Marine diversity: the paradigms in patterns of species richness examined*

By J. Gray. 2001

231 citations recorded by the source corpus.

SUMMARY: The two central paradigms of marine diversity are that there is a latitudinal cline of increasing species richness from poles to tropics and that species richness increases with depth to a maximum around 2,000 m and thereafter decreases. However, these paradigms were based on data collected in the late 1950’s and early 1960’s. Here I show that the 1960’s data, are not representative and thus the paradigms need re-examination. New data from coastal areas in the northern hemisphere record species richness as high as the highest recorded in the deep-sea. Whilst this suggests that the cline of increasing diversity from shallow to deep-sea does not exist, however, the database for the deep sea is not sufficient to draw such a conclusion. The basic problem with the data from the 1960s is that samples were taken on ecological scales and yet they are used to answer evolutionary questions. The questions that such data were to answer were why do the tropics have higher species richness than polar regions or why do deep-sea sediments have more species than coastal sediments? Evolutionary questions need data from much larger spatial areas. Recently, data representative of large scales have been collected from coastal areas in the northern hemisphere and show that there is a cline of increasing species richness from the Arctic to the tropics, but there does not yet seem to be a similar cline in the southern hemisphere. A number of hypotheses have been proposed for the observed patterns in biodiversity. In terrestrial ecology the energy-productivity hypothesis has gained wide acceptance as an explanation for the latitudinal gradient. Here I examine this and other hypotheses critically. Finally an analysis of research priorities is made. Assessment is urgently needed of the spatial scales and dynamics of species richness from point samples to assemblages, habitats and landscapes, especially in coastal areas and in the tropics, where the threats to biodiversity are greatest. New technologies are available, such as side-scan sonar, acoustics, and under-water digital video cameras but as yet have been relatively little used. Conservation of marine biodiversity must be based on sound theory, yet marine diversity studies lag well behind those of terrestrial habitats.

Subfields: Global and Planetary Change, Oceanography

View Paper: https://www.semanticscholar.org/paper/a1300f4cec21631d4b59e732115179bed26c3a73

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In Global and Planetary Change

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Citations in the corpus

Towards a generalized biogeography of the Southern Ocean benthos (2009, background): “We show that the most striking broad-scale patterns to emerge from species counts (of model taxa) per region are a strong east–west hemispheric asymmetry, also noted by Crame (2000) and Gray (2001).”
Inter-reef vertebrate communities of the Great Barrier Reef Marine Park determined by baited remote underwater video stations. (2007, unknown): “The weak northward increase in species richness of about 1 species for every 3° of latitude was expected, given general patterns in aquatic species diversity (Gray 2001) and previous studies in the GBRMP (DeVantier et al. 2006).”
ORIGINAL ARTICLE: Fish species richness decreases with salinity in tropical coastal lagoons (2006, background): “Numerous mechanisms have been suggested for generating patterns in species richness (Gaston, 2000; Gray, 2001).”
GLOBAL MARINE BIODIVERSITY TRENDS (2006, background): “However, there are some disagreements about the reality of some patterns and enormous disagreement about the underlying causes of the patterns (31, 32).”
Species richness of marine soft sediments (2002, background): “In the context of this paper, point-species richness is the richness of a single grab or core sample (Whittaker 1975, Gray 2001).”
Deep, diverse and definitely different: unique attributes of the world's largest ecosystem (2010, background): “Indeed, for many taxa, a parabolic pattern in species diversity in relation to water depth has been observed (Rex, 1981; Pineda and Caswell, 1998; Gray, 2001, 2002; Levin et al., 2001).”
Sea urchin barrens as alternative stable states of collapsed kelp ecosystems (2014, unknown): “The trend of increasing marine species richness and ecosystem complexity from the Arctic to the tropics (Gray 2001) may explain this discrepancy because the more simplified food webs in temperate ecosystems may collapse more readily.”
A hierarchical framework for classifying seabed biodiversity with application to planning and managing Australia’s marine biological resources (2010, background): “Studies of marine biodiversity have focused almost exclusively on local-scale processes which are typically less informative than biogeographic processes for understanding species richness patterns (Gray, 2001).”
On the use of abiotic surrogates to describe marine benthic biodiversity (2010, background): “Depth has been a consistently powerful explanatory variable in benthic studies (Gray, 2001).”
The exploration of marine biodiversity: scientific and technological challenges (2006, background): “Beyond these black boxes, the measure of species richness at whatever spatial scale remains a challenge to science, conservation and management (Gray 2001).”