Featured Research

from universities, journals, and other organizations

The impact of human activities on a selection of lakes in Tanzania

Date:
December 28, 2011
Source:
Norwegian School of Veterinary Science
Summary:
An increase in human activity is posing a threat to natural aquatic ecosystems in Tanzania and contributing to environmental damage and ecological changes. New research shows that agriculture and livestock farming leads to eutrophication in lakes and the proliferation of cyanobacteria which produce microcystins. New information about microcystins and other mycotoxins in Tanzanian lakes is useful for appraising the risk linked to drinking water and edible fish, which in turn affects the health of both humans and animals.

Empty cans of pesticide in a ditch at a farm in Arusha, Tanzania.
Credit: Image courtesy of Norwegian School of Veterinary Science

An increase in human activity is posing a threat to natural aquatic ecosystems in Tanzania and contributing to environmental damage and ecological changes.

Related Articles


Doctoral research carried out by Hezron Emmanuel Nonga shows that agriculture and livestock farming leads to eutrophication in lakes and the proliferation of cyanobacteria which produce microcystins. New information about microcystins and other mycotoxins in Tanzanian lakes is useful for appraising the risk linked to drinking water and edible fish, which in turn affects the health of both humans and animals.

In Tanzania, there are many and varied wetland areas and aquatic ecosystems which are productive but also vulnerable. Hezron Emmanual Nonga's doctoral research project has studied how human activities affect ecosystems in wetlands and has also examined the incidence of cyanobacteria, the production of microcystins and the possible effects of these toxins on wild species.

The study was carried out on three alkaline (high pH) lakes (of which lake Manyara was the most important) in the north of Tanzania. In addition, similar experiments were conducted in the fresh-water Lake Victoria in the Northwest of the country.

Sociological, cross-sectional studies were conducted in order to ascertain what effects human activities have had on the wetlands and ecosystems around the lakes. The results of these studies show that non-sustainable human activities contributed significantly to the environmental damage detected in the selected lakes in Tanzania.

In addition, Nonga carried out field and laboratory experiments over a period of time in order to determine physical and chemical parameters, the incidence of phytoplankton, concentrations of different microcystins and microcystin-producing bacteria in the lakes. This research has resulted in new data which will be useful for appraising the risk of the lakes as sources of drinking water and edible fish.

Pathological examinations of dwarf flamingos (Phoeniconaias minor Geoffroy) at Lake Manyara revealed a high concentration of microcystins in the birds' liver, which may be one of the reasons for the observed mass death of these birds. However, further studies are needed in order to confirm whether microcystins are to blame for this increase in mortality.

The sociological study showed that Lake Manyara and the surrounding wetlands are valuable resources for local communities but that exploitation is too intensive. The main source of income for people living near the lake is from agriculture and livestock, and these are currently far from sustainable. Limited access to expertise, easily available pesticides and lack of knowledge about the latter has led to the uncontrolled spread of chemicals, with hitherto unknown consequences for the environment. Soil erosion and the frequent drying-out of Lake Manyara and rivers in the area have moreover led to a lack of water and high animal mortality.

In order to protect the resources of these wetland areas, human activities must be better controlled and a more sustainable exploitation of land and water resources introduced. It is necessary to make the farmers aware of the importance of environment-friendly agriculture and train them in the use of pesticides and pest control.

Nonga's doctoral research was carried out in Tanzania and at The Norwegian School of Veterinary Science in Norway.

Hezron Emmanuel Nonga defended his doctoral thesis on 19th December 2011 at The Norwegian School of Veterinary Science. His thesis is entitled: "Impact of human activities in selected lake ecosystems in Tanzania and occurrence of microcystins and potential microcystin-producing cyanobacteria."


Story Source:

The above story is based on materials provided by Norwegian School of Veterinary Science. Note: Materials may be edited for content and length.


Cite This Page:

Norwegian School of Veterinary Science. "The impact of human activities on a selection of lakes in Tanzania." ScienceDaily. ScienceDaily, 28 December 2011. <www.sciencedaily.com/releases/2011/12/111228134844.htm>.
Norwegian School of Veterinary Science. (2011, December 28). The impact of human activities on a selection of lakes in Tanzania. ScienceDaily. Retrieved November 26, 2014 from www.sciencedaily.com/releases/2011/12/111228134844.htm
Norwegian School of Veterinary Science. "The impact of human activities on a selection of lakes in Tanzania." ScienceDaily. www.sciencedaily.com/releases/2011/12/111228134844.htm (accessed November 26, 2014).

Share This


More From ScienceDaily



More Earth & Climate News

Wednesday, November 26, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Antarctic Sea Ice Mystery Thickens... Literally

Antarctic Sea Ice Mystery Thickens... Literally

Newsy (Nov. 25, 2014) — Antarctic sea ice isn't only expanding, it's thicker than previously thought, and scientists aren't sure exactly why. Video provided by Newsy
Powered by NewsLook.com
3D Map of Antarctic Sea Ice to Shed Light on Climate Change

3D Map of Antarctic Sea Ice to Shed Light on Climate Change

Reuters - Innovations Video Online (Nov. 24, 2014) — A multinational group of scientists have released the first ever detailed, high-resolution 3-D maps of Antarctic sea ice. Using an underwater robot equipped with sonar, the researchers mapped the underside of a massive area of sea ice to gauge the impact of climate change. Ben Gruber reports. Video provided by Reuters
Powered by NewsLook.com
Car Park Solution for Flexible Green Energy

Car Park Solution for Flexible Green Energy

Reuters - Innovations Video Online (Nov. 24, 2014) — A British solar power start-up says that by covering millions of existing car park spaces around the UK with flexible solar panels, the country's power problems could be solved. Suzannah Butcher reports. Video provided by Reuters
Powered by NewsLook.com
Yellow-Spotted Turtles Rescued from Trafficking

Yellow-Spotted Turtles Rescued from Trafficking

Reuters - Light News Video Online (Nov. 24, 2014) — Hundreds of Amazon River turtles released into the wild in Peru. Sharon Reich reports. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins