New Paper: Spatial and temporal variation in dolphin acoustic habitats

There is a growing awareness of underwater noise in our oceans and the potential impacts of such noise on marine life, an issue which was the major theme of my PhD thesis.  This is particularly relevant for “acoustically-specialised” species, such as dolphins.  However, before we can start investigating the effects of noise on these animals, we first need to define the soundscape of dolphin habitats and examine patterns of when and where noise occurs.

We get a glimpse of them at the surface – but what about their acoustic habitat beneath the surface? (Photo: Sarah Marley)

This description of noise in dolphin habitats formed my third PhD chapter, which has now been published online in the scientific journal Frontiers in Marine Science.  In this paper, I examine spatial and temporal variability in the soundscape of the Swan River using over 11,600 hours of acoustic data collected from five sites within the river system across eight years.  Multiple sound sources were recorded at these sites, but the prevalence of these sounds at each site differed, giving each location a characteristic soundscape.  Consequently, some sites were ‘noisier’ than others.

Deploying acoustic recording equipment with help from Fremantle Ports. Spot the dolphins in the background! (Photo: Jeanette Murray)

Want to know more?  The full paper is available online! I’d love to hear your thoughts 🙂

Marley et al. (2017) Spatial and temporal variation in the acoustic habitat of bottlenose dolphins (Tursiops aduncus) within a highly urbanised estuary.  Frontiers in Marine Science, 4: 197.

And watch this space, as the remaining three PhD papers should be going up online in the next few months!

 

 

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New Video: The Dolphin and the Sound

As you know, I’m fortunate enough to be sister to the amazing wildlife film-maker Lisa Marley.  I’ve written about her documentary on Scottish raptor poisonings here previously (and incidentally, this work is currently touring the film festivals – scroll to the end for details!).  But in June, we actually worked together on a short film project as part of the Aquatic Noise 2016 conference I attended in Dublin.

The conference held a public evening involving short lectures around the theme of underwater noise, and also invited submission of videos on this topic.  Lisa and I worked together to create a short film describing the effects of human noise on coastal dolphins, similar to the idea of my 3MT speech – but with much cooler visuals than just me standing on a stage!

I wonder if anyone recognises the locations involved in this production?  Suggestions on a postcard please…!

So now I have a professional video to highlight my research AND had the awesome experience of working on a creative project with my sister.  And all without a single sibling squabble to be seen!


“Red Sky on the Black Isle” lastest screenings:

  • Hebrides International Film Festival (on Lewis, Harris, Uist and Barra; UK):  14-17 September 2016
  • Aberdeen Film Festival (UK):  17 October 2016
  • Festival de Menigoute (France):  27 October 2016

Follow the film’s Facebook page for more updates!

Conference Attendance – Aquatic Noise 2016

Last month I had the privilege of flying to Dublin to attend this year’s “Effects of Noise on Aquatic Life” conference, also known as Aquatic Noise 2016.  Not only was I able to present the first two chapters of my PhD thesis, but I was able to contribute to the conference itself as part of the Media Committee.

Members of CMST attending the Aquatic Noise 2016 Conference in Dublin

Members of CMST attending the Aquatic Noise 2016 Conference in Dublin

Over 300 people from 23 countries attended the week-long conference, including representatives from universities, government research institutions, fisheries, and industry groups.  Talks were given regarding a variety of acoustic topics, including descriptions of noise sources, sound propagation analyses, and the responses of numerous animal species.  Conference attendees also included ten members of my lab, the Centre for Marine Science and Technology (CMST).  It was great to head overseas as a team, presenting our research to an international audience!

Poster PicMy talk was part of the student speed sessions – five minutes to describe our research and findings, followed by an evening poster session where we had the chance to answer questions, engage in discussions, and network.  I feel the talk went well, despite my nerves.  I’m much more used to interactive presentations involving members of the public than presenting to seasoned professional scientists.  But even without any audience participation, dramatic displays or unexpected explosions, I think I did alright!  You can view my poster by clicking here:  Marley AN2016 Poster.

Marley Dolphin Presentation AN2016

Being on the Media Committee meant I was part of a team responsible for promoting the conference, particularly our public evening.  This was attended by over 70 members of the public, who had an evening of lectures and short videos (more about this in my next post!).  I was also involved in live-tweeting the conference.  This was a way of extending the conference reach to the masses, scientists or otherwise, by posting summaries of each talk on Twitter under the conference hashtag.  I’ve now summarised each day of talks as a separate story using a combination of Tweets from myself and other conference attendees, which are available for anyone to read using the links below:

https://storify.com/sarahmarley86/aquatic-noise-2016-day-1

https://storify.com/sarahmarley86/an2016-effects-of-noise-on-behaviour-and-physiolog

https://storify.com/sarahmarley86/aquatic-noise-2016-day-3

https://storify.com/sarahmarley86/aquatic-noise-2016-day-4

https://storify.com/sarahmarley86/aquatic-noise-2016-day-5

The Last 55: Final chance for Maui’s dolphins

Maui's dolphinFifty-five is not a big number.  But it could mean a world of difference to one small dolphin species in New Zealand.

Maui’s dolphin is the world’s rarest and smallest known subspecies of dolphin.  Found only in New Zealand,they typically range close to the coast in small pods although they can also be found around harbour mouths and further offshore.  But their numbers have been decreasing due to entanglement in fishing gear and disease, with approximately 4 to 5 Maui’s killed each year.  Which doesn’t seem like too many, right?

A bit of maths

In the 1970s, the dolphin population was reportedly around 1,800 individuals.  But the species has rapidly declined since net-setting and trawling were introduced in the 1970s.  A 2012 research study estimated that only 55 Maui’s dolphins now remain.  Suddenly that 4 to 5 death rate seems a lot bigger.  So just since that study was conducted, we are probably already approaching a population size of around 40 animals. Extinction isn’t just a threat – it’s a very real likelihood.

If we are losing 10% of the population each year, you don’t have to be a mathematical genius to know that things aren’t looking good for the Maui’s.  Especially given their slow reproduction rate – females reach maturity at approximately 8 years of age, and only have one calf every 2 – 4 years.

What is being done?

The New Zealand government generally has a pretty good standing when it comes to conservation.  In 2003, a ban on commercial set nets was added to an existing ban on recreational netting from north of Auckland to north of Taranaki, covering out to four nautical miles from shore.  In 2008, this was extended to seven nautical miles and in 2012 the ban on set nets extended further south.  Last year, the Minister of Conservation finalised a Maui’s Dolphin Threat Management Plan, which includes codes of practice for seismic surveys, regulations for inshore boat racing, and the establishment of a Maui’s Dolphin Research Advisory Group.

So are things improving?

Debatable. Although various marine protected areas have been created with the aim of conserving Maui’s dolphins, the government has failed to extend protections to areas where there have been credible recent sightings of the animals.  That’s the thing about marine mammal conservation – these are free-ranging animals who cover large areas in a dynamic habitat.  Thus, the distribution of populations will change over time and so needs constant re-assessment if protected areas are to have a positive effect.  But this is an investment the NZ government seems unwilling to make.

And despite several promising moves on the government’s part, it looks like money might win through in the end.  This week, it has been reported by several news groups that the West Coast North Island Marine Mammal Sanctuary – home to the Maui’s dolphin – has been signed off for oil and gas exploration.

The NZ government signed off a block offer of sea and land in April, which includes a 3,000 square kilometre overlap into the sanctuary.  Oil and gas development in this area could have a devastating impact on Maui’s habitat by increasing levels of underwater noise through seismic surveys, as well as putting the area at greater risk of oil spills.

The government has already had previous bungles with the block offer, with Simon Bridges, the Minister of Energy and Resources signing off New Zealand’s biggest forest park for drilling – despite having never heard of it.  Not exactly reassuring that the government is taking conservation seriously.

In fact, politicians are arguing whether this is even an issue, and NZ Conservation Minister Nick Smith is insisting that there hasn’t been a single observation of a Maui’s dolphin in the proposed exploration area.  So no need to worry.

But you have to wonder how hard they’ve looked?

What you can do

Numerous scientific and conservation groups have already called for the New Zealand government to take action to save the Maui’s dolphin.  Just last week, the International Whaling Commission urged the government to do more to save the species, stating that it had “extreme concern” about the decline in Maui’s dolphins.

In a recent report, the IWC estimated that Maui’s will decline to just 10 adult breeding females in six years and become functionally extinct in less than 20 years – unless their full range is protected from gillnetting and trawling.

Screen Shot 2014-05-19 at 9.15.55 amWWF have stepped up their “Last 55” campaign to save the Maui’s dolphin, urging parliament to announce permanent measures that remove fishing gear which kills dolphins and help affected fishermen adopt dolphin-friendly fishing methods.   “Anything less will not give the species a fighting chance at survival.”

Support their campaign by signing the WWF online petition here.  And hopefully we can convince the New Zealand government to stop faffing around and start taking effective steps to save the Maui’s dolphin.

The Importance of Attending Conferences

In December 2013, the Society for Marine Mammalogy will be holding its biennial conference on the biology of marine mammals in Dunedin, New Zealand.  Last Friday, I was notified that I am lucky enough to be presenting at the conference!  But why are conferences such a big deal?

What is the SMM conference?

The Society for Marine Mammalogy (SMM) biennial conference is a gathering of marine mammal scientists from around the world, with the goal of enhancing collaboration, sharing ideas, and improving the quality of research on marine mammals.  Every SMM conference has a fantastic turnout, with hundreds of scientists in attendance.  This year promises to be no different, with over 1000 abstracts for talks and posters being submitted.  Unfortunately, about 20% of these were rejected.  But 200 talks and 400 posters have been accepted for the event.

What will I be presenting?

Pygmy blue whale and vessel; Geographe Bay, Western Australia

Pygmy blue whale and vessel (Geographe Bay, Western Australia) – how close is too close?

I will be presenting a poster based on work by myself and colleagues at the Southwest Whale Ecology Study (SouWEST).  Check out my Projects page for more information on this group.  The poster will document the responses of pygmy blue whales to vessel traffic during their migration through Geographe Bay, Western Australia.  Understanding the impacts of anthropogenic activities on marine fauna has become of increasing concern as the human population continues to expand its activities in the marine environment.  The SMM conference will be an excellent opportunity to share our research findings with the scientific community.

What’s the point of conferences?

Of course, conferences aren’t just a way of spreading the word about your own work – they’re also a great chance to hear about developments in your field and keep up-to-date with recent research.  The best part is that if you have questions or would like to know more about any particular topic, the researchers are right there to ask!  Conferences are great networking opportunities, whether you’re a student looking for a job, a professor looking for students, or a researcher interested in finding collaborators for a particular project.  Since presentations are often discussing work at varying stages (from preliminary findings through to recently published), it is also a good chance to get some informal peer-feedback.  Plus, you often get to travel to pretty cool places!

But for me the best thing about academic conferences is this:  inspiration.  Being surrounded by passionate people, new ideas, recent discoveries…  It all acts as a massive source of motivation and encouragement to continue in what can sometimes be a difficult field.  Everyone needs a pick-me-up sometimes, and I find the buzz of conferences invigorating.

So bring on New Zealand!