Science Newsletter - Scottish Natural Heritage

Mar 23, 2018 - replication, as well as further follow-up research would be desirable, but we often have to base policy on interpretation of complex or incomplete evidence. This paper is a clear example of the difficulty of using novel scientific evidence to shape policy. No doubt other items referred to in this newsletter may ...
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Scottish Natural Heritage

Science Newsletter

Issue 23 – March 2018 _______________________________________________________ __

In this issue:           

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Welcome from the SAC Chair IUCN National Committee UK River Restoration and Biodiversity project Launch of New Centre of Expertise in Plant Health Ecological traps for large scale invasive species control Natural England Scientific Advisory Committee Learning outside the classroom boosts educational attainment Pollinator Strategy gathers momentum Conferences and meetings News SNH Staff profile SAC Expert Panel member profile

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Welcome from the SAC Chair Bob Furness Welcome to this latest Science Newsletter. I want to introduce you to a recent paper, because it illustrates some of the problems of developing policy and advice when new evidence comes to light. The paper is Halttunen et al (2017) Sea trout adapt their migratory behaviour in response to high salmon lice concentrations. Journal of Fish Diseases DOI: 10.1111/jfd.12749. I think it is a really interesting paper. The authors tracked movements of tagged sea trout around a fjord in Norway where salmon cages are plentiful but where biennial fallowing, to reduce sea louse infestations, resulted in dramatic changes in sea louse abundance between years. As indicated in the title of the paper, sea trout adapted their behaviour to spend more time in freshwater when sea lice were numerous, which the authors interpret as adaptive behaviour to reduce infestation (because sea lice don’t survive in freshwater habitats). This novel research was very cleverly designed, and the results of the tracking are really impressive (over ten million acoustic detections of tagged fish). The results seem at face value to provide important insights into impacts of sea lice on wild fish where salmon farming is practiced. But the authors also point out that their analysis found no difference in survival of fish in years with high or low louse abundance, and no difference in survival between groups of trout treated with a prophylaxis against infestation and a control untreated group. So the same study shows strong behavioural impacts but no fitness consequence (but was based on only 3 years of study). Perhaps the altered behaviour might affect trout growth, in which case there may be a longer-term impact on fitness. Of course replication, as well as further follow-up research would be desirable, but we often have to base policy on interpretation of complex or incomplete evidence. This paper is a clear example of the difficulty of using novel scientific evidence to shape policy. No doubt other items referred to in this newsletter may create similar ambiguities of interpretation as well as help to establish consensus; science progresses as a significant body of evidence accumulates, preferably from multiple studies using a variety of approaches in different locations. But sometimes we don’t have the luxury to wait until the evidence base is compelling and clear.

IUCN National Committee UK River Restoration and Biodiversity project Angus Tree The three phase River Restoration and Biodiversity Project is led by SNH under the auspices of IUCN National Committee UK (NCUK). It has a steering group comprising representatives of the UK and Ireland’s nature conservation and environment protection agencies, the River Restoration Centre, and the IUCN NCUK. Phil Boon, who chaired the steering group until he retired from SNH in 2017, has kindly agreed to remain on it. The project forms part of the work planned for Priority Project 3 (Restoration of freshwaters) in Scotland’s Biodiversity Route Map to 2020. The work began in 2013 after Susan Davies (then SNH’s Director of Policy and Advice) was approached by the IUCN for ideas of projects that could be run under its patronage. Phil highlighted the paucity of evidence on the benefits of river restoration for biodiversity and, after discussion amongst fres