100 pieces of lead.
On a recent Strandloper Project reef survey at Gericke’s Point we located a barren section, an indentation in the rock bed, that was 2.8m x 1.6m and oval in shape.
Curious as to why there should be a barren gap in the otherwise vibrant reef, we investigated.
Ever wondered how many lost and discarded sinkers it takes to disrupt marine biodiversity?
At the bottom of the indentation (1.7m at low tide), there were 3 loose rocks and under them were exactly 100 lead sinkers, 4 spark plugs and one section of iron rod.
100 Lead sinkers recovered from 1m2.
Sinkers recovered from our research transect don’t display the level corrosion and abrasion that the 100 pieces did.
The conditions of the sinkers were unlike the bulk of sinkers that we recover from our research transect dives in that they were in an advanced state of corrosion and were well worn down.
Fixed Point Photographic Survey.
To evaluate whether the presence of the lead was the cause of the barren section of reef, we will be monitoring the site with fixed point photography to see if, now that the lead is removed, the area will be recolonized by marine life that is flourishing around it.
Similar in dimensions and 6m from the location where the 100 pieces of lead were recovered, the control site has well established marine life.
As a control, there is a similar indentation that is fully colonized by marine life, 6m away which had no lead in it.
From this site and other research we hope to evaluate the level of lead poisoning on marine reefs from lost recreational fishing tackle.
This fixed point photographic survey will complement our BRUV studies.
Chasing Windmills and Sunbeams 
Pingback: BRUV studies reveal new marine growth on reef. | Chasing Windmills and Sunbeams·
Pingback: Coastal Cleanup Day in the Garden Route. | Chasing Windmills and Sunbeams·
Pingback: Fish For the Future | Chasing Windmills and Sunbeams·