Lüderitz, 17-20 December

By Ruth Leeney

Having deployed 2 C-PODs in the Lüderitz area back in August as well, I had hoped to get down to the south, retrieve the units, download their data and get them back out in the water as part of this trip. As my schedule became more restricted, Jean-Paul Roux at the Lüderitz offices of the Ministry of Fisheries and Marine Resources was invaluable in helping out. He organised the retrieval of both units, to have them waiting on land for me when I arrived. Unfortunately, only the C-POD with the surface marker buoy, deployed in Shearwater Bay, was retrieved, so hopefully, efforts in the new year to grapple for the Guano Bay POD will be successful. For now, at least, the first ever acoustic monitoring dataset for this region has been collected - the C-POD logged over 100 days in an area known to be used by small groups of Heaviside's dolphins, and plenty of detections are evident in the data.
The Shearwater Bay C-POD was re-deplyed in the same spot on the 19th of December and will continue to collect habitat use data in this area. I hope to see some seasonal patterns in these data start to emerge, as well as the interesting diel (day-night) patterns already evident!
Many thanks to Heiko and Stefan Metzger on Zeepard for their assistance in the field, and for the 'lekker' place to stay, and to Jean-Paul for his ongoing involvement with this project.

Keeping the acoustic monitoring 'clicking' over....

By Ruth Leeney

December in Walvis Bay. Turns out the sun actually shines here sometimes! I have come back for a short visit, to check up on the C-PODs Simon and I deployed, with the help of Johann from Levo Tours, at the end of August. It has been just over 3 months, so the batteries are reaching the end of their running time, and after that long in the often-wild waters of the Namibian coastline, I thought it wise to check that the moorings were also still in place and were holding up well against the storms!

The project's 2 C-PODs at Pelican Point were retrieved last week. After we received a report that the surface marker buoy from this mooring had gone missing (thanks to all our local friends who were on watch in our absence!), a team from Namib Diving went out to the location and grappled for the gear, in and around the deployment location. The waters at Pelican Point have almost zero visibility and are thus not diver-friendly, so we really appreciate the time and effort they put into finding this gear for us. Three months' worth of data were downloaded from each C-POD and at first look, there are plenty of Heaviside's dolphin detections throughout that time period! More details will follow on our findings from this, our first long(ish)-term acoustic data set. Meanwhile, the PODs were spruced up a bit (in the rich waters of Walvis Bay, 3 months is ample time for an assortment of encrusting organisms to make any unsuspecting POD their home), given new batteries and re-set for more data collection, and with the help of Kurt and Darius from Namib diving, I redeployed them at Pelican Point today, whilst numerous Heaviside's dolphins surfaced a few hundred metres away. We also stopped at Aphrodite Beach, to retrieve the third C-POD, which will be re-deployed shortly. A solitary Heaviside's dolphin, about 500 m west of the Aphrodite Beach, was perhaps the first of this species that I have seen in this area, perhaps mirroring the more dispersed pattern of this species in summer, observed by Simon last year. A huge thank you to Gert Le Roux and the staff at Namib Diving for helping me get this done in a short time window.

On another note, the dusky dolphin which live-stranded in Walvis Bay on the 3rd of December generated a bit of press for the Walvis Bay Strandings Network which we have been working to re-invigorate over the past 18 months. John Paterson oversaw the successful refloatation of this animal and by passing the story on to the Namib Times, generated some good press for the Strandings Network and helped to spread the word amongst local people about what action to take, and who to contact, in such a situation.

Interns

From 2010 onwards we will be accepting interns as part of the Namibian Dolphin Project.

Interns will take part in all project activities and learn a whole host of field and data management skills. Having extra hands to help out will allow us to do more things and get more days at sea and include some extra dimensions to our field research.

For more information on the programme, please see:
www.oceans-research.com

If you're a Namibian biology student and interested in working on the project, please contact me directly to talk about internship and potential student projects.
s_elwen AT yahoo . com

Hydrophones deployed!

With the hydrophones eventually in hand it has been out primary goal in the last few weeks to get them out to sea. We are happy to announce that they have now been successfully deployed in both Walvis Bay and Luderitz. In Walvis they are deployed at Pelican Point, to investigate Heaviside's dolphin habitat use, and near Aprhodite beach on the east side of the bay where the bottlenose dolphins are frequently seen to rest.

Although we towed Nanuuq all the way through the desert (see pic) from Walvis to Luderitz, the wheel bearings couldn't deal with the dust and we had to leave the boat in Aus (100km from the sea at 1600m altitude!!) for more than week while the problem was sorted out! Luckily we still managed to get the hydrophones deployed in two known Heaviside's hotspots at Shearwater and Guano Bays. We couldn't have done this without the phenomenally generous help of Heiko Metzger of Zeepard tours (see pic) and the knowledge and support of the local Ministry of Fisheries and Marine Resources scientists, especially Jean-Paul Roux.

Although we're naturally somewhat nervous about the moorings being pulled up, dredged, trawled, entangled in propellers or washed out to sea, we're quite excited about getting the data back from them in a few months time!

August

Trevor and my student Theo have left, headed back to Pretoria. Theo is doing his honours (4^th) year project looking at the distribution of bottlenose dolphins in the bay, and particularly how their behaviour varies in different areas. It’s still in progress, but by the end of the year we’ll have a much better idea of what’s happening out there.

Ruth has now arrived from the US – with hydrophones (C-PODs) in tow! This is great news for us as they are rather expensive and we’ve been struggling to get them funded. We have eventually been successful through a Matching Grant from the NACOMA project (see links) in a joint proposal with the Ministry of Fisheries and Marine Resources. These instruments will be used for long term monitoring of the dolphin populations and habitat.

The C-PODs (http://www.chelonia.co.uk/about_the_cpod.htm) are very new instruments and replace the older, simpler T-POD. Last year we borrowed some T-PODs from Simon Northridge at St Andrews University in Scotland to investigate dolphin habitat use at Pelican Point and got some very interesting and unexpected results which differed from the visual observations quite considerably. Ruth has worked closely with the manufacturers for many years and we also managed to get one of the very first C-PODs built to test (although there were many teething issues which thankfully now seem to have been solved). We’ve already put in one at Pelican Point and are really looking forward to what we see with the longer term deployments we’ll get this year. In an exposed environment like Namibia, the PODs are ideal instruments for long term monitoring of habitat use as they can stay in the sea 24 hours a day for months at a time, while we are limited to calm sunny days. We’ll be putting 2 more in the bay in the near future and 2 down in the Lüderitz area.

Other than that, all has been going well. We’ve had a few days off the water with bad weather (or bad decisions on my part, but the weather forecasts here are about as good as throwing a dice) but the data is coming in. Lots of sightings of bottlenose dolphins, including some great jumping and socialing on one day which is always fun to see and photograph. Heaviside's dolphins have been a bit scarce and whales too have been few and far between this year. There have only been 4 humpbacks since I got here and 2 right whales were in the bay last week but we missed them unfortunately.

Mid July 2009

The winter field season has started again. I’m rather behind in updating the blog as you’ll notice from the date! Have been pretty busy and doing most things on my own for the first few weeks.

In summary – Unfortunately Pedro, who we used last year as a phenomenally generous loan from Pelican Tours, wasn’t available any more. However, the project is making good head way and we’ve managed to secure our own boat this year which makes us more flexible in terms of time spent at sea and when and where we launch. She’s a nice little boat, which I’ve called Nanuuq (which is Inuit for polar bear – I wa trying to avoid the more obvious dolphin based names). As a new acquisition which had been standing for a while in the previous owners driveway, she has unfortunately taken a fair bit of teasing back into shape. New batteries, spark plugs, had to get most of the safety equipment, winch strap broke after seeing too much sun in the last few years, dirty carbs…lots of frustrating little things like that to keep us busy.

Ruth couldn’t make it out for the beginning of the season this year due to work commitments, so I started this season by roping in a colleague of mine from the University of Pretoria, Trevor McIntyre to do some skippering for me. Trevor is doing his PhD work on elephant seal foraging behaviour in the southern ocean. He’s using data from electronic tags attached to the seals on Marion Island. Fascinating stuff and a quite different approach to the type of work we’re doing here, but in many ways answering the same core questions of distribution and ecological interactions.

We had a few good days out to sea in between all the boat mechanicing. There were some really dominant east wind conditions here to start the field season, which made for hot, dry sandy mornings with katabatic winds howling down off the desert. But these conditions always drop in the afternoons as the southerly winds fight back, often resulting in a warm, calm truce out in the bay. Nice for us to get out in the afternoons a few times as its almost impossible during the rest of the year due to the strong winds in the afternoons – and it’s really lovely to be on the water in just a t-shirt in this part of the world!! The Heaviside's dolphins have been as fickle as always, some days they’re all there and super boat friendly, while other days you can barely find a single one.

Time flies! Already we’re making preparations for our next season, currently planned for mid July until the end of August. During the last few months we’ve been processing data, trying to publish some of our initial findings and working on grant applications. Now having data from a summer and winter season, we are able to look at how the animals behave in different environmental conditions and are starting to build up a more confident picture of how the dolphins are using the bay.

These findings are very relevant at the moment as it has just come to our attention that Namport (the port management authority) are planning a vast expansion to the current harbour for a container terminal. Obviously we’re concerned over the effects this will have on the environment and wildlife in the bay. See details on the Namport webpage and register as an “IAP” (interested or affected party) to voice your concerns:
http://www.namport.com/content/show.php?m=4


On a different note, one of the projects we’re trying to get up and running in Namibia is a “strandings network” which we think is very worthwhile and needed for both conservation and science reasons. You may recall the stranding of a live humpback whale in February and of 19 bottlenose dolphins in the upper lagoon in March. Recently there was an even bigger mass stranding of 50-odd false killer whales just outside Cape Town. The perceived lack of organisation and the decision to euthanise animals which it was not possible to rescue has met with serious criticism from some quarters. However, knowing many of the people who were involved in the Cape Town stranding, I’m confident they made the best decisions possible at the time, it was clearly a very difficult situation . It is important to keep in mind that events such as this, although tragic, are natural occurrences that have been happening for thousands of years without human interference. Either way, we hope that by developing a network of trained people who can coordinate events and make decisions in the event of further live strandings of animals, Walvis Bay residents can be confident of the best response in these situations.