Monitoring macroinvertebrates and diatom populations in East Stoke, Dorset

As part of a long term, collaborative research project between BU and the FBA, PhD researcher Tadhg Carrol and BU research assistant Jack Dazley have been assisting freshwater biologist John Davy-Bowker in sampling two rivers in East Stoke, Dorset for aquatic macroinvertebrates (such as insect larvae, aquatic worms and water beetles) and diatoms (microscopic plants with a glass-like ‘shell’). The research aims to understand how environmental changes, such as increased temperature and altered riverbed composition, affect the abundance and species diversity of these groups.

Samples were collected from 5 sites at each river – the Frome and the Piddle, where a square sampling area 10m wide was set up from each bank. Macroinvertebrates were collected using the kick sampling method (pictured), whereby the person sampling would rigorously kick the river bed, exposing mud and stones, and with them the invertebrates, which flow into the net. Environmental measurements were also taken, and included width and depth of the site, percentage cover of each species of aquatic plant, and substrate composition of the riverbed (i.e. what types of rocks/stones are present). Once collected, the samples were preserved to allow identification at a later date.

Diatoms were also collected from each site, and were done so by collecting 5 large stones (one from each corner of the site and one from the centre) which had clearly visible signs of algae growing on them, such as green mats on the surface. Using a toothbrush, a section of the green mat was scrubbed off into a plastic tray to collect the diatoms, and to work out the abundance the scrubbed area was traced onto acetate. The diatoms were preserved to be analysed at the lab.

Alongside collecting macroinvertebrates and diatoms, careful note was taken in the Piddle upon the capture and rerelease of protected species, including bullhead fish and white clawed crayfish. These native crayfish are particularly monitored as they are susceptible to diseases carried by the non-native signal crayfish. Infact, the Piddle is thought to be one of the only sites in Dorset where the white clawed crayfish is relatively abundant.

This project is incredibly important to understanding the future of river communities from a bottom up perspective – diatoms and macroinvertebrates form the basis of the food chain in river ecosystems, and so support larger freshwater organisms such as fish and birds.

Lake Oleiden: A Biodiversity Hotspot in Kenya

Whilst in Kenya, one project that the team was carrying out was an ecological survey of freshwater microbes in several different locations across Kenya, and whether the diversity of microbes correlated at all with the diversity of animals species seen. One such location which was sampled was Lake Oleiden, which proved to be a hotspot for wildlife.

Lake Oleiden is located next to the much larger Lake Naivasha, from which it has recently separated, and is slightly saline in nature. The lakes are home to many fish species, a whole host of water birds, and hippopotamus. The water samples collected showed that the lake is rich in phytoplankton (microscopic plants) and many species of flagellates, tiny single-celled organisms which use a tail-like appendage called a flagellum to move around in the water. Flagellates and phytoplankton are important sources of food for tiny invertebrates such as water fleas and copepods, which are in turn eaten by small fish.

Just a small sample of the waterbird species seen: great white pelican, pink-backed pelican, long-tailed cormorant and great cormorant

As a result, there was an incredible diversity of fish-eating bird species, with over 10 different species of bird seen on the lake. There were two species of cormorant seen, and they had established several nesting sites at the banks of the lake, supporting one of the largest congregations of these birds in the country, according to our local guide. Also present were several flocks of great white pelican (pictured within a multi-species community with cormorants and gulls), which were seen feeding alongside terns, gulls and a pair of pied kingfisher, which we were lucky enough to see hunting for fish. At the shore of the lake were a variety of herons and storks including the little egret, marabou stork, yellow-billed stork and the black heron, which has an ingenious hunting strategy, using its wings as shade, attracting fish for it to catch. The lake is also home to the impressive African fish eagles, seen swooping to catch fish from the water’s surface.

This great diversity can be sourced back to the microbes. They provide food for tiny invertebrates which are in turn consumed by the fish in the lake. And of course it is the fish which attract the birds to the area, promising a rich source of food, and by extension, a suitable breeding ground for several species.

Manure moving day

On the 4th April, we were able to start loading all the boys cubicles with the manure that had been collected earlier in March. All 10 IBC containers in the boys cubicles had been secures and piping attached. 1000 litres of both cow and goat manure had been collected and left for microbial reactions to take place, where methane bubbles were being produced. It is essential that we loaded some of the containers with the manure so that the microbial reaction that causes the methane to be produced could be kick started. Take a look here:

Turd nerds assemble

During the first few days at the school, both the art project and toilet construction excelled rapidly:

Toilet project:

  • In each cubicle of the boys toilets, the holes for each toilet seat were cut out and seats were installed
  • All 10 IBC containers were moved into the lower tier of the toilet structure and piping was attached

Eco-art project:

  • All sponsored doors had a white base coat, and designs were drawn on and painted
  • Teachers at the school designed a mural for the toilets around that themes that had meaning to them


Many hands make light work

On the 28th March, the UK volunteer team arrived at in Kenya ready to get involved with the toilet project. The initial visit to the school and arrival included working with a group of older students to make devices that will increase the surface area within the digestion tanks. These devices will act as additional surface for the microbes within the digestion tank to attach to.

Green toilets panels are blue

The panels of the toilets were initially going to be painted in three tiers. However, when the steel panels arrived they turned out to be bright blue. The team agreed to keep the colour as the background to the environmental education mural which will feature a tree of life showcasing species from microbes to mammals. The internal panels were also installed and painted with primer. These will be then painted with specific designs for each door that have been designed for each sponsor.

Bournemouth University postgraduate student Katie Thompson will lead the environmental art project, incorporating science and art collaboratively.


23 containers and 300m of piping arrives

The toilet structure design went through a lot of changes before a final plan was confirmed. The final plan was to use a two-tier system with the cubicles on the top level and IBC’s (Intermediate bulk containers) containers collecting waste underneath. There are 23 cubicles in total, with an 1000 litre water tank underneath each. Having an individual tank for each toilet means that if any errors with one, the system can carry on producing gas from the others and any issues can be addressed easily. The piping for the toilets also arrived on site which will link the toilet basin to the IBCs.


Toilet skeleton structure completed at lightning speed

The beams of the eco-toilet structure were constructed at such a rapid speed! Over the period of a few weeks, the land was dug out in preparation for the structure and local workers were employed to work on the construction phase. It is essential that we can construct the toilets at a rapid speed for future use in deployment in disaster zones and lower economic communities.

This is the first chance we had to see the size of the structure and the next stage of the project…





Pee power (urine-tricity) joins poo power!

Researchers from Bristol University are now working with Akamba Children Education Fund, installing microbial fuel cell technology to generate electricity from urine. This is a massive step in the project, as we will now be generating power from both urine and poo. The microbial fuel cells work by feeding on urine (the fuel) using the biochemical energy that is generated and converted directly into electricity. All that is needed to generate this power is the waste product, making it a sustainable green technology solution. The combination of biogas production, and using microbial fuel cells to use urine and mud to generate power makes the project unique.