the zone in the ocean that the majority of marine organisms are found is coastal habitats and coral reefs.
the zone in the ocean that the majority of marine organisms are found is coastal habitats and coral reefs.
where is the zone in the ocean that the majority of marine organisms are found?
coastal habitats and coral reefs
in the deep ocean, marine snow is a continuous shower of mostly organic detritus falling from the upper layers of the water column. it is a significant means of exporting energy from the light-rich photic zone to the aphotic zone below which is referred to as the biological pump. export production is the amount of organic matter produced in the ocean by primary production that is not recycled (remineralised) before it sinks into the aphotic zone. because of the role of export production in the ocean's biological pump, it is typically measured in units of carbon (e.g. mg c m d).the term was first coined by the explorer william beebe as he observed it from his bathysphere. as the origin of marine snow lies in activities within the productive photic zone, the prevalence of marine snow changes with seasonal fluctuations in photosynthetic activity and ocean currents. marine snow can be an important food source for organisms living in the aphotic zone, particularly for organisms which live very deep in the water column.
marine snow
for either aragonite or calcite, the two polymorphs of caco₃ produced by marine organisms, the saturation state of caco₃ in ocean water is expressed by the product of the concentrations of co₂²⁻ and ca²⁺ in seawater relative to the stoichiometric solubility product at a given temperature, salinity, and pressure. waters which are saturated in caco₃ are favourable to precipitation and formation of caco₃ shells and skeletons, but waters which are undersaturated are corrosive to caco₃ shells, and in the absence of protective mechanisms, dissolution of calcium carbonate will occur. because colder arctic water absorbs more co₂, the concentration of co₃²⁻ is reduced, therefore the saturation of calcium carbonate is lower in high-latitude oceans than it is in tropical or temperate oceans. in model simulations of the arctic ocean, it is predicted that aragonite saturation will decrease, because of an increased amount of freshwater input from melting sea ice and increased carbon uptake as a result of sea ice retreat. this simulation predicts that arctic surface waters will become undersaturated with aragonite within a decade. the undersaturation of aragonite will cause the shells of organisms which are constructed from aragonite to dissolve. this would have a profound effect on a large variety of marine organisms and has the potential to do devastating damage to keystone species and to the marine food web in the arctic ocean. laboratory experiments on various marine biota in an elevated co₂ environment show that changes in aragonite saturation cause substantial changes in overall calcification rates for many species of marine organisms, including coccolithophore, foraminifera, pteropods, mussels, and clams.
ocean acidification in the arctic ocean