Water conditions affected by insect extinction

Dec 10, 2013
Biologist André Frainer

Because of the large effects that humanity has on nature, species are already becoming extinct at rates never seen before due to increased farming, urbanization, and industrialization. Even protected natural areas of Västerbotten are suffering the risks of species extinction.

André Frainer asked himself if all are really necessary to maintain nature working properly. Perhaps, as some might say, with a handful of species and some technology we could survive in the future as well as we do now.

In his study he chose to survey a number of stream ecosystems of Umeå, Lycksele, Hörnefors, Vindeln, Botsmark, Robertsfors, and several other localities in Västerbotten.

In these , common aquatic insects as stoneflies and caddisflies play important roles in maintaining freshwaters working properly. These little insects are the basic food items for many fish and, also, they help decomposing the leaf litter that falls into the streams in autumn. By feeding on litter, they turn leaves into smaller particles, 'cleaning' the streams from this dead material. Although this role does not sound very sophisticated, it has large implications to the health of our streams, lakes, and coastal waters. The decomposition of leaf litter is a natural fertilizer to freshwaters, as it makes all nutrients found in the leaf available to other , being fundamental to life in streams.

André Frainer found that several disturbances in the ecosystems affect the number of insect species present, or at least the type of species present.

One example is reduced riparian vegetation and increased land fertilization around streams that run through farmland, which affects the quality and quantity of stoneflies and caddisflies. Another typical disturbance in Västerbotten is the stream channelization for log transport, which happened many decades ago. The dredging and channelization of streams still affects the composition and the role of the aquatic insects.

One way to study how leaf litter is decomposed by invertebrates in natural streams is to place known amounts of dried leaf in plastic litter-bags and follow how much biomass is lost within a certain period of time.

As a consequence, the leaf litter in the streams is not decomposed efficiently, which may affect the cycling of nutrients, the water quality and the health of the streams.

Although the water conditions in Västerbotten are good compared to the streams in southern Sweden or most of Europe, we can still do more to help maintaining the diversity of and therefore the health of the stream, André Frainer emphasizes.

"Healthy streams have boulders and dead trees across its channel. These structures enhance the habitat conditions for insects, allowing the insect decomposers to flourish. Large restoration efforts including such features can already been seen in Västerbotten. The riparian vegetation should also be as large as possible, helping both with the input of , and as a natural absorbent for the excess fertilization that may occur in farmlands", says André Frainer.

Explore further: Hopes, fears, doubts surround Cuba's oil future

add to favorites email to friend print save as pdf

Related Stories

Tadpoles not just baby frogs

Feb 06, 2013

(Phys.org)—Tadpoles may be vital in helping maintain the ecosystems of freshwater streams, a James Cook University researcher is discovering.

Aquatic life declines at early stages of urban development

Jun 03, 2010

The number of native fish and aquatic insects, especially those that are pollution sensitive, declines in urban and suburban streams at low levels of development — levels often considered protective for stream communities, ...

Climate change impacts stream life

May 04, 2007

Climate change is warming Welsh streams and rivers, affecting the number and variety of some of their smallest animals, a major Cardiff University study has found.

Recommended for you

Hopes, fears, doubts surround Cuba's oil future

10 hours ago

One of the most prolific oil and gas basins on the planet sits just off Cuba's northwest coast, and the thaw in relations with the United States is giving rise to hopes that Cuba can now get in on the action.

New challenges for ocean acidification research

Dec 19, 2014

Over the past decade, ocean acidification has received growing recognition not only in the scientific area. Decision-makers, stakeholders, and the general public are becoming increasingly aware of "the other carbon dioxide ...

Compromises lead to climate change deal

Dec 19, 2014

Earlier this month, delegates from the various states that make up the UN met in Lima, Peru, to agree on a framework for the Climate Change Conference that is scheduled to take place in Paris next year. For ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.