aquatic biology Aquatic means relating to water; living in or near water or taking place in water; does not include groundwater, as "aquatic" implies an environment where plants and animals live. Aquatic(s) may also refer to: * Aquatic animal, either vertebrate ...

, the paradox of the plankton describes the situation in which a limited range of resources supports an unexpectedly wide range of

plankton Plankton are the diverse collection of organisms found in Hydrosphere, water (or atmosphere, air) that are unable to propel themselves against a Ocean current, current (or wind). The individual organisms constituting plankton are called plankt ...

species, apparently flouting the

competitive exclusion principle In ecology, the competitive exclusion principle, sometimes referred to as Gause's law, is a proposition that two species which compete for the same limited resource cannot coexist at constant population values. When one species has even the sligh ...

which holds that when two species compete for the same resource, one will be driven to extinction.

Ecological paradox

The

paradox A paradox is a logically self-contradictory statement or a statement that runs contrary to one's expectation. It is a statement that, despite apparently valid reasoning from true premises, leads to a seemingly self-contradictory or a logically u ...

of the plankton results from the clash between the observed

diversity Diversity, diversify, or diverse may refer to: Business *Diversity (business), the inclusion of people of different identities (ethnicity, gender, age) in the workforce *Diversity marketing, marketing communication targeting diverse customers * ...

of plankton and the

, also known as Gause's law, which states that, when two

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

compete Competition is a rivalry where two or more parties strive for a common goal which cannot be shared: where one's gain is the other's loss (an example of which is a zero-sum game). Competition can arise between entities such as organisms, indivi ...

for the same resource, ultimately only one will persist and the other will be driven to

extinct Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

ion. Coexistence between two such species is impossible because the dominant one will inevitably deplete the shared resources, thus decimating the inferior population.

Phytoplankton Phytoplankton () are the autotrophic (self-feeding) components of the plankton community and a key part of ocean and freshwater ecosystems. The name comes from the Greek words (), meaning 'plant', and (), meaning 'wanderer' or 'drifter'. Ph ...

life is diverse at all

phylogenetic In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups o ...

levels despite the limited range of resources (e.g. light, nitrate, phosphate, silicic acid, iron) for which they compete amongst themselves. The paradox of the plankton was originally described in 1961 by G. Evelyn Hutchinson, who proposed that the paradox could be resolved by factors such as vertical gradients of light or turbulence,

symbiosis Symbiosis (from Greek , , "living together", from , , "together", and , bíōsis, "living") is any type of a close and long-term biological interaction between two different biological organisms, be it mutualistic, commensalistic, or parasit ...

commensalism Commensalism is a long-term biological interaction (symbiosis) in which members of one species gain benefits while those of the other species neither benefit nor are harmed. This is in contrast with mutualism, in which both organisms benefit fro ...

, differential

predation Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill the ...

, or constantly changing environmental conditions. This was supported by later studies which found that the paradox can be resolved by factors such as: zooplankton grazing pressure; chaotic fluid motion; size-selective grazing; spatio-temporal heterogeneity; bacterial mediation; or environmental fluctuations. More generally, some researchers suggest that ecological and environmental factors continually interact such that the planktonic

habitat In ecology, the term habitat summarises the array of resources, physical and biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species habitat can be seen as the physical ...

never reaches an equilibrium for which a single species is favoured. In Mitchell et al. (2008), researchers found that small-scale analysis of plankton distribution exhibited patches of aggregation, on the order of 10 cm, that had sufficient lifetimes (> 10 minutes) to enable plankton grazing, competition, and infection.Mitchell, J.G., Yamazaki, H., Seuront, L., Wolk, F., Li, H. (2008) Phytoplankton patch patterns: Seascape anatomy in a turbulent ocean. ''Journal of Marine Systems'' 69, 247-253.

References

External links

The Paradox of the Plankton
by

Klaus Rohde Klaus Rohde (born 1932 in Brandenburg an der Havel, Germany) is a German biologist at the University of New England (UNE), Australia, known particularly for his work on marine parasitology, evolutionary ecology/zoogeography, and phylogeny/ult ...

{{modelling ecosystems, expanded=none Biological interactions Biological oceanography Aquatic ecology Mathematical and theoretical biology Paradoxes Planktology

Ecological paradox

See also

References

External links