User:Lanemk/sandbox

Article Ideas
- rain ratio

- ocean chemistry

- Aleutian Current

- forams

- mesopelagic zone

Article Evaluation
- Forams: this page is pretty good. I think jumping straight in to a lengthy taxonomic list is a bit unwieldy. I would have put that later. I think there is lacking information on the paleoclimate and paleoceanography uses of forams. They discuss deep dwellers but don't mention planktics or benthic forams. Finally, the algal symbionts are only alluded to.

Overview
The "Twilight Zone" 200-1000m

Ecology [edit][edit]
''Although some light penetrates the mesopelagic zone, it is insufficient for photosynthesis. The general types of life forms found are daytime-visiting herbivores, detritivores feeding on dead organisms and fecal pellets, and carnivores feeding on those detritivores.[2]Phytoplankton do not inhabit the mesopelagic layer, due to lack of light.[3] The biological community of the mesopelagic zone has adapted to a low-light, low-nutrient environment.''

''Examples of animals in the mesopelagic zone are bristlemouth, swordfish, squid, wolf eels, cuttlefish and other semi-deepsea creatures. The bristlemouth is the Earth's most abundant vertebrate, numbering in the hundreds of trillions to quadrillions.[4] The small amount of sunlight is sufficient for animals, such as the chain catshark, to be fluorescent.''

Microbial and metazoan ecology[edit]
Microbes and metazoans in the mesopelagic zone play a very important role in recycling organic matter from the surface ocean, known as the biological pump. This is a very efficient ecosystem with many organisms recycling the organic matter descending from the epipelagic zone. Overall, biomass typically declines exponentially with depth in the mesopelagic zone. However, microbial diversity has been shown to increase with depth in some locations. Viruses and microbes communities also show vertical stratification, with Crenarcheota comprising 40% of picoplankton. These different communities can take advantage of the different levels of nutrients and light. Biomass is also higher at higher latitudes, decreasing towards the tropics, likely linked to the productivity levels in the surface waters.

A diverse zooplankton community is associated with the mesopelagic zone. Many inhabitants of the mesopelagic zone also move between the epipelagic zone during the night, and retreat to the mesopelagic zone during the day to avoid prediction, known as diel vertical migration. Many squid have developed very sensitive eyes to pick up the limited available light. Bioluminescence is also very common in the mesopelagic, which is used for a variety of functions like communication, prey attraction and mating. Most life processes, like growth rates and reproductive rates, are slow. The mesopelagic shrimp-like mysid, Gnathophausia ingens, lives for 6.4 to 8 years, while benthic shrimp only live for 2 years.

Fish ecology[edit]
There are thirty families of mesopelagic fish. The dominant fish in the mesopelagic zone are lanternfish (Myctophidae.) They have prominent photophores along their ventral side. The Myctophid group includes 245 species distributed among 33 different genera.

Many organisms are black, because these colors appear black due to light penetration. Many fish also have rows of photophores, which are small light-producing organs, mirrors on their sides angled to reflect the surrounding ocean and protect the fish, or countershading, with light colors on ventral side and dark colors on the dorsal side.

Food is often limited and patchy, leading to dietary adaptions. Many fish have sensitive eyes, huge jaws and small bodies, reducing the effort put into building muscles.Adaptations include jaws that can unhinge, elastic throats, and massive, long teeth. Other predators develop bioluminescent lures, like the angler fish, that can attract prey.

Mesopelagic fish have a global distribution, except for the Arctic Ocean. Biomass estimates range, from 1 billion tons, but it is suggested to be the largest fishery in the world. Their numbers are often estimated by looking at echosounders and finding the 'deep scattering layer' through the backscatter received from these acoustic sounders.

This area could become a commercial fishery. (check Dani's section)