Competitive coexistence of coral-dwelling fishes: the lottery hypothesis revisited

Evidence for competitive lotteries among reef fishes has remained elusive despite this being the group of organisms for which the lottery model was first developed. I used a combination of laboratory and field experiments to test the mechanisms of coexistence between two closely related species of coral-dwelling goby, Gobiodon histrio and G. erythrospilus, that occur in similar abundance at Lizard Island on the Great Barrier Reef. These two species exhibited similar patterns of habitat use and nearly identical ability to compete for vacant corals. Furthermore, there was a priority effect where the first species to occupy a vacant coral excluded an interspecific intruder of similar body size. The relative abundance of recruit and juvenile G. histrio and G. erythrospilus in the field matched the relative abundance of adults, as expected where there is no post-recruitment displacement by a competitive hierarchy. Finally, a reciprocal competitor-reduction experiment confirmed that G. histrio and G. erythrospilus compete for vacant space, with the removal of either species leading to an increase in the abundance of the other species. Therefore these two species are nearly ecologically equivalent and appear to coexist by means of a competitive lottery for vacant space

Reanalysis shows there is not an extreme decline effect in fish ocean acidification studies

Clements and colleagues [1] claim there is an extreme decline effect in studies published between 2009 and 2019 on the impacts of ocean acidification (OA) on fish behaviour, with the modelled average effect size declining from >5 in 2009 to 2010 to <0.5 after 2015. Here, I show that the extreme decline effect reported by Clements and colleagues is a statistical artifact caused by the way they corrected for zero values in percentage data, which was more common in the earliest experiments compared with later studies. Furthermore, selective choices for excluding or including data, along with data compilation errors and missing studies with strong effects, weakened the effect sizes reported for papers after 2010, further exacerbating the decline effect reported by Clements and colleagues. When the data is reanalysed using appropriate corrections for zeros in percentage and proportional data and using a complete, corrected, and properly screened data set, the extreme decline effect reported by Clements and colleagues no longer exists (Fig 1A and 1B). Instead, there is a more gentle and consistent decline in effect size magnitude through time, from a modelled average <3 in 2009 to 2010 (Fig 1C) and remaining well above zero in 2018 to 2019 (Fig 1D)

Transgenerational acclimation of fishes to climate change and ocean acidification

There is growing concern about the impacts of climate change and ocean acidification on marine organisms and ecosystems, yet the potential for acclimation and adaptation to these threats is poorly understood. Whereas many short-term experiments report negative biological effects of ocean warming and acidification, new studies show that some marine species have the capacity to acclimate to warmer and more acidic environments across generations. Consequently, transgenerational plasticity may be a powerful mechanism by which populations of some species will be able to adjust to projected climate change. Here, I review recent advances in understanding transgenerational acclimation in fishes. Research over the past 2 to 3 years shows that transgenerational acclimation can partially or fully ameliorate negative effects of warming, acidification, and hypoxia in a range of different species. The molecular and cellular pathways underpinning transgenerational acclimation are currently unknown, but modern genetic methods provide the tools to explore these mechanisms. Despite the potential benefits of transgenerational acclimation, there could be limitations to the phenotypic traits that respond transgenerationally, and trade-offs between life stages, that need to be investigated. Future studies should also test the potential interactions between transgenerational plasticity and genetic evolution to determine how these two processes will shape adaptive responses to environmental change over coming decades

Inward investment, transaction linkages and productivity spillovers

The article examines the extent to which foreign manufacturing firms in the UK promote productivity growth in the domestically owned manufacturing sector through their buying and supplying relationships. Evidence for intra- and inter-regional externalities from the presence of foreign manufacturing, and intraand inter-industry effects is brought to light. Externalities in the domestic sector are most noticeable where foreign manufacturing sells to domestic manufacturing. These externalities are, however, not wholly robust to different specifications of spatial dependence. The findings are positioned in a debate, which has tended to view backward (as opposed to forward) linkages from multinationals to domestically owned supply bases as a critical driver of indirect economic benefits. © RSAI 2004

Resolving the Turkana Jet—Impact of Model Resolution in Simulating Channel Flow and Inversions

The Turkana Jet plays a pivotal role in the meteorology of East Africa across timescales, and owes its existence to both large‐scale dynamics and the representation of intricate local‐scale processes. However, much of our understanding of the jet relies on reanalysis, and these along with climate models that produce important projections do not represent these local‐scale processes. We systematically investigate the impact of changing model horizontal and vertical resolution in simulating the Turkana Jet, and associated local and large‐scale processes. We perform simulations to coincide with the Radiosonde Investigation For the Turkana Jet (RIFTJet) campaign, enabling direct model‐sonde comparisons in unprecedented detail. We find that increasing horizontal model resolution significantly increases the strength of the jet throughout the channel by up to 30%, while vertical resolution changes have little impact. Horizontal resolutions finer than 2.2 km produce a nocturnal jet ∼2 m/s stronger than observed but perform better during the day. The elevated inversion, which is strongly tied to the strength of the jet, is much better represented in resolutions as high as 1.1 km, whereas the global model at resolution O(∼10 km) is unable to produce any nocturnal elevated inversion. Predictions of jet strength are improved at higher resolution, indicating an important role of local process given that models inherit the same large‐scale state. Despite further improvements at resolutions finer than 4.4 km, we recommend that 4.4 km is the minimum horizontal resolution required to capture realistic interactions between these processes. Underestimation of the Turkana Jet could cause considerable errors in moisture advection into Africa