SANParks and their Honda-powered semi-rigid reasearch vessel continue to monitor the changing face of the Swartvlei estuary (By Nick Hanekom)

Swartvlei, which has been rated as the seventh most important estuarine system in South Africa, consists of a large (9 km²) and fairly deep lake, which is linked to the sea by a 7 km long estuary. The estuary is open to the sea approximately 50 percent of the time, and is often closed during the winter months. The estuary has large sandflats which provide an important habitat for burrowing, invertebrate bait species, which in turn are a food source for fishes and birds frequenting the estuary.

Field surveys done by SANParks in 2008 noted that the intertidal sand-flats were mostly bare of Cape eelgrass and supported large populations of the common sandprawn, but relatively few burrowing shellfish. However, since 2009 there has been a progressive increase in size of intertidal eelgrass beds, and in the abundance of burrowing shellfish, such as beaked clam, lesser heart-clam and littoral tellin, a concomitant decrease in the size of the sandprawn beds.

This was especially prominent on the sandflats of the lower and middle reaches of the estuary, and by late 2012 the extent of the sandprawn beds had decreased by approximately a quarter of its original size. Researchers from the University of Cape Town noted that the densities of the common sandprawn colonising the sandflats of Langebaan Lagoon were negatively correlated to the cover of Cape eelgrass, and at sites where eelgrass was absent sandprawns extended farther up the shore and reached a larger maximum size than in its presence.

The common sandprawn is itself an important structuring agent of faunal assemblages of sandflats. Through its burrowing and feeding activities, the sandprawn continually turn over the substratum and reduce its micro-algae contents. Experiments have shown that this process exerts a strongly negative influence on the feeding of the beaked clam and the surface grazing tick shell (a tiny whelk), and appears to substantially reduce the densities of these species on the sandflats.

Therefore, the current abundance of clams in the Swartvlei estuary is apparently closely linked to the extent of eelgrass cover. The distribution of eelgrass in temporary open and closed estuaries, like Swartvlei, is influenced mainly by the substratum and the height and turbidity of the water. A stable substratum and clear water generally promotes the growth of Cape eelgrass. Thus, the current situation in Swartvlei is likely to persist until the next large flood smoothers the eelgrass beds with fine silt. SANParks will continue to monitor the situation…


NSRI’s Spirit of Dawn safely brings ashore three passengers on a charter diving boat suffering from severe motion sickness

Just after 08h30 on Saturday the 14th of March NSRI Shelly Beach’s duty crew launched SPIRIT OF DAWN following a request for assistance from the charter diving boat C-FREAKS reporting three passengers to be suffering severe motion sickness at Protea Banks.

On arrival on the scene, at Pinnacle Point, Protea Banks, 4.5 nautical miles from their sea rescue station, three women, one from Kimberley, one from Brits and a local from San Lameer were transferred onto the sea rescue craft, along with the husband of the lady from Brits, and were brought safely ashore. They were assisted with rehydration and some medical treatment for their acute motion sickness and then released requiring no further assistance.


Honda-powered Ocean Odyssey helping to protect the Knysna ‘Hope Spot’ and as a result sustain the health of the ‘Earth’s Blue Heart’, the very Ocean around us

Honda-powered Ocean Odyssey

Honda-powered Ocean Odyssey

Covering almost 3000 kilometres, South Africa’s rugged coastline is hugged by an aquatic realm show-stopping in its fertility. Five key areas along this coastline were recently recognised as International Hope Spots by the celebrated marine biologist and acclaimed oceanographer Sylvia Earle of the organisation Mission Blue. Knysna is one of these Hope Spots, which is hardly surprising considering it embodies everything that is wonderful about our natural world.

Sylvia calls the ocean ‘Earth’s Blue Heart’. The truth of the matter is that our blue heart is taking serious strain. The Hope Spot initiative comes amid worrying indicators regarding the diminishing health of our oceans. Less than 3% is under any formal protection and human impact is proving devastating. Sylvia and the global partners of Mission Blue remain ‘hopeful’ is that if we ALL act now we can possibly turn the tide on this disturbing trend!

Hope Spots are essentially aquatic zones around the world which have been identified as being critical to the health of our oceans as a whole because of the prosperous diversity of life they hold. Everything on earth is intrinsically linked and the health of these defined areas is crucial for “sustaining biodiversity, providing a carbon sink, producing oxygen, preserving critical habitats and allowing for certain low-impact activities such as ecotourism to thrive”. Simply put, what’s good for the ocean is good for us.

Ocean Odyssey is an ecotourism operation in Knysna which thrives because of both the natural beauty of the area and the wonderful array of life that is encountered here. The Knysna Estuary is the most significant in terms of biodiversity in the whole country – and our ocean is equally jam-packed with life.

Ocean Odyssey is committed in its efforts to help protect this universally important Hope Spot within which they operate. They are passionate about creating awareness through their highly informative tours as well as through weekly blogging about the various species that thrive here. They assist university students monthly with important research on the rare Indo-Pacific humpback dolphin. They make use of only biodegradable products throughout their operation and recycle all paper, plastic and glass, thus minimising waste.

All their vessels are powered by Honda, whose outboard motors comply with very stringent environmental standards, including ultra-low emissions and an air intake system that includes a silencer; both important considerations for this type of operation in terms of minimising as much as possible any impact they could have on this marine environment.

We all need to do our part to help our ailing ‘blue heart’. If we don’t…both the oceans future and ours won’t be bright.




The NSRI is replacing the engines of two of their rescue boats with new Honda’s in March 2015. Rotarian Schipper, a 6,5 metre RIB based at Bakoven will be fitted with two new Honda BF90 HP engines and Rotary Onwards, a 7,3m RIB based at Yzerfontein, will be fitted with two new Honda 135’s

Simon’s Town’s 6.5m RIB - Spirit of Surfski 2

Simon’s Town’s 6.5m RIB – Spirit of Surfski 2

Late last year Simon’s Town’s 6,5m RIB, Spirit of Surfski 2 was launched and she is powered by two 90hp Honda’s.

Honda engines are a trusted brand of outboard used in Sea Rescue’s fleet of Rigid Inflatable Boats (RIBS). The charity has over 900 unpaid volunteers who respond 24/7/365 to save lives on South African waters using a total of 90 Sea Rescue vessels.

NSRI Operations Director, Mark Hughes said, “Honda four stroke engines give us excellent fuel economy, longer range and have what is arguably the most environmentally friendly technology … all of which is important to us at NSRI.”

“Our rescue crews need superb quality and reliability from their outboards … and minimum fuss. Honda does this for us.”

“But perhaps the most important thing for Sea Rescue is the exceptional service that Honda give us. They are simply the best in this department,” said Hughes.