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Open Access Publications from the University of California

To meet the challenges of marine conservation, the Center for Marine Biodiversity and Conservation (CMBC) was established at the Scripps Institution of Oceanography (SIO) in May 2001. Its goals are:

  • Investigation: Assess the state of marine ecosystems now and in the past and develop predictive models for the future
  • Education: Train new marine biodiversity and conservation scientists in the United States and around the world
  • Integration: Develop novel interdisciplinary approaches linking the biological, physical, social and informatic sciences
  • Communication: Increase public understanding of scientific issues and provide sound scientific analyses to policy makers
  • Application: Design technically sophisticated, regionally appropriate strategies to prevent and reverse biodiversity collapse

Dr. Lisa Levin, Director
http://cmbc.ucsd.edu
cmbc@ucsd.edu

Cover page of Quantifying scales of spatial variability in algal turf assemblages on coral reefs

Quantifying scales of spatial variability in algal turf assemblages on coral reefs

(2015)

Quantifying variability over multiple spatial scales is a fundamental goal in ecology,providing insight into which scale-dependent processes most strongly influence community structure.On coral reefs, the ubiquitous turf algae are the primary food source for herbivores and competitorsfor space with corals. Turf algae will likely increase in the future, because they thriveunder conditions that reduce coral cover. Turfs are typically treated as a single homogeneousfunctional group, but analyzing them as a variable assemblage is more informative. We used ahierarchical sampling design to quantify 4 scales of variability in turf assemblages from centimeters(within single dead coral heads) to kilometers (across islands) on the rarely studied LhaviyaniAtoll, Maldives. We used 4 metrics, each reflecting different ecological processes: percent cover,canopy height, richness, and assemblage composition. For most of these metrics, variability wassignificant at multiple spatial scales. However, for all metrics, the smallest scale (centimeters)explained the greatest proportion of overall variability. The least variability in cover, canopyheight, and richness occurred among sites (100s meters), suggesting that processes such as competition,predation, and vegetative growth are heterogeneous at small scales. In contrast, assemblagecomposition was least variable at the largest scale (kilometers), suggesting that oceanographicprocesses or a well-mixed propagule supply reduce variability. With declining coral andincreasing cover of turf on reefs worldwide, it will become increasingly important to understandthe dynamics of coral−turf competitive interactions. However, because turf assemblages arehighly variable at small spatial scales, these interactions require more detailed consideration.

Cover page of Analysis of complete miochondrial DNA sequences of three members of the Montastraea annularis coral species complex (Cnidaria, Anthozoa, Scleractinia)

Analysis of complete miochondrial DNA sequences of three members of the Montastraea annularis coral species complex (Cnidaria, Anthozoa, Scleractinia)

(2005)

Complete mitochondrial nucleotide sequences of two individuals each of Montastraea annularis,Montastraea faveolata, and Montastraea franksi were determined. Gene composition and order di•ered substantially from the sea anemone Metridium senile, but were identical to that of the phylogenetically distant coral genus Acropora. However, characteristics of the noncoding regions di•ered between the two scleractinian genera. Among members of the M. annularis complex, only 25 of 16,134 base pair positions were variable. Sixteen of these occurred in one colony ofM. franksi, which (together with additional data) indicates the existence of multiple divergent mitochondrial lineages in this species. Overall, rates of evolution for these mitochondrial genomes were extremely slow (0.03–0.04% per million years based on the fossil record of the M. annularis complex). At higher taxonomic levels, patterns of genetic divergence and synonymous/nonsynonymous substitutions suggest non-neutral and unequal rates of evolution between the two lineages to which Montastraea and Acropora belong.