Quantification of microfibre levels in South Africa's beach sediments, and evaluation of spatial and temporal variability from 2016 to 2017

The microfibre content of beach sediment samples was established at 175 sampling sites along over 2700 km of South Africa's coastline in 2016 and again in 2017. The average microfibre content was 80 +/- 102 F/dm(3) in Feb/March 2017 (n = 161), and 87 +/- 84 F/dm(3) in May/June 2016 (n = 128). These average values, and the observed ranges of 0 to 797 F/dm(3) in 2017 and 4 to 772 F/dm(3) in 2016, are consistent with global observations. The highest microfibre levels were observed at sampling sites close to large coastal waste water treatment work discharge points. Several instances of temporal variability are observed, only some of which can be associated with seasonal changes in river runoff. This baseline data set is a valuable reference point for identification of priority study sites for more detailed study of marine ecosystem response to microfibre pollution.