Hollywood, U.S.A. - Jenny Fenton is passionate about swordfish. After all, they are a top ocean predator whose survival is vital to balancing the ocean’s ecosystem as well as being an important food source.

But years of overfishing in the Florida Straits — where America’s swordfish nursery is located — have depleted their population. So much so that long line fishing gear is now outlawed in the Straits and juvenile swordfish caught there measuring 47 inches or less must be released. Long line gear uses up to 1,000 hooks strung on a single line to catch large quantities of fish.

Fenton, a graduate student in marine biology at Nova Southeastern University’s Oceanographic Center, decided to make her passion a research project. During the last two years, she has been analyzing the survival rates of juvenile swordfish caught by fishermen using rod and reel and buoy gear. Her research is the first study of its kind.

Of the 20 satellite tags she plans to put on the captured fish, data from 16 have been analyzed. Five of the fish have died within a day, while nine survived without problems.

Her findings are important because the federal government is considering a measure that would allow recreational fishermen to catch swordfish for commercial use. If that happens, the number of juvenile swordfish caught could skyrocket in the Florida Straits, which goes through South Florida. Most of the adult swordfish found in waters throughout the Eastern Seaboard were born in the Florida Straits.

Swordfish were once abundant in South Florida. However, long line fishing gear dramatically depleted the species. In response, federal authorities banned this type of gear in the Florida Straits in 2001.

In 2003, a limited swordfish buoy gear fishing method developed in the Straits that uses only about 15 single hooks and float combinations, near the ocean’s surface. However, NSU Oceanographic Center research Scientist David Kerstetter, Ph.D., Fenton’s graduate advisor, conducted a study from 2007 to 2010 that found a few juvenile swordfish deaths from the buoy gear.

More than a decade after the long line ban, local swordfish stocks have returned to healthier levels. However, catch-and-release fishing has resulted in some dead swordfish. A potential decision to allow recreational fishermen to sell their catch commercially would put more juvenile swordfish at risk.

Fenton, whose study is sponsored by the NOAA Fisheries Service, will share her data with the federal agency. Then it will be up to resource managers to decide whether allowing swordfish anglers to sell their catch commercially is worth the fishing pressure it would put on their nursery grounds.

“This has been a fascinating project working with such an important species to both recreational fishing and the commercial fishing industry,” Fenton said. “I hope my data will be used to sustain healthy populations of swordfish for future generations to enjoy, as well as balancing the ecosystem.”

Fenton, who is using this project as her master’s thesis, said the four remaining tags will be deployed soon.

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This early January, a team of marine scientists discovered a new species of life in a most unlikely place: on the ocean floor, hidden from sunlight and steeped in pressures of thousands of pounds per square inch, swarming around vents that spurt scorching water.

Boarding the vessel, Atlantis, the team – led by marine biologist Dr. Jon Copley and marine geochemist Dr. Doug Connelly – descended five kilometers to the Cayman Trough, located south of the Cayman Islands in the Caribbean. At the Cayman Trough, like at other trenches, two tectonic plates are slowly shifting apart 0.6 inches or 15 mm per year, producing fresh ocean floor. Hydrothermal vents often sprout at trenches due to the volcanic activity occurring below.

Found commonly in ridges, they are essentially seafloor chimneys – as tall as ten meters – that spew mineral-filled water, whose temperatures range from 300 to 400° C (600-750° F). Their heat comes from magma chambers under the ocean floor. Upon reaching their destination, the marine scientists were surprised to see two hydrothermal vents that were six meters tall. The team did not expect to find vents because it was thought that they did not exist in the area.

This type of vent, known as a “black smoker vent,” gushes 450° C (~850° F) water, filled not only with minerals, but with metallic particles, making the water appear smoky. The explorers named the vents the Beebe Vent Field, after William Beebe, an American scientist who was the first deep-sea explorer. The team was surprised even further when they spotted a new species of shrimp clustering (2,000 per square meter) around the vents and feeding on the minerals.

In lieu of eyes, the ghostly white shrimp have a light-sensing organ on their backs to help them navigate through the dim glow emanating from the vents. Furthermore, white anemones were found laying on the sea floor, where they fed off of the copper-rich water that seeped through. In a previous expedition, the team also found vents around Mount Dent (3 km high), an underwater mountain located at the Cayman Trough.

“Finding black smoker vents on Mount Dent was a complete surprise,” Dr. Connelly says in the National Oceanography Center news release. Dr. Connelly works at the National Oceanography Center. “Hot and acidic vents have never been seen in an area like this before, and usually we don’t even look for vents in places like this.”

With their finding vents at Mount Dent and now at the Cayman Trough, the marine scientists surmise that there is more volcanic activity in the ocean than previously thought. Recently, another team of scientists discovered new species of crab and octopus – called the yeti crab and the pale octopus, respectively – hanging around vents in Antarctica.

With the combination of the discovery of life at the bottom of the Antarctic and at the Cayman Trough, marine scientists all over the world are expanding their perception of what sorts of conditions life can thrive in, especially in the deepest parts of the oceans. “Studying the creatures at these vents and comparing them with species at other vents around the world will help us to understand how animals disperse and evolve in the deep ocean,” states Dr. Copley of the University of Southampton, United Kingdom.

“One of the big mysteries of deep-sea vents is how animals are able to disperse from vent field to vent field, crossing the apparently large distances between them,” he adds. “But maybe there are more ‘stepping stones’ like these out there than we realized.”

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