Showing posts with label deep ocean. Show all posts
Showing posts with label deep ocean. Show all posts

Wednesday, July 21, 2010

New Finds in Newfoundland: discoveries in cold Canadian depths

One often thinks of near-Arctic waters as not a likely environment for corals and sponges - or for much else for that matter. And if it's deep, when we think of life, we think of thermal vents and the temperatures and nutrients that spawn unusual species.

And yet, scientists and researchers from the Canadian Fisheries Department, Canadian and Spanish universities have discovered new coral and sponge species off the coast of Newfoundland - species whose coloration and beauty would befit a tropical reef.

Using a robotic submersible (ROV), the researchers plumbed the depths as deep as 9,800 feet (3 km) in an area protected by the North Atlantic Fisheries Organization. At these deep depths, species of coral, like gorgonian sea fans, grow extremely large (over 3 feet in height) and provide shelter for sealife and even protection from currents - much like trees.

As reported in the Montreal Gazette, according to Fisheries Department scientist Ellen Kenchington, “It’s a similar function a tree would serve in the forest, cutting down wind, providing branches for birds. We have the same type of communities that take shelter down there.”

As the researchers continue their work for the next few weeks, they will be assessing the condition of this protected area to determine whether additional sanctions are needed in other areas to better insure that populations of commercial fish remain at sustainable levels.

Click here to view a slide presentation of fascinating deep sea creatures.

Read article in Montreal Gazette. Photos by HANDOUT, Fisheries and Oceans Canada.

Sunday, July 11, 2010

New Deep Ocean Species: RRS James Cook studies the Mid-Atlantic Ridge

Perhaps you have heard it said that over 75% of the Earth's surface is covered by water but that we have explored less than 5% of the world's oceans. Some have said we know more about the backside of the moon than we do about the ocean depths right here at home.

Whenever scientists pull back the curtain and gaze into the depths, something new is always discovered - a new species, a new geographical formation, or a new process invaluable towards understanding the complex inner workings of marine ecosystems.

The renown U.K. research vessel, RRS James Cook, has recently released pictures taken of several potential new species from the ocean depths along the northern portion of the Mid-Atlantic Ridge. Using the ROV named ISIS, which was able to view the creatures alive and free swimming at depths as deep as 8800 feet (2700m), researchers from the University of Aberdeen noted the marked differences in sealife on either side of a 10-mile wide span of the ridge (where northern cold waters meet warmer southern waters).

Click here to view a series of images taken by ISIS, published in the Guardian.

The Mid-Atlantic Ridge actually is the meeting of two major tectonic plates in the Atlantic Ocean and runs a considerable distance beginning near Greenland and extending all the way into the South Atlantic, below Africa. Along the way, there are deep trenches and mountain ridges. In the past, scientists have trawled the bottom to see what type of animals live there, but such methods often did considerable damage to the specimens. With today's advanced submersibles and ROVs, researchers are now able to see these animals unharmed and living in their natural environment.

The deep oceans are a major part of the macro-marine ecosystem and so it is important that we study and gain a better understanding of these mysterious regions as to how they survive, how they interact with and impact shallower bodies of water, and how our activities can affect these great depths which, in turn, could alter the overall health of the oceans and the planet.

Saturday, July 10, 2010

Seen & Unseen: Dave Gallo talks about some of the ocean's amazing ways

Here's just a little reminder - a fun one - as to why the ocean and all the animals that call it home need our support in conserving and protecting this vital environment. David Gallo, Director of Special Projects for the Woods Hole Oceanographic Institution, is a great speaker and puts on presentations that always leave the audience in awe and amazement. Here is a wonderful video clip from 2007 given at a TED meeting (TED is an interesting organization, dedicated to Technology, Entertainment, and Design - which means a wide range of fascinating speakers and subjects):



Bioluminescence in the greater depths and a cephlapod's camouflage through manipulation of skin color and texture - two of nature's fascinating ways it perpetuates life in the aquatic kingdom.

Monday, May 31, 2010

Understanding Seamounts: More study of an oceanic oasis is needed

Seamounts are fascinating oceanic structures - mountains really, rising up from the sea floor, pushed up by volcanic forces. While a seamount that reaches the surface, thereby producing some sort of island formation, is still technically a seamount, scientists generally describe seamounts as submerged, typically rising 1,000 meters above the seafloor, thousands of meters from the surface.

I was reviewing several scientific papers about seamounts and how these unique structures carry significant ecological, commercial and conservation implications.

Ecological
Each seamount serves as an oceanic oasis, often harboring tremendous biodiversity including localized animals and pelagic species. Tuna, billfish, sharks, and other pelagic fish have been known to frequent seamounts. Studies are ongoing to determine whether such species are attracted due to food sources or whether the seamounts act as breeding grounds - or both. Studies have shown that pelagic biodiversity appears to be higher at locations further away from coastal habitats.

The somewhat isolated nature of seamounts makes them of special interest regarding genetic diversity and evolution. While challenging to study, one report called for more scientific research so as to better understand the interconnectivity within and between these unique ecosystems, particularly in the face of negative impacts from commercial fishing and mining.

"In fact, the large variety of interconnected mechanisms that promote or impede the genetic connectivity of seamount communities via dispersal (and the long-term maintenance of species or the subsequent divergence of populations leading to speciation) are key unknowns to understanding the fundamental evolutionary processes that structure both the diversity and biogeography of deep-sea fauna" from Seamounts: Deep-ocean laboratories of faunal connectivity, evolution, and endemism/Oceanography.

Commercial
Because of increasing demand for seafood and with stocks declining in other open water or coastal areas, seamounts have become targets for industrial fishing, and subject to bottom trawling and longlining.

Reported in Seamount fisheries: Do they have a future?/Oceanography, "Today, seamount fish populations are in trouble following a 30-year history of overexploitation, depletion, and collapse, with untold consequences for global biodiversity and the complex, delicate, but poorly understood, open-ocean food webs. We estimate present global seamount catches to be about 3 million tonnes per annum and increasing – vastly in excess of estimated sustainable levels."

In addition, because of the geological/volcanic nature of seamounts, they have an untapped potential for metals and minerals in the eyes of commercial mining companies. While the technology to obtain these ocean resources is still quite formidable, as terrestrial resources decline, commercial mining interests will ultimately make the effort to expand beyond current levels of mining activity.

Conservation
With commercial interests having an impact and the potential for even greater exploitation lying ahead, the need for proper management of seamounts is critical. But much still needs to be learned regarding these unique ocean formations. Current mapping techniques have only scratched the surface as to location and true number of seamounts. And while there have been many studies made of individual locations, according to one report, there is a lack of study to better understand the links between these formations, how they interact with each other, and what would be the consequences on the total marine ecology from negative impacts on individual locations. Seamounts may be relatively isolated but they do not exist within a vacuum.

"Extractive processes such as fishing and mining are degrading seamount ecosystems considerably, raising serious concerns about the impacts of these practices on global ocean biodiversity and key fluxes. Despite the data collected to date, we remain ignorant of the quantitative details of many of these issues," reports Can we protect seamounts for research? A call for conservation./Oceanography.

More understanding of seamounts is needed - individually and holistically - so as to develop proper management policies. Across the ocean floor, seamounts may serve as vital connected waystations that feed, foster, and perpetuate the entire oceanic web of life.

Order special issue on Seamounts from Oceanography. Click here.

Sunday, May 9, 2010

Colossal Squid: study suggests its not the aggressive monster of myth

There is so little that we know about the deepest recesses of the oceans. Our ignorance and our fears often unleash our imagination to conjure up the worst of monsters - not just in today's sci-fi movies, but for centuries man has felt that there are unspeakable horrors lurking in the ocean's blackness.

As many of my readers know, in March I was on assignment for National Geographic to film the jumbo squid, or Humboldt squid, in Baja, Mexico. Working with Scott Cassell of the Undersea Voyager Project, who has spent many years encountering and studying the jumbo squid, this was my first opportunity to meet these voracious predators on their home turf. I soon learned these are very aggressive animals that will attack just about anything if they think it means a potential catch.

There are actually three large species of squid - each with a name that one-ups it's smaller cousin. The jumbo squid, followed by the rarely seen giant squid, and topped by the even rarer colossal squid. Each squid is considered a powerful and aggressive predator based on what evidence was available on any of the species combined with anecdotal evidence such as bite markings on large whales, like sperm whales who, as one of the larger squids' natural enemies, are suspected of diving deep and hunting large squid using echo-location.

It is now being suggested in a recent scientific study, that the colossal squid, the rarest of the rare and the world's largest invertebrate, may not be as aggressive as our imaginations lead us to think. Reported in the BBC's Earth News, the study by Dr. Riu Rosa of the University of Lisbon and Dr. Brad Seibel of the University of Rhode Island suggests that the colossal squid just may turn out to be a slow moving, lies-in-wait ambush predator. This theory is based on metabolism studies of related squid species and then extrapolating those findings to account for the colossal squid's size, in addition to other factors, such as the cold temperatures in which the squid lives.

"Our findings demonstrate that the colossal squid has a daily energy consumption 300-fold to 600-fold lower than those of other similar-sized top predators of the Southern Ocean, such as baleen and toothed whales," says Dr Rosa.

Studies of trace isotopes in tissues samples from the few dead specimens of colossal squid that have been found, show evidence of one of the squid's primary food sources: the arctic toothfish. Based on that, the study determined that an 11-pound (5 kg) toothfish could nourish a 1000-pound (500kg) colossal squid for up to 200 days. It all makes reasonable sense. Given that the deep depths contains less large scale bio mass than in shallower, sunlight-bathed waters; a large predator would need to maximize its use of whatever it could catch, and a lower metabolism - which can equate into less activity - would be one way to accomplish that.

Nonetheless, based on the few specimens that have been examined, the colossal squid is a formidable source of nightmares and mythological legends. It can reach a length of possibly 50-feet (15m) from the tip of its large mantle to the end of its tentacles, equal in length to that of a sperm whale. And whereas the jumbo and giant squid have small teeth that ring each sucker disk on its arms and tentacles, the colossal squid has large, swiveling hooks to latch on to their prey. Yikes!

We know so little about the ocean depths. It has been said that we have more data about the backside of the moon than we do about the oceans depths that make up the vast water volume of our blue planet. The more we commit ourselves to studying it, the more we will learn what is happening to our fragile marine ecosystems and what we should do to protect them. And along the way, a few nightmares might get dispelled, a few legends might get rewritten.

All the same, I'll sleep with the light on tonight.

Read the complete article in the BBC Earth News.