DOLPHINS

5 09 2010

DOLPHINS

Which species of dolphins do we find around Dyer Island ?

There are 2 different species of dolphins which are regular visitors in our waters; the Humpback dolphin and the Indo-Pacific bottlenose dolphin.

We have a resident pod of humpback dolphins (Sousa chinensis) around Dyer Island. These dolphins can be easily confused with the bottlenose dolphin. Humpback dolphins have a long, slender beak, and their body is lighter in colour than that of the bottlenose dolphin. Humpback dolphins have a small dorsal fin and a round hump before this dorsal fin, hence their name. The belly tends to be white and the calves and juveniles are paler than the adults (very light grey). Like all cetaceans with teeth, they have just one blowhole (nostril). These dolphins often surface at a 45° angle when coming up to breathe. These dolphins measure between 2 and 2.5 meters long with an average weight of 150 kg. They are usually found along the coast where they inhabit the shallows or inshore waters. They are rarely found in waters deeper than 20 meters, placing them in frequent contact with human activities.

The Common bottlenose dolphin (Tursiops truncatus) is the archetypal dolphin. They are most commonly seen dolphin on television and in aquariums. Around Dyer Island, we can encounter the Indo-Pacific bottlenose dolphin which is a sub-species of the bottlenose dolphin. The best way to describe the Indo-Pacific bottlenose dolphin is to compare it with the Common bottlenose dolphin. Indo-Pacific bottlenose dolphins have a longer and more slender beak than the Common bottlenose dolphin and their whole body is smaller and slimmer. Their body colour is also lighter than that of the Common bottlenose dolphin. Their belly tends to be white and dark spots appear when the animal reaches sexual maturity. The dorsal fin is large and curved. They usually measure between 2.4 and 2.5 meters long and weigh between 180 and 230 kg. They are usually found in coastal waters and are rarely found in waters deeper than 30 meters. Bottlenose dolphins are therefore commonly in contact with human activities. This makes them particularly vulnerable to the alteration or loss of their habitat.

What do the dolphins eat around Dyer Island ?

The Humpback dolphins mainly eat fish that can be found in shallow waters such as sardines, mackerels and mullets but they can also eat cuttlefish and small squids.

The Indo-Pacific bottlenose dolphins mainly eat fish and cephalopods (e.g. squid & ocotopus) that can be found in shallow waters but they can also feed on pelagic and off-shore fish species.
Do dolphins have a social life ?

Humpback dolphins live in small groups and we observe them in pods ranging from 1 to 12 individuals. In the Dyer Island area, we most commonly see groups with only 2 or 3 dolphins. In other areas, the biggest group ever observed was composed of 25 dolphins.

Bottlenose dolphins live in groups from 5 to 15 individuals but can sometimes be seen in groups of 100 animals or more. The society of these dolphins is believed to be quite stable, with closely related females living together, and groups of adult males, with strong bonds, coming to visit them for mating or feeding.

For both species, births occur predominantly in summer. Females have usually one calf every three years and they take care of their young for at least 3 to 4 years. The female is sexually mature between 5 and 12 years old, the male between 10 and 12 years. The gestation period (pregnancy) is one year. The calf measures approximately 90 to 130 centimetres long at birth with an average weight of 30 kg, and is born tail first. The female will nurse the calf with milk for approximately 18 to 24 months and the young animal will start to have a mixed diet (milk and fish) between 9 and 12 months.

What are the main threats to dolphins ?

Due to their habitat range, these dolphins are extremely vulnerable to human activities such as boating, shark nets and also pesticides used on land from farming and agriculture. As they live in shallow waters, they are more likely to be exposed to every type of pollutant coming from the rivers to the seas. The toxins that are entering the marine environment can concentrate in the dolphins’ fat (via contaminated fish) and can negatively affect their health. They also get entangled in the nets that are used to prevent the sharks from coming close to the beaches, as well as in fishing nets. Dolphins are known to be curious animals and can also become easily entangled in pieces of marine litter, such as pieces of plastics, ropes, etc.

How can we recognize different individuals?

Each dolphin has a unique dorsal fin, both with regards to shape and notches along the edge of their fins. Dorsal fins can therefore be used to recognize different individuals. We have already identified over 35 humpback dolphins in the area using this method of photo identification.

© 2010 Dyer Island Conservation Trust





CAPE FUR SEAL

5 09 2010

CAPE FUR SEAL
ORDER: Pinnipedia
FAMILY: Otariidae
GENUS: Arctocephalus
SPECIES: pusillus
SUBSPECIES: pusillus

The Cape Fur Seal breeds at > 40 colonies in southern Africa between Algoa Bay (Port Elizabeth) and baia dos Tigres (southern Angola), at mainland sites or on islands nearby the coast. There have been several new colonies established in recent decades. In South Africa, seals are protected under the Seabirds and Seals Protection Act, and they are faced with threats such as being drowned in active fishing nets or being deliberately killed by fishermen. They often become entangled in marine litter such as discarded nets, fishing line, or plastic.

Description

Arctocephalus pusillis are the largest of all the fur seals, with adults distinguished by their coarse brown fur, and pups are born with a soft black coat. Males are considerably larger and more robust than females, averaging 2.5 m in length and weighing about 300 kg, whereas the females are usually less than 2 m long and weigh under 100 kg.

Biology

Spending much of their lives at sea, the fur seals diet consists mainly of pelagic fish such as pilchards, anchovies, hake and maasbanker, in addition to squid, octopus and rock lobster. They mainly feed over the continental shelf, in the cool, nutrient rich waters of the Benguela Current. Cape Fur Seals have been reported diving to more than 400 m and have a lifespan of up to 25 years of age. Breeding adult males come ashore or ‘haul out’ in October to establish and defend territories. Shortly afterwards, in November, the females arrive and become part of the male’s harem, which can consist of up to 30 females. The females then give birth to the previous season’s pups during late November or early December, and then mate again shortly thereafter. Embryo implantation into the uterus is delayed for four months, with an eight-month gestation period ensuing, resulting in synchronous annual seasons of birth. Mothers alternate foraging trips to sea lasting for three months or more days, with shore visits of 1-3 days to nourish their pups. Weaning usually occurs when the pups are about 9-11 months of age.

Population and behaviour

Between the 17th and 19th centuries, the fur seal population was badly depleted by sealing. Thereafter quotas were enforced and seal harvesting was controlled. Approximately 2.7 million seals were harvested in the 20th century; nevertheless, the population has recovered in size and is currently estimated at almost 2 million. This rate of increase seems to have slowed since then. Although Cape Fur Seals normally travel alone, large groups are often seen rafting together in the kelp. Predators of this species include sharks, orcas and humans, with further losses of seals occurring through poaching, entanglement in discarded fishing nets and lines, by-catch in fisheries, marine pollution and changes in prey availability. Seals are known to negatively affect breeding seabirds via habitat displacement and predation.

References

ATTWOOD, C., BRANCH, M., MANN-LANG, J., MATTHEWS, S. & GLAVOVIC, B. 2001.
CoastCare Fact Sheet Series. Department of Environmental Affairs and Tousirm, South Africa.

BRANCH, G.M., GRIFFITHS, C.L., BRANCH, M.L. & BECKLEY, L.E. 2005.
Two Oceans – A guide to marine life in southern Africa. 2nd edition. David Philip, Cape Town. 360pp.

REEVES, R.R., STEWART, B.S., CLAPHAM, P.J., POWELL, J.A. 2002.
Sea Mammals of the World: A Complete Guide to Whales, Dolphins, Seals, Sea Lions and Sea Cows. A & C Black Publishers, London.

© 2010 Dyer Island Conservation Trust





Dyer Island Blog #8 – 06 October 2009

5 09 2010

Dyer Island Blog #8 – 06 October 2009

Major news the past few weeks in South Africa’s marine environment was the grounding of the bulk carrier ‘Seli 1’ shortly before midnight on Monday 7th September at Blouberg in Cape Town. This 29-year- old Turkish ship was headed for Gibraltar and was carrying 660 tons of fuel and 30 000 tons of coal.

The removal of the fuel began on Friday 11th September, and according to reports, by 20th September, 500 tons of the 600 tons had been removed and the threat of an oil spill was considered over.

The environmental risk that this fuel posed was considerable, given the proximity to Robben Island, a very important breeding area for seabirds (including African penguins and Cape Cormorants to name a few).

This first link takes you to the South African weather service’s website, where you will be able to see some pictures of the ship and a map showing it’s proximity to the coast and Robben Island. The second link takes you to the report of the oil spill threat being over. If you would like to read how the story developed, you can click here.

Speaking of all things oil, some of you may have read Blog # 6 titled Dyer Island. It was all about oiling and I made mention of the oil spill that had occurred in Namibia and gave a few details of the African penguin rescue operation underway. Well, Dr Jessica Kemper ,seabird biologist at the Namibian Ministry of Fisheries and Marine Resources has written a wonderfully, heart felt diary of the events that occurred. Click here to read. Dr Kemper has a fabulous; unique style of writing and she provides a humorous yet really touching account of what she; the NMFMR; the Luderitz community and others did to get these oiled birds the treatment they needed. The Namibian government will be proud to have such incredibly dedicated staff. And, with some seabirds in southern Africa facing a seemingly continuous downward population trend, I’m so grateful that there are scientists like Dr Kemper at the helm.

As for Dyer Island, oiled African Penguins continue to be caught and sent off for rehabilitation, as are many with seal bite injuries which is cause for concern. Just today I saw an oiled penguin on my rounds but it was too close to the water for me to catch. Very frustrating, and worrying given the consequences if I can’t catch it tomorrow.

To end off with for this instalment, a rather sweet story. On my nest rounds last week I came across a nest where previously the adults were incubating two eggs. I’ve been interested to see what happens to this nest as it is very late in the season for penguins to be incubating. They ‘should’ be coming to the end of breeding and preparing for their moult fast. As I checked the nest, it was apparently as I thought what might have happened. There were two dead day old chicks in the nest that had possibly been abandoned by parents who had left for their pre-moult fattening. I collect all the dead specimens I come across for analysis so grabbed my plastic sample bags. However, as I picked up my dead sample…it ‘peeped’ at me. This little chick was slowly dying of hunger and cold, and I honestly thought it was dead, it certainly looked like that from the way it was lying in the nest. Inspecting its sibling…to find it was in a similar state. These two little things brought my monitoring to a complete standstill and we rushed inside the housing area at Dyer, blowing on them to keep them warm. Once inside the house….now what do we do? The weaker one stopped breathing and the manager, Deon Geldenhuys from CapeNature (www.capenature.org.za) blew in it’s mouth. After throwing up some green liquid (the chick…not the manager), it started breathing again. So to cut a few crazy hours short, we managed to keep the chicks warm, and with a call to Venessa Strauss from SANCCOB, set up a feeding regime. SANCCOB had donated a lamp that we could use to warm chicks up, and so Deon performed some MacGyver trick and set up an incubator for the chicks.

They were 60g when we found them and needed feeding 10% of their body weight every 6 hours. At night when the generator was switched off, they had a hot water bottle, which was changed at 2 am in the morning to make sure it stayed warm. We knew they had survived the night, when around 5 am they were screeching for food. After a few days, we were able to get them to SANCCOB, and the last I heard they were about 120g. Will let you know what happens. Once off the island, I’ll post some video clips of the chicks on U-tube.

That’s it for now. Some counts to do tomorrow before the weather turns in the next day or two.





Waiting for our tagging permit

16 08 2010

by DICT’s Marine Biologist Alison Towner

As we wait for our tagging permit, we are certainly enjoying some awesome sharks this month, with an average of 6-10 sharks per trip seen of Shark Fever.

Weather conditions have been relatively stable for mid winter with only a couple of small cold fronts passing through the area. The predominant wind direction has been gentle north westerlies, with water temperature remaining surprisingly cool at 14 Celsius. Interestingly the majority of sharks we have located have been patrolling the East side of Dyer Island, specifically East of Geyser rock and visibility has been so fantastic the sea floor has been visible on many days!

Exciting shark observations

Most of the sharks this month have been 2-2.5m males, showing quite active and responsive behaviour to our chum. Slashfin finally made his appearance this year- very late indeed. Usually we first encounter this 3.5m male shark at the start of winter season around March- April and he stays around for a month or so. He was first spotted on the second week of July and has consequently been encountered on various occasions since. This is his sixth year on record in our area and there is no mistaking his distinctive slash- scarred fin!

Another large shark we named Ilona- became a real favourite of ours. She had a large fresh bite mark on her right side gill slits and two hooks in each side of her mouth. Often these bites are inflicted by other sharks of similar size or even possible early mating attempts by male sharks. Despite her injury she is an extremely relaxed and gentle animal and she physically dwarfs the cage as she swims by it in her slow and inquisitive manner.

‘Saviour’ is another shark we have been fortunate enough to encounter in the area during the whole world cup season. Measuring at 2.8m we named her due to the fact that she saved us on a number of trips by allowing people the chance to dive repeatedly with her- she would generally stay with us from the moment we arrived until we left! Her distinctive trait is a small patch of parasitic crustaceans known as copepods attached to her head.

Predation observations

One of our real highlights of the month was a 3.5m female who showed up at the end of our morning trip on the first week of July. Her behaviour was noticeably slow and almost lazy! On closer observation underwater we noticed what looked like a white string trailing from her gill slits- and one heck of a round stomach on her. We presume she had just consumed a seal pup for breakfast and what we were observing were the intestines on the poor victim sticking out of her gills! This would explain her behaviour as she was clearly very satisfied with the high calorie meal sitting inside her belly and just felt like having a look at what was going on at our boat. As she glided by the divers in the cage she proceeded to rub her stomach on the cage as she passed! Needless to say, a stunning dive for those underwater at the time.

One giant petrel and one penguin were sadly bitten and then ignored by sharks this month. Both accounts were observed by our shark vessel. Sadly both birds died form the impact of the investigatory bites and blood loss. White sharks are real connoisseurs when it comes to their diet and clearly the birds had far too many feathers and bones to be worth the effort of consumption and digestion for the great whites responsible.

Interns learnt to use the CTD

We recently enjoyed a great afternoon on Lwazi with our Interns teaching them how to make use of the CTD. For a detailed explanation of this, see my previous shark blog. It is great to have our interns (and volunteers) who have been so incredibly passionate about what we do that they continually inspire us.

As we move on in to August we expect the weather to pick up to its winter peak, with the end of August notorious for ocean storms. However, shark wise we remain very optimistic and look forward to what marine life and surprises are in store for us.





Research team gain new scientific device

19 05 2010

The last few weeks have seen the beginning of an exciting new phase of research in Klein Bay which that will help us to understand the behaviour of the great white sharks here for the first time. Things are coming together nicely with new equipment, discounts, donations and team spirit! Research Team Gain New Scientific Device – A CTD! Measuring white shark movements in relation to environmental parameters is certainly easier said than done! However, thanks to one of our scientific supervisors, Dr Malcolm Smale of Bayworld in Port Elizabeth, the first phase of the inshore shark project has begun. Malcolm kindly permitted the research team to use his CTD which as the abbreviation implies measures water conductivity, temperature and depth.

After an in depth training session from Malcolm’s research assistant, Michelle du Toit, the team went into the field to sample water within the Bay and around Dyer Island. We sampled four sites inshore, one in Shark Alley itself and one just over the Geldsteen side of the Island (a well known area for the sharks in winter). The graph (above left) may look like three pretty ordinary lines to most folk but in fact these are extremely accurate plots of the turbidity (red line), salinity (blue line) and temperature (green line) at sample site 6 of our transect test grid – just outside the mouth of Shark Alley.

Such water sampling has never been previously conducted in Gansbaai. Furthermore, the plots paint a picture of what’s going on down the entire water column right to the sea bed as opposed to just surface data. They provide a really detailed picture of favourable conditions for sharks and why they might spend time in some areas of our bay instead of others at certain times of the year. We are privileged to have use of such a fantastic piece of equipment, from both oceanographic and biological points of view. We are thrilled to see the results over-laid with the shark tracks – specifically in the summer months.

Special Discount – Vemco Equipment Canadian telemetric corporate Vemco has chosen the inshore shark DICT project proposal as a winner telling us: “Congratulations your proposal has been selected to receive the student discount offer”.

To actively tag and track a shark is a costly process. One has to first purchase the acoustic tags, which cost up to US$ 600 a piece. Then there is the implementation of the tag on the shark and actively following the animal by receiving its signal. Once this is done the data has to be downloaded, which involves extensive/expensive software and time. So you can imagine the Trust research team’s delight when we received an email on 20th April telling us of the award more than halving the normal ZAR 60,000 cost of a vr100 kit plus tag. This massive saving in costs is great news and fills us with even more confidence in the project!

Marine Dynamics Continue To Have Excellent Autumn Shark Sightings What a wonderful month shark wise! We have had lovely warm water up to 17 degrees Celsius during much of March and April. The sharks have been around in vast numbers with large males and females sighted regularly around the island.

On one occasion there were seven sharks in view at one time. A shark we were quite thrilled to see the return of was Big Nemo. This shark has a distinctive hole in his dorsal fin. Oliver Jewell identified the fin in a catalogue from being satellite tagged in Mossel Bay in 2003. The tag as it aged on the sharks dorsal fin gathered a lot of algae on it, and as a result caused quite a distortion to the fin. Nonetheless the shark is extremely active and always a pleasure to interact with at sea.

Sharks Need Your Support

Shark sales are going really well, we have reached over ZAR 73,000 so far, which means we certainly can buy our own tracking equipment, made even more possible with this new offer. The film crew from German’s Planetopia, supported us by buying 30 spaces – ZAR 4500. Watch their production on German television 10-11th May. Now we just need continued support to keep buying tags – and every little bit of support really does go a long way.

We hope to fill our spot map completely before the soccer World Cup!

Please do think about helping us and donating





Approval granted

18 02 2010

by DICT’s Marine Biologist Alison Towner

Progress with UCT! After an official letter of acceptance from the department of Zoology at UCT I was finally able to register. After waiting for so long for this opportunity I think its safe to say I was the happiest second time student in Africa- if not the world! To add to the great news the department of Avian demography reimbursed me a fee based on the work the DICT has supported over the years- which has helped enormously. All is looking good!

I would just like to say a huge big thanks to all who have supported and donated so far. The amount of conservation and ‘pro shark protection’ people we get on our cage diving boat actually restores all my faith in humanity and to date we have now received over 400 donations- (all from shark cage clients!). This means in our tagging kitty we have now R60,000 to buy equipment to follow the sharks with.

We are hoping to begin our first tracks towards the end of March, by which time hopefully the MCM research permit will be issued by Marine and Coastal Management.

In conjunction with the white shark project Meaghan McCord is now back in the Breede river based on other species of sharks in the Western Cape – the Zambezi or Bull shark. The first expedition was funded by MD cage diving clients last year. On the first study Meaghan and her co workers at SASC managed to land, tag and track the world biggest Zambezi shark- a four meter female. This year we can confirm she has two more male animals bleeping away with transmitters on their dorsals in the system and the success of the project continues to rise. Marine Dynamics guests can feel good about this! Meaghan will be helping out with our white shark research program too and her tracking expertise will be welcomed.

January shark sightings

We have had the perfect start to the New Year. The sharks have been great the water warm, and our guests extremely satisfied with their sightings. The most repeated sentence spoken between the Marine Dynamics crew on board Shark Fever has been “This cannot be January!”

The month started off with repeated winter bouts of weather every few days- very similar to last month. These westerly wind intervals continued the whole way through January and kept our water temperature between 15 and 18 degrees Celsius (only dipping as low as 13.2 on two occasions). This is seriously tropical conditions for Gansbaai that can get as low as 9 Celsius at this time! Visibility has also been relatively good clocking up to 5m on a few occasions during the last week of the month.

And so shark activity has been stunning! Still (touch wood) we have not yet had a miss trip/ no show so far. On average we have been sighting 4-7 sharks a trip, notably the activity levels of the sharks have been super high. In particular we seemed to pick up certain sharks that would stay around and interact with us for the whole trip. Combined with this there has been a real abundance of sharks around. One of the major assumptions about the summer inshore area for white sharks is that there are generally very few males and around 90% are females and juveniles.

However, it seems this January we have encountered more than 40-50% males usually sub adults which leads us back to the two questions of why and what is different?

Famous and familiar fins

Our celeb shark of the month has been a 2.9m female we named ‘Ilze’ after a good fried of ours who is a South African tour guide and joins us on the boat regularly. This shark has a fantastic nature and inquisitively approaches our cage very closely. We have also reached the conclusion that she simply loves our boat as we encountered her everyday non stop for over a two week time period! Another great shark in the area is a male we know as ‘Jagger’. His extremely distinctive dorsal fin got him the name and we recognise his dorsal but cannot place it with our database. The shark is encrusted with copepods (parasites) by the posterior of his body and his dorsal. Often sharks arrive in Gansbaai fouled with copepods and they fall off during their stay. We get the impression that Jagger has been away from Gansbaai for a while and only just returned. He is a very bold shark in nature and quite greedy too!

Another small male named ‘Micky’ has the most remarkable beauty spots on his dorsal and tail. These white marks are often useful with identification and are referred to as ‘rosies’. It is believed that they may resemble something similar to a human birth mark. Micky has huge star shaped rosies on both left and right sides of his dorsal.

Two familiar fins this month are Prop and Speedy. Prop is a small 2.3m male- with the tiniest claspers (male genitals on a shark)- which we only discovered this month- and he is our case study shark on wound healing study. Speedy arrived in and left Gansbaai very quickly but there was no mistaking her unique character and appearance. Firstly, she’s big around 3.5m. Secondly, she’s feisty and has the tip of her tail missing. Her name describes her perfectly.

Other marine life- cetaceans and birds

Finally our Southern right whales have moved off. The whale season was a nice long one with quite a few loose groups of whales still hanging around the Western Cape hotspots well into early January. Now it is believed they migrate off to the Antarctic waters to indulge on krill (zoo plankton rich in protein). Towards the end of the month our company director, Wilfred Chivell, decided to run a pelagic excursion on the Whale Whisperer. We took the boat out 20-25km behind dyer island into the open ocean where the depth is over 80m. It was a stunning morning with perfect sea conditions. The four hour trip allowed us to observe huge Brydes whales go about their thing quietly in the blue. On our return journey we were fortunate to observe a complete bird frenzy with literally thousands of Cape Cormorant and every other species gathering busily to feed on fish. Accompanying the cormorants were thousands of Cape gannets which dived spectacularly from the sky into the water in pursuit of their meal. Amazing to watch!

Seals

On the odd ventures up to Dyer Island that we made this month it was clear to see ‘their time is coming if only they knew!’. The Cape fur seal pups are swarming the shores of Geyser Rock- eagerly dipping their flippers into the water and learning the manoeuvres of how to swim and survive. Interestingly with the westerly winds intervening there have already been a few white sharks sighted and worked with at the Island.

IWSS International White Shark symposium

The International White Shark Symposium is being held next month from the 7-10th of February. Both Hennie Otto (Marine Dynamics shark boat skipper) and I will be attending. We look forward to getting the latest information on the most up to date white shark research conducted by the world’s best in the field. South African researcher Alison Kock of Save Our Seas will be one of the symposium directors and will undoubtedly do South Africa proud by discussing all the hard work she has been doing with False Bay’s whites. I will be presenting my very first scientific poster on the wound healing of great whites and I’m really excited about the whole event. Not to mention, the location happens to be in the exotic island of Hawaii! We shall keep you updated on the symposium in next months newsletter.





Observations and wound healings

10 12 2009

by DICT’s Marine Biologist Alison Towner

Early November saw our supervisors, Prof. Les Underhill and Dr Malcolm Smale here for a weekend to go over the project’s finer aspects and planning. Malcolm’s expertise in the project is extremely beneficial and he was full of ideas as to how, why, when, and what else we should look at with the white sharks in the tracking area. Les- renowned for being a statistical genius gave some great insight on how best to analyse and collect data- along with incorporating oceanographic parameters into the picture. Together they really are an encouraging team and we very much look forward to their input throughout the project! We await word from the University on the go ahead.

SHARKS

But most importantly what of the sharks. November has been a great month for shark sightings, even though there was some strong wind in the first week. The water temperature increased to 17° C, the highest temperature recorded all year. The shallows are very busy and 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 20th 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 an area very close to where the sharks were patrolling. 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.

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 re-sighted 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 that Oli (our other marine biologist) named and identified in Mossel Bay. 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 re-sight 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.

WOUND HEALING

Finally the most exciting re-sight 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. The injury we estimated was very close in depth to her vertebrae. It 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. This is an interesting topic and one that very little baseline research has been focused around it.

Many sharks have been observed with bite marks on their bodies this month- the majority 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. 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 shallows 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.

FUNDING

You can now purchase a block of research area on the web site (click here). You will receive a certificate of recognition for your support and be listed as a shark supporter. Makes a great and unusual gift for the nature lovers out there.

Support is growing. Any potential corporate sponsors can please get in touch with me for a formal proposal.

Thanks to all for the support!








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