Understanding physical drivers of recruitment variability in fish populations: influence of winter storms on the quality of sandy beaches as fish nurseries


Sandy beaches cover 70% of open ocean coasts and are of immense socioeconomic value, but their position at the land-sea interface exposes them to threats from climate change and local impacts. Sandy beaches critically support production of key fisheries species and harbour the venomous lesser weever fish. Two-thirds of UK flatfish landings are from species depending entirely on shallow areas of sandy beaches as juveniles while weevers are a coastal hazard which dominates lifeguard time and resources. Predicting how sandy beach nurseries determine recruitment variation in these socioeconomically important fish populations is important to implement effective management in the face of natural and anthropogenic environmental change.

Spatial variation in physical characteristics of sandy beaches influence resident faunal assemblages, but patterns and causes of variation in fauna among years are poorly understood. Winter storms cause substantial sediment redistribution with extensive beach / dune erosion and deposition in subaquatic areas followed by a multiannual process of recovery under modal wave conditions. Both initial impact and recovery vary among beaches depending on storm conditions and site characteristics. Storm events thus affect physical characteristics such as wave climate, sediment composition and beach morphology, which are strong determinants of sandy beach faunal assemblages. However, very little is known about the link between interannual shifts in beach states and associated fish assemblages. 

The aim of this PhD is to understand how variations in physical beach characteristics, particularly interannual changes due to winter storms, influence their nursery role. To achieve a mechanistic understanding the goal is to assess not only abundance, but also functional metrics of habitat quality related to growth and survival that underlie recruitment.
<p>Fish distuished by sand</p>
<p>View of a beach with rocks in the foreground.&nbsp;</p>
<p>2 people carrying a net into the sea with a red beach buggy driving past</p>


Using the diverse beach types adjacent to Plymouth as a natural laboratory, the student will sample surf-zone fishes broadly across the southwest English coast. Together with existing long-term datasets available at the University of Plymouth, this will support the creation of a unique, 17-year time series of sandy beach fish abundance at up to 77 beaches. In parallel, the student will work in the laboratory to develop a range of diet and biochemical growth analyses which will be applied to characterise nutritional condition of fishes caught during sampling. Finally, building on expertise within the Coastal Processes Research Group (CPRG), the student will use environmental samples collected at beaches and extensive physical datasets to describe beach morphology, sediment characteristics and wave conditions. These approaches will be used to establish fundamentally how beach morphology, wave climate and sediment characteristics determine spatial and temporal variation in fish assemblage structure, abundance, diet, growth and condition. Building on this, we will investigate the impact of extreme winter storm events (particularly the 2013/2014 winter) on populations of surf zone fishes. This will enable development of an environmentally-forced recruitment model for commercially important flatfish / weever which will be tested against fisheries data.

Student training and experience

By bridging complementary research strengths in field ecology, biochemistry and physical oceanography, from across the School of Biological and Marine Sciences, we offer a unique interdisciplinary training opportunity in the field, laboratory and numerical tools necessary to understanding the population dynamics of key coastal species. It is expected that the student will be supported by broader scientific and management communities through collaborations with important stakeholders in beach ecosystems (e.g. RNLI, Natural England, Inshore Fisheries & Conservation Authority) and through participation with international working groups (e.g. ICES WGVHES). 
By understanding the drivers of variation in inshore fish assemblages, this project provides a basis for sustainable conservation and management of important inshore fishes. The PhD is therefore an unrivalled opportunity to develop and apply expertise in a suite of valuable research tools to support effective fisheries and ecosystem management.
Individuals with interests in fish ecology and coastal processes, an aptitude for combining field and laboratory work with analysis of large datasets, and a degree in biological, environmental, marine or related science are encouraged to apply.

Key papers by supervisory team

  • Ciotti BJ, Targett TE, Burrows MT (2013) Spatial variation in growth rate of early juvenile European plaice Pleuronectes platessa. Mar Ecol Prog Ser 475:213-232
  • Morris MT, Hauton C, Baylay AJ, Peruzza L, Targett TE, Ciotti BJ (2021) Spatial variation in the gastrointestinal microbiome, diet, and nutritional condition of a juvenile flatfish among coastal habitats. Mar Environ Res 448:346-359
  • Scott T, Masselink G, O'Hare T, Saulter A, Poate T, Russell P, Davidson M, Conley D (2016) The extreme 2013/2014 winter storms: Beach recovery along the southwest coast of England. Mar Geol 382:224-241
Should you have any questions regarding the position, please contact Ben Ciotti - benjamin.ciotti@plymouth.ac.uk

Supervisory team