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Entries in Florida (6)


A site visit to Harbor Branch

The submersible Johnson Sea Link aboard R/V Seward JohnsonOn Thursday morning Bruce Carlson and I rose early and headed out to visit Harbor Branch Oceanographic Institute in Fort Pierce Florida; the first visit for both of us.  I had long been aware of their marine engineering division and the important role of the R/V Seward Johnson and its attendant submersibles - the Clelia (which we had on display at Georgia Aquarium for a while) and the Johnson Sea Link - in NOAA’s UNOLS oceanographic fleet, but there was much more in awaiting us at that storied campus than I think either of us expected.

Harbor Branch was established in the early 70’s as a private non-profit ocean research center by J. Seward Johnson, the son of Johnson & Johnson founder Robert Wood Johnson.  More recently HBOI became a part of Florida Atlantic University, based a ways up the A1A in Boca Raton

As we toured the site with Assistant Executive Director Megan Davis on the first day, I was first surprised and eventually staggered at the scale of their aquaculture actvities.  Their experimental production facilities extend over several acres of spotless Quonset huts on the shores of the Indian River Lagoon and include programs on conch (queen and fighting), clams (hard and sunray venus) and marine snails, though some of their biggest efforts are currently directed towards Florida pompano.  Harbor Branch also has an extensive marine drug discovery program that searches for active compounds among the thousands of species in their collection, which might then be used to treat human diseases.  There’s a great synergy between that program and the ocean exploration group in that submersibles can bring back new candidate species (especially deep sea sponges) from research cruises around the world, which the clever biochemists and microbiologists can then go to work studying for their potential applications.  Its painstaking and tremendously challenging work, but they’ve had at least one anti-cancer drug through to Phase I clinical trials, so the potential is there.  Finally there’s a well-established marine mammal program at Harbor Branch, which includes studies on the health of dolphins and manatees in Indian River Lagoon and is responsible for responding to all strandings on that part of the Atlantic Florida coast and the pathology research on those unfortunate animals that don’t make it.  The aquarium is intimately involved in these studies because our Cheif Veterinary Officer Dr. Greg Bossart was based at HBOI for many years

On the second day we also toured Oceans, Reefs and Aquariums: a private ornamental fish and coral culture company that is co-located on the HBOI campus and breeds over 70 varieties of marine ornamental fishes.  Many people are surprised to learn that marine ornamentals like clownfish, dottybacks, cardinal fish, mandarin gobies and seahorses can be and are bred on commercial scales; there seems to be a well-entrenched dogma that marine species don’t breed in aquariums.  Of course, thats not true, they breed all the time.  But, as Bruce would say, its not the spawning thats the problem, its the early rearing and especially the need for speciality foods.  Why so hard?  Well, many species cultured for food have large yolky eggs and big larvae that can feed on common foods like brine shrimp nauplii straight out of their eggs, but reef fishes are different; they often have tiny eggs and larvae that are smaller than many of the food items they might otherwise be fed.  Perhaps not surprisingly, those marine ornamentals that have been bred so far have larger eggs than some of their relatives, but successfully rearing fishes like angels and butterfly fish is still proving to be a tremendous challenge.  Not so with corals.  ORA’s coral culture greenhouse is replete with relatively low-tech trough systems where technicians skillfully “frag” coral colonies (cut little bits off the branches) in exactly the same way as a horticulturist might take cuttings from a plant.  The end result is successful multiplication and large scale propagation of many branching, plating and massive corals.  This provides a premium marketable product while reducing impact on natural reef systems because no further extraction is needed after the earliest parent colonies.  In cheesy business-speak: it’s truly a win-win.

Happy acroporid coral frags at the ORA facility

While we were there, Bruce and I also gave seminars about our respective studies - his on resiliance of Fijian coral reefs to bleaching and mine on (what else?) whale sharks.  It was a lot to fit into two days, but I came away with a much deeper appreciation for the breadth and depth of programs at one of the world’s best-known marine science facilities.  I hope it was the first of many such visits because they’ve got a lot of great stuff going on there.


Slow down = mow down?

This post was chosen as an Editor's Selection for

Manatees in Florida are a battle hardened lot.  A large proportion of the sluggish sea cows have injuries from boat strikes, which is something of an occupational hazard when you live in the heavily trafficked coastal waterways of the sunshine state.  Indeed, lots of manatees have multiple scars from a lifetime of encounters with leisure craft, and boat strike is the biggest human cause of manatee deaths in that state.  The solution seems obvious, right?  Slow down!  Give the manatee a chance to get out of your way, and maybe human and manatee can live together, sharing the coastal waterways in relative harmony.  But what if that’s exactly the wrong thing to do?  What if that makes things worse?  How could that be, and what should we do instead?  Science to the rescue…

When legislation was first introduced to slow coastal recreational boats in manatee habitat, the number of boat strike injuries went up, yes up. Significantly.  Enter acoustics experts Ed and Laura Gerstein.  Through a painstaking research program into the hearing capabilities of manatees and the soundscape of Florida waterways, the Gersteins teased apart the problem and showed its surprising and counterintuitive basis.

The research began with studies to determine what a manatee can hear.  This is not as easy as it might seem.  We’ve all had audiograms done: they put you in the little booth with the headphones and ask you to press a button if you hear a sound.  They systematically play different frequencies at different amplitudes and, by your button, you paint a response curve for them about what you can and can’t hear.  Well, with manatees, the principle is the same, but the execution was a bit different, because you can’t ask a mantee whether or not it heard a sound.  Or can you?  Actually, you can train a mantee to push a paddle with its nose when it hears a sound (in exchange for a monkey chow biscuit), using the same training approaches as any mammal training.  Once the manatee has that behaviour down reliably, you can play it, under controlled conditions, all the frequencies and amplitudes of a typical audiogram, and thus determine what it can hear.  Its a great example of training (operant conditioning) as a research tool.  It took the Gersteins over a year at the Lowry Park Zoo in Tampa to train two manatees to do this, and 4 more years to complete the sound study, but the resulting audiogram held the key to unlocking the boat strike problem.  The Gersteins showed that manatees are not very good at hearing low-frequency sounds and that their peak sensitivity to sound is up in the 14-16KHz range (which would be audible but very high to human ears). 

 Next they went to the waterways and measured the ambient sound and then the sounds of boats traveling at different speeds.  And there it was, the answer:

What a manatee can hear is represented by the grey line - if its above the line, then they can hear it, if below, then they can’t.  Thus the background noise (the black line) is below what a manatee can hear - they live in a largely silent world.  A 27ft recreation powerboat zooming by right overhead is the red line - they can certainly hear that!  The same boat when its 16 seconds travel away (the pink line) cannot be heard yet.  But heres the kicker: slow the boat down to 3mph (5kmh - the blue lines) as the law requires, and the response curve drops below what a manatee can hear, even if the boat is right on top of them.  Slowing the boat down means that you’re effectively sneaking up on the hapless mammal, so that they never know what hit them.  The effect is exacerbated by two other things.  Firstly, a slower boat not only makes less noise (its “quieter”) but it also makes lower frequency noise (basically, it rumbles, not whines) and as we saw earlier, manatees don’t hear well down in the low frequencies.  Secondly, to make it even worse, there’s something called the Lloyd mirror effect, where low frequency sounds are muffled or even cancelled out completely in  shallow water, because the sound waves reflect off the surface of the water and the bottom and negate each other in the water column.  The sum of these three factors - boat amplitude, boat frequency and Lloyd mirror - is that manatees are effectively deaf to recreational boats in shallow water.  These results also explained why manatees also get hit by barges, which are large and move very slowly.  In another study, the Gersteins showed that this was made worse by a sort of sound shadow that occurs in front of a barge because the propellers are at the back and their sound proagates behind, but not in front of, the vessel.  Thus even a large and slow barge can still sneak up on a manatee.

Never fear, this story has a happy ending.  The Gersteins have taken the knowledge they gained through this elegant research and turned it into a solution to the problem: a device that can be attached to the front of every boat to emit an alarm sound that manatees can hear and thus avoid.  In this endeavour they’ve been sensitive to the problem of “sound pollution” in the coastal environment.  By using flanking ultrasound emitters, the device focuses the alarm sound in a 6 degree wedge in front of the vessel, making what Ed describes as a “laser of sound”.  Validation studies are showing that manatees in the vessel path do hear the alarm and take evasive action and that, importantly, this effect doesn’t wear off.  In other words, they never grow accustomed to or ignore the alarm sound.

This seems to me a great example of science showing that the obvious (slowing down) is not always the correct course of action in a complex world.  It reminds me of well-intentioned minimum legal size limits for recreational and commercial fisheries, which can cause fishers to take the largest and most fecund fish in the population or, worse still, take all the females in those species that change sex as they grow.  Through careful and time consuming bioacoustics research, with a healthy dose of animal training in an aquarium setting, the Gerstein’s may well have helped save countless manatees from future harm.

Gerstein, E. (2002). Manatees, Bioacoustics and Boats American Scientist, 90 (2) DOI: 10.1511/2002.2.154


Follow this NOAA expedition on a new "Deep Corals" blog

Lophelia, a deep sea coral.Fun news from colleague Andrew Shepard at Harbo Branch (Florida Atlantic U.), via Kim Morris-Zarneke:

“Tomorrow, Nov. 9, 2010, the NOAA ship Ron Brown departs Pensacola, FL, on the Extreme Corals 2010 Expedition. Chief scientists, Steve Ross, UNCW, and Sandra Brooke, Marine Conservation and Biology Institute, lead the effort to explore and characterize deep coral ecosystems from the West Florida Shelf to the northern Florida east coast using WHOI’s Jason ROV. We have set up a Web portal for the expedition at The NC Museum of Natural Science is partnering on this web offering, providing access to daily blogs from sea, image gallery, education materials and more at


ISAAH 6 underway!

Today was registration day for the International Symposium on Aquatic Animal Health at the (very grand) Marriott Waterside in Tampa.  Usually thats a mellow check-in day but it was also ExCom meeting time for the Fish Health Section and then a Session Chair co-ordination meeting.  I was delighted to see again a colleague from Kamchatka, Tatiana Gavruseva, who I first met at a US/Russian bilateral exchange meeting last year in the DC area.  Kamchatka-Moscow-Washington-Tampa - what a flight, can you imagine? I am aurprised she can keep her eyes open.

Ice-breaker calls….



Do you know about this course?

My colleagues at the University of Florida are running an online Aquatic Animal Conservation course, with credit offered at both the undergraduate and graduate levels.  If you’re into marine conservation or you have a particular interest in Florida’s aquatic ecosystems, you might really dig it.

Check out the flyer here.



Tampa - brace yourselves...

Next week I will be in sunny Tampa for the 6th International Symposium on Aquatic Animal Health, a great meeting that happens every four years covering the gamut of AAH from aquaculture to fisheries to aquariums and even marine mammals (they’re OK too, ‘spose).  The energetic Andy Kane from UF and the lovely and talented Sarah Poynton from Johns Hopkins are chairing the program and it looks to be a great set of folks attending. They’ve got me co-chairing a session about parasites in molluscs, which should be fun, and my own talk will be about metabolomics in whale sharks, a collaboration with colleagues at Georgia Tech.  What’s metabolomics, I hear you say?  Well, perhaps I’ll post about it while I’m there (you know, AFTER I make the powerpoint.  I should probably start that…).



The AGM for the Fish Health Section of the American Fisheries Society will also be there, so we’ll be mixing hundreds of science talks with some serious chit-chat about the state of fish health science in this country, which has evolved significantly of late, in part because of new disease epizootics (VHSV anyone?), the National Aquatic Animal Health Plan and the increasing role of veterinarians in fish health research (the more the merrier, I say).

Should be a great meeting.  Anyone got any “must hit” spots while I am there? or want to meet up for a cuban sandwich, or better yet, a couple of cervezas?