A trip in two kayaks was made from Salcombe, North Sands, to Kingsbridge and back.
Click image for larger version
The up-stream trip was undertaken on an incoming Neap Tide with a tidal coefficient of 46 (i.e. its height was only 46% of that of the mean height of all Salcombe Spring Tides). The return trip was with the outgoing tide.
The wind was a moderate easterly so the route took advantage of the sheltered eastern shore.
| Time (UTC) | Event |
|---|---|
| 12:31 | leave North Sands |
| 14:13 | arrive Kingsbridge |
| 15:02 | High Tide Salcombe |
| 15:04 | leave Kingsbridge |
| 16:54 | arrive North Sands |
Click image for larger version
Temperature measurements were made from both kayaks. As both followed similar courses the temperatures were very similar.
Click image for larger version
The following links show the temperature measurements overlaid on mapping.
Near the sea the water temperature was around 10°C, moving upstream the temperature increased to above 16°C. The highest temperatures were found in Bowcombe Creek and by Kingsbridge Quayside.
Click image for larger version
Superimposed on this upstream increase and downstream decrease were a number of temperature 'spikes'. Most of these were associated with shallow water off points or promontories. The following image shows the temperature measurements off West Charleton.
Click image for larger version
One of the largest spikes (over 3°C above nearby waters) was off Halwell Point. The following images show the temperature, salinity and turbidity measurements in this area.
It is not clear what caused this particular temperature spike, the water was not noticeably shallower than adjacent water. In many ways it has the hallmarks of a discharge, but no outlet was visible.
Click image for larger version
Click image for larger version
Measurements of salinity were estimated at 10 second intervals using an electrical conductivity probe. The conductivity measurements were temperature corrected and converted to salinity values.
Click image for larger version
The following link shows the salinity measurements overlaid on mapping.
In he majority of the estuary the salinity varied between 34 and 37 ppt (parts per thousand). Considerably lower values were measured bear Kingsbridge Quay and in Bowcombe Creek where some fresh water was likely to be flowing in.
Click image for larger version
Click image for larger version
Click image for larger version
Measurements of turbidity (cloudiness) were taken using a probe which detects light scattered at right angles to a beam of IR light. This reports the frequency output of a photo detector. Higher frequencies indicate higher turbidity.
Click image for larger version
The following link shows the turbidity measurements overlaid on mapping.
The highest values of turbidity (cloudiness) were observed near the top of the estuary over mud.
Click image for larger version
Click image for larger version
