The biggest thing that sucks about studying mosquitoes

cameronwebb_mosquitoes_theleaderI enjoy studying mosquitoes but there is one problem. They don’t take summer holidays and, unfortunately, neither do I.

I started studying mosquitoes in the summer of 1994-1995. Within days of finishing my BSc(Hons) degree I was looking down a microscope trying to identify mosquitoes. I haven’t had a summer holiday since. That’s 20 years. Yep, 20 years without an Australian summer holiday. It never really bothered me. That was, until my children started school.

Summer school holidays are busy, expensive and probably pretty stressful times but a few weeks by the beach sounds pretty to me. Long summer days spent on the beach and in the surf. Yep, sounds pretty good. I’m even happy to put up with some sweaty shopping centre crowds en-route to the beachside holiday!

There are a lot of things about studying mosquitoes that can be unpleasant. Sticking your arm in a cage of mosquitoes and letting a few dozen mozzies feed on your blood isn’t fun. Neither is sloshing about in wetlands when the temperature tops 40°C. Mud, spider webs and getting spooked by snakes (and the occasional angry magpie) keeps the work day interesting too. Pre-dawn starts and post-dusk finishes can be exhausting but there are also some fringe benefits. Notwithstanding the occasional onslaught of biting mosquitoes (the kind of waves of swarming mozzies that drive you back into the car within seconds of stepping out), it can be beautiful being in the wetlands. I also feel I’m making a contribution to improving public health. KooragangIslandSunriseMosquitoes, and the tides and rainfall that drive their populations, don’t take a break on weekends or during the festive season. From mid October through to the end of April I’m pretty much “on call”. Weekly monitoring of environmental conditions and surveillance of mosquito populations in multiple locations throughout the state can get a little draining.

When we’re coordinating mosquito control activities, where there’s only a small window of opportunity to effectively treat wetlands, skipping a day of field work because its the weekend can have significant “knock on”effects. I need to keep my eye on the mozzies. I’ve been out in the field on Christmas Day and New Years Day. I’ve heard the distant rumble from the Big Day Out while doing mosquito surveys in the wetlands of Sydney Olympic Park on Australia Day. There have been times when I’ve felt like the only person working as I chase mosquitoes in coastal towns during the summer holidays (with apologies to the local fish and chip shop owners who, I suspect, work a lot harder than me!). xmastreesaleFunnily enough, I never really worried about missing out on summer holidays. Despite growing up spending every school holiday (and lots of weekends in between) at our family holiday house on the south coast of NSW (sadly not in the family anymore), adjusting to life studying mosquitoes and working through the summer months wasn’t so bad. I still love it. It takes me to some unusual places and I get to see a side of the Australian environment many actively avoid (they’re missing out). It wasn’t until my daughter started school that reality hit. That first summer school holiday period left me with a feeling of melancholy. As those holidays quickly approach again, I’m reflecting on my own childhood memories, and the current absence, of summer holidays. Not just for me but also my kids. It would be nice to be planning a family summer holiday. summer_rockpoolsIt isn’t just the holidays themselves. As most people seem to be winding down towards Christmas, I’m increasing the workload. Oh how I wish the last few days before a holiday were filled with “pointless busy work”….just like the last few days of school. A few lazy days of desk cleaning and book shelf sorting wouldn’t be so bad. I’ve been stretched during December. Notwithstanding the routine field work, this summer has been plagued by unusual rainfall and tide patterns that have had me out in the field more than usual. This is coupled with some major manuscripts due early in the new year that have had me up late most nights.

Normally, I wouldn’t mind skipping late night shopping and carols by candlelight or slow drives down streets full of Christmas lights. Thing is, my kids love it and I want to share their excitement! I’ve found myself having the weigh up the benefits of having a manuscript reviewed on time or singing jingle bells with the family in the local park. Not something I considered when embarking on a career in medical entomology.

This all leads to my 2015 new years resolution. Perhaps I need to learn to say no more often. Take on fewer projects. Don’t say yes so often. Plan my time a little better and not end the year with so much to get done. I wonder how that will work out next year? If you’re an ecologist, entomologist or fish and chip shop owner, how do you deal with working through the holidays? Join the conversation on Twitter.

— The photo at the top of this post is taken from the 2014 article, “More mosquitoes on the way” that appeared in the St George and Sutherland Shire Leader January 2014. —

World Wetlands Day: Rehabilitation, Agriculture and Mosquitoes

hexham_floodgatesWetlands are some of the most important, but most threatened ecosystems in the world. February 2 is World Wetlands Day and an opportunity to celebrate local wetlands and raise awareness of their importance. Can we rehabilitate wetlands without creating more opportunities for mosquitoes?

What is World Wetlands Day?

World Wetlands Day is celebrated each year on 2 February and marks the anniversary of the signing of the Convention on Wetlands of International Importance in Ramsar, Iran, on 2 February 1971.

As described by the Australian Department of the Environment:

“World Wetlands Day was first celebrated in 1997. Since then government agencies, non-government organisations and community groups have celebrated World Wetlands Day by undertaking actions to raise public awareness of wetland values and benefits and promote the conservation and wise use of wetlands.”

The 2014 theme for World Wetlands Day is “Wetlands and Agriculture” and may, at first, seem a little unusual. However, wetlands play a critical role in supporting many agricultural pursuits by improving water quality and assisting water conservation, providing a buffer against flood and storm events, assisting nutrient removal from runoff and supporting populations of predators of agricultural pests.

rushesWetlands, agriculture and Australia

Wetlands, although important in many ways to local communities and economies, have not always had a healthy relationship with agriculture in Australia. Draining, filling and polluting of wetlands have all resulted from agricultural development in both coastal and inland regions of Australia. Debate regarding the allocation of inland river flows to environmental and agricultural uses continues today. However, there is an increasing awareness of the need to balance the interests of agriculture and wetland conservation in many regions and an integrated approach is required. Fortunately, many land owners are now actively engaged in sustainable land management practices and efforts are made to limit impacts to onsite and offsite wetlands.

Looking ahead, there are new opportunities too. There is much potential in carbon farming or “blue carbon” that may see an increase in wetland areas. At the least, this may provide a valuable opportunity to assign an economic value to our wetlands, something that is often difficult to achieve but may eventually help with their conservation.

Historically, coastal floodplains have been significantly impacted by flood mitigation, agriculture and urban development. Most importantly, the restriction of tidal flows through the construction of sea walls, levees, roads, railways and floodgates have substantially altered the hydrology of these environments leading to changes in flora and fauna. In many instances, the “reclaimed” land has been used for agriculture, particularly grazing livestock. The decision to install floodgates may have been driven by concerns regarding potential flooding and to increase available area for grazing, limited consideration appears to have been given to the potential impact on the environment. Over 4000 structures have been identified in NSW alone that influence tidal flows into coastal wetlands.

cowsRehabilitating wetlands impacted by floodgates and restricted tidal flows

Coastal wetlands in Australia are under threat on many fronts so where there are opportunities to rehabilitate degraded habitats, strategies should be implemented to improve environmental health. So, don’t you just open or remove the floodgates?

With tidal flows restricted from these degraded habitats for decades, there have been substantial changes in these local environments. Understanding how re-establishing tidal flows may impact the existing flora and fauna across the local estuary is critical.

One of the largest estuarine wetland rehabilitation projects in the southern hemisphere is the Hexham Swamp Rehabilitation Project near Newcastle, NSW. The wetlands cover approximately 2,000 hectares and rehabilitation plans have been underway for over 30 years. Floodgates were installed in 1971 and have resulted in significant changes to the local vegetation. While remnant areas of saltmarsh and mangrove remained, the exclusion of tidal water, as well as the accumulation of rainfall runoff, shifted the vegetation to a freshwater dominated system. In particular, the wetlands became dominated by extensive stands of Phragmites australis. While these dense stands of vegetation provided habitat for a range of birds, frogs and snakes, with regard to locally important wading birds, the quality of the habitat wasn’t up to scratch. With the loss of coastal saltmarsh a major concern for local authorities, a strategy was developed to reestablish tidal flows to Hexham Swamp.

hexham_grasslandExtensive hydrological model was undertaken to inform the strategy of floodgate openings. However, despite some complex modeling to predict how tidal waters would move into and out of the system, it really wasn’t until the floodgates were opened that the wetland hydrology could be measured. A staged opening of floodgates over a number of years was undertaken with all gates open in August 2013.

There has already been a dramatic change in the local environment. In areas where tides are now penetrating and increasing salinity, there has been a substantial die off in freshwater vegetation. This is now steadily being replaced with estuarine plants such as saltmarsh. There has been a big shift in the birds visiting the site too with an increase in waders in many areas. There are more fish and an increase in prawn populations in the local estuary has been credited to the openings of the flood gates.

redmudflatWhat about the mosquitoes?

It will come as no surprise that concerns regarding potential increases in mosquito populations were expressed at early stages of this rehabilitation plan. There were some key site-specific issues to consider here. Firstly, the Hunter estuary contains extensive existing and productive mosquito habitats. Hexham Swamp, while significant, is surrounded by a number of other extensive saltmarsh and mangrove environments that are well documented as productive habitats for the saltmarsh mosquito, Aedes vigilax.

The impacts of these saltmarsh mosquitoes as important vectors of Ross River virus, prompted the formation of the “Living with Mosquitoes” group. This group contains five adjacent local governments, as well as a number of other stakeholders, with oversight from the local health district. The group assists local authorities develop coordinated surveillance and community education programs to raise awareness of mosquito risk. Even without changes in the mosquito populations produced from Hexham Swamp, the region would still have an ongoing mosquito issue to address.

Tracking the mosquito populations and changes in their diversity and abundance with the reintroduction of tidal flows, a couple of key observations were made. Firstly, there was a dramatic decline in the abundance of “freshwater” mosquito populations. This was expected and it was hoping that any declines in freshwater mosquitoes would offset any increases in estuarine mosquitoes. Secondly, although an initial “first flush” of mosquitoes were produced following the introduction of tides, populations appear to have stabilsed (perhaps even fallen) in line with other habitats in the local estuary.

The factors contributing to the “first flush” are not completely understood but the most likely scenario is that an accumulation of mosquito eggs over previous years were laying in wait for those first big tides to flood in. Although some of these eggs would have hatched following major rainfall events, there would rarely have been the volume of water in the wetland following rainfall compared to the major tidal flooding events now the gates are open.

mangrovesOur experiences with the Hexham Swamp rehabilitation program show that it is possible to “bring back” estuarine wetlands that may have almost disappeared through the restriction of tidal flows and damaged caused by agriculture (particularly cattle grazing). It is also possible to improve the health of these wetlands without creating additional or increased mosquito problems. Surveillance and planning (and perhaps a little mosquito control) will be required but it appears that if the health of the wetland improves, mosquitoes can be maintained at reasonable levels. It is important to remember that mosquitoes are a natural part of Australia’s wetlands and eradication should never be an objective of management.

Have fun during World Wetlands Day 2014! Don’t forget to check out the free eBook on managing urban wetlands produced by the Sydney Olympic Park Authority.

Making music from environmental sounds

Ward Pound Ridge Nature Preserve

I normally only post about my mosquito/medical entomology related activities but since World Listening Day 2013 is just around the corner, i thought I’d post about one of my hobbies, sound recording. Over the last 10 years or so I’ve had the opportunity to turn my love of environmental sound recording into a (mostly) self supporting hobby through the release of records under the name Seaworthy.

I wish I had the time to devote to studying the more academic aspects of acoustic ecology. Perhaps in the years to come, when I have more spare time, I’ll be able to delve into this pursuit. I will have more spare time in the future right? For now, I thought I’d write a short piece on the background to a recently released album, “Wood, Winter, Hollow”. Although not a purely an album of field recording, many of the sound sources were recorded in the local environment.

I recently had the good fortune to visit Westchester County, New York. I had the opportunity to stay with a friend and fellow musician (not to mention a wonderful photographer), Taylor Deupree. This was intended as a quick visit while i was on my way to Atlantic City for the American Mosquito Control Association meeting. I’d never had the chance to visit New York City but it was nice to also get out of the city and into a part of the world I’d only ever read about before. It was also the first time I had visited a region of the world with endemic Lyme disease (but I wasn’t there to study ticks this time around).

I visited in February. Winter. The local countryside was a world away from the Australian summer. The woodlands of (mostly) leafless tree were sparse and silent. There was a healthy snow cover and the ponds and lakes dotted throughout the countryside were mostly frozen over. Very few animals to be seen besides a few birds and deer. Despite what may sound a little like desolation, it was really quite beautiful.

Taylor and I took the opportunity to do some recording while I was there. What started out as just being an opportunity for me to record some of the wintery environmental sounds of Westchester County, turned into a couple of days of rapid fire recording.

PoundRidge_WWHFB_June10eMuch of our time was spent in the nearby Ward Pound Ridge Nature Preserve/Reservation. The park covers over 3000 acres and, as well as containing a number of historic buildings, is a biodiversity reserve containing extensive woodland and grassland habitats dissected by creeks and wetlands. I have no doubt that these environments are alive with sound during the summer but during winter there really is an eerie silence.

The relatively silent ambiance can force you into listening to most subtle sounds. Tiny crackles of water flow beneath a frozen stream surface or the faint rustle of those last few leaves clinging to otherwise barren branches. The otherwise incidental sounds like these can take on much more significance during winter where they would otherwise be drowned out during the buzz of insects, birds and frogs during the summer.

In these circumstances, it is often impossible to actually sit and listen to these sounds. You can only really appreciate them when they’re amplified or captured with special microphones. In particular, much of my recording is done using hydrophones. These are underwater microphones most commonly associated with the recording of whale songs. These can also be useful in recording aquatic arthropods too. The real joy for me though is recording the crackle and rattle of small streams where water is rushing through debris and rocks and tiny bubbles fizz creating the most wonderful sound. These types of recordings are even more abstract when made beneath the frozen water surface.

PoundRidge_WWHFB_June10fI usually approach environmental recordings from two perspectives. Firstly, it is impossible to switch off my “science” brain from searching and analysing the recordings to identify the source of the sounds. What animal is making that sound? What species of bird is it? What type of call is it? (One of my first ever research projects required analysis of sound recordings to identify the diversity of frogs across Western Sydney) Even amongst the abstract sounds recorded with the hydrophone, I’m trying to determine what physical processes are underway beneath the water surface to create the changes in water direction or pressure waves.

Secondly, I’m very attracted to the abstract sounds. I rarely set out to record the pure sound of particular species as you may hear in audio field guides (e.g. birds, frogs). I tend to generally record the ambient soundscapes through a filter of recording hardware and the placement of the microphones. I particularly enjoy the sounds that aren’t immediately identifiable. These can often be “happy accidents” where the microphone has picked up my own movements or may be due to some technical short comings on my behalf on operating the equipment! While these sounds may not strictly be “environmental sounds”, there is no doubt that I would be unable to recreate them in the studio. These sounds can sometimes be the most inspiring, or at least can trigger other ideas to investigate at another time.

PoundRidge_WWHFB_June10Unlike many other sound artists who work purely with environmental recordings (some of my favourites are Jana Winderen, Tom Lawrence and Chris Watson), I tend to incorporate my recordings with more traditional instruments. There are many other artists that pursue this methodology, many incorporate electronics or process the original recordings to such an extent that they may no longer become recognisable. A few of my favourite artists that fall into this category are Lawrence English, Marcus Fisher, Simon Scott, Stephen Vitiello and Matt Rosner.

Back in Westchester County, once a collection of environmental recordings were made, it was back to the studio to compose a series of music pieces. These were generally built on top of a bed of sounds and textures recorded from the woodlands and creeks of Ward Pound Ridge. For the most part they were improvisational but certainly many of the seeds of ideas were planted out in the field and in direct response to the recorded sounds. Once various instruments were layered, additional environmental recordings were then interwoven throughout the pieces.

IMG_6973Overall, it was a great experience and this release will forever be a perfect reminder of my time in Westchester County. Working on a project like this is not dissimilar to working on a collaborative research project. The opportunity to work with other people, who each bring a difference perspective and skill set typically results in a better outcome than if working alone. I know that many of my scientific publications would have been much poorer if it hadn’t been for the statisticians or microbiologists that brought their skills, that I lack, to the table.

The release of a CD is a lot like finally getting your research project published too. Perhaps music reviews aren’t quite as critical as the reviews of a newly submitted manuscript but, at least at this stage, a couple of people have enjoyed the music (Folk Radio UK and Fluid Radio). If you’re interested in reading more about this release and listening to some sound samples, please visit the 12k website.

If you’re interested in reading more about acoustic ecology, field recording and soundscapes, there is an excellent series of recent posts by Caleb Kelly up on the Sound Thoughts blog. One of the most cited references on the topic is “The Soundscape: Tuning of the World” by R. Murray Schafer (originally published in 1977). There is also nice article on soundscape ecology here.

You can also visit the Environmental Sounds blog run by Matt Rosner and myself that contains a number of recordings from both the east and west coast of Australia. We’re both trying to dedicate some more time to keep that blog updated!

Photos from the field (2012-2013)

I rarely head out into the wetlands without my camera. Having a stockpile of photos from my various study sites always comes in handy, not only for conference and workshop presentations or lectures but also to assist in interpreting some of my mosquito data. Shifts in the extent of tidal flooding of coastal saltmarsh or growth of invasive aquatic macrophytes across constructed wetlands can be captured pretty easily with a quick shot.

While I hope to upgrade my current camera (Canon PowerShot S5iS) to a digital SLR someday, having an iPhone (and being an avid user of Instagram) has opened up a whole new range of possibilities. The convenience of carrying around a reasonable quality camera has been great. Certainly much easier than carrying my other camera bag when I’ve got mosquito traps and other equipment to lug around.

I regularly post photos from the field to my “Wetland Field Guide” tumblr but I thought I’d put together a bunch of my favourite photos here from the recently completed “mosquito season”. This collection is from those posted to Instagram during the season. The vast majority of my field work is conducted between November and April each year. While it isn’t unusual to be out collecting data in early Spring, or even into May occasionally, it looks like I can pack away the gumboots for this season.

I hope you enjoy these shots.


Hexham Swamp (Newcastle) IMG_7511

Kooragang Island (Newcastle)


Newington Nature Reserve (Sydney Olympic Park)


Badu Mangroves (Sydney Olympic Park)


Narrawang Wetlands (Sydney Olympic Park)


Jerrabomberra Wetlands (ACT)


Gungahlin Wetlands (ACT)


Badu Saltmarsh (Sydney Olympic Park)


Kooragang Island (Newcastle)


Ironbark Creek, Hexham Swamp (Newcastle)


Ironbark Creek, Hexham Swamp (Newcastle)


Saltmarsh, Newington Nature Reserve (Sydney Olympic Park)


Saltmarsh, Newington Nature Reserve (Sydney Olympic Park)