Fossil Communities with Multi-Modal Size-Frequency Distributions

Nature ◽  
1965 ◽  
Vol 206 (4991) ◽  
pp. 1336-1338 ◽  
Author(s):  
RAYMOND W. SHELDON
Keyword(s):  
Frequency Distributions ◽  
Size Frequency ◽  
Modal Size

scholarly journals Linking population size structure, heat stress and bleaching responses in a subtropical endemic coral

Coral Reefs ◽  
2021 ◽  
Author(s):  
Liam Lachs ◽  
Brigitte Sommer ◽  
James Cant ◽  
Jessica M. Hodge ◽  
Hamish A. Malcolm ◽  
...  
Keyword(s):  
Heat Stress ◽  
Size Structure ◽  
Temporal Trends ◽  
Early Recovery ◽  
Size Frequency Distribution ◽  
Frequency Distributions ◽  
Community Organisation ◽  
Size Frequency ◽  
Eastern Australia

AbstractAnthropocene coral reefs are faced with increasingly severe marine heatwaves and mass coral bleaching mortality events. The ensuing demographic changes to coral assemblages can have long-term impacts on reef community organisation. Thus, understanding the dynamics of subtropical scleractinian coral populations is essential to predict their recovery or extinction post-disturbance. Here we present a 10-yr demographic assessment of a subtropical endemic coral, Pocillopora aliciae (Schmidt-Roach et al. in Zootaxa 3626:576–582, 2013) from the Solitary Islands Marine Park, eastern Australia, paired with long-term temperature records. These coral populations are regularly affected by storms, undergo seasonal thermal variability, and are increasingly impacted by severe marine heatwaves. We examined the demographic processes governing the persistence of these populations using inference from size-frequency distributions based on log-transformed planar area measurements of 7196 coral colonies. Specifically, the size-frequency distribution mean, coefficient of variation, skewness, kurtosis, and coral density were applied to describe population dynamics. Generalised Linear Mixed Effects Models were used to determine temporal trends and test demographic responses to heat stress. Temporal variation in size-frequency distributions revealed various population processes, from recruitment pulses and cohort growth, to bleaching impacts and temperature dependencies. Sporadic recruitment pulses likely support population persistence, illustrated in 2010 by strong positively skewed size-frequency distributions and the highest density of juvenile corals measured during the study. Increasing mean colony size over the following 6 yr indicates further cohort growth of these recruits. Severe heat stress in 2016 resulted in mass bleaching mortality and a 51% decline in coral density. Moderate heat stress in the following years was associated with suppressed P. aliciae recruitment and a lack of early recovery, marked by an exponential decrease of juvenile density (i.e. recruitment) with increasing heat stress. Here, population reliance on sporadic recruitment and susceptibility to heat stress underpin the vulnerability of subtropical coral assemblages to climate change.

Determinacy of fecundity in sole (Solea solea) from the Bristol Channel

1990 ◽  
Vol 70 (4) ◽  
pp. 803-813 ◽  
Author(s):  
J. W. Horwood ◽  
M. Greer Walker
Keyword(s):  
Bay Of Biscay ◽  
English Channel ◽  
Potential Fecundity ◽  
Frequency Distributions ◽  
The North ◽  
Size Frequency ◽  
Solea Solea ◽  
The North Sea ◽  
The Common ◽  
Common Sole

Ovaries of the common sole (Solea solea (Linnaeus)) were collected prior to, or at the beginning of, spawning from the spawning grounds in the Bristol Channel. Size frequency distributions of oocytes over 100 μm are presented. They clearly show a break in the size frequency distributions, at about 170 μm, indicating that the production of new oocytes to be spawned that season had ceased. It indicates that the sole is a determinate spawner and that, at least for this population, an annual potential fecundity can be measured. Estimated annual fecundity at length of Bristol Channel sole is calculated, and values are compared with those found for sole from the North Sea, eastern English Channel and the Bay of Biscay.

scholarly journals Nonparametric Assessment of Multimodality for Size Frequency Distributions

2002 ◽  
Vol 15 (4) ◽  
Author(s):  
I.H. SALGADO-UGARTE ◽  
M. SHIMIZU ◽  
T. TANIUCHI ◽  
K. MATSUSHITA
Keyword(s):  
Frequency Distributions ◽  
Size Frequency

Some Uses of Probability Paper in the Analysis of Size Frequency Distributions

1954 ◽  
Vol 5 (3) ◽  
pp. 513 ◽  
Author(s):  
RM Cassie
Keyword(s):  
Frequency Analysis ◽  
Length Frequency ◽  
Scale Reading ◽  
Frequency Distributions ◽  
Probability Paper ◽  
Size Frequency ◽  
Graph Paper ◽  
Probability Graph ◽  
Age Determinations ◽  
Length Frequency Analysis

Methods are described by which the component groups may be extracted from polymodal size frequency samples by the use of probability graph paper. Four examples are given illustrating: the solution of a distribution with more than two modes and with only one exposed flank; the coordination of fish age determinations by the two methods, length frequency analysis and scale reading; a bivariate sample where the two means coincide though the standard deviations are different; a method of correcting for truncation.

Sign in / Sign up

Export Citation Format

Share Document