amount of minerals
The major environmental factor limiting the numbers of autotrophs at great depths in the ocean is the amount of light reaching those depths
it's deep depths and tempretures
Modern sponges are predominantly marine, with some species adapted to freshwater environments, ranging from the inter-tidal zone to depths of 6,000 meters (19,680 feet). Certain types of sponges are limited in the range of depths at which they are found. sponges are worldwide in their distribution, and range from waters of the polar regions to the tropical regions. sponges are most abundant in both numbers of individuals and species in warmer waters.
It is essencial to photosynthesis, they way that autotrophs (basically) get their energy. Autotrophs are at the bottom of the food chain, so indirectly supply energy to everything else. In fact it may not be the sole source. Various species of life has been found in the ocean depths miles below the limit of sunlight penetration, fed by geothermal (volcanic) energy from fumeroles and 'stacks'.
Ctenophores are found in most marine environments: from polar waters to the tropics; near coasts and in mid-ocean; from the surface waters to the ocean depths.
Gneiss is more likely to form at great depths where mountains are being pushed up, typically in regions undergoing high pressure and temperature conditions associated with deep crustal or subduction zone environments. Shallow depths are more conducive to the formation of rocks like granite rather than gneiss.
Brown tube sponges (Agelas spp.) are primarily found in tropical waters, such as the Caribbean and the Indo-Pacific regions. They typically inhabit shallow coral reef environments, where they attach themselves to hard substrates like rocks or coral reef structures. Brown tube sponges can be seen at varying depths, from a few feet to over a hundred feet below the surface.
Into the Depths was created on 2004-08-23.
Depths of Peril happened in 2007.
Murky Depths was created in 2007.
The Depths of Time was created in 2000.
Into the Depths of Sorrow was created in 1991.