SARF017: Identifying the risk of deoxygenation in Scottish Sea Lochs with isolated deep water

Start Date: 1/12/05
End Date: 30/11/06
Main Contractor(s): SAMS
Other Sponsor(s):  

Objectives

1. To estimate the BOD and time scale to anoxia, TO, for all (silled) Scottish sea lochs as listed in the Sea Loch Catalogue (19). 

2. To estimate the rate of basin mixing and the average residence time, TR, (i.e. time scale between successive deep water renewal events) for all Scottish sea lochs. 

3. To provide a list of sea lochs in order of those most likely to suffer from depleted oxygen levels. 

4. To validate predictions of basin water renewal and deoxygenation against available data.

Summary

This proposal is a response to the SARF call for a rationale for the identification of sea lochs with isolated deep water, to help assess the risk of widespread basin de-oxygenation. It seeks to establish methods for predicting the average residence times for sea loch basin waters and the time scale for the basin water to reach anoxia based on a specified input of organic matter. By calculating and comparing these time scales for all Scottish sea lochs, as detailed in the Scottish sea loch catalogue, we will predict the propensity of those lochs to basin water de-oxygenation.