Expedition 2024
For our 6th Coastal Research Expedition, we hiked eastwards from Pringle Bay to Struisbaai, completing a distance of 228km.
We started hiking on the 5th October and finished on the 17th October.
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Expedition Objectives
The goal for our second series of expeditions is to get a comparison of the ocean plastic waste and fishing debris along the shoreline that we have already surveyed. To this end, we will again use a combination of survey methods to capture geo referenced data using CyberTracker.
Expedition Survey Methods
Trashy20 Survey
Conducted every 5km, this survey entails collecting and categorizing all plastic waster and fishing debris in three 10m x 2m transects.
Mini Transects
A total count of micro plastics, nurdles and plastic bottle tops along a random transect of between 1m and 10m.
Bottle Transect
A total count of plastic bottles over a measured distance.
Incidental Survey
Documentation of plastic waste and fishing debris not included in structured surveys.
Marine Fauna Surveys
Documenting the number and status of marine fauna seen. Details of injury and possible cause of death are also recorded, especially plastic ingestion, entanglement and ghost fishing.
African Black Oystercatcher Survey
A focused survey of this species to map the population density variations along the shoreline. Read a report on the factors influencing the variations of African Black Oystercatcher population density in the Southern Cape : Read Here
Cape Clawless Otter Survey
A focused survey of this species to map the population density variations along the shoreline. In addition to live sightings, we record scat and spoor.
Special Focus
In August 2020 approximately 176tons of plastic nurdles were lost at sea along the Eastern Cape coastline. From November 2020, a three year cleanup program was conducted by SpillTech. The clean up operation was a manual process involving sieving sandy beaches and removing the nurdles. During the sieving process, large amounts of micro plastics were also collected. Sadly, the protocol, because it was not within the nurdle cleanup contract, was to dump the micro plastics into piles on the beach after the nurdles had been removed. On our 2021 expedition, we documented numerous plastic middens between Struisbaai and Pearly Beach. This was a lost opportunity to remove micro plastic from the shoreline.
Results
Plastic Lids
Of the hard plastics recorded, plastic lids were the most common item along the entire expedition. They were located primarily on the western facing section of shoreline, indicating that westerly winds are instrumental in the drift and washout of these and other plastic items. Sucker sticks, cigarette lighters and earbud shafts also ranked as the most prolific hard plastic items that washed up.
Shopping Bags
Crisp packets, sweet wrappers, food packaging and shopping bags were the most prolific soft plastic items recorded on the expedition. Most shopping bags were filled with shells, bait or plastic trash. The bags filled with shells, were usually associated near sights associated with abalone poaching activities. Some also contained trimmings from the shucking process of poached abalone.
Condoms
The most prolific poaching activity that is conducted in the region is that of abalone, Haliotis midae, a high value herbivorous mollusc that lives on rocky substrate in the Kelp Forest. Poached for export to the far east, teams of between 5 and 80 divers will collect the abalone. Their activities are blatant and they seem to operate with impunity. In order to remain in contact with the shore based team, they keep their phone in condoms while diving, and then tear the condoms and discard them once they have exited the sea and war waiting for collection above the high water mark. At some locations, the number of condoms exceed 100.
Between Danger Point and Quoin Point, poachers seem to operate with impunity, and don't make an effort to conceal themselves as readily as poachers further west. This is evidenced in the reduction of discarded broken condoms along this section of shoreline. The easy access for vehicles along the shoreline most likely contributes to the ease with which poachers operate along this section of coast.
Ghost Fishing and Monofilament
The sheer amount of washed up monofilament, lost and discarded by recreational fishermen, along this section of the coastline is the highest density that we have recorded on our expeditions. A consequence of this is the associated high record of ghost fishing mortalities, particularly of small sharks species.
The heat map of monofilament, shown above, shows that the highest density of monofilament is from Franskraal to Struisbaai. The majority of the monofilament that we recorded was entangled in washed up kelp. Fishing in kelp forests has a high incidence of recreational terminal tackle snagging on kelp stipes, forcing fishermen to break off the line.
Microplastic
Most often overlooked, micro plastics can range from a few pieces per meter to >300 pieces per meter. There is a bias for the highest densities to be recorded on sandy beaches as it is extremely difficult to see the small pieces of plastic on rocky shorelines. Even the shade of sandy beaches can influence the count of micro plastics, with lighter whites and greys more difficult to see on beaches composed of broken shell fragments. Usually we record a higher count of white and grey pieces, but on this expedition the blue/green/purple pieces had the higher numbers.
African Black Oystercatchers
In total, we captured 491 sightings and recorded 1204 African Black Oystercatchers. For the section between Struisbaai and Grotto Beach, we recorded a 6.4% increase in oystercatchers compared to our 2021 expedition. Within this section, we recorded 159 birds between Grotto Beach and Klipgat Cave at De Kelders, a 103.8% increase over the 78 birds recorded for the same section of coastline in 2021.
This incredible increase was most likely a combination of two factors. Firstly, in 2021, the tide was high tide at mid day as we hiked this section of shoreline. In a pre expedition survey in 2021, 74 oystercatchers were recorded in the Kleinrivier Estuary. It is most likely that this year, when the tide was low, the oystercatchers had flown from the estuary to forage along the shoreline. Secondly, the mass of sand mussel shells along the shoreline this year indicates an incredible food resource. In 2021 we did not encounter a wash out of sand mussel shells, indicating a diminished availability of food resources for oystercatchers in 2021.
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Support and Sponsorship
The success of each of the Strandloper Project is entirely dependent on a phenomenal team of volunteers and sponsors. Our core requirements for each expedition are accommodation, fuel, catering and apparel, especially all weather protection. Contact our team by email to find out how you or your company can support Strandloper Project on their valuable citizen science research expedition. |
