Im currently doing my A2 level Biology coursework on "the effect of the salinity of sea water on the rate of a barnacles cirri beats". i understand that it is to do with osmosis etc. but i dont know how to start my methodology for my plan. for example, what salinity levels should i measure and how should i measure them?? would be extremely grateful of your help!!
Measuring salinity is difficult and really requires special equipment. The following web site does give a simple method involving evaporation of the water
It would be better to make up artificial sea water by dissolving different amounts of salt in water. Normal sea water has a salinity of about 3.5%, so this should be the centre of your range