SCUBA Travel News

Census of Marine Life scientists have inventoried an astonishing abundance, diversity and distribution of deep sea species that live down to 5,000 meters (around 3 miles) below the ocean waves.

Revealed via deep-towed cameras, sonar and other technologies, animals known to thrive in an eternal watery darkness now number 17,650, a diverse collection of species ranging from crabs to shrimp to worms. Most have adapted to diets based on meager droppings from the sunlit layer above, others to diets of bacteria that break down oil, sulphur and methane, the sunken bones of dead whales and other implausible foods.

Edward Vanden Berghe, who manages the Census’ inventory of marine life observations, notes that the number of species recorded falls off dramatically at deeper depths – a function of the dearth of sampling in the deep sea.

While the collective findings are still being analysed for release as part of the final Census report to be released in London on 4 October 2010, scientists say patterns of the abundance, distribution and diversity of deep-sea life around the world are already apparent.

“Abundance is mostly a function of available food and decreases rapidly with depth,”
says Robert S. Carney of Louisiana State University, co-leader of the Census project
studying life along the world’s continental margins. “The continental margins are where we find the transition from abundant food made by photosynthesis to darkened poverty. The transitions display the intriguing adaptations and survival strategies of amazing species,” says Dr. Carney.

Abundance in the deep sea requires one or more of the following:
* Swift current, which increases an animal’s chance of encountering food;
* Long-lived animals, populations of which grow numerous even on a meager diet;
* Abundant food in higher layers that either settles to the depths or to which deep animals can migrate;
* An alternative to photosynthesis of food, such as chemosynthetic production.

At 1,000 to 3,000 meters (~.6-1.9 miles): NOAA researchers led by Mike Vecchione of
the Smithsonian Institution collected a very large specimen of a rare, primitive animal known as cirrate or finned octopod, commonly called “Dumbos” because they flap a pair of large ear-like fins to swim, akin to the cartoon flying elephant.

The jumbo Dumbo netted by Census explorers was estimated to be nearly two meters (~6 feet) long and, at 6 kg (~13 pounds), the largest of only a few specimens of the species ever obtained.

Altogether, nine species of gelatinous "Dumbos" were collected on the Mid-Atlantic
Ridge, including one that may be new to science. Scientists were surprised to find such a plentiful and diverse assemblage of these animals, which rank among the largest in the deep sea.

Further Reading:
Census of Marine Life

What do you think of this news item? Join a discussion.

The International Union for Conservation of Nature (IUCN) hopes that its new project will reveal the mysteries of southern Indian Ocean seamounts and help improve conservation and management of resources.

Two research expeditions will survey seamounts. These underwater mountains are magnets for marine life. The aim is to determine priority areas for the establishment of future marine Protected Areas, and improve the management and conservation of the ocean's species.

“It is critical that we get more information on the impact of climate change on these deep-water species, in order to help set up protective measures. Deep-sea species are particularly vulnerable to climate change” said Dr Alex David Rogers, Principal Scientist and Marine Biologist at the Zoological Society of London.

You can read about the expedition's progress on their blog at http://seamounts2009.blogspot.com/

IUCN is the world’s largest global environmental network - a union with more than 1000 government and NGO member organisations, and almost 11000 volunteer scientists in more than 160 countries.

What do you think of this news item? Join a discussion.

Swarms of miniature robotic ocean explorers that could one day help predict where ocean currents will carry oil spills, and which marine areas should be protected.

These autonomous underwater drifters will trace the fine details that can determine underwater ocean currents of a few kilometers. These are important for understanding marine protected areas, algal blooms, oil spills and the path sewage takes after it is pumped into the ocean.

"Maybe there has been an oil spill in the ocean and we want to establish very quickly how and where the spill might move. We are developing the algorithms that will keep a swarm of autonomous underwater explorers (AUEs) coordinated so they can follow the flow of the ocean currents and give us data on the spill as it is moving around," explained Jorge Cortes, a professor in the Mechanical and Aerospace Engineering Department at the UC San Diego Jacobs School of Engineering.

In addition to predicting where oil will travel, scientists can use this information on the flow of ocean currents in order to improve their models—and ultimately their understanding—of how ocean currents operate on the scale of kilometers and what this means for ocean life and for determining where marine protected areas should be established.

According to Jules Jaffe and Peter Franks, the two Scripps Institution of Oceanography researchers, the robot swarms could aid in science’s development of marine protected areas by following currents for determining critical nursery habitats and for tracking harmful blooms of algae.

The project differs from related work on networks of underwater robots in that the robot swarms the UCSD researchers are developing are significantly smaller and less expensive. At the same time, these robot swarms will be far more capable of making use of the information they collect on the fly in order to improve the accuracy of their task at hand.

Small armies of such robots will concurrently map currents and sense the environment. The robots relay their sensed data when they surface.

The robots will work through a system under which several football sized devices are deployed in conjunction with many—tens or even hundreds—of pint-sized underwater explorers. As they move about the ocean, the smaller-sized robots will use acoustic transmissions from the "motherships" to ascertain their positions. Collectively, the entire swarms of robots will help track fine ocean currents and flows that organisms at the small scale, tiny abalone larvae, for example, experience in the ocean.

"AUEs (Autoonomous Underwater Explorers) will give us information and statistics to figure out how the small organisms survive, how they move in the ocean and the physical dynamics they experience as they get around," said Franks. "AUEs should improve our ocean models and eventually allow us to do a better job of following the weather and climate of the ocean, as well as help us understand things like carbon fluxes."

Franks, who conducts research on marine phytoplankton, among other areas, says the new concentration on dense sampling at small scales will help resolve some of the patchiness in understanding the physical and biological properties on those scales.

"Plankton are somewhat like the balloons of the ocean floating around out there," he said. "We are trying to figure out how the ocean works at the scales that matter to the plankton. You put 100 of these AUEs in the ocean and let 'er rip. We'll be able to look at how they spread apart and how they move to get a sense of the physics driving the flow."

Further Reading:
UC San Diego Jacobs School of Engineering
National Science Foundation
Ocean Research Robots: A Future Vision for Ocean Observation

What do you think of this news item? Join a discussion.

Labels: environment, research, SCUBA News, technology

The National Science Foundation has announced agreement for vast undersea observing network. Called the Ocean Observatories Initiative (OOI) it will provide a network of undersea sensors for observing complex ocean processes such as climate variability, ocean circulation and ocean acidification at several coastal, open-ocean and seafloor locations.

Continuous data flow from hundreds of OOI sensors will be integrated by a sophisticated computing network, and will be openly available to scientists, policy makers, students and the public.

Advanced ocean research and sensor tools are a significant improvement over past techniques. Remotely operated and autonomous vehicles go deeper and perform longer than submarines. Underwater samplers do in minutes what once took hours in a lab. Telecommunications cables link experiments directly to office computers on land. At sea, satellite uplinks shuttle buoy data at increasing speeds.

What do you think of this news item? Join a discussion.

Labels: environment, SCUBA News, technology

A tracking study of white sharks in the northeastern Pacific Ocean shows they follow a rigid migration route across the sea, returning to precisely the same spot on California coast each time they come back. Over tens of thousands of years, this behavior has made the population in the northeastern Pacific genetically distinct from other white shark populations.

"White sharks are a large, highly mobile species," said researcher Salvador Jorgensen. "They can go just about anywhere they want in the ocean, so it's really surprising that their migratory behaviors lead to the formation of isolated populations."

Scientists with the Tagging of Pacific Predators (TOPP) program combined satellite tagging, passive acoustic monitoring and genetic tags to study great white sharks (Carcharodon carcharias) in the North Pacific. Details of their study are published in the Proceedings of the Royal Society B.

The fact that the northeastern Pacific white sharks undergo such a consistent, large-scale migration, and that they are all closely related and distinct from other known white shark populations, suggests that it is possible to conduct long-term population assessment and monitoring of these animals.

Barbara Block, professor of marine sciences at Stanford and a coauthor of the paper, said, "Catastrophic loss of large oceanic predators is occurring across many ecosystems. The white sharks' predictable movement patterns in the northeastern Pacific provide us with a super opportunity to establish the census numbers and monitor these unique populations. This can help us ensure their protection for future generations."

The researchers used a combination of satellite and acoustic tags to follow the migrations of 179 individual white sharks between 2000 and 2008. The tags reveal that the sharks spend the majority of their time in three areas of the Pacific: the North American shelf waters of California; the slope and offshore waters around Hawaii; and an area called the "White Shark Cafe," located in the open ocean approximately halfway between the Baja Peninsula and the Hawaiian Islands.

Genetics techniques were used to examine the relationships of the California sharks to all other white sharks examined globally. Studies of maternally inherited mitochondrial DNA sequences show that the populations are distinct, and suggest that the northeastern Pacific population may have been founded by a relatively small number of sharks in the late Pleistocene – within the last 200,000 years or so. The other populations of white sharks are concentrated near Australia and South Africa.

Depletion of top oceanic predators is a pressing global concern, particularly among sharks because they are slow reproducers. White sharks have been listed for international protection under the Convention on International Trade in Endangered Species (CITES) and the World Conservation Union (IUCN). Despite these precautionary listings, trade in white shark products, primarily fins, persists. Information on population and distribution of oceanic sharks is critical for implementing effective management efforts and the absence of such data impedes protection at all scales. Combining electronic tagging and genetic technologies can help protect sharks.

Further Reading:
Salvador J. Jorgensen, Carol A. Reeb, Taylor K. Chapple, Scot Anderson, Christopher Perle, Sean R. Van Sommeran, Callaghan Fritz-Cope, Adam C. Brown, A. Peter Klimley, and Barbara A. Block
Philopatry and migration of Pacific white sharks
Proc R Soc B 2009 : rspb.2009.1155v1-rspb20091155.

What do you think of this news item? Join a discussion.

Labels: marine biology, research, SCUBA News, sharks

The SCUBA Travel best selling diving books in the third quarter of 2009. Yet again the Dive Atlas of the World keeps its top spot. Previous quarter's position is shown in brackets.

1. Dive Atlas of the World: An Illustrated Reference to the Best Sites by Jack Jackson
   300 pages detailing some of the world's best dive sites. (1)
   
2. Fifty Places to Dive Before You Die by Chris Santella
   The fifth in Santella's bestselling "Fifty Places" series. (2)
   
3. Dive in Style
   by Tim Simond
   Luxury diving around the world.(3)
   
4. Coral Reef Guide Red Sea (Coral Reef) by Ewald Lieske, Robert Myers
   Covering jellyfish, corals, nudibranchs, starfish, sea urchins, fishes and turtles of the Red Sea. (5)
   
5. Coral Reef Fishes: Indo-Pacific and Caribbean by Ewald Lieske, Robert Myers
   A compact, guide to over 2000 species of fish you might see whilst diving on coral reefs. (6)
   
6. The Blue Planet DVD
   The BBC television series on DVD - action shots of the intriguing behaviour of the underwater world with commentary by David Attenborough. (--)
   
7. The Underwater Photographer: Digital and Traditional Techniques
   by Martin Edge
   Hints, tips and advice on taking underwater photos. (--)
   
8. Thailand (Lonely Planet Diving & Snorkeling Guides) by Tim Rock
   Dive sites of Thailand. Includes city guide to Bangkok. (10)
   
9. Top Dive Sites of the World by Jack Jackson
   With contributions from authors like Lawson Wood, Guy Buckles, Nick Hanna and Paul Naylor, focuses on 75 world-class dive sites in waters as diverse as the icy Northern Atlantic and the tropical seas of the Pacific. (--)
   
10. Diving and Snorkeling the Sea of Cortezs by Susan Speck
    91 Dive sites of Baja California described in detail. (--)
    

What do you think of this news item? Join a discussion.

Labels: books, SCUBA News, SCUBA Travel