Science...it's not all about pretty pictures of dolphins...

Blog entry by Hannah "Banana" Murphy...

The first day we went out to sea, I did not go out to sea.  When I was informed of this tragedy, I replied, “Oh, okay! That’s great!”  I did not, however, think it was great.  I was dying a little on the inside.  We all woke up at 6 and I waved at everyone as they filed out the door with excitement in their voices.  I locked the door behind them and turned around to face the empty house.  I trudged to the office and plopped down next to the stack of data forms that I was going to enter into an Excel spreadsheet.  There were so many! “Well,” I thought to myself, “someone has to do it… and it might as well be me.”  I prepared myself for the boring task ahead.  Only a few minutes passed before I was intrigued by the information on the data sheets!  The first thing that I leaned was that being on a boat is not conducive to good hand writing.  I now read Simon Hieroglyphics and Tess Hieroglyphics almost fluently.  It was super difficult at first, but got easier as the day went on.  I felt like I was learning more about dolphin behaviour than the people were on the boat! It was so cool! Before long, I could recognise where the dolphins liked to hang out! When I got on the boat the next day, I picked up the data form and knew exactly what I was doing! It was great!! The next week when my office day came around, I was excited to sit in my PJ’s, drink tea, and enter really interesting data about dolphins!

Necropsy Day

While we have interns, we’ve asked them to write the blog entries for us to get across some of the excitement and novelty of doing all this for the first time.  I think that having done this for a few years now I sometimes forget what an impression a whale necropsy makes when you do it for the first time.  I loved Kassler’s contribution so much I’ve left it entirely unedited except for correcting place names.

I think in all the excitement and ‘gore’, some of the interns may have missed the bit where we looked for parasites, obvious signs of death and collected skin and blubber samples for genetic, stable isotope and pollutant analyses.  The skulls of both animals have been collected and are going to the National Museum in Windhoek in due course.

Both animals described below were discovered by Naude Dreyer of Sandwich Harbour tours who is one of the key members of the Walvis Bay Strandings team.  

I've put in some photos below showing the stages from collection on the beach to final remains. Also a photo showing the small hair follicles on the snout, the shark bites on the tail stock (after death) and Tess looking up cranial structure as we tried to look for the sound producing organs

7th June, Tuesday, 2011

By Kassler Peh – Oceans Research Intern from Singapore

Necropsy of killer whale (calf) and Heaviside’s dolphin (calf)

We set off for Swakopmund early in the morning and reached the offices of the Ministry of Fisheries and Marine Resources at about 0900 hrs. Somewhere within fisheries laid our prized possessions, the dead killer whale and Heaviside’s dolphin. The whale was about 2.3m in length while the dolphin was much smaller, only about 80cm long. Excitement could be sensed all across the intern’s faces and everyone was ready for the necropsy. There were even two journalists present, sharing the exciting moment with us. But little did we know that what started off as a pleasant day would soon turn into a day filled with gore and blood.

First up was Mel, who had the task taking off the killer whale’s head. As soon as the knife sliced through the layer of blubber on the whale, blood started oozing out of the slit. Gas from within the whale started escaping as well and soon, the whole room was filled with the foulest smelling stench ever. As soon as the head came off, Simon took over and dismembered the beast like a seasoned butcher. Together with a few other interns, we started tearing and cutting off the blubber and flesh of the whale. Bits of whale flesh and blood started spewing and spurting all across the room, finally exposing the insides of the whale after about an hour. From the oesophagus all the way to the anus, every bit of the whale was pointed out by Simon expertly. It was a really insightful day for the interns albeit the gore and mess. Finally, the whale was chopped into pieces and packed into small bags, ready for disposal.

Next up after lunch was the Heaviside’s dolphin. Relatively easier to butcher due to its size, the insides of the dolphin was exposed in a matter of minutes. The surprising thing was that the lungs of the dolphin actually had dark patches in it and lung worms were present in its lungs. Milk was also discovered in the stomach and intestines of the dolphin. Just like the whale, the dolphin was also chopped up into pieces and packed into bags.

 

The only remains of the two corpses were their skulls, which will be transported to the National Museum in Windhoek. Removing the flesh and brain matter off the skull was the last thing on the agenda that day. Once that was done, signs of relief can be witnessed all over the intern’s faces and all of us gladly left the fishery with a huge sense of achievement. What a bloody Tuesday indeed.

     

 

Namibian Humpback Whales

06 June 2011 - by Simon Elwen

Humpback whales are one of the most well studied large whales in the world and yet there is still  great uncertainty about many aspects of their lives. Even such relatively simple facts such as where exactly they feed and breed can be surprisingly complicated as individuals sometimes mix between these grounds. The International Whaling Commission (the body which governs and controls global whaling) has defined the  stock of humpback whales which breed off the West coast of Africa as 'Breeding Stock B'. This stock is split in a northern (B1) and southern (B2) component based mainly on historic whaling data records.

Most of the work on this population has taken place in Gabon (by the Wildlife Conservation Society), which is a breeding area and in South Africa (by the University of Pretoria), which is largely seen as a migratory corridor, and there is very little information from the thousands of km of coast in between. Genetic analysis of whales from South Africa and Gabon, has shown some evidence of stock separation, supporting the B1/B2 split. However individual animals have been resighted (from photographs and using genetic sampling) in both South Africa and Gabon showing that at least some animals use both areas. However there is still some confusion about how all these stocks, breeding areas and migratory corridors actually fit together.  Data from the areas in between SA and Gabon are particularly valuable right now in trying to help the IWC answer these questions.

In addition to our main dolphin focus, the NDP has been collecting photographs and genetic samples from humpback whales at sea and from strandings as much as possible since we started. We've also been collating photographs and records from tour boat operators in Walvis Bay which has greatly increased our data set of humpback whale photos. Most of these photos have been taken by Mike Lloyd and Orlanda Sardinha who work on the Cataraman Charters vessels (http://www.namibiancharters.com).  Recently, a colleague of mine who did his PhD work on the humpback whales off western South Africa, matched the photographs we've collected in Namibia to his catalogue of known animals from SA. Unfortunately no matches have been found yet between Namibia and South Africa, but we'll keep looking. Although this is a very small sample (only 35 individuals were identified from tail flukes in Namibia), it is still an interesting result and is being presented as paper SC-63-SH21 at the meeting of the Scientific Committee of the International Whaling Commission which is being held right now in Tromso, Norway (www.iwcoffice.org).

Next up is matching our Namibian whales to the catalogue from Gabon. Meanwhile, work continues here in Walvis Bay and we hope to see lots more humpback whales this winter!

                           

Some of the NDP's work on the Walvis Bay population of bottlenose dolphins was presented recently at the South African Marine Science Symposium at Rhodes University - this conference is the preeminent get together of marine scientists in Southern Africa. http://www.atas.co.za/SAMSS2011/

Presented was:

Individual variation in bottlenose dolphin ranges in Walvis Bay, Namibia. Implications for managing restricted areas.
by Lauren Snyman with Simon Elwen, Marthán Bester, Tess Gridley, Theodore Meyer and Ruth Leeney as coauthors

Also accepted was a talk I was meant to give entitled

Shrinking or emigrating? Decreasing abundance trends of a vulnerable population of common bottlenose dolphins (Tursiops truncatus) in Walvis Bay, Namibia, subject to high human impacts.
by Simon Elwen with Ruth Leeney, Tess Gridley, Lauren Snyman and Justina Shihepo as coauthors.

Unfortunately, due to unforeseen circumstances, I wasn't able to make the conference to present my talk, but Lauren did us proud getting our research out there.

March 2011 - Luderitz

by Simon Elwen

A flying month in Namibia, I wish we could stay longer as there is so much to do as always!

Just spent 10 days in Ludertiz where we serviced the hydrophone (unfortunately, one is AWOL..), and had a remarkably good run on the weather front. We got in a 7 days on the trot of photo-ID data collection on Heaviside's dolphins and defintely had some resightings of animals previously ID'd there.

As always, the Heaviside's in Luderitz were lovely, although a little thinner on the ground than normal (possibly due to the odd weather down there recently, there has been very little wind and its very warm)

However, we had a good few encounters and some super friendly animals which really helps for photography! I've pasted in a few pics below, including one of a young animal with some diatoms on it which is interesting and one of the tall ship Picton Castle which was in town for a few days while we were there.

Just up in Walvis Bay now, so more updates will follow soon!

by Simon Elwen 20 Jan 2011

A quick update to say we're working on the annual report for the project in amongst trying to get some papers published from all the data we've been collecting in the last few years.

The project continues and we'll be back for a short field season in March (Walvis and Luderitz) and then another long field season in June-July based mainly in Walvis Bay.

If you don't receive a copy of the report by early in Feb, please get hold of me. I've put in a little teaser map below. This figure shows a 'probability density distribution' of bottlenose dolphins in the last 5 seasons (i.e. where we have and are likely to see them). One map for each season and one with all combined.

Walvis Bay Strandings Network

This month, the Walvis Bay Strandings Network finally got some much-needed strandings equipment. In 2009, the Namibian Dolphin Project received a Walvis Municipality Environmental grant to support the network in this way. DDP Industries in Walvis Bay made up the stretcher, and very kindly sponsored the production of a second one also. The equipment also includes buckets and blankets to keep beached animals wet and protected from the sun and wind.
In my final week in town, I carried out a short training session with some of the network's volunteers, to familiarise them with techniques for getting a stranded animal into the stretcher easily (using our inflatable dolphin!), and the important things to remember in the refloatation process. For example, once a stretchered animal has been brought to the water, it needs time to get used to the water again and to start to use its swimming muscles again, before removing the stretcher support.
The strandings gear is looked after by Strandings Network members and anyone who finds a stranded whale, dolphin or turtle in the Walvis Bay - Swakopmund area should contact Sandwich Harbour Tours or Mola Mola Tours in Walvis Bay. Many thanks to the Walvis Bay Municipality, George Wolfaardt at DDP Industries, Simon Wearne, John Paterson, Naude Dreyer, Francois du Toit and all the network members and volunteers who have given freely of their time for stranded animals. Keep up the good work!