Sei whale stranding in Druridge Bay, Morpeth, Wednesday 26 September

A sei whale (Balaenoptera borealis) stranded on the beach in the early morning yesterday in Druridge Bay. It was first reported as a minke whale but at closer inspection it was found that the 8.6m whale was a young female sei whale. This is only the sixth specimen ever stranded in the UK, so a very unique event. The whale was alive when it stranded and was reported to the British Divers Marine Life Rescue (www.bdmlr.org.uk) that has trained staff to deal with live marine mammals. BDMLR makes every effort to refloat stranded animals that are in good physical condition. Unfortunately, the sei whale was emaciated and the local veterinary that was called out to assess the health status of the animal made the final decision that it was too weak to refloat. The vet therefore euthanized the animal which this case was considered the humane approach to end the animal’s suffering. Even if the whale had been healthy enough for refloating this would not have been an easy task. An 8.6m sei whale weighs about 5-6 tons and that takes a lot of lifting power to assist the animal back into deep enough water.

Once a marine mammal is dead it becomes the responsibility of the Defra funded UK Cetacean Strandings Investigation Programme, to carry out a post mortem to investigate what may have caused the animal to strand (http://www.facebook.com/pages/Cetacean-Strandings-Investigation-Programme-UK-strandings/142706582438320). A CSIP team from the Institute of Zoology (IoZ), Zoological Society of London (Rob Deaville and Matt Perkins) came up from London up to Morpeth. IoZ contacted Dr Per Berggren, our school’s marine mammal expert, for assistance. Per together with Simon Laing (Newcastle University) and Dan Gordon (the Great North Museum) arrived at the stranded whale at 5pm just in time for the post mortem.

The post-mortem starts by taking a series pictures and measurements of length and girth of the animal. This is followed by stripping the skin and blubber off one side with the help of the car winch! The relatively thin blubber thickness and muscle condition confirmed the emaciated state of the animal. Samples were then taken from various tissues including skin, blubber, muscle, lung, liver kidney, brain, ovaries and uterus. A gross examination of parasites showed non-elevated levels (all marine mammals have some parasite load in e.g. lungs, kidneys, liver, stomach and intestines). There were a couple of pieces of plastic found in one of the animal’s three stomach but neither this nor the parasite load were likely to have caused the animal to strand.

We collected a range of samples that will be used for genetic, foraging ecology (using stable isotopes) and contaminant analysis which will be conducted in collaboration between IoZ and Newcastle University. We also kept one of the flippers, the dorsal fin and some baleen which eventually will be displayed at the Great North Museum.

We would have liked to save the entire skeleton but would then have needed to bury the carcass for up to a year to get the bones cleaned by the bugs in the ground. Unfortunately, this was not allowed in this case due to the extremely potent sedative that was used to euthanize the animal which made it necessary for the carcass to be taken for incineration.

So what caused the animal to strand? Sei whales are not native to the North Sea so basically this juvenile female was in the wrong place at the wrong time. She clearly had not been eating properly and this gradually made her weaker and made her start metabolising blubber and muscle tissue. The confusion of being in an unfamiliar area and the severe weather conditions during the last few days likely made her lose her bearings and strength and caused her to strand. A very sad ending for such a magnificent animal.

Description of the sei whale

The sei whale has a mainly offshore distribution in the North Atlantic, North Pacific and Southern Hemisphere. They migrate between winter mating grounds in tropical and subtropical latitudes to summer feeding grounds in temperate and sub-polar latitudes.  They can be found off the northwest British Isles in the summer and very rarely in the North Sea.

Adult sei whales reach a length of 12–17m and weight of 20–40 tonnes (females slightly larger than males). Primary prey is small crustaceans like copepods and euphausiids (krill/shrimp). Sei whales reach sexual maturity when they are around 14m in length, at 8–9 years. Females give birth to one calf every two years. The lifespan of the sei whale is estimated to be 53–60 years. Sei whales have 300–400 baleen plates in two rows (left and right), suspended from the upper jaw. The body of the sleek sei whale is coloured dark grey above and light grey-whitish on the throat, belly and the underside of the flippers and tail flukes.

Sei whale populations were subject to commercial whaling in the North Atlantic until the 1970s. Surveys reveal little sign of recovery of sei whales in the northeastern Atlantic. A survey in part of their summer range revealed around 10,500 animals in 1989 since when there have been no catches. There are currently insufficient data to undertake an assessment of their status (www.iwc.office.org). Sei whales are currently listed as Endangered by the IUCN Red List of Threatened Species (http://www.iucnredlist.org/details/2475/0). Sei whales are still a target for modern whaling and Japan takes 100 animals per year in the North Pacific as part of their scientific permit catch.

The name ‘sei’ is Norwegian for the saithe fish (Pollachius virens) and was given to the whale because both the ­ fish and the whale occur in Norwegian waters at the same time each year. The sei is the third-largest whale after the blue and ­ fin whales.

Per Berggren

Bermuda field trip September 2012

Well, where to start?!  Another eventful trip to the Bermuda Institute of Ocean Sciences (BIOS) is coming to an end, and as always, we’ve had a great time.  Following issues with hurricanes in 2010 and 2011 we were relieved when we all got checked-in at Gatwick for the start of our trip.  After a slightly bumpy landing we arrived at BIOS in time for a late dinner on Wednesday 12th September, after which the 25 students on the trip received an induction talk from the Reservations Manager, Jane Burrows.  After a long journey we gave them the rest of the night off, so they were fresh and ready to start work on Thursday morning.  The students first got a tour of BIOS and the opportunity to check out the amazing facilities here.  They then got stuck into work with two lectures from one of the Newcastle staff, Dr Sara Marsham, taking them through coral and fish ID and introducing them to the common organisms they were likely to see on the local reefs.  After a hearty lunch (there is no chance of going hungry here!) we set off to Walsingham to visit the mangrove and cave systems there.  Dready was our guide and got all of the students jumping off ledges into one of the salt-water ponds in the mangroves and then led them on a snorkel through one of the large caves.

Snorkeling in Walsingham Caves

The evening saw Dr Andrew Peters give a lecture on the anatomy of Bermuda as an oceanic island and present some of the research his group have been conducting into water and air quality around the islands.

Friday was the first chance for us to get in the water and the morning saw us snorkeling a new site that we had not visited before at Bailey’s Bay.  Within the Bay were the Pigeon Rocks around which was a great coral reef with lots of fish species.  We saw parrot fish, butterfly fish, lizard fish and even a remora sat on the sandy floor!

A remora at Bailey’s Bay

After getting to grips with snorkelling on the reefs, Friday afternoon was planned for reef survey method development at Tobacco Bay.  Unfortunately we had to abandon this plan soon after getting into the water as a huge storm came in complete with thunder, lightening and horizontal rain!  Not the best conditions for laying a transect!

Sheltering from the storm at Tobacco Bay

After getting dry and warm back at BIOS, Sara along with the other member of Newcastle staff, Prof. Matt Bentley, ran a coral point count practical on Friday evening.  This introduced the students to a different technique of surveying the coral cover using video transects and VLC software.

Saturday saw us take the public bus to the Bermuda Aquarium Museum and Zoo (BAMZ).  This was not just a bit of fun for the students; they had to observe both the marine and terrestrial organisms in captive environments and understand the role of aquaria and zoo in conservation and management programmes.  As usual there was a wide array of both marine and terrestrial organisms on display, including Sara’s favourites, the giant tortoises.

Happy after being stroked 🙂

After the aquarium and zoo we went up to the far end of the islands and visited the historic dockyards, where there is a maritime museum, Dolphin Quest and shopping malls.  One of our students is an animal trainer and knew the staff at Dolphin Quest so managed to give some of the students the opportunity to swim with the dolphins!

Sunday saw us on our way to South Shore to learn about the local geology and flora from our guide, Rob Chandler.  We started at Warwick Long Bay and walked along the lithified sand dunes to Horseshoe Bay.  The day was scorching hot so after a quick packed lunch at Horseshore Bay we headed into the sea for a swim to cool down.

Cooling down at Horseshoe Bay

After the swim we got the public bus back to BIOS and the afternoon was spent project planning ready for project data collection after the weekend.  However, before the data collection could begin, on Monday morning the students had a tour of the BIOS research vessel, the R/V Atlantic Explorer followed by a lecture on the BATS time-series data programme delivered by James Sadler.

The original plan was then to go to Nonsuch Island in the afternoon to visit an area of Bermuda that has been restored back to its native state.  Most of the invasive species affecting the rest of the islands have been removed and the area has been replanted with native and endemic species.  There is also a breeding programme for the endemic cahow, which is a nocturnal seabird once thought to be extinct on the islands.  In 2012 there are now 101 breeding pairs using Nonsuch Island.

However, the vessel we normally use to ferry us around was out of action with a broken oil pump and the other vessel, the R/V Rumline was in use by another group.  So, as is often the case with field work, plan B was initiated, which involved the project groups taking themselves off to Whalebone Bay or Tobacco Bay to start their project work.  Sara and Matt stayed back at BIOS to catch up with their marking 🙁

After a successful afternoon in the water, the students had another evening lecture, this time delivered by Dr Kristen Buck that covered microbial oceanography.  Every year this lecture is well received by the students and this time was no different, with them enthusing about oceanography at the end of it!

So, Tuesday morning and we headed to Nonsuch with our guide Gary, who also brought along his mother-in-law and her friend to join the group!  The R/V Rumline moored just off the Island and we all swam ashore to start our adventure.  Little did we know the adventure was only just beginning…

Approaching Nonsuch Island

After two hours wandering around and learning about the Island and the conservation efforts, we swam back to our vessel to start the long journey back to BIOS for a late lunch.  However, the R/V Rumline had another plan in mind…  Problems with the engine meant we were not going anywhere, and the only boat big enough to tow us was out taking another group on a dive.  So a rescue mission was launched with three different vessels of varying size carrying passengers from five to twelve coming to take us back ashore.  The students didn’t seem to mind and spent the time waiting swimming and practising their diving technique off the side of the boat.  Just over three hours later, Sara, Matt and the two remaining students finally made it back to BIOS for a very late lunch (what did I say about not going hungry…?!).  Thankfully George in the kitchen had saved us some food!

The first rescue mission on R/V Mussel Pie

Students making the most of the wait!

Which brings us to today…  Some students continued with project work this morning by heading off to Tobacco Bay while another group went on R/V Sea Dance to the Hogbreaker reef to collect their project data at an offshore site.  The rest of us?  Well, thanks to J.P. Skinner we took the opportunity to take Polaris and visit another new site nine nautical miles offshore where there was the impressive wreck of the Madiana that was built in Scotland in 1877 and wrecked off of Bermuda in 1903.  Both boilers and the drive shaft were clearly visible from the surface and the coral and fish abundance was stunning!

Boiler of the Madiana

This afternoon students are finishing collecting their project data at Whalebone Bay and Tobacco Bay before a coral lab tonight.  Tomorrow each group will give us a presentation on their projects: what they did, why they did it, how they collected their data, and their preliminary findings before we go back to the airport and fly back to Gatwick.

Monday will see Sara and Matt back on campus in Newcastle to welcome the new Stage 1 students, with these Stage 3 students returning for their induction on Tuesday.  The weather here has been good to us (apart from that afternoon at Tobacco Bay!) so we hope it is nice and sunny in Newcastle…?

Blog 7: Risso’s Dolphin Necropsy 21/07/2012

Zanzibar Humpback Whale Research Project 2012

Blog 7: Risso’s Dolphin Necropsy 21/07/2012

Saturday the 21st of July was the start of Ramadhan in Zanzibar which, coupled with a rough sea, resulted in the project team enjoying a quiet day off. We used this precious down-time to get some computer based project work done and to do some washing. After a fairly relaxing morning, the team received a call from Pandu (one of our local contacts) who informed us a by-caught dolphin had been landed in our neighbouring village, Kizimkazi-Mkunguni. After quick preparations to bring the necropsy kit and data forms together we were driven straight to Mkunguni to take photos and collect samples from the dolphin.

The “dolphin” found by fishermen from Kizimkazi-Mkunguni

The “dolphin” found by fishermen from Kizimkazi-Mkunguni

 However, when we arrived, to our surprise we discovered it wasn’t a bottlenose or humpback dolphin but a species we don’t normally see in the waters around southern Zanzibar. We were relieved when we found out the fishers found it dead and floating in the water meaning it was not another by-caught dolphin. At first glance, Kyla thought it might be a pygmy killer whale (Feresa attenuata) or melon-headed whale (Peponocephala electra) based on the body size, shape and colouration but we were baffled as some features, such as the very tall dorsal fin and the teeth (or lack thereof!) didn’t seem right. Of course, after sending photos to the project leader Dr Per Berggrenat Newcastle, he suggested it might be a Risso’s dolphin calf; Risso’s dolphins (Grampus griseus) are very scratched resulting in a greyish colouration but a calf/juvenile is still quite dark and Risso’s dolphins have very few teeth.

 Kristin and Kyla looking for the teeth…and only finding two tiny ones at the front!

Kristin and Kyla looking for the teeth…and only finding two tiny ones at the front!

 As soon as we arrived at the fish market at the beach in Mkunguni we started taking photos, measurements and collected tissue samples of the dolphin. As mentioned above, no teeth could be seen initially; we thought it might be an older animal with very worn teeth, but on close inspection we found two very small teeth at the front of the jaw. So, a section of the jaw bone with the two teeth was removed as a sample. The cause of death was not identifiable as there were no external signs such as lacerations, or injury from fishing gear, however, the animal looked under nourished. We were not able to conduct a complete necropsy on the animal but we collected the stomach contents for possible dietary analyses.

 Yunusu, a friend of the project, helping us collect samples

Yunusu, a friend of the project, helping us collect samples

Members of the research team checking out the Risso’s calf with fishers from Mkunguni watching with curiosity.

Members of the research team checking out the Risso’s calf with fishers from Mkunguni watching with curiosity.

One thing we didn’t think about when we collected the bucket of guts to take back with us was the smell we’d have to endure on the drive back to Kizimkazi-Dimbani! We ended up driving the entire way with back of the car open, much to the amusement of all the locals. All in all, it was a very unexpected but interesting day!

Photographs © Zanzibar Humpback whale Project

 

 

Blog 6: First whales of the season! 15/07/2012

Blog 6: First whales of the season! 15/07/2012

Early Sunday morning was a very exciting day for the Zanzibar Humpback Whale Research Project team. A local fisher called us reporting two whales in the area outside Makunduchi off the southeast coast of Zanzibar. We eagerly got our equipment together, jumped into our boat and headed in the direction given by the fisher. We were hopeful to find the whales although it takes about an hour to reach Makunduchi from Kizimkazi-Dimbani. And they were! Kristin was the first to spot a blow about 1500m ahead of us. The team sprang into action, with spotters at the bow and behaviour recorders at the stern, all barely able to contain their excitement at finally seeing the first whales of the season! The whales turned out to be a mother, her calf and an escort whale travelling slowly along the south east corner of the island with beautiful tail dives providing excellent opportunities for photo ID. After an hour the whales started travelling faster and were soon too far away so we left them alone to survey for other whales.

It was during our lunch break that Kyla suddenly shouted ‘Whale!!’ She had spotted a breaching whale 2500m, directly ahead of us. Lunch was quickly packed up and replaced by cameras and other equipment. There were two adult whales and a juvenile which were socializing and resting. We followed them until we had collected enough data and then decided to leave them alone. The wind was picking up and we decided to head home, very happy with our two first whale sightings.

On the way back we decided to do some target practise with the crossbow with an old life jacket, with the intention of collecting future small biopsy samples from the whales. Skin and blubber samples will be used for genetic studies to investigate how the whales off Zanzibar are related to those found in other areas off Africa and elsewhere around the world.

Back at the house, we discussed the day’s activities over dinner. After months of preparation we had successfully conducted our first whale survey. It gave our new students Yussuf, Nat and Lynne a great opportunity to practise the data collection and to see what happens when we encounter a whale. We all went to bed happy and excited at the prospect of seeing more whales in the morning.

Blog 5 of Zanzibar Humpback Whale Research Project 2012

Zanzibar Humpback Whale Research Project 2012
Blog 5: Elevating our survey approach 13/07/2012

This year the survey methods are being broadened to increase our survey area and the type of data we collect to improve our ability to research the humpback whales off Zanzibar and East Africa. One opportunity to do this has come in the form of Makunduchi Lighthouse which provides a unique, 44m above sea level, platform from which to conduct land based survey of cetaceans and boat traffic. The lighthouse sub-team lead by Dr Per Berggren  assisted by Nat and Yussuf travelled to Makunduchi Lighthouse to calibrate the survey equipment ready for a 10 day pilot study which will start later in the season. It was incredibly hot and we soon valued the shade provided by the light housing and the bottled water we had brought.

Yussuf and Nat at the Makunduchi lighthouse 

We use mounted binoculars to allow for tracking of the whales focusing on positioning but also to study respiration rates and behaviour of the whales and how these may be altered by interactions with vessels also using the area.

The views from the lighthouse will hopefully provide the perfect area to survey the passing whales but unfortunately there were no whales to be seen during this first visit. Instead we utilised our research boat to calibrate the method to estimate distance by knowing the GPS locations of both the lighthouse and the boat and the number of binocular range reticles that this distance was equivalent to.


Yussuf calibrating the binoculars, see the boat?
We will provide an update later from 10-day lighthouse pilot study.

Photographs © Zanzibar Humpback whale Project