Southern Right Whales Mating Frenzy in Algoa Bay
By Jake Keeton

1. News

Yesterday 23 August was an exceptionally good day for us at Raggy Charters. Waking up to a favourable wind and swell forecast made us eager to prep our boat "My Bru" and meet our guests at the Yacht club. Our guests arrived right on time dressed for the chilly morning and quickly became acquainted with each other and our crew. After a detailed briefing about our company, the Baywatch Project, recent sightings and the tour ahead, excitement levels amongst the group lead to a brisk walk down to our boats.

We exited the harbour and shared our plan for the cruise with our guests. With a light North Easterly blowing and forecasted to drop off we decided to take a shallow route to St Croix island, saving the deep run for the journey home once the wind chop had subsided.

The first 30 minutes of the cruise along the coast was unusually quiet with only the view of the dunes and beaches to catch our eye. We couldn’t help but think, 'well you can’t have good weather and great sightings on the same day'. I can laugh now knowing just how wrong we were to think that.

After a short stop at the first island, Jahleel, we found ourselves close to the beach directly inshore from St Croix Island where we had our first luck. I turned around to talk to some guests on the roof of the boat and caught a glimpse of a tail fluke disappearing below the water about 50 meters behind the boat. We quickly stopped the boat, made a U-turn and idled back in the direction we had just come. What followed was a great sighting of a female Southern right whale with a rather inquisitive calf. We spent our time limit with the pair, snapping shots and sharing stories before heading for St Croix Island.

Quickly conversations turned to how finding a pod of dolphins would put the cherry on top of what was fast becoming an amazing day at sea. As we got to St Croix Island one of our guests shouted “dolphins!” And there they were, a pod of about 100 individuals making their way around the island towards us. The dolphins put on a real show, racing, playing and mating around our boat. With the wind having dropped off completely we left the island on a deep course back towards the harbour, not knowing that our best sighting was still to come. Just a few miles from the island we spotted the distinct 'V-shaped' blow of a Southern right whale. When we got closer, we found that there were in fact 5 whales. The whales were seemingly oblivious to our presence and proceeded to mate continuously as we watched in awe.

Southern right whales migrate to our shores for a short season every year. They are present on our coast during July, August and September in order to have their calves and mate in the warmer waters.  With the gestation period of these whales being 12 months, the males must follow the females and mate with receptive females.

Calves are born with very little blubber to protect them from the icy waters in the South seas. Luckily for the calves they grow very quickly after birth as mom’s milk is made up of 43% fat. This high fat percentage allows the calf to grow roughly 3 cm per day and build up a layer of blubber. This fat layer is essential for survival in their summer feeding grounds where water temperatures hover around 2°. Providing such nutrient rich milk to the calf is a huge task for mom as she will not feed at all in our waters, but rather survive off the fat reserve she built up during the summer months.

In the South Seas summer there is plenty of sunlight and ice cold, nutrient rich water, perfect conditions for tiny aquatic plants to grow. Phytoplankton blooms occur and the south sea turns green, a phenomenon that can be seen from space. Swarms of krill then feed on the phytoplankton, multiplying as time goes on and providing an abundance of food for Southern right whales. The presence of whales in the South seas increases the amount of food available as their movements in the water bring cold water to the surface where it meets the sunlight and mixes with waste from the whales, this aids plankton blooms. So, in a sense the whales are assisting in the production of their own food.

With only one month left to see Southern Right Whales we are excited for our next cruises out into Algoa Bay.

Mother and calf Southern right whale close to the beach, directly inshore from St Croix Island.

Two adult Southern right whales mating with St Croix and Brenton Island in the background.

A close up shot of a Southern right that decided to inspect the occupants of our boat.

Southern right whales mate by Sperm Flushing, in most cases the male that mates last will father the calf.

Two adult Southern right whales mating close to us. After swimming 4000 miles they cannot afford to be shy.