All posts by Randall

About Randall

Dr. Randall Hughes is an ecologist and marine biologist focusing on the causes and consequences of species and genetic diversity in coastal systems. She has conducted experimental work on plants and animals in seagrasses, salt marshes, oyster reefs, and kelp forests. The common thread throughout these activities is a long-standing interest in generating information that can enhance the effectiveness of conservation and management decisions.

Experimental spat tiles, open, closed, and partially open.

Fear and the Choices Oysters Make

Last week, Dr. David Kimbro broke nutrients and oysters down for us.  But what if oysters are too scared to eat the nutrient fed plankton they need to survive?  David and Randall take us another step closer to understanding the Ecology of Fear, examining oysters’ choices and how their behavior affects the important habitat they create.  Stay tuned over the following weeks as they unravel the relationships between predators and prey on oyster reefs and their neighboring coastal ecosystems.  We’ll also continue to follow David’s crew in Apalachicola, Hanna and Stephanie, as they research the oyster fishery crisis.

Dr. Randall Hughes FSU Coastal & Marine Lab

IGOR chip_ predators_NCE 150I recently moved and was faced with the dilemma of finding a place to live. This can be a touch decision, especially when you’re in a new city or town. Which neighborhood has the best schools? The best coffee shop? Friendly neighbors? Low crime? My solution was to find something short-term while I scope the place out some more, and then I can decide on something more permanent. (As anyone who has me in their address book knows, “permanent” is a very relative term – I have changed residences a lot over the last 15-20 years!) But imagine you had just one shot – one, for your whole life – to decide where to settle down. Talk about a tough decision! That’s what oysters have to do, because once they settle down and glue themselves to their location of choice, they don’t have the opportunity to move around any more. So how do they decide?

This oyster shell, harvested from an intertidal St. George Island reef, had been settled by multiple young oysters called spat. Spat grow into mature oysters with a hard shell, fused with the oyster on which they originally landed. Clumps of attached oysters form a crucial coastal habitat.

It turns out that oyster larvae (baby oysters swimming in the water) can use a number of “cues” to help them in the house-hunting process. First of all, they can detect calcium carbonate, the material that makes up oyster shells (and other things) – if there’s lots of calcium carbonate in an area, that could be a good sign that it’s an oyster reef. (Or it could be a sign that people have put a lot of cement blocks in the water in the hopes that oysters will settle and create a reef – that’s how a lot of oyster restoration projects are started.) Some recent research even shows that oysters can detect the sounds of an oyster reef, and then swim in that direction! Maybe these guys are smarter than we think…

Regardless of how oysters decide, there are times when we are also faced with the question of what makes good oyster habitat, or deciding which area is better than another. As scientists, we turn to experiments. One type of experiment that we have perfected over the years involves getting juvenile oysters- (either from the field, which can be pretty difficult -as you can see from the first round of our tile experiment, or from a hatchery), and gluing them to portable sections of “reef” (ceramic tiles weighed down by bricks). LOTS of ceramic tiles and bricks. We’re talking 800+ ceramic tiles and 700+ bricks last summer alone! That’s enough to make a path that is ~2 football fields long. All moved by truck, hand, boat, hand, kayak, and hand to their temporary location on a reef (and then moved back again when the experiment is done). But I digress.

In the second incarnation of the tile experiment, oyster spat were attached to tiles with an epoxy used in the repair of boat hulls. The tiles in the first version- the ones in the video above- were assembled differently. In a video we'll premiere later this month, we'll look at the twists and turns the experiment took.

After attaching the juvenile oysters to the tiles with a lovely substance known as z-spar, we enclose some tiles in cages to protect them from oyster predators, and we leave others with no cage so they are “open” to predators. (There’s also a 3rd group – the “cage control” – that get 1/2 a cage so we can test whether the cage has effects on the oysters other than keeping out the predators.) Then we take our oyster tiles and put them out in the field at different sites that we want to test. By observing the survival and growth of the ones in the cage (where no predators have access), we can get a general sense for whether it’s a good environment or not. Lots of large, live oysters are a sign of a good environment – plenty of food, good salinity (not too salty or too fresh), good temperature, etc. Also, by comparing the survival of the ones in a cage vs. not in a cage, we can get an idea of how many predators are around – lots of live oysters in the cage and none out of the cage is a pretty good sign that oysters are getting eaten. (If oysters in the cage are dead and oysters outside of the cage are missing, it’s a little tougher to figure out exactly what’s causing it, but it’s clearly not a good place for oysters to live!)

Experimental spat tiles at the Guana Tolomato Matanzas National Estuarine Research Reserve- open, closed, and partially open.

Of course, the oysters themselves don’t know whether they are nice and safe inside our cages, or easy pickings for a predator. So if there are lots of predators lurking around the reef, the oysters may try to “hide”. Obviously, hiding for an oyster does not mean packing up and moving elsewhere, but they do have a few tools at their disposal. In the short term, the oysters can choose not to open up their shells and feed (filter water) as often. This strategy has 2 benefits – 1, they are less vulnerable to predators when their shells are closed and 2, they aren’t releasing lots of invisible chemical cues in the water when they’re closed, so it’s harder for the predators to tell they are there. But as any of you who have been sticking to your New Year’s resolution to lose weight will know, there’s only so long that you can go without eating before that strategy loses its appeal! Over the longer term, the oysters can decide to devote more of the energy that they get from eating to create a thicker, stronger, rougher shell, rather than plumping up their tissues.

So, those are the big-time decisions that an oyster faces: where to live, and when to eat. Sounds kind of familiar…

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In the Grass, On the Reef is funded by the National Science Foundation.

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Learning to Tell a Story

Like Randall Hughes and David Kimbro, Dr. Randy Olson is a scientist who wants to make science understandable to a general audience.  Dr. Olson’s passion for communicating science led him to USC School of Cinema and a second career in film making.  He will be here next week to help bring the inner storyteller our of twelve graduate students, and he’s brought his latest film with him.  We hope you can join us.
Dr. Randall Hughes FSU Coastal & Marine Lab

Stories of high school football never grow old!

There’s nothing like lots of time with family over Thanksgiving to drive home the fact that some people are inherently better storytellers than others. How else could you stand to listen to the same story about the come-from-behind, last-minute win (that I witnessed first-hand) year in and year out? Or have someone recount something as mundane as a TV commercial and have you falling out of your seat laughing? Or watch an impersonation of a dog’s attempts to garner some attention that is funnier than the original video? My family is blessed with a number of good storytellers, and I’ll confess that I’m not one of them. So is there any hope for me?

If you’d asked me that question a few years ago, I would have answered with a resounding “No”. I’ve always considered storytelling as one of those innate gifts that some people have and others don’t, with me in the latter category. For one, I prefer to write things down, organizing and re-organizing my thoughts on the page until I get them just right. That way, if I forget the ‘punch line’, I can come back to it later, a strategy that definitely doesn’t work well when telling a joke aloud! Also, I’m much more comfortable coalescing others’ ideas into an organized fashion for a fact-based paper than creating a novel story from scratch (think English 101 vs. Creative Writing). But other than not being the most entertaining relative at family gatherings, does my inability to tell a good story really matter?

Early mornings in the field do wonders for sibling relationships!

This time, I’d have to answer “Yes”. Over the last several years, I’ve become more and more concerned about the disconnect between the scientific world and the “everyday” world. (The fact that it’s acceptable to suggest that science is somehow divorced from everyday life without raising lots of eyebrows is an indication of what I’m talking about.) And I think part of the responsibility for fixing this divide lies with scientists, in that we need to do a better job of explaining to our friends and family (for starters) why our work matters to them. But only the closest and most devoted of relatives (thank you, Mama Jennie!) will read my scientific publications, and only the most in need of a job (here’s looking at you, Jules!) will commit to working as my research assistant for a summer to learn the ins and outs of what I do. So we’re back to the need for me to tell a story, and a good story at that, to grab people’s interest and inspire them to want to know more.

Randall being interviewed by WFSU producer Rob Diaz de Villegas at the FSU Coastal & Marine Lab in July 2010.

Enter my collaboration with WFSU. Just prior to the Deepwater Horizon oil spill, I had a meeting with Kim Kelling-Engstrom about the possibilities of a joint effort to communicate David’s and my research to a general audience with help from the professionals at WFSU. When the spill occurred, the impetus to document our research on the amazing coastal ecosystems of northern Florida became even more urgent, and we launched this blog. For someone who rarely agrees to having my picture taken, it was a big leap to regularly go in front of a camera and talk about what I do, and why I think it’s important. And it’s been a steep learning curve! But I’m beginning to realize (hope?) that telling a story is a lot like playing sports – some people start with a leg up in the talent department, but everyone gets better with practice.

So how do you learn to tell a convincing story? What are the tricks of the trade? To find out more, David and I have invited Dr. Randy Olson, the self-described scientist-turned-filmmaker, to come give a workshop at FSU this month on just this topic. The workshop is for science graduate students interested in learning how to better communicate their ideas and research to a general audience. Randy went to graduate school at Harvard and had a tenured faculty position in marine biology at the University of New Hampshire until he decided to leave his job and enroll in the University of Southern California School of Cinema. Since finishing film school, he’s directed several entertaining and thought-provoking films, as well as written a book about communicating science. So he’s rather uniquely qualified to speak about the particular pitfalls that plague scientists when it comes to telling a good story, as well as how to overcome them.

I’ll be listening in carefully during the workshop, and I’m sure I’ll have some useful tips to share with you (and implement) on this blog in the weeks following. We’re also excited that Randy has offered to do a screening of his movie Sizzle: A Global Warming Comedy at the FSU Student Life Cinema at 7pm on Tuesday, December 11. The movie will be followed by a panel discussion featuring Dr. Olson and several FSU faculty members. The event is free and open to all who are interested, so come join us!

We want to hear from you! Add your question or comment.

In the Grass, On the Reef is funded by the National Science Foundation.

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The Benefits of Coastal Living

This fall we’ve been looking at the ecosystem services provided by the various habitats, whether it’s the food it provides us or the protection they provide us from storm surge. Merely living near the coast and its natural habitats can be beneficial.

Dr. Randall Hughes FSU Coastal & Marine Lab

I love the coast, and I especially love living along the coast. Seeing the ocean daily gives me a definite sense of peace, even when the water itself is not very peaceful. This good feeling appears to be shared by others – a study out of England found that people living near the coast reliably report that they are healthier than people of similar age, gender, etc., who live farther inland. The exact cause of this increased health (or increased feeling of health) isn’t entirely clear – it may be that people living along the coast are more physically active than their inland counterparts, or it may be that they have reduced stress levels. But the pattern suggests that there is a health benefit to living near the ocean.

Of course there are myriad reasons that people live near the coast, including job opportunities, abundant natural resources, culture, and climate. I’m thankful that my career as a marine ecologist ensures that I will always live somewhat near the ocean! And I am certainly not alone. Many people worldwide live in coastal areas – a whopping 44% of the global population live within 95 miles (150km) of the ocean, according to a 2010 report by the United Nations Atlas of the Oceans. That’s 44% of 6.8 billion people, and that’s a lot!

And herein lies something of a dilemma – how can we ensure that people can live near the coast and take advantage of the many economic and personal benefits of coastal ecosystems without harming the ecosystems themselves and losing those benefits? Or the even more vexing problem of one group of people taking advantage of the ecosystems and causing OTHER PEOPLE to lose the benefits of those ecosystems? (We don’t have to go far for an example of this latter issue – just think of the effects of upstream water diversions in the Apalachicola River system on the downstream oyster fishermen.)

That’s when we need good, creative, dedicated people. People who work to strike a balance between the desire to develop coastal areas with the need to preserve and conserve these same areas. People like Pat Hamilton, featured in the video. Because if you don’t protect coastal ecosystems like oyster reefs, marshes, and seagrass beds, then you can lose a lot of the benefits that we derive from the coast, including productive fisheries, outdoor recreational opportunities, erosion control, storm protection, and water quality. And if you do protect them, you can even increase the value of the surrounding areas – for instance, a study by researchers at North Carolina State University found that homes in urban areas that were within 1/2 a mile to a wildlife refuge were worth 7-9% more than homes away from these wilderness areas.

Our region of the Big Bend of Florida is unique in that significant tracts of undeveloped coastal areas remain. As people continue to discover all that this region has to offer and the desire to develop the coast increases, I hope that David and my research will help inform ways to strike that balance between both using and protecting important coastal ecosystems.

In the Grass, On the Reef is funded by the National Science Foundation.

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Notes From the Field: First cold snap

We had to break out our neoprene waders this week for the first cold snap of the year! The picture doesn’t do it justice, since the sunshine gives a false indication of warmth. Meagan, Ryan, and I shivered our way through setting up 20 plots (out of 80!) for a new marsh experiment.

Thankfully all of the exertion of digging and sieving helped us warm up a bit.  In the process of sieving lots of mud to remove any plant roots and rhizomes, we came across a few interesting items -

1. Many small crown conchs that apparently wanted to avoid the cold, and

2. A few large and interesting (but as yet unidentified) worms that we haven’t seen before. We’ll be out digging again tomorrow and will get a picture of them this time!

Our thoughts go out to everyone dealing with far more than just cold in the wake of Hurricane Sandy.

- Randall

Randall snorkels in a seagrass bed in Saint Joseph Bay Peninsula State Park. Photo by Dr. Peter Macreadie. Peter is a researcher from the University of Technology, Sydney, who is visiting Randall and David.

What Have Seagrasses Done For Me Lately?

Episode 6: Blue Carbon Where the Stingray Meets the Horse Conch

At the beginning of September, Randall and David had a visit from Dr. Peter Macreadie of the University of Technology, Sydney.  In this video, Randall takes Dr. Macreadie for a snorkel in St. Joseph Bay.
Dr. Randall Hughes FSU Coastal & Marine Lab

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We now focus our attention to seagrasses, which as it turns out, often don’t get a lot of attention, at least in comparison to other marine habitats like coral reefs or even salt marshes.

Randall snorkels in a seagrass bed in Saint Joseph Bay Peninsula State Park. Photo by Dr. Peter Macreadie. Peter is a researcher from the University of Technology, Sydney, who is visiting Randall and David.

In part, this lack of attention is due to the fact that seagrasses typically live completely underwater, except at very low tide, and so they are not as noticeable as marshes are. In addition, seagrasses often occur in shallow estuaries not known for their great visibility (and thus not as ideal a location as coral reefs for snorkelers or scuba divers). And, although I disagree, some people just don’t find them very pretty.

Last week as I was starting to think about this post, there was a small uptick in the number of media articles related to seagrasses, at least in Australia. The increased interest was in response to a proposal by the Environment Minister, Tony Burke, to require greater seagrass protection from mining and development projects (read more in this article from the Brisbane Times). As justification for the increased financial burden on companies, Mr. Burke cited the many benefits that seagrasses provide. And just what are those?

Scallop in St. Joseph BaySeagrasses (like salt marshes and oyster reefs) provide habitat for many, many fishes and invertebrates. Studies have found that the number of animals living in seagrasses beds can be an order of magnitude higher than the number living in adjacent coastal habitats. Many of these animals rely on the seagrass beds as a “nursery” that protects them from predators until they grow larger. And lots are recreationally and commercially important species that we like to eat. (Scallops, anyone?)

Seagrasses are also incredibly productive plants, sometimes growing more than 1cm per day, and rivaling our most productive crop species like corn. Because a significant portion of this plant material (particularly the roots and rhizomes below ground) stays in place once the plants die, seagrasses can also serve as important ‘carbon sinks’, or buried reservoirs of carbon. In fact, a recent study estimates that the carbon stored in the sediments of seagrass beds is on par with that stored in the sediments of forests on land!

Although lots of the productivity of seagrass beds makes its way underground, some of it does get eaten. Major consumers of seagrasses include urchins and fishes, as well as the more charismatic dugongs, manatees, and sea turtles.

Spider Crab in St. Joe BaySeagrasses (like salt marshes) also play an important role in reducing nutrients that run off from land into the water. Unfortunately, these nutrients can also lead to the loss of seagrasses, by promoting increased growth of algal “epiphytes” that grow on the blades of the seagrasses themselves. When there are not enough small fishes and invertebrates around to eat these algae, they can overgrow and outcompete the seagrass, leading to its decline. And when the seagrasses become less abundant, the animals that rely on them are also often in danger.

The Big Bend and Panhandle of Florida are home to expansive seagrass beds that also often go unnoticed. But they contribute to the productivity, diversity, and beauty of this area in many ways, as anyone who has been scalloping recently has surely realized!

Here is a quick guide to the animals featured in the video above:
0:40 Horse conch and sea urchin joined suddenly by a stingray
1:41 Juvenile pinfish
1:18 Two shots of a bay scallop
1:33 Sea urchin
1:49 Pen shell clam covered in sea stars (2 shots)
1:56 Horse conch

In the Grass, On the Reef is funded by a grant from the National Science Foundation.