Greetings from Down Under

Greetings from down under! I’ve just arrived in Sydney to work with one of my all-time top science heroes, Dr. Emma Johnston, at University of New South Wales (UNSW). It’s all thanks to support from the National Science Foundation and the Australian Academy of Science, through a program they jointly fund called EAPSI – East Asia Pacific Summer Institute.

Twitter post following rocky landing in Sydney

My Twitter post after landing amidst Sydney’s 100-year storm

Of course, it’s not at all summer here in Australia. My approach into Sydney Airport was among the most exciting aviation experiences I can recall due to a 100-year winter storm that was pounding the coast of New South Wales. Upon deplaning, I discovered a usually fair-weather city deep in the throes of winter weather chaos. City buses were rerouted, sirens of emergency vehicles chirped persistently in the distance, and Hassan, my Uber driver, had to turn around on three different occasions to avoid downed power lines.

Of course, my first reaction as a wise American tourist was to instantly flock to the water’s edge to watch. Here was the scene above iconic Bondi Beach in East Sydney:

Zaza Silk (pictured) lost her swimming pool and her mother’s ashes as the sea gobbled up her yard and home. Photo credit – top: © Seven/Sunrise, bottom: Peter Rae.

Harrowing stories from the storm’s victims have since emerged. Storm surge and wave action seized up to 50 horizontal meters of shoreline in a single night in some locations, wreaking havoc for residents and businesses.

Of course, the fact that the sea poses such a risk to coastal communities (both in Australia and around the world) is a small part of why I am here conducting research. I study the artificial structures we build to protect shorelines from seawater inundation, also known as shoreline armoring. As climate change raises sea levels and human populations migrate towards the coasts (Neumann et al. 2015), the need for shoreline armoring is more critical than ever. Yet, we must balance this need with the potential negative consequences of armoring. Previous research suggests that artificial structures such as seawalls and breakwaters alter the composition of marine ecosystems (Bulleri and Chapman 2010). These changes could influence the goods and services that marine ecosystems provide to coastal communities, such as pollution processing and recreational fishing.

Over the next few months, I will work closely with researchers at UNSW to examine how marine trophic (feeding) relationships compare between natural and armored shorelines in Sydney Harbour. Sydney is the epicenter for research on urban marine ecosystems, and researchers here have unparalleled knowledge of the species that live on artificial structures locally. This knowledge will enable me to use stable isotope analysis and next generation sequencing to identify the position of each species in the food chain and its original source of photosynthetic energy. By comparing these characteristics between organisms living on altered and natural shorelines, we will gain insight into how the structure and function of marine communities may be influenced by shoreline armoring.


Happenings, Sites and Critters

Green Seas in the Emerald City

If you’re a barnacle, clam, mussel, or any other filter feeder in Seattle, you’re likely rejoicing right now in the recent profusion of food! Just as terrestrial plants throughout the northern hemisphere have exploded with new leafy growth and flowers, photosynthetic plankton have proliferated in the springtime sunshine. As a result, the seasonal seas of temperate coastal cities like Seattle are now a deep, soupy green, and marine invertebrates are having a feast!

Here’s a video I compiled from recent dives in Seattle. Everyone in the underwater environment has joined in on the celebratory affair. Orange sea cucumbers shove plankton-covered tentacles into their mouths. Serpulid worms collect passing food particles with their colorful branchial crown. Tubesnout fish hover in a milieu of green plankton, sucking in food as they go. Barnacles frantically fan the water with their feathery feeding appendage in an effort to get the most from the surrounding bounty while it lasts.

Now is the time for marine organisms to take up as much energy as possible and store it in their tissues or send it off as offspring. Within a few weeks, the plankton bloom will have run its course. The water will once again become clear and blue, making each fanning motion a bit less lucrative for barnacles and their filter-feeding compatriots. As dying plankton sink to the bottom and blanket the seafloor, detritus feeders like the California sea cucumber (Parastichopus californicus, below) may continue to lie about in satiation well after the party has ended. But for everyone else, it’ll be back to life as usual, as clear waters restore order to the underwater cityscape.

Parastichopus californicus, (c) James Watanabe

Parastichopus californicus, (c) James Watanabe


Research Blitz – Science for Adaptation Planning

I’m en route to the Friday Harbor Labs for a much anticipated research blitz – a 72 hour research intensive with fellow graduate students in the IGERT Program on Ocean Change (IPOC). Over the course of the coming weekend, we hope to make considerable progress on an interdisciplinary collaboration we started last fall. Our objective: Use a case study approach to identify how scientists can best support the planning process undertaken by coastal cities as they adapt to rising sea level.

From the IPCC's 2013 Report (see link in text)

From the IPCC’s 2013 Report (see link in text)

For many years now, the Intergovernmental Panel on Climate Changes (IPCC) and concerned scientists have warned of the impending rise of global sea level and the risks it poses to coastal communities, particularly in high density, urban areas. Projections published by the IPCC in 2013 suggest that sea level could increase by more than 3 feet by the end of the century. But more recent research suggests that the threat may be much more extreme and immediate in some locations due to geographic unevenness in the rate at which sea level is rising. Cities like Miami are already beginning to experience periodic inundation from the surrounding ocean, and record-breaking storm surge events like that from Hurricane Sandy now pose considerable risks to New York and other low-lying metropolitan areas. For many coastal cities, sea level rise is no longer a possibility in the distant future; it’s a process that is already underway, with very real social and economic consequences.

The question many coastal cities therefore face is not how to prevent sea level from rising, but how to adapt to the additional increase we’re already fairly certain will occur. Adaptation plans are under development in most major coastal cities, with the Dutch leading the pack. Many of these plans employ both traditional engineering solutions, like the construction or reinforcement of seawalls and dikes, as well as “soft engineering” approaches, such as restoring wetlands that serve as barriers from encroaching seas. Though economists, social scientists, policy buffs, and the design and urban planning community have already made extensive research contributions to the field of adaptation planning, we’d like to know what more natural scientists (climatologists, oceanographers, biologists, ecologists) could do to help.

Adapting to sea level rise will most certainly require creative approaches that draw on expertise from a wide range of disciplines. What better way to learn about adaptation planning and the science behind it than with an interdisciplinary group of IPOC fellows!


Happenings, Sites and Critters, Uncategorized

Urchin barren video

Last fall, I posted photos from an urchin barren at Elliott Bay Marina. It’s taken me forever to compile video from the same dive, but here it is in all its glory – video of the urchin barren at Elliott Bay Marina from November 2014:

I’ll return to the site as this year’s kelp begins to establish to see whether we can expect the kelp forest to return. More on that soon!

In related news, here’s a an article from National Geographic about what researchers are seeing in California in the way of urchin populations. Though major increases in urchin densities have been observed locally following sea star wasting syndrome, it’s interesting to see that’s not a uniform trend.


Tire covered in green urchins
Happenings, Sites and Critters

Urchin take-over?

Plastic penguin statue (Seacrest Park, Jan 2015)

Green urchins, Strongylocentrotus droebachiensis, on a plastic penguin statue (Seacrest Park, Jan 2015)

There’s been much talk in the local dive community recently of an urchin take over in Puget Sound’s urban waterways. Divers at some of Seattle’s busiest dive sites have noticed a sudden influx of green urchins, Strongylocentrotus droebachiensis. They travel in hungry mobs, marching with the help of lots of little tube feet, presumably in search of greener pastures. At dive sites like Seacrest Park, in West Seattle, you can see them covering submerged objects by the hundreds, clearing the substrate of algae and smaller invertebrates as they go.

Traffic cone (Seacrest Park, Jan 2015)

Urchins on a traffic cone (Seacrest Park, Jan 2015)

Long-time divers note this is the first they’ve seen green urchins out in such force. What’s more, the apparent invasion seems timed with the recent die off of large sea star predators due to sea star wasting syndrome. In particular, the sunflower star, Pycnopodia helianthoides, was hit hard by the disease in the fall of 2013, and is known to be an important predator of green urchins. Any diver who’s seen green urchins clambering over one other in response to an approaching Pycnopodia will agree that urchins take the threat quite seriously. So perhaps the two events are connected….

Has the absence of Pycnopodia caused the urchin population to explode?  To address this, here are a few points I think are important to consider:

– The majority of green urchins that I’m seeing at sites in Seattle are 25-30mm in diameter or larger. Here’s the size frequency distribution I found back in November (below) when documenting the urchin barren that recently formed at Elliott Bay Marina Breakwater. The urchins I’ve seen at Seacrest Park are of a comparable size range.

Size frequency distribution of Strongylocentrotus droebachiensis at Elliott Bay Marina Breakwater in November 2014.

Size frequency distribution of Strongylocentrotus droebachiensis at Elliott Bay Marina Breakwater in November 2014.

– Based on published growth parameter estimates for S. droebachiensis (below; see Chapter 18 by Scheibling and Hatcher in  Edible Sea Urchins), we know that individuals of this size range (25mm in test diameter or greater) are at least 2-3 years of age. Green urchin recruitment occurs in the winter and spring, so we expect baby urchins that have settled since Pycnopodia populations disappeared in fall 2013 are no bigger than 15mm across at this point.

Growth curve for Strongylocentrotus droechiensis based on  published estimates of von Bertalanffy parameters.

Growth curve for Strongylocentrotus droechiensis based on published estimates of von Bertalanffy parameters.

Therefore, we cannot conclude that the high urchin densities we’re seeing at some sites are the result of an increase in population size. While juvenile urchins could very well be experiencing lower predation rates in the wake of sea star wasting syndrome, those that have actually arrived since the disease hit are not the ones we’re seeing out in force at dive sites like Seacrest Park.

So what is going on?

It’s important to note that urchins of all kinds are commonly found in very patchy distribution patterns. In some cases, this is the clear result of patchiness in predation, as Jane Watson and Jim Estes have documented beautifully in their work on red urchins around Vancouver Island (Watson and Estes 2011). In other cases, the reasons for their patchy distribution pattern are unclear.

It’s possible that the mass mortality of Pycnopodia has shifted the behavior of green urchins, allowing them to aggregate and travel more freely from one location to the next. The formation of urchin mobs may just as easily be the result of a localized depletion of algae and other food resources, however. Since we don’t even know where these urchin aggregations were living before they showed up at common dive sites, it’s quite hard to tease apart what caused their mobilization in the first place.

Lastly, I’ll add that patchiness in the distribution patterns of species like green urchins is a phenomenon that occurs over both space and time. Who knows what green urchin populations looked like 100 years ago, or even 500 years ago. If in fact the increase in urchin densities proves to be widespread and persistent, we can certainly expect to see some changes in the community of species that dominate Seattle’s subtidal ecosystems (urchins are quite effective at clearing space on hard structures and facilitate high turnover rates of sessile invertebrates and macroalgae). Whether such changes are “desirable” or “undesirable”, “natural” or “unnatural”, “destructive” or “restorative”, depends very much on your perspective and your objectives and goals for how urban marine ecosystems, which are in a sense our own creation, should function.


Urchin Barren at Elliott Bay Marina

Graph of urchin density over time

Density of urchins estimated from photoquadrats.

In my recent visits to the breakwater at Elliott Bay Marina in Seattle, its become apparent that the site is officially an urchin barren. Urchin barrens are a well documented phenomenon in the Pacific, but to my knowledge, have not previously been observed in Puget Sound. They occur when urchin populations go unchecked by predators and consume canopy forming kelps.

Elliott Bay Marina’s breakwater was constructed in the early 1990s, but has long been home to a vibrant seasonal forest of Nereocystis luetkeana (bull kelp). In the summer time, the site was a magical and diverse refuge for marine life in the heart of the city. Kelp stretched thirty feet or more from the sea bottom to the surface, housing a myriad of invertebrates, rockfish, the occasional wolf-eel, and obese lingcod that could not have been less than 6 feet in length.

We’ve been collecting photo quadrat data at the site since May of 2013 and had our eye on it after the density of green urchins (Strongylocentrotus droebachiensis) began to increase. It wasn’t until we returned to the site last summer, however, that it became clear the increase in urchin density had had such a large effect.

Here are some photos from my last dive there with Ed Gullekson.

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We’ll keep documenting changes and will keep you posted. I’m hearing some talk of urchin densities increasing in other areas as well, but have yet to confirm. More to come…

Salish Sea Conference Logo

2014 Salish Sea Ecosystem Conference

The Salish Sea is the network of inland marine waterways in western Washington and British Columbia that includes Puget Sound. This week, several hundred scientists, tribal leaders, managers, conservationists, and educators gathered at the Washington State Convention Center to discuss the state of marine ecosystems in the Salish Sea. It was the 7th annual Salish Sea Ecosystem Conference, and involved three days of concurrent presentation sessions on a whole suite of issues, from water pollution to dam removal projects to local effects of ocean acidification.

Talks that were of particular interest to me included one by Jameal Samhouri on the differences in intertidal and stream communities between more and less urbanized environments. Correigh Greene, Sean Naman, Casey Rice, and colleagues also presented a series of fascinating talks on an intensive pelagic sampling program they conducted in 2011. A complete list and description of the sessions at this year’s Salish Sea Ecosystem Conference can be found here. The list of talks throughout the three day meeting is provided here.

Photo of Giant Pacific Octopus
Happenings, Recent Research

New discoveries about giant Pacific octopus

Last week, I posted about the 2nd Biennial giant Pacific octopus symposium that was to be held at the Seattle Aquarium. The meeting went off without a hitch. It was the first meeting I have attended in which talks from scientists were so seamlessly weaved together with talks from conservationists and educators.

Giant Pacific octopus are part of a class of mollusks called cephalopods, and possess some extraordinary characteristics. They are highly intelligent and dexterous, and are able to open jars, mimic other octopus, and get through mazes in lab tests with ease. (Here is a great article in Slate Magazine about octopus smarts.) They also have tiny structures in the cells just below their skin that allow them to rapidly change color. When watching an octopus in the wild, you’ll also see them change the texture of their skin to look impressively similar to surrounding kelps and algae. Giant Pacific octopus are the largest known octopus species, growing up to 30 feet from tip to tip. They live for 3 to 4 years and mate only once near the end of their life.

The symposium at the Seattle Aquarium last weekend presented on several aspects of giant Pacific octopus biology and ecology. Shawn Larson, curator of conservation research at the Seattle Aquarium, presented her genetic findings from specimens in Puget Sound, the outer coast, and other locations regionally. Her work suggests that there is some degree of mixing between geographically separated individuals and that there is little evidence of a genetic bottleneck, or reduction in genetic diversity, which we would expect to see if the population size had declined rapidly in association with human activities. David Scheel, from Alaska Pacific University, also gave a a fascinating talk about his work over several decades. He presented compelling evidence that giant Pacific octopus are actually comprised of two (or more) separate species, which can be distinguished both genetically and by morphological differences. In addition, he explored some interest ecological relationships between octopus in Alaska and their prey, suggesting that the adornments on some crab species, which were traditionally thought to be adaptations that make them less visible to predators, may also be texturally cryptic, meaning their texture allows them to blend in with their surroundings when octopus are groping around under the bottom sides of rocks. We also heard from Jennifer Mather, who is developing an ethogram for giant Pacific octopus, Reid Brewer, who has done extensive research on giant Pacific octopus population density in the Aleutian Islands, and many others.

Finally, the meeting honored an important figure in octopus science and conservation, who recently passed away. Roland Anderson was a biologist at the Seattle Aquarium for many years and was the reason the Aquarium began hosting this meeting two years ago. In his memory, the symposium will hopefully continue for many years to come, highlighting further discoveries about giant Pacific octopus and connecting biologists, ecologists, conservationists, and educators from all around the Pacific Rim.


Advertising graphic for octopus conservation at the Seattle Aquarium

Giant Pacific octopus symposium

This Saturday, the Seattle Aquarium will be hosting its second biennial symposium and workshop on giant Pacific octopus. The day promises to be full of interesting information about these charismatic creatures, as I expect we’ll be hearing from scientists and educators alike. The symposium is open to the public, with a registration fee of $40. If you’re interested and in the Seattle area, come join us!  Here’s the link.