Issue 7 ~ January 2019
The members quarterly of the Lower Breede River Conservancy Trust.
The puffadder shyshark
When people hear the word “shark” a shiver secretly travels up and down their spine, or better yet, if they’re in the water and hear “shark” many people come pretty close to walking on water … really fast.
But the puffadder shyshark definitely doesn’t fall into this category. It is probably the cutest shark yet. “How did they get their name?” you ask? Well, that is because when they feel threatened or cornered, they try to hide their face as much as possible. They do this with their tail fin and place it on top of their head, which we humans interpret as shyness, but it is actually a defence mechanism. The common name of the puffadder shyshark comes from the fact that the pattern on this shark looks a lot like the patterns you would find on a puffadder snake, but that is where the similarities end.
This shark is endemic to the coast of South Africa, and has three other shyshark buddies in its genus Haploblepharus: The Brown shyshark, the Natal shyshark and the Dark shyshark. The Dark shyshark, can be found all the way up in Namibian waters and the rest of the Haploblepharus species are endemic to South Africa.
In Greek, Haploblepharus means “single eyelid”. This is extremely descriptive, since, like most sharks, the puffadder shyshark has what is called a nictating (a protective third eyelid) membrane. Apart from sharks, some reptiles and birds also have a nictating membrane. Even some mammals, such as polar bears, seals and aardvarks, have full nictating membranes.
These relatively small sharks grow to about 62cm when they have reached their full length. They only reach sexual maturity by about the age of seven and can live up to 22 years. The shyshark is an oviparous animal (which means it lays eggs and the egg cases are often found on beaches). After the baby shark has hatched, the casings are commonly referred to as mermaid’s purses.
The puffadder shyshark is preyed upon by larger fish, such as the broadnose sevengill shark (Notorynchus cepedianus). The Cape fur seal (Arctocephalus pusillus pusillus) has been documented capturing and playing with puffadder shysharks, tossing them into the air or gnawing on them. The shark is often injured or killed during these encounters; the seal may eat torn-off pieces of flesh, but seldom consumes the entire shark. On occasion, kelp gulls (Larus dominicanus vetula) take advantage of this behaviour and steal the sharks from the seals.
The first-ever mention of the puffadder shyshark was by George Edwards in 1760. George Edwards was a naturalist and nicknamed the “Father of British Ornithology”. George, however, was not the one to describe the puffadder shyshark. The animal was named after him, since he was the first to discover it, but Heinrich Rudolf Schinz was the one to name the puffadder shyshark Haploblepharus edwardsii in 1822. The Swiss Schinz was a naturalist as well as a physician.
Harmless to humans, the puffadder shyshark can be easily caught by hand. Not targeted by commercial fisheries because of its small size, it is taken incidentally and discarded by bottom trawlers operating between Mossel Bay and East London, and by fishing boats in False Bay. Many are hooked by recreational anglers casting from the shore, who also generally discard or kill them as minor pests. Some local exploitation of this species does occur for lobster bait and the aquarium trade. The International Union for Conservation of Nature (IUCN) has assessed the puffadder shyshark as Near Threatened. Although it remains abundant, the small range of this shark lies entirely within a heavily fished region, and any increase in fishing activities or habitat degradation could potentially impact the entire population.
So next time you hear, “Sharks are scary” or “Do you have a death wish? Why would you want to swim with Jaws?”, don’t think about scary or has a lot of teeth, instead, think of this little guy who covers his face because he’s shy of people.
Season Ranger’s Report
• We tried to ensure that all dangerous obstacles were marked in the estuary and the office requested help in obtaining new marker drums. We were fortunate In that a member sponsored some bright yellow drums that had been cleaned out for this purpose. We received a complaint from Ward 1 residents of some dangerous submerged tree stumps. These were subsequently marked, although we had to dive to tie the buoys on the trees.
• We were approached by Riverine Body Corporate to assist in marking off a safe line along the jetties to keep speeding boats away from jetties and water users. An objection was received citing the SAMSA regulations for granting approval of placing buoys in the estuary.
• Shifts were set out so that all parts of the day were covered. It was noted that the busiest times for boating are definitely mid-morning and then late afternoon.
• The main methods of patrols upriver are by boat. This is because of the many private launching sites and jetties, where access to boats would otherwise be difficult. Our patrols were done to incorporate all areas and also times, including early morning as well as evening
• Patrols were once again concentrated on providing a high degree of visibility. We always wore uniform and the boats insignia help show our presence on the water.
• Patrols upriver were timed to coincide with the patrols boat from downriver in order to drop and collect paperwork as well as swap information.
• We are pleased to report that compliance in general is improving. Compared to previous seasons there were also more new and bigger boats in the system.
• More houses are being rented out which made it important for us to educate new river users to local rules and requirements.
• The main contraventions are still approaching too close to the side and not staying in the middle of the river. There is a marked improvement in skiing rules and most boaters now have skippers tickets and SAMSA documentation.
• We were mostly reactive during this period as we had many complaints and information from the public which we responded to.
• It must be reported that there was little presence from any government departments in the river over the whole season. Swellendam SAPS conducted some vehicle patrols and we were able to communicate with them directly via the Whatsapp Community Policing Forum Group. We were instrumental in getting concerned locals to report fisheries contraventions to the local SAPS. The Department of Agriculture Forestry and Fisheries are still taking a very low stance in the area, despite numerous complaints. All the efforts to renew our Fishery Officer Appointment cards seem to have been unnoticed by DAFF and it is placing undue efforts on the Municipal appointed officers, who are patrolling but unable to oblige complainants who expect action.
• Early in the season we received many complaints that there was mass noncompliance regarding the night fishing ban in the estuary. We assisted CapeNature in conducting a night patrol and two fines were issued. There was a sharp drop in night fishing after this. We also informed certain property owners upriver to ensure holiday tenants were aware of the night ban. This was after information received around a poaching syndicate removing Kob from jetties in Diepkloof at night.
• Other fines were for skiing without having a second person on board to act as an observer.
• Warnings were issued when other transgressions took place and were recorded on the municipal compliance database.
• The boating public was always assisted in getting the necessary documentation, whether DAFF permits, SAMSA buoyancy certificates, Certificate of Fitness, skippers licences or municipal licences.
We might have had a rocky start to the winter rain but when it rained, it poured! From light showers to melting snow to frosty mornings, the Breede estuary got its fair share of freshwater. The salinity graph, noticeably from August to October shows a dip. This was the freshwater in the system. Freshwater retains heat better than salt water so there was a slight rise in temperature of the water, allowing a bit of fish movement to prepare for the springtime. The water became a bit darker allowing us to only see a third of a meter deep upstream. But there are no complaints. The freshwater restarts our water systems and brings exciting times ahead for the summer holidays.
Salinity (PSU) for April 2018 to December 2018
Temperature (⁰C) for April 2018 to December 2018
Turbidity (m) for April 2018 to December 2018
Plight of the Dusky
Dusky Kob (Argyrosomus japonicus) is highly sought-after by recreational fishermen due to their large size and good eating. Within southern Africa, Dusky Kob has a cosmopolitan distribution (Cape Point to southern Mozambique), but is most abundant between Cape Agulhas and northern KwaZulu-Natal (KZN). A large proportion of adults are migratory and move from the Western/Eastern Cape to KZN to spawn in winter/spring.
This species has several life-history traits that make it vulnerable. Juveniles up to 15 cm total length (TL) are completely dependent on estuaries, which means these critical habitats need to be protected from degradation. Many South African estuaries have been impacted by anthropogenic forces, with only 16% considered to be in excellent condition. The Breede River Estuary is in a good condition (estuarine health category B), with some modification to its natural processes. Due to the importance of the Breede River Estuary to Dusky Kob, it is imperative the Breede does not become heavily degraded as this will impact these fish.
Older juveniles (15 – 80 cm TL) are predominantly found in estuaries with a high silt load, but can also found in the adjacent surf zone. Dusky kob between 80 cm-100 cm TL are mainly found in the inshore marine environment, but can be recorded in estuaries. Additionally, late maturity (6 years at approximately 100 cm TL) and slow growth rate (42 years to reach a maximum of 80 kg and a length of 205 mm TL) makes kob susceptible to high fishing pressure.
This species is currently overexploited with severe exploitation being recorded since the 1990s. The global population for this species has not been assessed by the IUCN red data list, but regionally it is listed as vulnerable. Current rules and regulations are ineffective in protecting this species from overfishing and exploitation. Locally, East of Cape Agulhas; shore-based and estuarine recreational fishermen are only allowed 1 kob per person a day at a minimum size of 60 cm total length (TL). Boat-based recreational fishermen are allowed 5 kob a day, with a minimum size of 50 cm. However, only one of those fish may be bigger than 110cm TL.
Read more about the state of the Dusky Kob stock in the South African Association for Marine Biological Research’s Southern African Marine Linefish Species Profiles, page 154, by following the button below.
Bird species trend
Birds, unlike trees and shrubs, are very dynamic. Meaning they’re able to move from place to place. No bird you see in your garden will be the same bird you see the next day. Like many of us, we would avoid the cold all together if we could. Many bird species migrate to southern Africa during and start arriving in time for spring.
Gardens, fynbos shrubs and the estuary become full of songful birds due to many bird species starting to breed and are looking for a potential mate. Many species of waders, raptors and swifts and swallows descend onto Witsand from the Northern Hemisphere to avoid the cold and fill up on a good supply of food.
The Breede experiences the highs and lows of bird numbers and species. The graph shows that during winter, the number of species seen on the estuary drops to 24, but during late spring and summer it can get as high 46. This is due to an abundance of food and ideal weather conditions. There was a decrease in the number of species recorded in December to 36, but this could be due to the high level of disturbance due to an increase of holiday makers.
The area between the mouth and Powerline is the most productive in the entire estuary with 20 bird species recorded in this zone. This area has diverse habitats from rocky shores through to sandbanks and extensive mudflats.
Bird biodiversity for April 2018 to January 2019
The most dominant piece of litter recorded this quarter were tiny pieces of plastic (less than 2.5cm) (22.1%), followed by glass bottles (22%). Broken pieces of glass bottles less than 2.5cm accounted for 7% of all litter. On the main beach there was an increase in cigarette butts recorded from November – December (10.2% to 28.7%). Overall, cigarette butts were the third most abundant litter recorded. This has been recorded in several studies which found cigarette butts to be the top 5 most recorded litter on beaches. Fishing debris was accounted for a large proportion of all litter at Blokke to Tidal pool and main beach. Oysterbeds to Groenpunt again showed a percentage of glass related litter (alcohol bottles, particularly beer).
Between November and January, glass bottles and pieces, tiny plastic pieces and cigarette butts accounted for 55% of the litter recorded on Witsand’s beaches. Unusual litter recorded during this period were a cooldrink can from Asia, fishing glow sticks, a fully functional squeegee mop and a toothbrush. We are still finding nurdles on the beach and these small pieces of plastic are an environmental disaster. If you find them, please collect them and bring them to the LBRCT in a container and we can dispose of them properly. Throwing them in the bin/ recycling does not help and moves the problem elsewhere. Broken glass on the beaches is a safety hazard, so where possible please pick up after yourself/after others.
We hope you enjoyed this quarterly issue. Should you have any feedback, questions, or matters you would like us to cover in a future issue, please do not hesitate to write to us at email@example.com.