November 2009

November has been an exceptional month for shark sightings. The month started with some strong westerly winds blowing consistently for the first week. This made working conditions a little difficult in joubertsdam which is an exposed and gets very choppy-quickly. However when the winds finally died down- water temperature climbed substantially remaining above 16º C for the rest of the month. On the 22^nd, 26th 27^th and 28^th the water temperature climbed up to 17ºC! the warmest temperatures all year!- needless to say- the divers had a blast in the cage!

Resights and shark activity

As usual we recognised quite a few familiar fins during November- with shark activity very high all through the month. Gill was our first familiar shark to arrive. She is a large (3.2m) female we first named and identified in September 2007. Since then she has been resighted at Dyer Island (2008) and on numerous occasions this month. Her distinguishing feature is her ‘ Orions belt’ shaped pigmentation on the right of her dorsal fin. This shark also has a real personality and always comes across as very relaxed.

Another familiar fin this month is ‘Wolfgang’ -a small female shark Olli (our other marine biologist) named and identified in Mossel baai. On arrival in Gansbaai he immediately recognised her and matched her dorsal id. Wolfgang (named after a German videographer) has a small white pigmentation spot on the right of her dorsal and is a feisty shark- often rushing about. ‘Moony’ was the third distinctive resight and arrived at the end of November. This shark was last seen at Dyer Island in July 2008. She has distinctive crescent half moon shape on the right of her dorsal and a very inquisitive nature. She loves to pass by the cage very slowly indeed- and always seems to turn with her belly angled towards the surface- stunning shark.

Finally the most exciting resight of the month was ‘Prop’. This very special female shark was last observed at the beginning of the year- and documented in November 2008. Sadly she had a chronic propeller injury on her ventral surface- just between her head and dorsal fin. This was sustained from a recreational vessel in the bay who relayed the incident immediately afterwards. Every opportunity to document her wound was utilised via underwater videography and surface photographs during her stay. ‘Prop’ returned during the second week of November this year and was hardly recognisable. Her wound had completely healed and there was no raised scar tissue or clear indication there ever was a chronic wound! On close inspection of the healed wound it is clear to see these sharks have an incredible healing ability and rate. This is a topic we are now busy compiling a research paper on- to compare the white sharks healing to other animal taxa.A very interesting topic.

Alot of sharks have been observed with bite marks on their bodies this month- many of these bite marks are from ‘smaller mouths’. One theory is the possibility of bull seals. There are many of them around Geyser rock now and these large seals are known for their aggression and ability to inflict a bite on an opposing animal.

Sharks in the shallows

November is always a spectacular time to view sharks in the shallows in Gansbaai. It’s always so fascinating to see how many individuals crowd and patrol such a small area of coastline. On various occasions this month we launched the Dyer Island Conservation trusts new research vessel ‘Lwazi’ and patrolled the shallows to make observations on the sharks movements. Interestingly the sharks seem very unresponsive- and distracted. They did not respond to a decoy after various attempts. Over 20 individual sharks were observed in the shallows on the 20^th of November! A gyrocopter took to the air- working with us on the 27th and filmed from above. Its stunning to see just how much the dark silhouettes of the sharks stand out on the sandy bottom and also just how close to the beach they get. The aerial footage revealed some really interesting interactions between sharks too.

At the same time- talking to the local fishermen in Kleinbaai revealed some excellent Chokka and Geelbek catches in the same area as the sharks.

Dolphin activity

On the second week of November we observed tiny bottle nose dolphins- no adults with them- cruising just next to white sharks along the beach. It seemed as if the sharks were circling the quick and agile little dolphins- then the dolphins disappeared. Similarly the indo pacific humpback dolphins have been observed in the bay again on various occasions.

Seal activity

There have been numerous predations documented this summer season in Joubertsdam. It seems that the sharks will readily go for a seal if it is in the area. Up at Geyser rock the young of the year cape fur seal pups are battling with getting swept off the rocks. At this young phase they are very weak swimmers and often tire out and drown. One baby we rescued in shark alley was in a bad way. With its umbilical cord still attached the tiny seal had no energy and was coughing up water. Nature has to be cruel to be fair sometimes. There are always a large amount of bull seals on Geyser rock this time of year. As mentioned before- these menacing seals have been observed chasing sharks away actually in Shark Alley previously.

Whales and birds

Southern right whale season has been consistent however the whales are fewer in number this year than previously. The whale whisperer’s skipper Albert Scholtz informed us that there are currently seven mother calf pairs in Pearly beach- but the young are very small and new born. This in turn makes the mothers extremely protective of their young ad often if a boat is around the pairs will dive down.  Bird wise- we have seen lots of swift terms this November- they are now starting to synchronise their mating flights. Its incredible to see how far the pairs can swoop down together in perfect synchrony! Also a few Caspian terns have been sighted (relatively rare). On the first week of November an albatross landed on the back deck of a shark boat and sat preening in front of the clients for twenty minutes- this just goes to show- one never knows what to expect on a trip out to sea in our area!