yellow-green algae)
Blue-green algae is not an algae but a kind of bacteria and hence does not come under the different types of algae listed above.
What is the difference between Algae and Blue-green algae/Cyanobacteria ? 

The main difference between algae and cyanobacteria is that algae contain chloroplasts (eukaryotes) whereas cyanobacteria do not contain chloroplasts in their cells ( prokaryotes). However, both algae and  cyanobacteria derive their energy through photosynthesis.

Cyanobacteria are also commonly referred to as Blue-green algae , even though they are actually bacteria(prokaryotic),.

There are over 2000 species of blue-green algae.  

Is blue-green algae (same as cyanobacteria) Useful or Harmful ?  
Some types of blue-green algae are used for treating precancerous growths inside the mouth, boosting the immune system, improving memory, increasing energy and metabolism, lowering cholesterol, preventing heart disease, healing wounds, and improving digestion and bowel health.

Wild or cultivated algae Spirulina, Chlorella and Klamath are all blue-green algae (or cyanobacteria), known for their health benefits. Klamath can only be found in one place on earth, Lake Klamath in Oregon, United States. Spirulina is also cultivated in open-channel, ponds.

Some species of blue-green algae produce harmful toxins which take effect when eaten, inhaled or skin contact is made. Ingesting toxins can also cause gastroenteritis symptoms, such as vomiting, diarrhoea, fever and headaches. Toxins can also have an effect on the liver and the nervous system.

A series of tests has to be done to identify the type of blue green algae and to establish if they are useful or harmful. Visually this difference cannot be identified

What are algal blooms?

An algal bloom is a rapid increase or accumulation in the population of algae. This results in a dense layers of tiny green plants that occur on the surface of the water.  These blooms occur when a lake/water body has a high concentration of nutrients (especially phosphorus). High levels of nutrients are often caused by human pollution, such wastewater, sewage, manure and fertilizer runoff from agriculture.

PC: Google
The harmful effects from such blooms is due to the toxins they produce as well as due to the reduced level of oxygen in the water as these algae use up the oxygen in the water. This can then lead to fish kills. Bird kills are caused when birds eat contaminated fish.

Not all algal blooms are harmful. In some cases algal blooms only discolor water, or produce a smelly odor, or add a bad taste to the water. 

What are the precautions that I need to take when I see a water body with algal blooms ? 

- Do not swim or boat in areas where the water is discolored  or where you see algae on the water.
- If you get in contact with the algae rinse off with fresh water as soon as possible.
- Do not let pets or livestock swim in or drink if the water is discolored  or where you see algae on the water.
- Do not use the water for irrigation or watering lawn with algal growth
- Report any smell or taste in wells/borewells.

 How can we prevent algal blooms?

Algae need light, nutrients and high temperatures for optimal growth. Lowering any of the three will help reduce algal growth.  Stagnant waters see rapid growth of algae. Algal blooms are less frequent in flowing/moving water. Preventing fertilizers and pesticides runoff, waste water, sewage entering into the water body can prevent algal blooms.

Friday, August 16, 2019

Biodiversity Walk at Kaikondrahalli Lake

As part of the Citizen Science and Lakes Initiative another Biodiversity Walk was held at Kaikondrahalli lake on Sunday, August 11th 2019. The walk was led by Aswathy Joseph and started near the Kalyani entrance. Aswathy started by explaining the importance of mutualism in nature. In the case of ficus trees, each variety of ficus trees has a certain species of wasp essential for its pollination. The wasps in turn depend on the figs for a safe haven to lay their eggs. Image 2 below is of a ficus tree being worshipped near the Northwestern Entrance.

Image 1: Aswathy leading the Biodiversity Walk at Kaikondrahalli lake
Image 2: A ficus tree being worshipped at the lake
Aswathy mentioned that a week ago the tree was blooming with red figs but a week later we could only spot a couple on the entire tree. An interesting story she shared was that since so many birds, insects and mammals depend on ficus trees throughout the year, one of the ficus trees in the area always has figs growing on it. She also stated that figs were one of the first plants domesticated for human consumption. Another species we came across was the Babul tree as shown in Image 3, it’s a thorny tree with yellow flowers. The same Babul species in Jakkur lake was more like a shrub while the one we saw in Kaikondrahalli lake was a surprisingly large tree. 

Image 3: Participants observing the large Babul tree
Throughout the walk all the participants were really engaged and shared any additional knowledge they had on the biodiversity of plants and insects around the lake. What was supposed to be a one and a half hour walk lasted for over two and a half hours due to the enthusiasm of the participants. 

Venkatesh Peedhanna - one of the younger well diggers was also a participant

To learn more about the previous walks we have had, please refer to the following links: