![Diatoms through the microscope](https://upload.wikimedia.org/wikipedia/commons/3/31/Diatoms_through_the_microscope.jpg)
In
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
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 ...
, 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 ...
or
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.]
See also
*
Unified neutral theory of biodiversity
The unified neutral theory of biodiversity and biogeography (here "Unified Theory" or "UNTB") is a theory and the title of a monograph by ecologist Stephen P. Hubbell. It aims to explain the diversity and relative abundance of species in ecolog ...
References
External links
The Paradox of the Planktonby
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