Escalão A2 | Article in english

Today we are going to communicate
Laura Gonçalves, Mariana Rodrigues, Mónica Fialho
Externato Cooperativo da Benedita; Alcobaça12/06/2009

Resumo

In the ambit of the Daphnia's Project, promoted by Visionarium in partnership with CIMAR, happened, last March 18th, in Santa Maria da Feira, a meeting about this Project, which main objective was to create a place where the participant schools could share their experiences and show their projects.

Artigo

In the ambit of the Daphnia's Project, promoted by Visionarium in partnership with CIMAR, happened, last March 18th, in Santa Maria da Feira, a meeting about this Project, which main objective was to create a place where the participant schools could share their experiences and show their projects. The meeting, open to the participants and all interested people, had communications, expositions and workshops.

The students Mónica Fialho, Laura Gonçalves e Mariana Rodrigues (11thA) developed a scientific project called "Tell me what have you got and I'll tell you what you are…", included in the subject Biology and Geology from the 11thgrade of Sciences and Technologies (highschool). The aim of the project was to estimate the high toxicity level of the water from two effluents (treated and non treated) from two cutleries for Daphnia magna, and also determine their influence in this microorganisms cardiac rhythm.

The Daphnia has biological responses very similar to human's and because they are completely transparent their inside organs can be quite clearly seen under the microscope. We can see, for example, the digestive tub, the heart beating, fecundity or the eye functioning. Daphnia magna is the ideal for scientific projects which supervise cardiac rhythm and test the quality of the water.

Even if aquatic ecosystems are able to assimilate physical and chemical changes caused by the launch of pollutants on the environment, locomotion, reproduction, survival and aquatic organisms' growth can be affected. Toxicity tests, with the physical and chemical analysis, allow the assessment of the effects of toxic agents on the aquatic ecosystem or water public mains. The principles of toxicity are based on the recognition of the organisms' answers (exposure) to the contaminants and depend on the exposure to toxic agents (level of exposure).

In this way, these tests can and must be used with the objective of checking the impact caused in the aquatic ecosystem, when contaminants, coming from industrial, domestic and agricultural effluents are thrown in water courses without a right treatment.

One of the most important purposes of the Education in Sciences is to provide citizens with the necessary knowledge so that they can develop a critical thought in the context of socio-scientific-technological interaction. Informed citizens are also capable of taking decisions and solving problems.

Laura Gonçalves, Mariana Rodrigues, Mónica Fialho; Externato Cooperativo da Benedita; Alcobaça; Portugal.