‘Come have a look at this’, Jonathan called above the wind and the rumble as the surf pulled back from the sloped pebble beach.
He was standing next to a postbox red, sit-on-top-of plastic kayak, its bow buckled and split, with goose barnacles sprouting from the surface.
Jonathon pointed out a sticker of an adventure company based at Storm’s River Mouth in the beverage holder. Chris, knowing the owner, messaged him, asking when the kayak has been lost. Minutes later, the response came through, ‘Washed out to sea on the 10th of August’. In just less than 10 weeks, the kayak had drifted over 400km to wash up west of Suiderstrand.
It was the 11th day of our coastal research expedition and we had already collected over 13,000 records of washed up ocean plastic waste ranging from hard plastics – such as lids, sucker sticks, toothbrushes, buckets and crates to soft plastic like bread bags, shopping bags, dog poo bags and condoms. There were plastic bottles, pieces of polystyrene and plastic cutlery.
Some sandy bays had a slick of microplastics, broken down pieces from a multitude of plastic containers and nurdles, the raw material used to manufacture every plastic item that we use on a daily basis.
In 12 days, we had completed 228km of hiking along the shoreline from Pringle Bay to Struisbaai, documenting all the plastic and fishing debris that we could. Using a bouquet of five survey methods to categorise types of plastics and determine their density and distribution along the shoreline, our objective was to determine the source of plastic pollution and where it flows into the ocean.
Figure 1: Using a collection of 5 survey methods, our team of six hikers collected over 14,500 records of plastic pollution. Front left to back : Liz Bazin, Chris Leggatt, Mandy Pelser, Ariadne Van Zandbergen, Jonathon Britton
The range of items suggested that the bulk of plastic washing up on the beaches originates from land based urban settlements and that it flows into the ocean through municipal infrastructure and gets flushed from rivers during flood pulses. In essence, coastal communities are connected to inland urban areas by a stream of plastic waste, which after drifting on currents, eventually washing up on the shoreline.
Density, shape and size of items, driven by winds and currents influence how far certain types of plastic drift and ultimately where it washes out. Along the section of shoreline hiked during this expedition, most of the plastic was recorded on the western facing shoreline, with lower densities recorded on the eastern facing sections.
Figure 2: A heat map of plastic lids shows the highest densities on west facing shoreline
Entangled in Kelp Forests
During our 2022 expedition from Arniston to Hermanus, we recorded the highest density of monofilament of the four expeditions we had done at that stage. Again, this year, this 228km section of the coastline ranks as the highest density of monofilament along 1,050km of coastline that we have surveyed between Pringle Bay and Cape Recife. Snagging in kelp stipes, the lost recreational terminal tackle poses both an entanglement and ghost fishing threat to marine birds and fish respectively. In additional as the monofilament disintegrates from UV exposure, it remains in the marine ecosystem as microplastics.
Adrift with Plastic
Finding the kayak provided a glimpse of some of the distances that plastic washed into the ocean can drift before washing out. Some items that had drifted even further than the kayak, were a selection of medical packaging and small packets of snacks. Released from containers lost at sea during a storm offshore of East London, a mix of snack packets and medial packaging began washing up at Port Alfred on the 9th of September and in the Garden Route on the 19th of September. By the time that they started washing ashore near Pearly Beach in the second week of October, they had drifted over 840Km. These specific items are part of a surge of cargo losses in South African waters as a result of the conflict in the middle east which has resulted in ships being rerouted around the Cape of Storms.
Oystercatchers numbers increase
In addition to surveying plastic and fishing gear, we also use the opportunity to marine fauna on our expeditions. A species that we have collected valuable data on, are the African Black Oystercatchers. This year, the total number of oystercatchers that we recorded was 1,204, with a mean density of 5.3 birds/Km. In comparison with our 2021 expedition data for oystercatchers, it was encouraging to record an overall increase of 6.4% in numbers for the section of shoreline between Struisbaai and Grotto Beach.
Figure 3: The highest densities of African Black Oystercatchers were along shorelines with rocky intertidal zones.
Future Change
Analyses of our expedition data over the past six years show that the bulk of ocean plastic waste originates from terrestrial sources. To stem the flow of plastic into the ocean is going to take a modification in how we, both municipalities and society, manage our plastic waste. For our future, we desperately need a paradigm shift to utilise plastic waste as a resource and to commoditize the collection and upstream processes that will end the current status quo of single use white noise.
Note : Expedition crew
- Mark Dixon
- Chris Leggatt
- Jonothan Britton
- Mandy Pelser
- Liz Bazin
- Ariadne Van Zanbergen
- Nick Leggatt – back up driver
For more information you can visit their website at www.strandloperproject.org or email expedition leader Mark Dixon on ghostfishing@strandloperproject.org
Distributed by Theresa Gibbon, Theresa Gibbon PR, 082 820 8437, theresa@theresagibbonpr.co.za