North Atlantic's Hydrothermal Vents: Irish expedition sets out to study the Mid-Atlantic Ridge

Marine scientists have examined some of the world's deep ocean thermal vents that harbor remarkable sealife found no where else on the planet. Living without sunlight, sometimes in temperatures that could bake bread, bacteria, worms, and crabs flourish at the site of these vents which often spew what looks like smoke but is actually a rich cocktail of minerals. The vents typically exist along fault lines that run deep in the ocean.

Running basically down the center of the Atlantic ocean is the Mid-Atlantic Ridge and scientists from Ireland are preparing to study the northern portion of the ridge, in search of deep water corals and thermal vents. Using a remotely operated vehicle (ROV), researchers from the University College, Cork and UK's National Oceanography Centre set out this past week to examine in greater detail the "45 degree North MAR hydrothermal vent field" which was first discovered in 2008. The ROV will be working at a depth of over 9,800 feet.

As reported in the Irish Weather Online, "'This expedition offers us the first opportunity to investigate mineral deposits and vent animals in this unexplored and important part of the Mid-Atlantic Ridge,' said Dr. Bramley Murton of the National Oceanography Centre, who is now leading the mineralisation study on the expedition. 'Nothing is known about the hydrothermal vents, their mineral deposits or the life they support on the Mid-Atlantic Ridge between the islands of the Azores to the south and Iceland to the north. Because this part of the ridge is trapped between these islands, vent animals may have evolved in isolation and be quite unique from elsewhere.'"

The expedition is being documented by National Geographic for an upcoming series on the ocean. Many of the research institutions involved are hoping that this research effort will help establish Ireland as a recognized deep sea science center. However, while a little nation pride can be a good thing, the focus of attention will be on the possible discovery of heretofore unknown animals. In addition, the economic potential of the types and quantity of minerals given off by the vents will be investigated.

It was always assumed that virtually nothing could survive in the deepest reaches of the ocean. But with the discovery of hydrothermal vents and deep water corals, scientists are having to re-write some of the rules as they continue to discover ecosystems based on entirely new biological principles.

Read about the expedition in the Irish Weather Online.

Ireland's Basking Sharks: a high percentage of a rare species

As a follow up to my post on wobbegong shark behavior: researchers in Ireland are studying their resident populations of basking sharks and, as with the wobbegong studies, are able to draw conclusions on changing environmental conditions based on changes in animal behavior.

At the 14th European Elasmobranch Association conference held in Galway, Ireland, marine biologists and shark experts from across Europe gathered to discuss the state of shark populations and consider new research techniques to better understand the fate and future of sharks and rays worldwide. Irish researchers who have been working with Ireland's National Parks and Wildlife Service, presented their study which indicated that a high percentage of the remaining number of basking sharks move through Ireland's local waters.

Basking sharks are typically a cold water species and the second largest fish on the planet, topped only by the whale shark. Like the whale shark, the basking shark is a filter feeder, opening its cavernous mouth to strain hundreds of gallons of water, searching for zooplankton - a collection of tiny creatures including larval or minute juvenile forms of fish, mollusks, and crustaceans. Zooplankton are sensitive to changes in the aquatic environment, such as temperature changes due to global warming or changes in oxygen levels or pH, which can occur in response to acidification. Where the zooplankton go, so go the basking sharks.

“Tracking basking sharks may be far more effective than tracking zooplankton, and [may] provide one of the best indicators of the health of our seas and thus the planet,” said Dr. Simon Berrow, the study's group leader.

Extensive tracking of basking sharks has taken place off of Ireland, replacing the intense hunting that used to occur as the basking shark was prized for its sizable supply of shark oil. Worldwide estimates of basking shark populations have been placed as low as 20,000. Extrapolating population estimates from the 250 sharks that have been tagged, the study claimed that there are probably several thousand that frequent the cold waters off Ireland's coast, making the island nation a prime location and home for an increasingly rare shark species.

Read about the research in Irishtimes.com.