Sunday, August 21, 2016

Satisfying the Demand for Dorys: UF Tropical Aquaculture Lab Successfully Breeds Pacific Blue Tang in Captivity

Satisfying the Demand for Dorys: UF Tropical Aquaculture Lab Successfully Breeds Pacific Blue Tang in Captivity

            A major breakthrough in saltwater aquarium fish reproduction took place at the UF Tropical Aquaculture Lab in July, as Rising Tide Conservation announced that for the first time, Paracanthurus hepatus, widely known as the Pacific blue tang or “Dory,” was successfully bred in captivity.

            Working in conjunction with the Oceanic Institute, which pioneered captive reproduction of the yellow tang just last year, Rising Tide Conservation and the UF Tropical Aquaculture Lab replicated and applied similar methods to crack the code for breeding and raising blue tang in captivity.

The significance of this breakthrough is apparent given the surge in demand for Pacific blue tang expected following the release of the Disney-Pixar movie “Finding Dory” on June 17, 2016. The animated hit movie has generated over $800 million at the box office, raising concern over the exploitation of real-life Dorys, the Pacific blue tang, a highly valued reef fish found throughout the Indo-Pacific.

The blue tang, like many popular ornamental fish species, is supplied to aquarists solely through the capture of wild specimens. In fact, according to CORAL Magazine’s list of captive-bred marine fish, only about 12.5 to 15 percent of commercially available aquarium fish species have been bred in captivity.

Aside from its high demand due to the “Finding Dory Effect,” the blue tang was also a major target for Rising Tide researchers because of concern regarding local overfishing and destructive capture methods, such as the use of cyanide. While cyanide use in tropical aquarium fisheries is banned in most countries, it is still practiced in countries like Indonesia and the Philippines, which serve as major sources for US imported aquarium fish. This chemical compound is used to stun fish for easy capture, however, it also poses a deadly threat to coral and other organisms that share the blue tang’s habitat.

While there is still plenty of work to be done before laboratory-bred Pacific blue tang make their way into aquarium stores, captive reproduction of the species may eventually curb the use of cyanide and lower the demand for wild-caught blue tang.

Throughout the world, marine biologists are searching for answers to similar concerns regarding hundreds of other overexploited fisheries. According to the World Wildlife Fund, over 85 percent of the world’s fisheries have been pushed to or beyond their biological limits. With the human population constantly growing, especially in less developed parts of the globe, fisheries will continue to be a vital food source for future generations. However, with so many fisheries already exploited at or beyond their capacity, we are left to wonder how the world’s growing seafood demand will be met.

            Aquaculture, the cultivation of aquatic organisms in natural or controlled environments, may be the only sustainable solution. According to the Food and Agriculture Organization of the United Nations (FAO), global fish production from wild capture has peaked at roughly 90 million tons per year since the early 90s. As demonstrated in the chart below, aquacultural production has also skyrocketed. While the field of aquaculture still has plenty of hurdles to overcome, organizations like Rising Tide Conservation and the Oceanic Institute have shown promise with their recent breakthroughs.

About the Author:

"August (Gus) Plamann is a South Florida native pursuing a bachelor’s degree in natural resource conservation at the University of Florida. With a background in sport fishing, he intends to focus his studies on fishery management, stock enhancement, gamefish biology, and marine habitat restoration. In his free time, Gus enjoys fishing, playing basketball, watching Gators football, and going to the beach whenever he gets the opportunity."

Thursday, August 18, 2016

Awe, Schucks: An Oyster Tasting Guide

Awe, Schucks: An Oyster Tasting Guide

Natalie Simon, University of Florida

The waiter sets your glass of wine on the table. First, you check its color, opacity, and viscosity. Then, you gently swirl the wine in your glass and inhale the fragrance, searching for subtle notes of flavor. Are there aromatic hints of fruit, herb, or earth? Next, you take a sip, and your palate observes the wine’s subtle texture. Your taste buds detect the delicate changes in salinity, sweetness, or bitterness. Lastly, you make an inference of the wine tasting. Did you like the overall flavor profile of the wine, the texture, the uniqueness? Much like sommeliers (certified wine tasters) take the time to taste a wine, oyster connoisseurs take the time to appreciate the flavor nuances of the oyster in a half shell.

In the United States, five species of oysters are harvested for human consumption: The Atlantic or East Coast (Crassostrea virginica), Pacific or West Coast (Crassostrea gigas), Kumamoto (Crassostrea sikamea), European Native or Flat (Ostrea edulis), and the Olympia or West Coast native (Ostrea conchaphila). Sadly, none of these oysters produce pretty pearls but they are jam-packed with vitamins and minerals and are farmed sustainably! In fact, 95% of the oysters consumed worldwide are cultivated using aquaculture techniques, making them an ocean-friendly seafood choice. The health and environmental benefits, along with unique and distinct flavors have made the oyster a popular dish among food enthusiasts.

Oyster production occurs worldwide, including China, Australia, South Africa, France, Argentina, Mexico, United States, and Canada. While the same species might be grown in different places, the unique environmental conditions in each country vary biologically, chemically, geologically, and physically, resulting in diverse and unique flavor profiles of the oysters produced (Just like wine!). In North America alone there are 300 unique oyster varieties. Rather than feeling overwhelmed by the immense selection available, focus on ordering a few oyster varieties, usually between 4 and 6, and make sure to order two of each. This will give you a better sense of the flavor diversities found in each oyster variety.

When tasting oysters, it is important to keep in mind that similarly to wine tasting, oyster tasting has its own etiquette for fully appreciating the flavors and textures cultivated by the oyster. First, look at the size and shape of the shell. Are there any grooves? Is it smooth or rough? What is the color of the shell? The color of the meat inside? Does the meat appear to be plump and juicy? Next, smell the oyster for an aroma. Does it remind you of the ocean’s scent? Is it sweet? Follow this by sipping the oyster liquor, which is the natural juice found inside the oyster. The liquor should not be rinsed or dumped out because it gives the taster a sense of the salinity or brininess. Finally, the moment we’ve been waiting for, slurp the loose oyster meat by tilting the flat edge of the shell to your lips and savor the moment. Chew the meat a few time to release its essences and give your taste buds the opportunity to get aquatinted with the aroma, texture, saltiness, and progression of flavors. You have now fully experienced what food critics call meroir, or the difference in flavor profiles due to growth in different geographical locations.  This means that even though the species of oyster is the same, the flavor profile could be subtly or drastically different depending on the environment it came from. If you ever taste an oyster and are at a loss for words to describe the flavor, try using Patrick McMurray’s Oyster Tasting Wheel!

So what are the possible flavors you could taste? Often times you hear terms such as oystery, salty, or fruity to describe the taste of an oyster. Some other terms include cucumber, melon, and honeydew notes.  When someone refers to an oyster having a cucumber finish they are referring to the fresh, green, bitter flavor. For example, fruity flavors are frequently used to illustrate the taste of Pacific Oysters and Kumamoto. Eastern oysters tend to be briny, crisp, buttery, and light bodied, whereas west coast oysters are minerally, creamy, sweet, and medium bodied. Particular oysters may also exhibit subtle notes of nutty, citrus, black tea, copper, and springy flavors.
Interested in developing and honing your skills as an oyster aficionado? Keep a record of your tasting in this handy dandy notebook!\  

Not so interested in eating raw oysters? Try Oyster Rockefeller! In this popular dish, the oyster is served in the half shell after being cooked and topped with various ingredients including spinach, parsley bread crumbs, cheese, bacon, and wherever your imagination takes you. Try this recipe and enjoy!

Are you a huge oyster enthusiast and want to learn more?! Check out these links:
• Real Life Oyster Connoisseur Julie Qiu:
• Oyster Variety Glossary:
• 7 Things You Need to Know About Oysters:

About the Author:
Natalie Simon is from the Jersey Shore and received her BS in Marine Biology from Stockton University. While working at Rutgers’s Haskin Shellfish Research Laboratory as a hatchery technician, she found her love for oysters. Not long after, Natalie moved to Gainesville to attend the University of Florida (UF) for her Master’s degree in Fisheries and Aquatic Sciences. Her research interests include cryogenics, germplasm preservation, and molluscan aquaculture. In her spare time, Natalie enjoys nature, coffee, Netflix and quality time with her bearded dragon, Hector.

Monday, July 25, 2016

The FAD Fad

Julie Brown, University of Miami

History of FADs
Fishermen have long known that floating objects in the ocean have a natural tendency to aggregate fish. They have been using natural Fish Aggregating Devices (FADs) for decades, usually logs. There are many theories to explain fish’s fascination with floating objects. One is that the FAD provides the only visual stimulus in the open ocean, where there is otherwise an endless void of blue. Another hypothesis is that floating objects tend to accumulate in convergence zones, where moving bodies of water come together. Convergence zones are relatively productive areas where particles can accumulate, which is good for fish trying to feed or spawn. FADs could be visual markers for these barely detectable changes in oceanic conditions. In modern times, fishermen take advantage of this phenomenon by placing artificial FADs in the ocean, and return when the object has accumulated a satisfactory amount of fish to harvest.

Fad design and technology
The earliest FADs were made of natural materials, such as logs, bamboo, and palm fronds. These materials, of course, degrade over time, and fishermen have upgraded to a variety of man-made materials such as netting. Modern FADs can either be anchored to the bottom, or drifting. The rest of this article will focus on drifting FADs.
Today, many FADs for commercial fishing are equipped satellite-linked echosounder buoys, which let fishermen remotely estimate the fish biomass around the FAD. They can accurately time their fishing operations to maximize harvest, and minimize search time. These ecosounders can only provide information about biomass, however; they cannot tell the size or species of fish. Scientists have demonstrated that there is a higher incidence in bycatch (non-target species or undersized tuna) when fishermen set their gear around FADs, as opposed to free-swimming schools of Tuna

                                          Photo credit:

Increasing trend in fads
In the past decade, the use of FADs has increased dramatically in the Tuna Purse Seine industry. In the Eastern Pacific alone, the number of FADs deployed by this industry jumped from 8,006 to 13820 in seven years. And this only includes reported FADs. The actual number is probably higher, because the regional fishery management organization, IATTC (Inter-American Tropical Tuna Commission), does not require smaller vessels to report FAD use. The Pew Research Center
estimates that FAD use is also increasing in other oceans, although not quite as dramatically. The use of FADs now dominated the Tuna Purse Seine industry, which accounts for over 60% of the world’s tuna landings.
Ecological trap?
Around 1999, scientists began to question whether FADs could alter the biology and ecology of pelagic fish species (Marsac, Fonteneau et al. 2000). The ecological trap theory suggests that FADs, which are often seeded in offshore areas, attract and retain fish to areas that aren’t suited to their survival and reproduction. In fact, when tuna associated with a FAD were sampled, and 85% of them were shown to have empty stomachs, while only 25% of tuna from free-schools had empty stomachs (Ménard, Stéquert et al. 2000). Other studies, however, show conflicting evidence that the presence of a FAD has no effect on the body condition or lipid content of tuna (Robert, Dagorn et al. 2014). The verdict is still out for this hypothesis, and more studies are needed.

Stock hyperstability
Tuna fishing becomes significantly more efficient (more biomass harvested per “haul”) when FADs are used to congregate the schools. The schools are easier to locate, and less time is spent searching for fish. Free-swimming schools tend to be more sparsely distributed, travel faster, and are harder to spot. In other words, this technology increases the Catch and decreases the Effort. Because scientists use an index called Catch Per Unit Effort (CPUE) to estimate the status of fish stocks, an error in this calculation could occur if the technological advancements are unaccounted for. This phenomenon is called stock hyperstability, and it doesn’t just occur in the Tuna industry. Generally, we assume that CPUE and stock abundance follow a linear trend over time. Basically, if it becomes harder to catch as many fish, it’s because there are proportionately less fish available. FADs, however, congregate the few remaining fish, and they are easier to catch than they would otherwise be. This can mask the effects of overfishing.

Marsac, F., A. Fonteneau and F. Ménard (2000). Drifting FADs used in tuna fisheries: an ecological trap? Pêche thonière et dispositifs de concentration de poissons, Caribbean-Martinique, 15-19 Oct 1999.
Ménard, F., B. Stéquert, A. Rubin, M. Herrera and É. Marchal (2000). Food consumption of tuna in the Equatorial Atlantic ocean: FAD-associated versus unassociated schools. Aquatic Living Resources 13(4): 233-240.
Robert, M., L. Dagorn, N. Bodin, F. Pernet, E.-J. Arsenault-Pernet and J. L. Deneubourg (2014). Comparison of condition factors of skipjack tuna (Katsuwonus pelamis) associated or not with floating objects in an area known to be naturally enriched with logs. Canadian journal of fisheries and aquatic sciences 71(3): 472-478.