PhD Studentships: Differential Susceptibility to Copper in Wild Populations of Three-Spined Stickback (GASTEROSTEUS ACULEATUS)

Lauren Laing

University of Exeter

Supervisor(s): Eduarda Santos & Rod Wilson

Most aquatic environments in the UK and worldwide have been affected by anthropogenic environmental stressors. Such stressors vary from chemical pollution to habitat fragmentation and to changes in abiotic parameters such as temperature and dissolved oxygen or carbon dioxide. Populations of fish inhabiting these environments are often exposed to combinations of stressors and, as a result, their sustainability is critically dependent on their ability to adapt to the local environment. Despite this, legislation to protect the environment from chemical contamination is often based on toxicological measurements conducted under optimal laboratory conditions and that does not take into account the variation in susceptibility of wild populations or the multiple stressors affecting these populations.

For metals, extreme cases exist of fish populations that can survive in highly contaminated waters, including a brown trout population in the River Hayle, where concentrations of metals far exceed the LC50 for this species. Furthermore, even for populations of fish inhabiting relatively un- impacted waters, their toxicological responses to metals can vary significantly. This highlights the need to understand natural and exposure-induced variations in the response of fish to pollutants, in order to appropriately manage and protect fish populations in their natural environment.

My research explores three key questions, firstly to determine if wild populations of three spined sticklebacks exhibit differential susceptibility to copper and if those characteristics can be inherited under control conditions. Secondly, my research aims to determine if differential susceptibility can be induced by exposure to copper during early life. Thirdly, I plan to investigate the fitness cost associated with differential susceptibility to copper in this species.

Together, this research will allow for a greater understanding of the variation in the responses to chemical stressors in wild populations, how they are induced and maintained and what are the consequences of changes in susceptibility to a pollutant on other parameters of fundamental importance to population sustainability. The data will build on previous data generated at Exeter, and will have implications for toxicity testing and regulation and for the management of wild fish populations.

My report on my attendance at the Canadian Conference for Fisheries Research is here

Publication
Uren Webster, T. M., Laing, L. V., Florance, H. & Santos, E. M. 2014. Effects of glyphosate and its formulation, Roundup, on reproduction in zebrafish (Danio rerio). Environmental Science & Technology 48, 1271-1279.

Contact

Biosciences
College of Life & Environmental Sciences
University of Exeter
Exeter
EX4 4QD
UK

Email: ll292@exeter.ac.uk

PhD Studentships: Fish Ecology of Mesophotic Coral Reef Ecosystems

Dominic Andradi-Brown

University of Oxford

Supervisor(s): Alex Rogers (Oxford) and Dan Exton (Operation Wallacea)

Mesophotic coral reef ecosystems (MCE) occur in tropical regions extending from 30 m to the limit of the photic zone, c. 150 m. These reefs are often connected to shallow coral reef ecosystems, where it is suggested they provide an important reservoir of recruits for coral and fish populations. Existing reef fish studies are highly depth biased mostly < 30 m, making the importance of mesophotic reefs to overall reef resilience in the face of human disturbances such as overfishing largely unknown, with a lack of evidence for whether fish populations on shallow reefs and adjacent MCEs are connected. This study addresses this important information gap by using advanced diving technologies coupled with a newly developed stereo-video system and molecular ecology techniques to better understand fish communities by examining fish biomass distributions and community structure down depth gradients from shallow reefs to MCEs and by exploring the connectivity of MCE fish populations down depth gradients with shallow reefs and between mesophotic reefs. This project is being conducted in partnership with Operation Wallacea with fieldwork principally based at their field site on Utila, Honduras where MCEs connected to shallow reefs have been identified but are unstudied. The aims of the project are twofold, first to Investigate biomass and community structure. Fisheries value and ecological service provision requires biomass to be quantified as it provides a better indication of functional pressure exerted by a fish-feeding guild than richness or abundance. Fish biomass along transects will be assessed by stereo-video surveys capturing the shallow reef to MCE gradient at various fished and protected sites. Biomass will be standardised using fish length-weight relationships, through data from local fisheries monitoring programmes to obtain local length to weight ratios, but for any fish species not caught locally, through available datasets (e.g. Fishbase). To allow patterns in fish biomass and community structure to be explained, benthic composition will be quantified using point intercept video transects, quantifying coral (genera and morphology), algal and other coverage. Physical parameters will also be recorded including temperature, light and turbidity and HOBO loggers for detailed year-round temperature and light readings. The second aim is to Investigate connectivity in MCE fish populations. Levels of population connectivity between populations of depth-generalist fish species with residents found on both shallow reefs and MCEs are not known. This has major implications for conservation and sustainable management of MCE fisheries, as well as the design and location of marine protected area networks. Many studies have demonstrated the ability of molecular techniques such as microsatellites to identify population structure; these protocols can be applied to assess connectivity down depth gradients and between MCE specialist species on small spatial scales. Non-lethal fin clippings will be collected from fish using a hand net and a clove oil anaesthetic mix. Care will be taken to return individuals to the reef where they were caught. To assess connectivity along depth gradients, samples of depth-generalist reef associated fish will be collected at different depths at several sites. To assess population connectivity between MCEs, an MCE specialist fish species will be identified samples collected at several sites. Contact: Ocean Research and Conservation Group Department of Zoology University of Oxford The Tinbergen Building South Parks Road Oxford OX1 3PS UK Email: dominic.andradi-brown@zoo.ox.ac.uk Twitter: @dandradibrown URL: http://www.zoo.ox.ac.uk/group/oceans

PhD Studentship: Extent and Drivers for Cryptic Benthivory in ‘Pelagic’ Ocean Sunfish

Natasha Phillips

Queen’s University Belfast

Supervisor(s): Jon Houghton and Chris Harrod

The ocean sunfish (Mola mola) is often described as an inactive, obligate predator of gelatinous zooplankton, but new research suggests these long held beliefs need significant revision. A recent study has revealed evidence of cryptic benthivory in juveniles and this project aims to examine the extent of and ecological drivers for benthivory in sunfish ontogenetically. Specifically, we hypothesize that ocean sunfish have a counter-intuitive life history tactic where small sunfish target high energy, benthic prey becoming more pelagic as they grow and shifting to an under-utilised niche as specialist foragers of gelatinous prey.

By combining stable isotope analysis (SIA) of diet with electronic bio-logging of behaviour, the energetic basis, timing and extent of this strategy can be quantified. In collaboration with Monterey Bay Aquarium, USA, techniques will be developed on captive sunfish before being deployed in the field. Tri-axial accelerometers fitted to captive sunfish will provide proxies of energy expenditure for discrete behaviours, and these data can then interpret the accelerometer readings of wild sunfish. The captive sunfish will also enable development of non-lethal sampling techniques for SIA to estimate isotopic fractionation and turnover through diet switch experiments.

Field work will be in Camogli, Italy where there is a local abundance of ocean sunfish and ongoing collaborations with the fishery and Marine Protected Area authorities. Using wild specimens, a description of ocean sunfish age and growth will help determine whether benthivory is restricted ontogenetically. The trophic ecology of wild sunfish will be analysed using gut content analysis and SIA (δ13C, δ15N) to characterise diet. These data will then be compared between populations using ocean sunfish samples collected by colleagues globally.

Overall this project aims to provide an understanding of the cryptic ecology of a large, pelagic consumer that may play a complex role in ecosystem function, alongside policy and conservation recommendations recognising the complexities associated with mixed benthic-pelagic foraging strategies.

CONTACT

Email: nphillips01@qub.ac.uk
Twitter: @sunfishresearch

PhD Studentship: Integration of Sea Angling Associated Catch and Mortality for Stock Assessment

Graham Monkman

University of Bangor & CEFAS

Supervisor(s): Michel Kaiser, Kieran Hyder and Franck Vidal

There are c. 1 million recreational sea anglers (RSA) in the UK, spending annually over £1.2 billion and their removals of marine fish can be quantitatively comparable to commercial landings, as revealed by landings of the European sea bass, Dicentrarchus labrax. Hence angling removals should be included in stock assessments and fisheries management, accounting for catch and release and post-release mortality rates.

RSA catch has only been included in stock assessments of Baltic cod; a gap recognised by the European Commission, and in the Common Fisheries Policy that requires members to report on catches by RSA for some species to give a clearer picture of how fishing affects stocks. RSA data on commercially significant species are also required at a local level under the Marine and Coastal Access Act to provide an evidence-base when balancing the needs of marine environment users. However, national RSA assessments are expensive and complex, especially in the UK where sea angling is unlicensed, so there is little evidence to inform the development of a policy for UK sea angling despite the sector’s importance.

My research will seek to scope, develop and validate transferable, innovative techniques in the capture of RSA data on marine fish species of recreational and commercial importance, primarily within ICES ecoregions E and F. This work will comprise three synergistic strands:

To engage with the UK RSA community to determine the extent of existing catch data recorded by anglers and to collate those data to construct time series of catches and compare against existing fisheries independent and dependant time series.

To develop, evaluate and pilot practical, reusable low cost technological solutions to complement RSA data recording, including natural language processing of social media sources; machine vision in species identification, and optical character recognition in form processing complemented with SMS, email and mobile solutions and their application to local and national angler survey programmes.

To evaluate the viability and define success criteria for a citizen science programme on the ongoing assessment of recreational sea angling, based on the outcomes of the preceding strands.

Contact:
School of Ocean Sciences
Bangor University
Menai Bridge
Anglesey
LL59 5AB
UK

Email: gmonkman@mistymountains.biz

PhD Studentship: Differential Susceptibility to Copper in Wild Populations of Three-spined Stickleback (Gasterosteus Aculeatus).

Lauren Laing

University of Exeter

Supervisor(s): Eduarda Santos & Rod Wilson

Most aquatic environments in the UK and worldwide have been affected by anthropogenic environmental stressors. Such stressors vary from chemical pollution to habitat fragmentation and to changes in abiotic parameters such as temperature and dissolved oxygen or carbon dioxide. Populations of fish inhabiting these environments are often exposed to combinations of stressors and, as a result, their sustainability is critically dependent on their ability to adapt to the local environment. Despite this, legislation to protect the environment from chemical contamination is often based on toxicological measurements conducted under optimal laboratory conditions and that does not take into account the variation in susceptibility of wild populations or the multiple stressors affecting these populations.

For metals, extreme cases exist of fish populations that can survive in highly contaminated waters, including a brown trout population in the River Hayle, where concentrations of metals far exceed the LC50 for this species. Furthermore, even for populations of fish inhabiting relatively un- impacted waters, their toxicological responses to metals can vary significantly. This highlights the need to understand natural and exposure-induced variations in the response of fish to pollutants, in order to appropriately manage and protect fish populations in their natural environment.

My research explores three key questions, firstly to determine if wild populations of three spined sticklebacks exhibit differential susceptibility to copper and if those characteristics can be inherited under control conditions. Secondly, my research aims to determine if differential susceptibility can be induced by exposure to copper during early life. Thirdly, I plan to investigate the fitness cost associated with differential susceptibility to copper in this species.

Together, this research will allow for a greater understanding of the variation in the responses to chemical stressors in wild populations, how they are induced and maintained and what are the consequences of changes in susceptibility to a pollutant on other parameters of fundamental importance to population sustainability. The data will build on previous data generated at Exeter, and will have implications for toxicity testing and regulation and for the management of wild fish populations.

My report on my attendance at the Canadian Conference for Fisheries Research is here

Publication
Uren Webster, T. M., Laing, L. V., Florance, H. & Santos, E. M. 2014. Effects of glyphosate and its formulation, Roundup, on reproduction in zebrafish (Danio rerio). Environmental Science & Technology48, 1271-1279.

Contact

Biosciences
College of Life & Environmental Sciences
University of Exeter
Exeter
EX4 4QD
UK

Email: ll292@exeter.ac.uk

PhD Studentship: Fish Ecology of Mesophotic Coral Reef Ecosystems

Dominic Andradi-Brown

University of Oxford

Supervisor(s): Alex Rogers (Oxford) and Dan Exton (Operation Wallacea)

Mesophotic coral reef ecosystems (MCE) occur in tropical regions extending from 30 m to the limit of the photic zone, c. 150 m.  These reefs are often connected to shallow coral reef ecosystems, where it is suggested they provide an important reservoir of recruits for coral and fish populations. Existing reef fish studies are highly depth biased mostly < 30 m, making the importance of mesophotic reefs to overall reef resilience in the face of human disturbances such as overfishing largely unknown, with a lack of evidence for whether fish populations on shallow reefs and adjacent MCEs are connected.

This study addresses this important information gap by using advanced diving technologies coupled with a newly developed stereo-video system and molecular ecology techniques to better understand fish communities by examining fish biomass distributions and community structure down depth gradients from shallow reefs to MCEs and by exploring the connectivity of MCE fish populations down depth gradients with shallow reefs and between mesophotic reefs.

This project is being conducted in partnership with Operation Wallacea with fieldwork principally based at their field site on Utila, Honduras where MCEs connected to shallow reefs have been identified but are unstudied.

The aims of the project are twofold, first to Investigate biomass and community structure. Fisheries value and ecological service provision requires biomass to be quantified as it provides a better indication of functional pressure exerted by a fish-feeding guild than richness or abundance. Fish biomass along transects will be assessed by stereo-video surveys capturing the shallow reef to MCE gradient at various fished and protected sites. Biomass will be standardised using fish length-weight relationships, through data from local fisheries monitoring programmes to obtain local length to weight ratios, but for any fish species not caught locally, through available datasets (e.g. Fishbase). To allow patterns in fish biomass and community structure to be explained, benthic composition will be quantified using point intercept video transects, quantifying coral (genera and morphology), algal and other coverage. Physical parameters will also be recorded including temperature, light and turbidity and HOBO loggers for detailed year-round temperature and light readings.

The second aim is to Investigate connectivity in MCE fish populations. Levels of population connectivity between populations of depth-generalist fish species with residents found on both shallow reefs and MCEs are not known. This has major implications for conservation and sustainable management of MCE fisheries, as well as the design and location of marine protected area networks. Many studies have demonstrated the ability of molecular techniques such as microsatellites to identify population structure; these protocols can be applied to assess connectivity down depth gradients and between MCE specialist species on small spatial scales. Non-lethal fin clippings will be collected from fish using a hand net and a clove oil anaesthetic mix. Care will be taken to return individuals to the reef where they were caught. To assess connectivity along depth gradients, samples of depth-generalist reef associated fish will be collected at different depths at several sites. To assess population connectivity between MCEs, an MCE specialist fish species will be identified samples collected at several sites.

Contact:

Ocean Research and Conservation Group
Department of Zoology
University of Oxford
The Tinbergen Building
South Parks Road
Oxford
OX1 3PS
UK

Email: dominic.andradi-brown@zoo.ox.ac.uk
Twitter: @dandradibrown
URL: http://www.zoo.ox.ac.uk/group/oceans

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