First ever sei whale stranding in Namibia

A little later, but better than never :

By Sara Golaski

An estimated 15 ton whale, later identified as a sei whale (Balaenoptera borealis) was reported to the Namibian Dolphin Project (NDP) on July 19th by local windsurfers. It had beached itself along the speed strip next to the Walvis Bay Lagoon and rested in shallow water.  Before anything could be done by the Walvis Bay Strandings Network, a group of quick thinking kiteboarders and windsurfers had already managed to urged back into deeper waters, where it was lost into the choppy seas. They reported the valuable details to the NDP but were unable to identify the species as whales in this family can be difficult to tell apart. The whale was not found again that day, but was discovered the next morning by marine tour operators who reported that it was swimming in extremely shallow water near the salt works pump station, an area of frequent whale strandings.

The whale re-stranded there, and was afterwards attended by researchers from the Namibian Dolphin Project and volunteers from the Walvis Bay Strandings Network. The animal, very unresponsive though still breathing at this point was identified as an adult sei whale, an elusive offshore species of baleen whale. Sei whales occur in all oceans, but are rarely seen as they do not normally venture inshore. Unfortunately this one was far too large and too shallow for a rescue to be possible, though researchers were able to collect photographs and a skin sample for later analysis. The animal had passed away by the next morning without having moved from where it stranded. Basic measurements of the female sei whale taken at the scene put it at 15 meters long. Its dorsal fin alone was half a meter high and its tail flukes were 3 meters wide.

Although sei whales were historically caught in Namibia and west South Africa by commercial whalers, this is the first record of one stranding on the beach, highlighting the importance of these events for researchers to understand more about these animals. Nothing is known about the current population size or habits of sei whales in Namibia. They live offshore where they are difficult to study, but simultaneously exposed to several potential human threats including phosphate mining and seismic exploration for oil and gas.

A big thank you to Sara Golaski, John Paterson, Sue Roux and Margot Jefferson for getting out to the animal to assess it and collect data. Also to Willi Deetleefs for passing on the info to us on Saturday morning and most of all to Des and Miguel, for reporting the stranding to us in the first place.

A busy few weeks mid year

By Tess Gridley.

In between moving into new offices and analysing data, we've had a few days out at sea this month. It's been great weather all week and our first day out we had an awesome humpback whale encounter. The two animals were very relaxed and curious and circled the boat for over 15 minutes while we just sat with the engines off, watched and took photos. We are also collecting skin samples for genetic analysis, and luckily this proved very easy with these two beasties. On the same day we were able to get another humpback genetic sample and also a grey whale sample, which we will compare to an earlier sample to look for isotopic differences and evidence of feeding in the bay.

 VERY CURIOUS WHALE - CRUISED RIGHT PAST THE BOAT, COULDN'T ZOOM OUT ANY FURTHER!

LAZY HUMPBACK, JUST ROLLING ONTO IT'S BACK AND CIRCLING US 

On Monday we were alerted to the presence of a stranded dolphin in the Walvis Bay lagoon, thanks to Callie Geel and Willi Deetlefs. This tuned out to be a pygmy killer whale, another rare sighting for Namibia, and proof that the Walvis Bay strandings network is so very valuable. Simon and Sara kayaked out to the animal and took all the standard measurements and the skull which one day we hope to add to our collection at the new water front office.

 SARA WASHING DOWN THE WHALE SO WE COULD LOOK FOR SCARS & PHOTOGRAPH IT

Later in the week, we were out a sea again, this time working on the bottlenose dolphin population. We were lucky to have an early encounter with a mum-calf group near Independence beach and collected some good data, all before 10 am in the morning. However, by the end of this busy week our luck started to run out,  with no dolphins to be found on Thursday and poor weather on Saturday - Luckily the coffee at the waterfront is good enough to make up for hours of misty weather... :) and we've all got LOADS to do in the office right now, so back to it..

 SOME BOTTLENOSE DOLPHINS GUNNING PAST THE HARBOUR WALL. SO SHALLOW, THEY NEARLY HIT THE FLAMINGOS

Gray while still in Walvis Bay

The gray whale (which remains the only one known to be in the Southern Hemisphere) - is still in Walvis Bay.

It was first seen on the 04 May 2013 and was most recently photographed by us on 28 June 2013 on our day out with Manica and some top performing local biology students (see below). The whale has been hanging around the Pelican Point area on the west side of the bay (see blue line on map below), where it has been seen by local tour operators on a nearly daily basis. This is an area of known high productivity so it is likely that the animal is feeding here.  Looking at photos taken over the last three months it does look like the animal has fattened up somewhat.

Several humpback whales have already been seen in the bay since late June on their way to breeding grounds further north. No reports yet of fraternising between the species, but perhaps the gray whale will join up with some of them for a journey to new areas.  We'll keep you updated.

Top biology students head out to sea with Manica & the NDP

MANICA, the shipping and forwarding company decided to do a little double whammy of local support last week. Not only did they reward 5 top biology students from 5 local high schools with a day out on Sunsail's catamaran, but they also donated R10 000 to the Namibian Dolphin Project!

A big thanks from our side to Nolito and Manica for the donation - it is superbly well timed as it links with the opening of our new environmental office down at the Waterfront. We're going to use this money to kit out the office and get some nice education posters and branding printed up.

The sea day was all we could have asked for - great weather, glassy seas - good Heaviside's dolphins at the Point and Walvis Bay's own gray whale!   A few pics of the very enjoyable day below.

 

CAPT HANS AND HIS PELICAN

HOW MANY BLOWHOLES DOES A WHALE HAVE?

TESS AND SOME LITTLE PEOPLE

GRAY WHALE WATCHING

WHY LOOK AT THE ONLY GRAY WHALE IN THE SOUTHERN HEMISPHERE WHEN THERE'S HOTDOGS!!!? :)

Luderitz wrap up 2013

by Simon Elwen:

Our two month field season in Luderitz draws to a close today.  Our last sea day was an !Anichab survey of the central area on Monday-Wednesday.

A good season all round I think, we had:

24 days (166 hours) on Nanuuq in and around Luderitz Bay doing mainly photo-ID, behavioural and habitat surveys, and covering 852km of survey track.

12 days and 6 nights  (185 hours) on the !Anichab surveying 2800 km of dolphin habitat in and around the Namibian Islands Marine Protected Area (NIMPA).  No data summaries yet, but a good few dolphins, a few whales and lots of penguins. And albatrosses everywhere!

Remarkably few 'weather days' but some productive office time with data entered, proposals written, papers prepared, submitted or reviewed

Tomorrow we get back on the road with the dog and the baby in tow (the students have already left on a shuttle).  1200km of tar road via Windhoek to Walvis Bay - we're coming for you Mr Gray Whale!!

A rare and mysterious visitor in Walvis Bay

by: John Paterson, Albatross Task Force and Walvis Bay Strandings Network

Gray whales, Eschrichtius robustus, live in the high Arctic and northern Pacific Oceans coming as far south as Baja California and Mexico on the west coast of America and the Korean Peninsula to breed in summer. It used to occur in the North Atlantic Ocean, but was hunted to extinction in the 1700’s. It does not venture south of the equator. Or so we thought.

Last Saturday, 04 May 2013, tour boats doing dolphin cruises to Pelican Point saw a strange whale. Several more sightings during the following week seemed to indicate the unlikely fact that a gray whale was visiting Walvis Bay! On Sunday 12 May a member of the Walvis Bay strandings network confirmed the reports that there was a gray whale about. This is the first known record of this species in the Southern Hemisphere. The question is now “what is the origin of this whale?”

In May 2010 a gray whale was seen off Israel in the Mediterranean sea and the same whale was seen 22 days later in Spanish waters, also in the Med. This sighting raised much speculation on the origin of the whale and the reasons for its appearance. It was suggested that the whale originated from the eastern Pacific population and was able to navigate around the northern Canada due to the reduction in size of the Arctic ice cap caused by global warming. This climatic trend would potentially allow these whales to re-colonise their historic range in the north Atlantic. The authors of that report stressed that it was difficult to draw conclusions from a single event and were only proposing likely hypotheses. Three years later a gray whale makes its mysterious appearance in Walvis Bay. Comparing photographs of the Walvis Bay animal with the Mediterranean animal (courtesy of Aviad Scheinin -  http://www.hamaarag.org.il ), it seems unlikely that this is the same individual. Is it another individual that has traversed the North West Passage, or perhaps travelled around the southern tip of South America and across the Atlantic? Unfortunately, we’ll never know the route it followed to get here but keen eyes on the water may tell us where it goes next, so please send your reports to the WBSN if you see this animal.

Gray whales grow up to 14 m in length and undertake the longest known migration of any mammal completing a round trip of over 30,000 km between their summer feeding grounds in the high Arctic and winter breeding area off the coast of Mexico returning to the high Arctic again. The whale seen off Israel had completed the longest known stray by any mammal. Though they are baleen whales gray whales are unique in that they feed off the bottom of the sea floor by sucking up mud, usually through the right side of their mouths, and filter out the bottom mud dwelling amphipods on which they feed. This results in the baleen being shorter in one side of their mouths.

This sighting highlights the chances of seeing amazing animals in Namibia and also how important our marine environment is to sea life. Well done to the marine tour operators for locating this whale and operating in a responsible manner and not scaring the whale off. The Walvis Bay Strandings Network would like to thank the tour operators for passing on all sightings of this whale and particularly Mola Mola Tours for making space on their vessel so that we could confirm the identification and get photographs.

Cetacean Surveys of the Namibian Islands Marine Protected Area 2013

After a very successful series of surveys of the NIMPA in 2012, we are happy to be continuing the work here with the Ministry of Fisheries and Marine Resources.

The ship we're using has a lot of obligations: surveying for lobsters, doing environmental monitoring lines and supplying the islands (and islanders) with water, food and crew. Then there is bad weather…so there is always a queue to get on the ship and we were very happy to get a good clear 3 straight days last week in an excellent forecast.

The forecast held and we had some of the best weather I've ever had at sea on a ship. Day 01 was a bit swelly still (with some associated sea sickness from us all), but day 2 and 3 were glassy flat and lovely. The area we surveyed is just to the south of Luderitz Bay and straddles the heart of the main upwelling cell within the Benguela ecosystem. This upwelling cell is so strong and so fast moving that there is (counterintuitively) remarkably little life there as there hasn't been a chance for the nutrients to get converted into phytoplankton and move up the food chain. Last year, we only got one day in this area and no sightings but it was horrible misty, swell weather, so it was important for us to get into this area again to confirm our findings.  Given potential for low sightings, we were thus quite happy to have had 22 dusky dolphin sightings and 5 whale sightings over the 3 days (although they mostly happened close to shore and outside of the upwelling cell) and the hydrophone worked like a bomb the whole time.

A numerical summary:
3 days, 2 nights
842 km surveyed
22 dolphin sightings
5 whale sightings
and
~500 GIGS of acoustic data collected

Heaviside's dolphins echolocate at a very high frequency (are~120kHz), we have to record up to 250 kHz to cover the entire click's frequency range - this is more than 10X the data density (quality) of a normal 'human' recording. To put it in perspective, we fill a CD with data every 5 minutes.

A WILSON'S STORM PETREL OVER GLASSY FLAT SEAS

A DUSKY DOLPHIN SURFACES UNDER THE BOW OF THE !ANICHAB BEFORE DAWN

A BALEEN WHALE SEEN IN ABOUT 180M OF WATER - PROBABLY A MINKE, SEI  OR BRYDE'S WHALE

SURVEY ROUTE WE FOLLOWED