2. One Fish. Two Fish. Red Fish… No Fish.

3. Snow Caps Cones for Everyone.

4. Too Many Lionfish on the Dance Floor.

5. I See Deadzones.

6. No Escape from Plastic Monstas.

7. Where Have All the Coral Reefs Gone and Where are all the Cod?

8. Goodness Gracious, Great Plumes of Oil…and Mercury…and all that other crap we put in the sea.

9. I’m all alone and there’s no zooxanthellae inside me.

10. Fin.

The post 10 Reasons Why the Ocean’s Struggle is Real first appeared on Deep Sea News.

Randy Jordan, owner of Emerald Charters in Jupiter, Florida, discovered quite a treasure on a recent dive.

“We get down to the bottom and I see some fish that are swimming over to the right and I followed them,” said Jordan.  “They swam right up to this airplane. It was the most amazing thing.”  Right in front of them, Jordan said, were the remains of an aircraft.  “When you backed up, you said ‘that’s an airplane,’ ” he said…Jordan sent his images to the Warbird Information Exchange , an online source for historical aviation information.  Experts there told Jordan that the submerged aircraft could be a Curtiss Helldiver SBC2.  Some of those airplanes flew in the early 1940s during World War II.

Now that you watched the video once. Watch it again, but this time take notice of tremendous numbers of lionfish.  Note lionfish are native to the waters of the Indo-Pacific.  Over the last two decades they have invaded the eastern U.S. Coast and the Caribbean. I have personally witnessed them on dives from North Carolina to Belize.  The when, where, and how of this lionfish invasion remains somewhat of a mystery. Lore based on second knowledge has it placed to the Florida coast when in 1992 Hurricane Andrew destroyed an aquarium.  Later that year, six lionfish were potentially accidentally released in Biscayne Bay. But NOAA ecologist James Morris found documentation of them off the Florida coast in 1985, most likely dumped by an owner who had lost interest. Earlier this year, I edited a paper for the Journal of Biogeography by Ricardo and colleagues examining the genetics of invasive lionfish.  Their paper adds another piece to the overall puzzle suggesting that DNA evidence ties the expansion of lionfish throughout the Caribbean to a single invasion event as opposed to multiple introductions.

The video above is extremely alarming for the density for lionfish at a single location.  Hat tip to Aeolius for a link to the video and article.  Put your total counts of lionfish in the video below.

The post Scuba Diver Discovers Airplane and Haven for Lionfish first appeared on Deep Sea News.

Eric Heupel is a graduate student at University of Connecticut in Oceanography. He keeps a personal blog at Eclectic Echoes and Larval Images, and used to part of The Other 95% team along with me before we closed shop. You can find Eric tweeting as @eclecticechoes.

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Hey folks, Kevin asked me to do a stint as a guest blogger here at DSN. Right now I am writing this from South Water Caye in Belize, so this entry is going to be decidely less “Deep” than the normal posting at DSN. Unfortunately I’ll also have to submit it to Kevin after I get back stateside since there is no internet here on the island! (Strangely I love that!)

My advisor runs a Reef Fish Ecology class every two years so my lab mate (Tori) and I have to come down here as TA’s for the field research portion of the class. It’s a great job, but it is also work. Up at the crack of dawn and working until well past 10pm. Sunburn, mosquito bites, no air conditioning, no cell phone, no internet. On the plus side of course is the whole tropical isle thing, plus the reefs and animals surrounding us. Great tunes and a bit of One Barrel in the evenings doesn’t hurt either.

Our lab focuses on fish ecology and conservation so this class is directly related to our studies. In years past Peter has had students come up with studies related to patterns of diversity, territoriality (damselfish are amazing for this) and social foraging. This year the theme was “Seascape of Fear” with student groups creating studies to explore topics related to predation rates, piscivore feeding groups, reaction of fish to snorkel censusing etc. While helping the students (and counting snorkels) Tori and I were able spend a bit of time getting some snapshots and making observations that may turn into future project ideas for the lab or the next iteration of the class.

For me the “Seascape of Fear” was clearly defined by one animal. Not sharks or moray eels (usually the more feared tropical fish), for me it was a beautiful fish that at a stretch reaches 18″ long – the Indo-Pacific Lionfish (Pterois volitans).

Both Tori and I took the same class as undergraduates – I took the first offering of the class in 2007, while Tori went on the next trip in 2009. Neither of us spotted a single Lionfish the entire time we were in the water for either trip. This year however, we spotted a lionfish under the dock on the first evening on the island. I feared, correctly, that this was only a sign of things to come. Soon enough our worst fears were confirmed with lionfish being spotted in the coral rubble and patch reef right off South Water Caye. I counted 13 lionfish in a two hour active search (snorkeling though) over a small area of patch reefs about 100 square meters. There were four of them living in crevasses in one coral head about 3′ high and 5′ diameter. We found them on every dive, at 8 different dive sites, in mangroves, rubble, patch reef, continuous reef and in the seagrass covered rubble at the edge of a sinkhole.

If you’re not up to speed on the lionfish invasion, they were originally spotted off Southern Florida in 1992. By 2000 they were confirmed from Florida to North Carolina and in Bermuda. They now occur throughout much of the Caribbean and up the Atlantic Coast to Long Island Sound and southern Massachussetts. There is debate about how far north there is a year round population, as they have a minimum temperature of ~10°C. They have even been found by divers  at 400′ depths, which unfortunately also implies we will not be able to get them all, even if we decided to try.

The lionfish are predators and share a trophic level with many ecologically and commercially important species such as snapper and grouper. In a long-term evaluation of lionfish diet in the Bahamas, J.A. Morris found that they ate mostly bony fish such as gobies, wrasses, basslets, cardinal fishes and damselfish (all reef favorites!). Eating up to 20 fish in a 30 minute period these voracious predators are crowding out native predators through competitive exclusion and some evidence suggests they have become the dominant forage fish consumer in some areas. Smaller lionfish also eat crustaceans including shrimp and juvenile lobster. Unfortunately there have been few reports of anything in the Caribbean eating lionfish, except perhaps other lionfish.

Of course one of my major interests is the larval and juvenile stages of marine animals, and the lionfish is no disappointment here. After reaching sexual maturity it is thought the lionfish can potentially release in excess of 30,000+ eggs every other month. After fertilization by the male, the eggs drift in the currents for 3-5 days when the larvae emerge and begin hunting ciliates in the plankton. Larval duration is still being studied but it is believed that larvae continue to drift in the currents for another 3-5 weeks before settling out at about ~10mm length. This planktonic duration was sufficient to allow the lionfish to throughout most of the Caribbean and up the eastern seaboard in a very short time. The genie is well and truly out of the bottle now, no putting it back.

The best (only?) option at this point may be to create a viable fishery for the lionfish and eat our way out of the problem. In Florida this past fall I had the pleasure of trying them. They have a nice white flesh suitable for sushi, ceviche, filets or maybe frying whole with the fins spread wide for presentation Umph. Maybe culinary geniuses like Bun Lai from Maya’s Sushi in New Haven can help create a demand for the new Atlantic stocks of Indo-Pacific Lionfish.

Next time I’ll cover some of the other things I/we do in this lab including some work on deep sea conservation issues.

References:

Morris et al. (2009) Biology and Ecology of the Invasive Lionfishes, Pterois miles and Pterois volitans. Proceedings of the 61st Gulf and Caribbean Fisheries Institute pp. 409-414

Morris, J., & Akins, J. (2009). Feeding ecology of invasive lionfish (Pterois volitans) in the Bahamian archipelago Environmental Biology of Fishes, 86 (3), 389-398 DOI: 10.1007/s10641-009-9538-8

Shanks AL (2009). Pelagic larval duration and dispersal distance revisited. The Biological Bulletin, 216 (3), 373-385 PMID: 19556601

The post Scientist in Residence: My ‘Seascape of Fear’ first appeared on Deep Sea News.

Feed a fish a fish, it eats for a day; Teach a fish to fish, it eats forever. That basically seems to be the crux of a discussion currently playing out on NOAA’s online Coral List after my colleague and pal, Dr Melanie McField, posted the following field observation:

“Last week I had an amazing dive in Roatan during which a Nassau grouper and Mutton snapper closely followed our fearless lionfish hunter–and the Mutton snapper actually ended up eating the lionfish (after it was speared and offered). I think this record will increase the number of species that are confirmed to consume [lionfish].”

“Fish eats fish” is hardly news. What does make this newsworthy is that the fish being eaten is an invasive species, a venomous Red lionfish (Pterois volitans), that heretofore was believed to have no natural predatory controls in its new range.

Below is the video of the diver spearing the lionfish in Honduras (with filming and entertaining post-production by Melanie):

Melanie provides further details of the incident:

“In the video, you can see a licensed lionfish hunter feed a speared (and dead) lionfish to a Mutton snapper, as an interested Nassau grouper looks on. …The incident occurred about 15 minutes into the dive. The Nassau grouper began following Ian about 5-10 minutes into the dive and the Mutton snapper joined along shortly after. Both fish seemed particularly interested in following Ian and watching the spear keenly. Spearfishing is banned in Honduras, and the fish show no fear of the spear or the divers in general. In response to the lionfish problem authorities are allowing [resource] managers like the Roatan Marine Park to license certain trained individuals to use special lionfish spears to remove lionfish from the reef inside and outside the Roatan marine park. Both fish [grouper, snapper] were approximately 30-40cm length.”

Longtime readers will recall that I’ve been following the spread of lionfish, a venomous fish native to the Indo-Pacific, throughout the Caribbean. While no one is certain how the species was first introduced into the Caribbean, what is startlingly clear is the rate at which the lionfish has expanded into new territory. From initial sightings documented in The Bahamas, the venomous species is now found throughout the Greater Antilles, the entirety of the Mesoamerican Barrier Reef system, and as far as the northern coast of South America.

The explosive expansion of Caribbean lionfish is in part attributable to the super-fecundity of the species.  Lionfish are essentially swimming Xerox machines. NOAA researchers have determined that lionfish reach sexual maturity within two years and spawn multiple times during the spawning season, which may be year round. Each spawn can produce up to 30,000 eggs.  But successful lionfish expansion has also been a function of the lack of predator species in the Caribbean that recognize lionfish as food.

Research by Dr. Mark Hixon of Oregon State University, a scientist at the front lines of this invasion, has already determined that within a short period after the entry of lionfish into an area, the survival of small reef fishes is slashed by about 80 percent. Aside from the rapid and immediate mortality of marine life, the loss of grazing fish will also set the stage for seaweed to potentially overwhelm the coral reefs and disrupt the delicate ecological balance in which they exist.

I called Mark Hixon in Oregon to get his reaction to the report of Caribbean lionfish predation.  In short, Dr. Hixon considers the news, “Fantastic!”  He thinks that we may be approaching a tipping point where native predators begin to regard lionfish as potential prey.  Hixon explained that he has seen cases on Little Cayman of large Nassau groupers, trained by dive operators on the island to accept food from divers, accepting both dead and living juvenile lionfish.  “Nassau groupers are documented to possess the capacity to be trained,” commented Hixon,  “I have seen studies where naive native specimens who do not see lionfish as prey can learn to accept them as food. So there is definitely a possibility to train or condition large predators to see lionfish as prey.”

Training predatory fish like groupers to eat lionfish may involve something as simple as which end of a lionfish to eat first.  The image at the top of this post from Florida Sportsman shows what appears to be a very sad Nassau grouper with the head of an adult lionfish sticking out of its mouth.  “That would be the wrong way to eat a lionfish,” commented Dr Hixon.  As the lionfish’s toxic dorsal fin spines point tailwards.  “I would imagine that grouper will never eat a live lionfish again.”

Mark Hixon thinks divers could potentially habituate a group of what he calls “Teacher Groupers” to recognize lionfish as food. These Teacher Groupers in turn habituate other groupers in lionfish predation.  While Hixon had not heard of cases of Mutten snapper being trained, he was willing to explore possibilities with this species as well. Sort of The Manchurian Candidate meets Finding Nemo.

According to Dr. Melanie McField, dive tourism guides from Roatan, Honduras, have anecdotally reported seeing numerous reef species consuming speared lionfish, including several species of groupers, snappers (including mutton and yellowtail) spotted and green moray eels, and Grey reef sharks.

Not everyone is so quick to jump on the Teacher Grouper bandwagon.  Shortly after Melanie posted her observation on NOAA Coral List, a few concerns were raised.  One in particular cautioned,

“It is not a good idea to feed local fish speared lionfish.  First and foremost, you have no idea if the fish that eats the lionfish is going to catch a barb internally and end up dying from the toxic reaction at a later point.  Secondly, teaching any wild animal to follow spearfishermen to obtain a meal is asking for future trouble (both to humans and for the wild fish that becomes dependent on humans for food).  A much better practice is to remove the spines (with surgical snips) and carry the lionfish  back out of the water.”

All valid points.  But this incident still illustrates the importance of serendipitous field observations in  identifying potential pathways to conservation and the management of biological invasions such as the Caribbean lionfish.  Up till now, natural resource managers in the Caribbean have felt woefully outmatched in attempting to control reef and fisheries damage resulting from invasive lionfish.

“The scientific community still has a lot to learn about lionfish,” said Dr Mark Hixon, “What are their natural controls in the Indo-Pacific? We know their parasite loads are much less in the Caribbean vs their Pacific counterparts, so perhaps the Caribbean parasite community still doesn’t recognize lionfish.  And the much greater fish diversity in the Indo-Pacific may mean there is a greater suite of small fish predators that catch lionfish larvae.”

Plenty of fodder for new research. But aside from all of these ecological considerations, I like Melanie’s story of a native reef species eating an invasive for a wholly other reason as well.  If native Caribbean fish can actually learn to prey upon lionfish, it becomes the quintessential underdog story. A home team comeback tale. I can almost hear the music from Rocky swelling in the background.  There’s a certain poetic justice and satisfaction in the idea that invasive lionfish control could get a boost from some very clever Caribbean natives.

Sources:
Florida Museum of Natural History
SafeSpear: Frequently Asked Questions About Lionfish”
NOAA Coral Reef Information System
Coral Magazine: Lionfish Spread in the Caribbean

The post What’s Eating You? first appeared on Deep Sea News.

The latest PSA from filmmaker/scientist Randy Olson.

The post Kill It And Grill It first appeared on Deep Sea News.