Night vision on the reef

We’ve just returned from a week on Heron Island on the southern Great Barrier Reef. On this trip,  we did some highly experimental work with night-vision type equipment to allow us to see what happens on the reef at night when no one is around. Specifically, we were interested to find out who’s making the grazing halos we’ve been studying there – beyond the players we’ve observed from our daytime remote videos. To do this we used a fleet of modified, infrared-sensitive GoPro cameras, as well as unmodified GoPros, and red lights mounted on a custom-made rig designed by Osmar Luiz. Despite some hiccups (i.e., flooded cameras) and some eerie lagoon snorkels at dusk (i.e., dinner time for some of the reef’s larger inhabitants!), the trip was a great success. A huge thanks goes out to the awesome team of field assistants, too: Vincent Raoult from Macquarie University, Veronica Radice from the University of Queensland, and Nathan Caromel from Griffith University. We also had the good fortune of working with Morad Ait-Habbouche, a veteran French filmmaker working on a climate change documentary.

We’re just starting to process the nighttime videos now and are excited to see what we find…

A great time at the 2016 Gordon Conference on Predator-Prey Interactions

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I’ve just returned from the 2016 Gordon Conference on “New Frontiers in Understanding Predator-Prey Interactions in a Human-Altered World” in Ventura, California. It was an excellent meeting! This is the second meeting in this series (the first was in 2014) and it will be happening every other year into the future. This is one of my favourite meetings – it’s nice and small (with a cap of 200 participants), there’s plenty of time to have meaningful discussions with new and existing colleagues, and there’s a general sense of integration across disciplines that’s not often found at more system- or discipline-specific meetings. I presented our work on how human activities change marine ecosystems by altering predation risk (see poster above) and got some great feedback. Looking forward to the next meeting in 2018!

Swimming amongst the seagrass beds and grazing halos off Key West

While in Key West recently, we also had a chance to get a quick look at the grazing halos that are about 8 kms offshore within the Western Sambo Ecological Reserve. Years ago, Dr. Tom Adam pointed these out to me on Google Earth, and they’re still some of the clearest examples of grazing halos we’ve seen anywhere in the world. I’ve always been curious about what the patch reef communities within the halos look like. It turns out they’re quite beautiful, with lots of sea fans and sea whips and fairly high live coral cover (though no staghorn or elkhorn, at least at the ones we visited). There were also more predatory fish than I expected to see for a place as heavily fished as the Keys. The halo itself was as clear as you’d expect from the imagery, with essentially bare sand adjacent to the reef. This bare area extends for about 6-8 metres, at which point the seagrass becomes increasingly dense and tall – just as we’d expect from theory and the satellite imagery.

 

Checking out the amazing coral growth in the Florida Keys

We had a very short, but totally interesting, trip to Key West this week…while there, we visited Dr. Dave Vaughn and his astonishingly-fast-growing corals at Mote Marine Lab down at Summerland Key. They’ve been able to grow corals in the lab with growth rates many times faster than what we normally find in nature, and it seems the mechanism behind this is something to do with the process of breakage (akin to when we get a cut and it heals much faster than the rate at which the rest of our skin is growing). The PBS News Hour did a short feature on this cool work.

Dave Vaughn showing Elizabeth and Josh (not in picture) how he and his group are growing corals at roughly 25 times their natural growth rates.

Some of the early-stage ‘micro-fragmented’ corals they’re growing in the lab. Ultimately, he hopes to transfer these onto some of the Florida Keys’ struggling coral reefs to help restore them.

Osmar helps map the reef with the robot crew at Lizard Island

Osmar‘s just returned from a very windy, but successful, trip to Lizard Island on the far north Great Barrier Reef. He was there to help create extremely high-resolution 3D maps of the reef that was largely destroyed by category 4 Cyclone Nathan a few months ago. This work is part of a larger project led by Dr. Joshua Madin of Macquarie University and Sydney University’s Australian Centre for Field Robotics that uses robotic torpedoes help map our corals on Great Barrier Reef. Read more about it here.

The robotic torpedo used by the group to make maps of the reef on previous trips.

One of the composited 3D texture-mapped models of the reef.

Short but sweet Ningaloo Reef trip!

I spent the past few days aboard the vessel Ocearch at beautiful Ningaloo Reef in remote Western Australia. The trip was cut short by – yet again – a cyclone! This time it was Cyclone Quang that hit bang onto Ningaloo just as I was set to arrive. I guess there’s never a dull moment when you work in the tropics.

The reef, however, looked amazing – extremely high coral cover and an apparent abundance of predators big and small. I didn’t see any evidence of cyclone destruction in the spot where we were.

The Ocearch crew + the science team caught and tagged 20 tiger sharks in just nine days. You can follow those (and other) sharks’ movements here (and, if you’re like me, keep an eye on how close they are to your favourite surf spots!).

The reef, with quite high coral cover. Being next to a desert has its advantages...Ningaloo is spared much of the land-based pollution that washes into it's east coast analogue, the Great Barrier Reef.

The reef, with quite high coral cover. Being next to a desert has its advantages…Ningaloo is spared much of the land-based pollution that washes into it’s east coast analogue, the Great Barrier Reef.

A friendly turtle that joined our dive.

A friendly turtle that joined our dive.

What you can and can't do.

What you can and can’t do in the marine park.

The Ocearch vessel. Big and solid.

The Ocearch vessel. Big and solid.

Sunrise over the desert and reef.

Sunrise over the desert and reef.

Some beautiful landforms adjacent to the reef.

Some beautiful land forms adjacent to the reef.

Cyclone Quang.

Cyclone Quang.

Drones, kites and blue carbon at Heron Island

Our recent trip to Heron Island was a great success, despite a minor drone crash and some trying winds…the team was great and we had lots of fun in the process! One of the products arising from this work will be an open-source, best practices-type manual to serve as a toolkit to help other researchers, conservation practitioners and resource managers use drones to survey reefs and other marine environments. We also collected lots of samples to see how predators may indirectly affect blue carbon storage as part of the Global Change Institute grant. Stay tuned! (All photos are by Brian Sullivan unless otherwise noted.)

Team Halo 2014: Emily Darling, Edd Hamill, Trisha Atwood, Quinn Olivier, Elizabeth Madin. Also part of the team but not shown: Brian Sullivan (the man behind the camera), Alastair Harbourne, Andy Goodwin.

Team Halo: Emily Darling, Edd Hamill, Trisha Atwood, Quinn Olivier, Elizabeth Madin. Also part of the team but not shown: Brian Sullivan (the man behind the camera), Alastair Harbourne, Andy Goodwin.

Heron lagoon as seen from RV Boult. Photo: Elizabeth Madin

Edd Hammill working hard...

Edd Hammill and Trisha Atwood working hard…

One of the drones we used to get aerial imagery of the lagoon reefs. Elizabeth Madin and Andy Goodwin. Photo by Brian Sullivan.

One of the drones that Andy built to get aerial imagery of the lagoon reefs. Elizabeth Madin and Andy Goodwin.

Brian Sullivan recovers the drone after a flight… Photo: a selfie, perhaps?

The eagle ray kite we used to fly the camera post-drone crash. Photo: Emily Darling

The eagle ray kite we used to fly the camera post-drone crash. Photo: Emily Darling

Elizabeth learning how to take Underwater Street View imagery.

Elizabeth learning how to take Underwater Street View imagery.

Cyclone Ita cuts our Lizard Island field trip short :(

Bob Warner and Elizabeth in between dives at one of our field sites in the lagoon at Lizard Island.

Pre-cyclone fun…Bob Warner and Elizabeth in between dives at one of the field sites in the lagoon at Lizard Island.

Bob Warner wrangling one of the model predators (thanks, Mark McCormick!!).

Bob Warner wrangling one of the model predators (thanks, Mark McCormick!!) before setting it off on the underwater pulley system to scare smaller fish.

Cycle Ita passed recently right over Lizard Island (far north Great Barrier Reef, Australia) where Elizabeth and colleagues Prof. Bob Warner (University of California, Santa Barbara), Dr. Isabel Downs, and Dr. Josh Madin (Macquarie University) were working on an Australian Research Council-funded collaborative project with Dr. Lexa Grutter (University of Queensland) to look at the effects of cleaner wrasses on changing predation risk for bystander species. Sadly, much of the island’s infrastructure was destroyed, however the Lizard Island Research Station fortuitously survived the cycle largely intact. Fortunately, we got a solid week and a half of work in before the evacuation…