Multi-decadal shifts in the distribution and timing of Pacific herring (Clupea pallasii) spawning in Prince William Sound, Alaska

The location and timing of spawning play a critical role in pelagic fish survival during early life stages and can affect subsequent recruitment. Spawning patterns of Pacific herring (Clupea pallasii) were examined in Prince William Sound (1973–2019) where the population has failed to recover since its collapse in 1993. Abrupt shifts in spawn distribution preceded the rapid increase in population size in the 1980s and later its collapse by one and two years, respectively. Following the population collapse, spawning contracted away from historical regions towards southeastern areas of the Sound, and the proportion of occupied spawning areas declined from 65% to <9%. Spatial differences in spawn timing variation were also apparent, as the median spawn date shifted earlier by 26 days in eastern and 15 days in western areas of Prince William Sound between 1980 and 2006, and then shifted later by 25 (eastern) and 19 (western) days over a 7-year period. Effects of contracted spawning areas and timing shifts on first-year survival and recruitment are uncertain and require future investigation.

Patterns of flood timing trend across the global river networks

&lt;p&gt;Impacts of climate change on floods have been recently suggested to be more consistently seen in flood timing (or flood seasonality) as opposed to flood magnitude and frequency. Changes in flood timing can threaten the finely tuned water resource management systems and, if poorly understood, can alter flood risks in unpredictable ways. Nevertheless, patterns of global flood timing trend remain elusive. Whether climate change has played a significant role in shifting flood timing worldwide also remains unknown.&lt;/p&gt;&lt;p&gt;Here we obtained an unprecedented set of discharge records from tens of thousands of global gauges and model-reconstructed naturalized discharge at ~3 million river reaches to delineate flood timing trend across the global river networks from 1980 to 2019. Hydroclimate drivers possibly causing&amp;#160;these trends, including&amp;#160;maximum precipitation, antecedent soil moisture, and snowmelt timing, are also investigated to&amp;#160;disentangle climate change signals on floods. We found that the flood timing has been significantly earlier over the lower Mississippi, the Amur and the Amazon river basins, as well as large parts of the high-latitude Northern Hemisphere. Significant later floods are observed over the Yangtze and the lower Congo river basins, and the southeast Asia. However, ascribing these flood timing shifts to changing climate is not as obvious as previously suggested, implying the need for further research on this topic.&lt;/p&gt;

Rapid Audiovisual Temporal Recalibration Generalises Across Spatial Location

Recent exposure to asynchronous multisensory signals has been shown to shift perceived timing between the sensory modalities, a phenomenon known as ‘temporal recalibration’. Recently, Van der Burg et al. (2013, J Neurosci, 33, pp. 14633–14637) reported results showing that recalibration to asynchronous audiovisual events can happen extremely rapidly. In an extended series of variously asynchronous trials, simultaneity judgements were analysed based on the modality order in the preceding trial and showed that shifts in the point of subjective synchrony occurred almost instantaneously, shifting from one trial to the next. Here we replicate the finding that shifts in perceived timing occur following exposure to a single, asynchronous audiovisual stimulus and by manipulating the spatial location of the audiovisual events we demonstrate that recalibration occurs even when the adapting stimulus is presented in a different location. Timing shifts were also observed when the adapting audiovisual pair were defined only by temporal proximity, with the auditory component presented over headphones rather than being collocated with the visual stimulus. Combined with previous findings showing that timing shifts are independent of stimulus features such as colour and pitch, our finding that recalibration is not spatially specific provides strong evidence for a rapid recalibration process that is solely dependent on recent temporal information, regardless of feature or location. These rapid and automatic shifts in perceived synchrony may allow our sensory systems to flexibly adjust to the variation in timing of neural signals occurring as a result of delayed environmental transmission and differing neural latencies for processing vision and audition.