Comment on “Chemically Mediated Behavior of Recruiting Corals and Fishes: A Tipping Point That May Limit Reef Recovery”

Dixson et al. (2014) report that coral larvae navigate towards chemical cues associated with healthy reefs and avoid cues from degraded reefs. However, the swimming capabilities of coral larvae and well-established patterns of recruitment and reef hydrodynamics indicate that coral larvae will not be able to use these cues to recruit to healthy reefs. Perfuming degraded reefs, as suggested by Dixson et al (2014), will not enhance recovery rather it will distract from the difficult task of reducing fishing effort and improving water quality

A tenuis relationship: traditional taxonomy obscures systematics and biogeography of the ‘Acropora tenuis’ (Scleractinia: Acroporidae) species complex

Molecular phylogenetics has fundamentally altered our understanding of the taxonomy, systematics and biogeography of corals. Recently developed phylogenomic techniques have started to resolve species-level relationships in the diverse and ecologically important genus Acropora, providing a path to resolve the taxonomy of this notoriously problematic group. We used a targeted capture dataset (2032 loci) to investigate systematic relationships within an Acropora clade containing the putatively widespread species Acropora tenuis and its relatives. Using maximum likelihood phylogenies and genetic clustering of single nucleotide polymorphisms from specimens, including topotypes, collected across the Indo-Pacific, we show ≥ 11 distinct lineages in the clade, only four of which correspond to currently accepted species. Based on molecular, morphological and geographical evidence, we describe two new species; Acropora rongoi n. sp. and Acropora tenuissima n. sp. and remove five additional nominal species from synonymy. Systematic relationships revealed by our molecular phylogeny are incongruent with traditional morphological taxonomy and demonstrate that characters traditionally used to delineate species boundaries and infer evolutionary history are homoplasies. Furthermore, we show that species within this clade have much smaller geographical ranges and, consequently, population sizes than currently thought, a finding with profound implications for conservation and management of reef corals

Global biogeography of coral recruitment: tropical decline and subtropical increase

Despite widespread climate-driven reductions of coral cover on tropical reefs, little attention has been paid to the possibility that changes in the geographic distribution of coral recruitment could facilitate beneficial responses to the changing climate through latitudinal range shifts. To address this possibility, we compiled a global database of normalized densities of coral recruits on settlement tiles (corals m(-2)) deployed from 1974 to 2012, and used the data therein to test for latitudinal range shifts in the distribution of coral recruits. In total, 92 studies provided 1253 records of coral recruitment, with 77 % originating from settlement tiles immersed for 3-24 mo, herein defined as long-immersion tiles (LITs); the limited temporal and geographic coverage of data from short-immersion tiles (SITs; deployed for 20 degrees latitude). These trends indicate that a global decline in coral recruitment has occurred since 1974, and the persistent reduction in the densities of recruits in equatorial latitudes, coupled with increased densities in sub-tropical latitudes, suggests that coral recruitment may be shifting poleward

Polaron spin current transport in organic semiconductors

In spintronics, pure spin currents play a key role in transmitting, processing and storing information. A pure spin current is a flow of electron spin angular momentum without a simultaneous flow of charge current. It can be carried by conduction electrons or magnons and has been studied in many inorganic metals, semiconductors and insulators, but not yet in organic semiconductors. Charge carriers in π-conjugated organic materials are localized spin-1/2 polarons which move by hopping, but the mechanisms of their spin transport and relaxation are not well understood. Here we use ferromagnetic resonance spin pumping in a ferromagnet/conjugated polymer/nonmagnetic spin-sink trilayer to demonstrate the ability of polarons to carry pure spin currents over hundreds of nanometres with long spin relaxation times of up to a millisecond and to exhibit Hanle precession. By systematically comparing charge and spin transport on the same trilayer we show that spin-orbit coupling mediates spin relaxation at room temperature.This work was supported by the Cabinet Office, Government of Japan through its “Funding Program for Next Generation World-Leading Researchers”, PRESTO-JST “Innovative nano-electronics through interdisciplinary collaboration among material, device and system layers”, the Asahi Glass Foundation and the Engineering and Physical Sciences Research Council (EPSRC).This is the accepted version of the article. The final version was published in Nature Physics and is available at http://www.nature.com/nphys/journal/vaop/ncurrent/full/nphys2901.html. Nature Publishing Group's licence and reuse policy is available at http://www.nature.com/authors/policies/license.html

An Indo-Pacific coral spawning database.

The discovery of multi-species synchronous spawning of scleractinian corals on the Great Barrier Reef in the 1980s stimulated an extraordinary effort to document spawning times in other parts of the globe. Unfortunately, most of these data remain unpublished which limits our understanding of regional and global reproductive patterns. The Coral Spawning Database (CSD) collates much of these disparate data into a single place. The CSD includes 6178 observations (3085 of which were unpublished) of the time or day of spawning for over 300 scleractinian species in 61 genera from 101 sites in the Indo-Pacific. The goal of the CSD is to provide open access to coral spawning data to accelerate our understanding of coral reproductive biology and to provide a baseline against which to evaluate any future changes in reproductive phenology

An Indo-Pacifc coral spawning database

The discovery of multi-species synchronous spawning of scleractinian corals on the Great Barrier Reef in the 1980s stimulated an extraordinary effort to document spawning times in other parts of the globe. Unfortunately, most of these data remain unpublished which limits our understanding of regional and global reproductive patterns. The Coral Spawning Database (CSD) collates much of these disparate data into a single place. The CSD includes 6178 observations (3085 of which were unpublished) of the time or day of spawning for over 300 scleractinian species in 61 genera from 101 sites in the Indo-Pacific. The goal of the CSD is to provide open access to coral spawning data to accelerate our understanding of coral reproductive biology and to provide a baseline against which to evaluate any future changes in reproductive phenology

Larvae of Acropora millepora swimming in the end of the experiment

"age" is the larval age (h) at the end of experiment, "temp" is the temperature larvae were raised at; "rep" is the replicate number; "swim" is the number of larvae swimming in the end of the experiment; "larvae" is the number of larvae in the beginning of the experiment; "propswim" is the proportion of larvae swimming at the end of the experiment, calculated as "swim"/"larvae"