This document summarizes scientific work done on water in rivers and intertidal zones near Augusta, Portugal from November to March. Students from various grades studied the Belelle and Mandeo rivers, as well as Ortigueira's ria and Cobas beach intertidal zones. They observed parts of the rivers' courses, flora and fauna, chemical properties, human impacts, and more. In the intertidal zones, they noted how the environment changes with the tides and identified common plants and animals. Samples were also analyzed in a lab to separate seaweed pigments and measure seawater density. The document concludes by discussing observed human uses of and pollution threats to the studied areas.

1. Scientific work
related to water
, May 2012 Augusta

2. How we did the work
 We studied two rivers (Belelle and Mandeo) and two
intertidal zones (Ortigueira’s ria and Cobas beach).
 Dates: November and March
 Students involved: 1st ESO (12-13 year-olds), 2nd ESO
(12-13 year-olds), 3rd ESO (14-15 year-olds), 4th ESO
(15-16 year-olds) and 1st Bach (16-17 year-olds)
 Subjects: Biology, Chemistry and Science for the
Contemporary World
 We worked on the field, in the lab and in class.
 We organised some conferences about these subjects.

3. Belelle and Mandeo river

4. Ortigueira’s ria:situation
Ortigueira’s ria

5. Cobas beach:situation
Cobas beach

6. Rivers
Aspects observed:
 Parts of the course
 Flora and fauna
 Chemical data
 Anthropogenic
action
 Pollution
 Uses: energy, agriculture,
recreation

7. Parts of the rivers’ course
High course
- The river has more inclination and carries little
water.
- Due to the inclination the water is very oxygenated.
Middle course
- Higher flow; affluents; riparian
forest.
Low course
- Forms part of the estuary.
The course of the rivers is divided in three parts:

8. Parts of the rivers studied
 We only observed and collected data in the middle course and
the low course of the rivers.
 In the middle course the water is more dynamic and has more
disolved oxygen, so it is cleaner. This is the part where the
water for human supply (consumption) comes from.

9. The middle course of the river

10. The low course of the river
• The low course is less dynamic and the quantity of disolved oxygen is
lower.
• The low course may be under the influence of tides.

11. Flora: the riparian forest
 The riparian forest is one of the most outstanding
features of the river bank.
 It follows the river course.
 It’s important for the conservation of the river course.
 Common trees: European alder, sycamore plane,
hazelnut tree, bay laurel and oak.

12. Flora: the riparian forest
Sycamore plane
Acer pseudoplatanus
Hazelnut tree
Corilus avellana
Alder
Alnus glutinosa

13. Flora: the riparian forest
Bay laurel
Laurus nobilis
Oak
Quercus robur
In spring In autumn

14. Flora
Wild saffron
Royal fern
Osmunda Regalis
Willow - Salix sp.
Celery - Apiumgraveolens

15. FAUNA
Chysomela menthastri
on mint leaf
Mint beetle
Temporary frog
Calopterix virgo Salamander
Erithacus rubecula
European robin
Lutra lutra
European otter
Gerris lacustris

16. Chemical data
 We measured temperature, pH, conductivity and
dissolved oxygen in the middle course and the low
course of the river.

17. Chemical data
Part of the
river
Temperature pH Conductivity Dissolved
oxygen
Belelle river Middle
course
9.6 ºC 6.64 190 µS/cm 8.5 ppm
Low course 10.1 ºC 7.15 251µs /cm 8.3 ppm
Conclusions:
The highest pH and conductivity
are found in the low course due to
the influence of tides.
Portable digital Multiline P3 WTW

18. Chemical data: low course

19. Chemical data: middle course

20. Anthropogenic action
It’s noticeable all along the course
of the river
It has been present for a long time
because water is very useful and
necessary, as some constructions
we found on the way bear witness
to.
Nowadays, there is still pressure due
to the same reasons
Some constructions in
the river bank

21. ANTHROPOGENIC ACTION
The riparian forest has diminisheddue to the invasion of pastures

22. POLLUTION We found some sporadic
spots in the low course

23. Uses
The uses that we could observe were: household
consumption, irrigation, farming usage, power
generation, recreational uses
Waterwheel
Irrigation
Recreation

24. Uses
Hydroelectrical plant
Public washing place
Detour for consumption
Recreational uses
Agriculture and livestock

25. Intertidal zones
We studied two zones:
 Ortigueira’s ria
 Cobas beach

26. Intertidal zone
Zone of coast that is under water at high tide and above water at low tide

27. Intertidal zone: substrate type
Hard: rocky

28. Intertidal zone: substrate type
Soft: sandy-muddy

29. High tide line: supralittoral zone
The high tide line features species like:
Armeria flowers
Xantoria and Crythmun
maritimun
Crythmun marking the high tide line

30. High tide line
Yellow Xantoria Zone
Green Seaweed Zone
Dun Seaweed Zone
Red Seaweed Zone

31. FLORA: seeweed
Dun seaweed
Green seaweed
Red seaweed

32. FLORA
Salicornia sp.Limonium sp.
Examples of plants that
aren’t seaweed

33. Specific fauna
Limpet
Anemone
Balanus sp.
Monodonta sp. Litorina litoralis
Carcinus maenas
Pollicipes cornucopia
Clams / Cardium edule
Martesterias glaciaris
Holoturia

34. Intertidal zone:
occasional fauna
Cormoran
Seagull colony
Purple sandpiper
Rat
Anas platyrhynchos
Larus argentatus
Dolphin family -
Calderon

35. In the lab: seawater study
The aim of the study was:
 To separate the seaweed’s pigments
by paper chromatography.
 To extract iodine from seaweed.
 To measure the density of seawater.
A sample of seawater and seaweed was taken to the lab.

36. Seaweed chlorophyll
Extracting the pigments

37. Seaweed pigments
Filtering the extract

38. Seaweed pigments
Separating the green, red and brown pigments by
paper chromatography

39. Density of seawater
Finding out the density of seawater by weighting

40. Density of sea water. Results
Mass
(g)
Volume
(cm3
)
Density
(g/cm3
)
25,51 25 1.020
25,49 25 1.019
25,47 25 1.019
Density (g/cm3
) 1.019
The density of sea water in Cobas beach is 1019 kg/m3

41. Uses
– Fishing
– Recreation
– Energy: waterwheel
– Gathering seaweed for different uses

42. Changes and pollution
Private property, law isn’t respected.
No public walking path
Rats: waste waters
Discarded fishing gear

43. THANK YOU VERY MUCH FOR
YOUR ATTENTION