Deep Ocean Diving

- Exploring the deep sea and the ocean in general,

is always something special. The most pictured deep sea creature is possible the Angler fish a real deep sea animals of a very strange appearance.  But they are not the only deep sea water creatures there are plenty of others such as the deep sea monster, the octopus and giant squids. But deep sea life is probably not dominated by those sea monsters, its dominated by very small deep sea animals which move around in the total darkness, this includes some sharks. Many deep sea creatures found their habitat around a hydrothermal vent supplying minerals and nutrition. Lots of ocean diving is going on today to find raw materials on the ocean floor and mine them, the most popular is without any doubts crude oil which is already explored down to about 5000m depth.

Actually almost all discoveries of strange deep sea creature is somehow related to the technology built and financed by the oil industry which is a rather good example how private companies can do their share to the understanding of the deep ocean. Deep Sea Exploration is usually done by submersibles because nothing else has any chance to survive the immense pressure of the deep ocean.

Deep sea diving means diving into the dark by any means since its real dark below about 40 meters. Ocean diving with a submersible or dive robot has already reached the deepest trench which is the Mariana Trench just east of the Mariana Islands in the Pacific Ocean. The deepest part of the Mariana Trench is the Challenger Deep named after the dive vessel Challenger II,  a sea lab created by Swiss scientist Jacques Piccard. The Challenger II explored the deep of the ocean and measured 10,900 meters or 35,760 ft by a echo sound system at the Challenger Deep.

The deep-sea ecosystem and almost everything down there into the blue or rather

The magnitude of this diversity was not fully appreciated until extensive sampling of the Atlantic continental slope of the United States was undertaken in the 1980s by author Grassle's lab at WHOI and Nancy Maciolek's and Jim Blake's lab at Battelle Ocean Sciences. These samples were collected using a device called a box corer, (see photo on page 27), which collects quantitative samples of benthic organisms, including fauna that were not effectively sampled using previous gear.

the deep sea ocean!

Very few individuals are qualified to undertake identification of species in even one of the groups of deep-sea animals, and we were fortunate to have a high proportion of the world's deep-sea taxonomic experts working on this project. It is very difficult to find support for deep-sea systematizes, and this is one reason for a critical shortage of trained taxonomists. The numbers of species in this sampling area alone invite comparison with rainforests. Initial estimates by Terry Erwin (Smithsonian Institution) of tens of millions of species of insects and spiders in rainforests were based on his finding 1,080 species of beetles from 50-meter transects in four different types of forest within a 70-kilometer radius of Manaus, Brazil. We must point out, however, that most of the species found in both deep-sea and rainforest samples are very rare, while in most ecosystems a given sample will often yield a number of individuals of each species. It is very difficult to estimate total numbers of species for both the deep sea and the rainforest.

Because the composition of macro faunal species has been looked at in very few other quantitative or qualitative samples from the deep-sea floor, and the deep sea is so vast, it is not easy to contemplate what we may eventually find. Recent quantitative studies off southeastern Australia and off California, although less extensive, indicate that similarly diverse communities, made up of almost completely different species from those found off the US East Coast, occur in other regions of the deep sea. In addition, John Lambshead (Museum of Natural History, UK) suggests that the number of deep-sea species of smaller multi-celled animals (the meiofauna) is

even greater than the numbers of macrofauna. Not all deep-sea biological communities are species-rich. Hydrothermal vents are often described, again in sources ranging from the popular literature to university texts, as "oases in the ocean desert." When they were first discovered in 1977, hydrothermal vents generated great excitement because they indeed appeared as "oases" with high densities of extraordinarily large individuals. Organisms included new families and genera of organisms such as tube worms over 2 meters long and clams with shell lengths in excess of 25 centimeters. Nothing like it had ever been observed in the deep oceans, and the hydrothermal vent ecosystems remain among the most spectacular and fascinating on earth. Although the life forms discovered there are extremely unusual, the high temperatures and hydrogen-sulfide content of active-vent water combine to create a habitat that is inhospitable to most organisms.

Thus, species diversity at hydrothermal vents is quite low, with only a handful of extraordinarily adapted species able to thrive under the harsh conditions. Hydrothermal vent ecosystems are an "oasis" in terms of biomass and density of organisms, but in terms of species diversity they are extremely poor relative to other ecosystems.

- Given the physically harsh nature of hydrothermal vents,

it is hardly surprising that relatively few species are able to live there. The same is true for other deep-ocean habitats that present physically harsh or extreme environments. Deep-sea trenches, which are subject to frequent catastrophic sediment slumping, have relatively low diversities. David Thistle and co-workers (Florida State University) sampled an area of the bottom southeast of Nova Scotia subject to intensive underwater storms and strong bottom currents and found generally low diversity (though meiofaunal organisms were somewhat diverse).

and co-workers (Institute of Oceanographic Sciences, UK) in the northeast Atlantic revealed strong seasonal pulses of phytoplankton detritus sinking from surface waters to the sediment at depths of up to 4,100 meters. In addition to the seasonality of detrital input, these researchers also observed spatial variability in patch distribution.

As sampling frequency and spatial coverage in the deep sea increases, so does our perception of the heterogeneity of deep-sea ecosystems. For example, samples collected from the equatorial Pacific by Craig Smith (University of Hawaii) have revealed a similar heterogeneity in food supply to the benthos. This heterogeneity is now thought to be a critical factor in sustaining the diversity of deep-sea life. There is little doubt that food is in short supply in deep-sea communities, but it now appears that what is available may be extremely patchy in space and time.

One theory holds that the deep sea may be species rich with plenty of deep sea creatures because of small-scale patches created by events such as phytoplankton

and deep sea ocean bacteria  blooms; the sinking of fish carcasses, pieces of wood, or seaweed; small-scale physical disturbances created by fish feeding; and polychaete fecal   mounds. These patches create microhabitats that certain species may be able to utilize better than other species. The shifting mosaic of small-scale patches that occurs over the deep-sea floor may allow coexistence of all sorts of different species that would otherwise be competing for extremely limited food resources. In shallow water, physical events such as storms and tides tend to obliterate patches quickly so they cannot offer the same habitat heterogeneity as in deep-sea ecosystems.

In 1989, we conducted a series of experiments that were designed to determine whether different types of potential food patches in the deep sea would attract different organisms. A number of past studies show that pulses of organic matter attract a specialized fauna, but we reasoned that if small-scale patches were to serve as a mechanism for enhancing diversity, then different

Deep sea fish