Suretka is a small community which is the home to a river crossing essential to our visits to the Bribri reservation. the coordinates are:
Latitude : 9.567
Longitude : -82.933
Suretka is a part of one of the poorest regions of this country. A recent article in AM Costa Rica, says that the local Bribri population has an income of under $8 a day. It goes on to say that the Indigenous are looking for better paying jobs, not a handout.
This area is home to the upper portions of the International Banana Plantations because it is on the edge of the Indigenous Reservation. Originally we were going to utilize kayaks to take samples from Bribri and Sixaola (two towns downstream from Suretka).Our Kayaks didn't show up as planned, and being the quick thinkers we are, we turned our taxi driver into a day long concierge.
We arrived in Suretka at around 10 am we rented a dugout canoe to make stops at each of the three transects across the river. 2000 colones and a rushed few minutes later we had water and readings collected. (Sorry guys, we are busy bio-surveying, water testing, and cleaning the beach to get our photos uploaded and up with so little downtime, we will add them as soon as we can!)
There were banana plantations visible along the northeastern edge of the river, as well as to the northwest. The tests showed:
| Test 1 (Suretka) | C | B | A |
| Conductivity | 138.5 µS/cm | 142 µS/cm | 316 µS/cm |
| Total Dissolved Solids | 152 mg/L | 67.7 mg/L | 66 mg/L |
| Salinity | 0.1% | 0.1% | 0.1% |
| pH | 7.48 | 6.92 | 7.36 |
| Dissolved Oxygen | 9.09 mg/L | 9.20 mg/L | 8.90 mg/L |
| Turbidity | 8 units | 4 units | 5 units |
| Nitrates | 0.01 mg/L | 0.7 mg/L | 0.8 mg/L |
| Ammonia | 0.02 mg/L | 0.01 mg/L | 0.02 mg/L |
| Phosphates | 0.33 mg/L | 1.06 mg/L | 0.67 mg/L |
*Please note; the above was set up as the river flows from the top of the page to the bottom. A was on the east side, B in the middle, and C on the west side.
After Suretka, we traveled to the Town of Bribri about 20-30 km downstream. this is the area where the large plantations really begin in force, and run south to the border with Panama. At this site there was a small jetty which allowed me to walk 3/4 of the way across the river. Unfortunately I couldn't get all the way across, but our transect was pretty good. Those results are:
| Test site 2 (Bribri) | C | B | A |
| Conductivity | 142 µS/cm | 145.3 µS/cm | 152 µS/cm |
| Total Dissolved Solids | 67.7 mg/L | 69.3 mg/L | 72.5 mg/L |
| Salinity | 0.1% | 0.1% | 0.1% |
| pH | 7.38 | 7.35 | 7.27 |
| Dissolved Oxygen | 9.40 mg/L | 9.39 mg/L | 9.40 mg/L |
| Turbidity | 7 units | 5 units | 9 units |
| Nitrates | 0.4 mg/L | 0.2 mg/L | 0.5 mg/L |
| Ammonia | 0.02 mg/L | 0.01 mg/L | 0.03 mg/L |
| Phosphates | 0.33 mg/L | 1.09 mg/L | 0.19 mg/L |
After we climbed back up out of the river basin we headed south along one of the best roads in Southeast Costa Rica towards Sixaola. Again, without a kayak we had to improvise, and after another 20 km or so we came upon the bridge crossing over the Sixaola and into Panama.
At this location we were only able to wade out into the first transect (c) to record data and collect water.
Those findings are:
| Test 3 (Sixaola) | C | ||
| Conductivity | 149.3 µS/cm | ||
| Total Dissolved Solids | 71.2 mg/L | ||
| Salinity | 0.1% | ||
| pH | 6.97 | ||
| Dissolved Oxygen | 9.28 mg/L | ||
| Turbidity | 4 units | ||
| Nitrates | 0.1 mg/L | ||
| Ammonia | 0.01 mg/L | ||
| Phosphates | 0.99 mg/L |
So what does it all mean? well we have tried to provide you with some information on the items we tested for by putting a link under the test name. There are constants and normal levels listed for most of these. As we can see, most the numbers appear to be within the normal ranges, however phosphate levels throughout the lower portion of the river appear to be extremely high.
According to the Hach H2O University certain phosphate levels should not exceed the below tables amounts.
Total phosphate/ phosphorus* | Effects |
| 0.01-0.03 mg/L | Amount of phosphate-phosphorus in most uncontaminated lakes |
| 0.025 mg/L | Accelerates the eutrophication process in lakes |
| 0.1 mg/L | Recommended maximum for rivers and streams |
| * If an orthophosphate test cube or ortho/metaphosphate color disk gives you values above the total phosphate/ phosphorous values given above, there is cause for concern. | |
we did expect to find higher phosphates, but where does it come from? Phosphates come from fertilizers, pesticides, industry, and cleaning compounds. Natural sources include phosphate-containing rocks and solid or liquid wastes.
While we did not get the chance to test all transects in our last stop, we are definately going to keep an eye out on this area.
I wish I could elaborate more right now, but we are packing to go to Hitoy Cerere Biological Reserve for a few days. More to come!