IBIS posters - at SFG - October 2013.pptx

7/27/2019 IBIS posters - at SFG - October 2013.pptx

1/8

The effect of temperature on morphology in Arctic charr

Conservation action without good science to underpin it is like alchemy, or faith healing. Both sometimes produce desirable results, but

you have no idea why, and mostly they do not(John Lawton, 1997 The science and non-science of conservation biology, OIKOS, 79:3-5).

Oliver HookerSupervisor: Prof. Colin Adams

University of Glasgow

Methods

Eggs from nine pairings of adult fish collected from the River Coulin, Wester Ross ,Scotland were used.Eggs were separated upon reaching the eyed stage and then exposed to a warmand cold temperature treatment (Fig 1).Photograph samples used for analysing shape change were taken at 250 degreedays (dd), 600dd, 1000dd and 1400dd.A total of eighteen landmarks were digitised on to imagesShapes of warm and cold fish were compared using geometric morphometricanalysis.

ResultsCanonical variance analysis (CVA) compared shape change between groups andfound all sample stages to be significantly different for Mahalanobis distancesand Procrustes distances (table 1, fig 2).Classification/misclassification scores from discriminant function analysismeasured at 250dd, 600dd, 100dd and 1400dd are given in table 2.

DiscussionPolymorphic populations of Arctic charr that are occur living in sympatry primarily arise due to divergences in their foraging choices.Fish that feed on smaller (micro invertebrates) pelagic prey items are larger and characterised by having a narrower head, pointier nose, elongated headand jaw and a compressed more fusiform body. Fish feeding on larger (macro invertebrates) benthic prey items are smaller, having a wider and shorter,more robust head shape, and a deeper, thicker set body.These characteristics are consistent and well documented across sympatric populations of Arctic charr in Scotland and Northern Europe.In this study cooler water fish developed both a head that is more suited to feeding on pelagic prey items and body shape more suited to a pelagicenvironment, whilst warmer water fish developed a head more suited to feeding on benthic prey items and a body shape more in tune with a benthichabitat (Fig 2).This may have ecological consequences on fish populations at extreme latitudes by influencing the resources a species target and how it uses its habitat.

ntroductionClimate change is predicted to raise the average temperature of the Earthssurface between 2-5 Co causing an increases in water temperatures.In addition, changes in the form of winter precipitation (from snow to rain) mayincrease winter flows in rivers and reduce or remove snowmelt meaning laketemperatures increase more sharply in spring.A study by Beachamshowed that temperature during early developmental stagesin salmon can significantly influence differences in body shape.Growth rates in Arctic charr exposed to two different temperatures was exploredto identify if it is proportionate (isometric) or disproportionate (allometric) acrossthe fishes anatomy.

0

2

4

6

8

10

12

14

16

0 dd 0-250 dd 250-600 dd 600-1000 dd 1000-1400 dd

Temperature(C)

Sample stages

Sample

time

Mahalanobis

distances

among

groups: Cold v

Warm

P-values from

permutation tests

(10000 permutation

rounds) for Mahalanobis

distances among groups:

Cold v Warm

Procrustes

distances

among

groups: Cold v

Warm

P-values from

permutation tests (10000

permutation rounds) for

Procrustes distances

among groups: Cold v

Warm

250dd 2.2021.


2/8

Conservation Limits of Atlantic Salmon (Salmo salar)Julie Miller


Supervisor: Prof. C. Adams

Introduction

Atlantic salmon (Salmo salar) are listed under annexe II of the EU habitats directive. Despiteinternational conservation efforts wild populations are in decline (Prevost et al 2003) Under the EU habitats directive (92/43/EEC) conservation efforts designate importantsalmon riverine habitat as Special Areas of Conservation (SAC) and these together with theobjectives of the Freshwater framework directive (2000/60/EC) seek to protect salmonpopulations as per the precautionaryapproach (NASCO 1998). That is, the stocks are managedwithin safe biological limits, ConservationLimits (CL) The Foyle and its tributaries in Northern Ireland are an important area for Atlantic salmon.The Loughs Agency (LA) manages the system using conservation limits (CL) derived from amodel that places assumptions on egg deposition levels, female fecundity and quality of habitat.

Similar models are utilised by Loch Lomond Fisheries Trust (LLFT). The trust surveys riverscollecting data on habitat type and fish density at sites.

Aim to account for assumptions in the LA model via sensitivity analysis using alternative parameter values from scientificliterature and attempt to quantify, if any, the links between habitat and salmon fry density using LLFT data.

Conclusion To manage salmon populations in the context

of the precautionaryapproach it is necessaryto identify areas of uncertainty andassumption in models and populations. Assuch, sensitivity should be explored toidentify potential risk or over caution in

management strategies. There is a paucity of empirical studies linkinghabitat quality with juvenile density, not only inthe Foyle system but throughout the widerliterature.Management should strive to fill knowledgegaps of population variables on a river by riverbasis.The complex interplay between salmon andtheir environment not only presents difficulty inidentifying optimal habitat conditions forsalmon survival at each life stage but equally forrestoring, conserving and protecting salmonhabitats for optimum persistence of populations.

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

Mourne Finn Faughan Roe

FishNumbers(CL)

River

Absolute and mean sensitivity values of CLs

(Fecundity)

LA (Absolute values)

Sensitivity

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

10000

Mourne Finn Faughan Roe

NumberofFish

River

Absolute and mean sensitivity values of CLs

(Egg deposition)

LA (Absolute values)

Sensitivity

Egg Deposition

Per m2/Grade10 6.6 7.4 2.4

4.4

8.0

2.9

4.7

7.4

8.5-10.7

Source LA

Shearer

(1992)

Crozieretal

(2003)

Prevostet

al(2003)

OMaoildigh

etal(2004)

C ro zi er &

Kennedy(1995)

Methods Loughs Agency model was reviewed using most up to date habitat and GIS

information. Sensitivity analysis based on different scenarios of egg deposition(Table 1), habitat quality, fecundity of females (Table 2) and weight was conducted.

Fish density and habitat grade data analysed under H0- there is no differencebetween habitat grade and salmon density

Bayesian MCMC technique and LLFT electrofishing/habitat site data were used to

identify parameters important for juvenile salmon density, using DIC (Figure 3).Habitat grade then redefines according to results. These was then analysed underH0-there is no difference between habitat grade and salmon density.

Fish density and habitat grade analysed using sites sampled at different years underH0-there is no temporal difference between fish density and habitat grade

The H0 that there was no difference between fish density and habitatgrade was accepted, , p=0.3761 (Figure 6).

Post MCMC analysis habitat was re-graded based on the parametersindicated as increasing the probability of observing the fishcounts(Fig.7). Again analysis accepted the H0, p =0.9935. Furtheranalysis on temporal differences between the same habitat and fishdensity rejected the H0, p = 0.031 ,indicating a temporal difference.

Figure1 (LHS) & Figure 2 (RHS) both showing theFoyle catchment in Northern Ireland. Figure 2 depictsstudy sites included in the analysis. The River Roe

catchment: light blue, River Finn: dark blue, Mourne:dark green and Faughan: light green

Results The results for the sensitivity analysis suggested that of the 4 rivers the Finn and the Roe either

exceeded or fell within the 95% confidence intervals for sensitivity. The Faughan was either at thelower end of the 95% interval or below. On every occasion the Mourne was well below theconfidence intervals (Figs. 4 & 5).

Figure 3: Directed Acyclic Graph of Bayesmodel

Table 1: Egg deposition values and corresponding source

FecundityEggsperkg-1 1,000 1,430 1000-

2000

1,100 992-

1,543

1,878

SourceLA

Shearer(1992)

NASCO(1998)

Natura 2000Cowyx & Fraser

(2003)

AST/SNH(2012)

Crozier&

Kennedy(1995)

Table 2: Fecundity values and corresponding source

Figure 4: Egg deposition sensitivityresults with standard error

Figure 5: Fecundity sensitivityresults with standard error

Figure 7: Post analysis re-graded scatterplotof fish density and habitat grade

Figure 6: Scatterplot of electrofishingdensity and habitat grade

A project supported by the European Union's INTERREG IVA Programme managed by the Special EU Programmes Bodynces: CowxIG& Fraser D(2003). Monitoring the AtlanticSalmon. ConservingNatura2000 RiversMonitoringSeriesNo. 7, EnglishNature, Peterborough., W.W., andG.J. A.Kennedy (1995). "Therelationship betweena summerfry (0+) abundanceindex, derivedfrom semiquantitativeelectrofishing, andeggdeposition ofAtlantic salmon, intheRiver Bush, NorthernIreland."Journalof Fish Biology47.6 pp.1055-1062.

r, W.W., et al.(2003). "Acoordinatedapproachtowards thedevelopment ofa scientific basisfor management ofwildAtlantic salmoninthe North-East Atlantic (SALMODEL)."QueensUniversity ofBelfast, Belfast.O (1998)NorthAtlantic SalmonConservationOrganisation. Agreement on the adoption ofa precautionary approach.Reportof thefifteenthannual meetingof thecouncil.CNL(98)46 pp.4

lidigh, N., et al. (2004): "Applicationofpre-fishery abundancemodellingand Bayesianhierarchical stock andrecruitment analysisto theprovisionof precautionary catchadvicefor Irishsalmon( SalmosalarL .) fisheries." ICESJournal ofMarine Science 61.8 pp.1370-1378.st, Etienne, et al. (2003)"Settingbiological referencepoints for Atlantic salmonstocks: transferof informationfrom data-richto sparse-datasituationsby Bayesianhierarchical modelling."ICESJournal ofMarine Science: Journaldu Conseil60.6 pp.1177-1193.r, W.M (1992). The AtlanticSalmon.Natural history, Exploitation and Future Management, FishingNewsBooks, BlackwellSciencePublicationsLTD

tes: Figure1: http://www.fishpal.com/Ireland/Foyle/Map.asp, Atlantic Salmon Trust(AST)/Scottish NaturalHeritage(SNH):http://dpea.scotland.gov.uk/Documents/qJ14364/A2971555.pdf
http://www.fishpal.com/Ireland/Foyle/Map.asphttp://dpea.scotland.gov.uk/Documents/qJ14364/A2971555.pdfhttp://dpea.scotland.gov.uk/Documents/qJ14364/A2971555.pdfhttp://www.fishpal.com/Ireland/Foyle/Map.asphttp://www.fishpal.com/Ireland/Foyle/Map.asp


3/8

An alternative approach to measuring shape change in fish

Conservation action without good science to underpin it is like alchemy, or faith healing. Both sometimes produce desirable results, but

ou have no idea why, and mostly they do not(John Lawton, 1997 The science and non-science of conservation biology, OIKOS, 79:3-5).

Oliver HookerSupervisor: Prof. Colin Adams


Methods

Arctic charr were raised in a controlled environment and exposed to three different diets from first feeding.Fish were fed on either Daphnia, Bloodworm or Gammarus to induce morphological variation amongst groups

of individuals.Fish were photographed from a lateral and dorsal view before having landmarks (easily identified from bothviews) digitised on to images (Fig 1).Variation between and amongst dietary prioris was then analysed using the software MorphoJ.

esults

Both views differentiated between morphseffectively using canonical variance (CV) analysis(Fig 2 and 3).The dorsal approach accounted for more variation(72%) using the first CV.Comparisons between the three dietary groupsshowed higher levels of significance using the lateralview for Procrustes distances (Table 1).

Significance was lost when comparing Procrustesdistances between Daphnia and Gammarus usingthe dorsal view.

iscussion

The aerial view was not as sensitive to identifyingchange between groups.It does however give insight in to other shapechanges in the head that otherwise go unnoticedby a lateral view alone.Changes in head width can now be seen which isimportant when comparing ecomorphs.The angle at which the eyes are set also show a lotof variation which will effect the peripheral view

and thus is improtant in foraging efficiency andhunting.Both of these previously undetected changes inshape are important when studying functionalecology.An aerial view approach to geometricmorphometrics compliments and adds anatomicalinformation and is therefore important whentrying to further our understanding of the effect ofecological drivers on morphology.

ntroductionTraditional geometric morphometrics uses a lateral image when analysing shapes in fish.Generating 3D images can be laborious and costly so is often not possible.The result is that only part of the morphological variation is analysed.Valuable data can therefore be missed which may be important especially in the field of evolution andfunctional ecology.By using images taken from a dorsal approach it may be possible to asses changes that may other wise bemissed from a lateral image alone.The ability to distinguish ecomorphs of Arctic charr was explored to asses the efficacy of dorsal analyses andidentify any additional information that may be provided.

CV161%

View Lateral Lateral Dorsal Dorsal

Comparison Mahalanobisdistance

Procrustesdistance

Mahalanobisdistance

Procrustesdistance

Daphnia V Bloodworm


4/8

Geometric morphometric analysis of a sympatric

population of Brown trout, Salmo trut ta(L.)

Martin HughesUniversity of Glasgow

Introduction

Morphological plasticity is common in salmonids. We examined the morphological differences between a sympatric brown trout population.

As the anatomical design of a predatory fish is central in determining which prey species they can consume, we examined whole body morphologyof brown trout exploiting different resources.

Using geometric morphometrics and multivariate statistics, we examined differences between ferox (piscivorous) and brown (omnivorous) trout.

Adult ferox trout are classically described as sizeable trout with a disproportionally large head and jaw with significant teeth.

Despite various anecdotal records of ferox trout, morphological differences have yet to be investigated quantitatively.

Morphological variation could serve as a basis for genetic work if differentiation between populations were significant enough to suggestsegregated reproduction.

Identifying juvenile populations of ferox trout may be critical in conserving young cohorts of this potentially vulnerable life history strategy.

A project supported by the European Union's INTERREG IVA Programme managed by the Special EU Programmes Body

SummaryPreliminary results suggest differences in morphology exist between the sympatric forms of trout examined here in Loch Rannoch. Although size accounts for a significant amount of variation, each population is still distinguishable after removing size effects. Our initial results suggest ferox trout from Loch Rannoch are morphologically discrete from sympatric brown trout .

esultsfrom pooledwithin-groupregressions(Residuals& Predictions).

MATERIALS AND METHODS

Brown trout were collected from Loch Rannoch,Scotland. Each trout was photographed laterally andlandmarked using tpsDig software to generate thin

plate spline (TPS) files.

Twenty landmarks were digitized for each fish.

All computations for statistical analyses and graphicaldisplay of the results were carried out using routineswritten in MorphoJ software for this study.

We assessed the effects of allometry in the data bymultivariate regression of shape on centroid size.

Differences in brown trout forms were based onprocrustes distance and between group variation wasassessed using canonical variate analysis (CVA).

RESULTS

Figure 3. Canonical Variate Analysis (CVA) pooled within-group regression residuals.

Figure 1. Trout Wireframe

Figure 2. Ferox Wireframe

A regression was run for each form (brown & ferox), the permutation test for browntrout (n= 29) showed size did not have a significant effect on shape(P = 0.1301) .

Similarly for ferox trout (n=26) size had no significant effect on shape (P= 0.1041).

Between groups (n=55) size had a highly significant effect on shape (P =


5/8

Modelling the early life stages of Atlantic salmon to improve

conservation limit estimationsHannele Honkanen


Introduction Atlantic salmon has a long history of being the target of commercial and recreational fisheries and while Atlantic salmon as a species is far fromextinction due to the numbers of farmed salmon, the wild Atlantic salmon stocks throughout their range are declining with many populations nowextirpated (Parrish et al. 1998).

Conservation limit (CL) defines the level of spawning stock under which recruitment would begin to decline significantly (Anon, 2011).

Knowledge of the species biology and habitat requirements can be linked with habitat data to create a model that predicts the distribution of thatspecies. As salmonids have fairly strict habitat requirements, this can be used to estimate the relationship between the stream habitat and salmonidabundance (Armstrong et al. 2003).

Loughs Agency monitors salmonid populations in the Foyle and Carlingford catchments in the border region of Ireland and Northern Ireland and usesa model to estimate the sizes of salmon populations in the rivers. The model includes collected information on redd counts, electrofishing data onjuveniles, fish counters and habitat surveys, and is used to estimate river-specific conservation limits and management targets which form the basis of thefishery management in the area.

Improved understanding of the habitat requirements of juvenile Atlantic salmon

leading to a revised habitat grading system.


Summary In addition to the high fishing pressure at sea, additional reasons explaining thedeclining Atlantic salmon numbers could be found in the freshwater habitat.

Knowledge of the species biology and habitat requirements can be linked withhabitat data to create a model that predicts the distribution of that species.

Electrofishing and habitat surveys were done on 72 sites in Northern Ireland withthe aim to study the relationship between habitat and juvenile salmon abundance.

Methods

The sampling sites are chosen using the Lough Agency GISdatabase. Sites are chosen based on the grade andaccessibility. Three catchments (Roe, Faughan andCamowen) are sampled.

At each site, an electrofishing survey is conducted. Afterfishing, the fish are anaesthetised and then identified (salmonor trout) and measured. After recovery, fish are returnedback to the river.

After the electrofishing survey a habitat survey, whichmeasures the area fished, the flow conditions, depth,substrate, cover (instream, bankside and canopy), vegetationand bankside use, is done.

Aims Study if there is a relationship between habitat and juvenile

salmon abundance, and if so, establish which particularhabitat variables (and their potential interactions) areimportant in creating optimal juvenile habitat.

Create a revised habitat grading system for the LoughsAgency, leading to improved conservation limits for theirsalmon management program.

Study the accuracy of the current Loughs Agency habitatgrading system.

Study the role of suboptimal habitat for salmon productivity.

Results so far and future workA total of 72 sites were surveyed; 27 on Roe, 22 on Faughan and 23 on Camowen.

Overall 1983 fish (1605 salmon and 378 brown trout) were caught.

Analysis of this data is still ongoing.

In the coming months the model will be expanded with additional, long term data setson Atlantic salmon life history and catch records. The overall aim of the project is tobuild a comprehensive understanding of the ecology of the Foyle catchment salmon

and the factors that drive the population structure.

References: Parrish, D. L., Behnke, R. J., Gephard, S. R., McCormick, S. D., Reeves, G. H. 1998. Why arent there more Atlantic salmon (Salmo salar)? Canadian Journal of Fisheries and Aquatic Sciences, 55: 281-287. || Anonymous. 2011. Loughs Agency Salmon ManagementStrategy || Crozier, W. W., Potter, E. C. E., Prvost, E., Schn, P-J., Maoilidigh, N. (Editors). 2003. A coordinated approach towards the development of a scientific basis f or management of wild Atlantic salmon in the North-East Atlantic (SALMODEL). Queens University ofBelfast, Belfast. pp. 431. || Armstrong, J.D., Kemp, P.S., Kennedy, G.J.A., Ladle, M., Milner, N.J. 2003. Habitat requirements of Atlantic salmon and brown trout in rivers and streams. Fisheries Research, 62: 143-170.


6/8

Life History Strategies of the European eel

James Barry


Introduction

In the last 30 years, the European eel (Anguilla anguilla) has shown a 90% decrease in the number of juvenile fish found in European waters.

There is a large body of evidence from across the EU that European eel populations are continuing to decline and in some areas thepopulations are now below a sustainable threshold.

The vast geographical distribution and the two trans-Atlantic migrations the species makes to mature and reproduce means finding thereasons underpinning this decline have remained elusive.

The European Commission has made it a requirement that member states develop plans for the freshwater management of this species.

This project aims to investigate inland population dynamics through sampling of eels from sites throughout the study area, with particularinterest on trophic morphology, migrations and habitat use in study sites.

A complete assessment of eel populations in chosen study sites will be conducted which will improve our understanding of residentpopulations and will aid in developing a practical eel management plan based on sound scientific principles.

Summary

European eel populations are under serious threat from collapse

Using the methods outlined will help answer questions related to thehabitat use and trophic ecology of European eels within the study area.

Phenotypic response is driven by environment, changes in theecosystem whether natural or anthropogenic may then also induce shiftsin the ratio of both phenotypes.

This potential two way relationship between phenotype and ecologysuggests that efforts towards conservation may require the assessment ofmorphological variation within the population and its proximate causesespecially if there are fitness related consequences.

Evidence gained from this project will be used to set meaningful targetsand highlight appropriate management options to aid achieving EUtargets for sustainable eel stocks.

Identify effective conservation measures to aid the restoration of European eel populations

European eel life cycle

Glass eel(4-7cm), enter our estuariesfrom March-June.

Elver(7-30cm), migrate into our riverand lakes in search of suitable

habitat.

Yellow eel(>30cm), this is the feeding stage.Resident eels begin to condition

themselves in preparation for their

spawning migration.

Silver eel(>30cm), leave our rivers and lakes in late

Autumn and begin their spawning migrationestimated at 6000km in the direction of the

Sargasso Sea.

Eel larvaetravel 6000km from spawning

grounds, travelling on ocean currents

en route to European waterways.

Combining SIA, Morphometric

data and TelemetrySIA (Stable Isotope Analysis); C and N stable isotope analyses (SIA) of fish tissueis essential to enable identification of the long term foraging history of populationsand individuals.

Morphometric analysis; Individual specialisation within a population can lead tothe occurrence of discrete morphs. The existence of two morphotypes, broadheaded

and narrowheaded, in eels has been observed however little is known about theecological significance of this variation.

Telemetry; will provide insight into the habitat use and movement of eels withinthe study area.

Narrow headInsect feeder

Broad headFish feeder

Fitnessconsequen

ces,narrow

headdisplayingsignificantl

y higherbody fat

B

N

Comparison of broad and narrow headyellow eel specimens (both 48cm)

Inner ear bone used for ageingand growth analysis

Position ofreceivers and

detection zoneswithin Lough Finn


7/8

Partial migration: Why Do Some Brown Trout (Salmo trut ta)

Become Migratory (Sea) Trout?Jessica Fordyce


Introduction

Brown trout demonstrate partial migration (where some individual of a species within a population migrate, while others do not) as they have twodifferent life- history strategies where some brown trout remain resident and others migrate to sea (Figure 1) (Dringle and Drake, 2007). Theenvironmental trigger(s) which promotes a migratory life history are poorly understood (Klemetsen et al, 2003). The leading theory is that food availability is the driving force for partial migration in brown trout as low food availability would promote amigratory life history as a low growth rate is known to trigger migratory behaviour in brown trout (Hendry et al, 2003; Wysujack et al, 2009). There have been many studies which have examined gene flow between sympatric populations of resident and migratory brown trout but withdiffering results (Ferguson, 2006). Some have demonstrated that there is gene flow and others have show that there is none (Jonsson, 2006; Antunes et

al, 1999). Resident brown trout show great differences in both phenotypic and genetic structuring within and between populations (Charles et al. 2006;Antunes et al, 1999).Aims:

Determine if food availability is the environmental trigger which promotes a migratory life history in brown troutEstablish if there is gene flow between sympatric populations of migratory and resident brown troutDetermine the population structure of brown trout both phenotypically and genetically on a large, medium and fine-scale

Understanding the environmental trigger(s) which promote partial migration in brown trout and

their population structure


Summary

There are many gaps in the knowledge regarding brown trout ecologywith regards to partial migration and their population structure. Once the driving forces of partial migration are understood, bettermanagement practices can be implemented to increase migratory browntrout numbers. By determining the population structure of brown trout it is possible toconserve genetically and phenotypically distinct populations which iscritical to manage a species (Charles et al, 2006).

Results and Future work

A total of 61 migratory brown trout genetic samples were collectedfrom 5 sites and 1574 resident brown trout genetic samples werecollected from 26 sites. From these genetic samples both the populationstructure will be established and whether there is gene flow betweensympatric populations of migratory and resident brown trout. Furthermore, invertebrate kick samples were collected to determineif food availability is the trigger for partial migration in brown trout.

owledgements: Thank you to the Atlantic Salmon Trust who have helped fund this projectrences:Antunes. A., Apostolidis. A., Berrebi. P., Duguid. A., Ferguson. A., Garcia- Marin. J., Guyomard. R., Hansen. M., Hindar. K., Koljonen. M., Laikre. L., Largiader. C., Martinez. P., Nielsen. E., Palm. S., Ruzzante. D., Ryman. N. And Triantaphyllidis. C., 1999. Conservation Genetic Management of Brown Trout (Salmo trutta) in Europe. Available at: http://www.fs.fed.us/rm/boise/publications/BTWorkshop/Conservation%20genetics%20of%20BrnT%Europe.pdf [accessed5/2012]; Charles. K., Roussel. J-M., Lebel. J-M., Baglinire. J-L. and Ombredane. D., 2006. Genetic Di fferentiation Between Anadromous and Freshwater Resident Brown Trout (Salmo trutta L): Insights Obtained from Stable Isotope Analysis. Ecology of Freshwater Fish. 15, pp. 225-263.; Dingle. H. and Drake. V., 2007. What is Migration? BioScience. 57(2), pp. 113-121.; Ferguson. A., 2006. Genetics of Sea Trout with particular reference to Britain and Ireland. Sea Trout:gy, conservation and management. Chapter12, pp: 157-182. Published by Blackwell publishing limited (oxford); Hendry. A., Bohlin.T., Jonsson. B. and Berg. O., 2003. To Sea or Not to Sea? Evolution Illuminated: Salmon and their Relatives . chapter 3, pp. 92-125. Oxford University Press. ; Jonsson. B., 2006. Life History of Anadromous Trout. Sea Trout: Biology, conservation and management. Chapter14, pp: 196-223. Published by Blackwell publishing limited (oxford);etsen. A., Amundsen. P., Dempson. J., Jonsson. B., Jonsson. N., O'Connell. M. Mortensen. E., 2003. Atlantic salmon Salmo salarL., Brown trout Salmo trutta L. and Arctic charr Salvelinus alpinus (L.): a Review of Aspects of Their Life Histories. Ecology of Freshwater Fish . 12, pp. 1-59.; Wysujack. K., Greenberg. L., Bergman. E. and Olsson. I., 2009. The Role of the Environment in Partial Migration: Food Availability Affects the Adoption of a Migratory Tactic in Brown Trouto trutta. Ecology of Freshwater Fish, 18(1), pp.5259.

Methods The sites chosen for this project were located around the Foyle catchment, Northern

Ireland (Figure 2). The sites were surveyed by electrofishing in April/May for migratory brown trout andJuly- September for resident brown trout. Data collected from each brown trout was:genetic sample, scale sample, weight, length and a photo. To determine if food availability is the environmental trigger for migration, 6x 30second kick samples were collected from each of the 5 sites where migratory brown troutwere recorded.

Figure 2: This map shows where the sites are which were surveyed. Blue points are

where resident brown trout were collected and purple points are where migratory and

resident brown trout were collected.

Figure 1: This demonstrates the differences between a resident and migratory brown

trout. On the left is a resident brown trout and on the right is a migratory brown trout.


8/8

Assessing the toxicity of biocides on the American Signal crayfish

(Pacifastacus leniusculus) to aid eradication in Scotland

Sinead O Reilly


Introduction

The Signal crayfish (Pacifastacus leniusculus) is one of the most widely distributed non-indigenous crayfishspecies. Now established in 21 countries in the EU.

Introduced to supplement crayfish stocks, aquaculture and scientific research, pet trade and accidentally.

Arrived in Scotland in the mid 1980s, it is now established in several catchments e.g. Clyde, with up to 174kminvaded. It is also present in several large and small lochs e.g. Loch Ken & Loch Tay . Can also be found in small

quarry ponds and garden ponds.

Its impacts to Scottish freshwaters ecosystems and biodiversity are of great concern. Its having a negative impact onnative species such as salmonids, molluscs and benthic macrophytes .

With its broad range of diet including fish, detritus, macrophytes, invertebrates is impacting on the freshwater foodweb, competing for shelter, causing physical disruption of habitat by burrowing resulting in erosion andsedimentation. It is also a carrier of the chronic crayfish plaque , a disease fatal to the white clawed crayfish.

Listed on the Species Action Framework (SAF) by the Scottish Government as one of the five invasive non-nativespecies of concern in Scotland

Current eradication methods, both biological, physical and mechanical have been unsuccessful with the exception ofbiocides. Previous work with the biocide Pyblast may have been overused. Toxicity values for field application maybe more accurately predicted in the laboratory.

Investigate the acute toxicity of the biocide Pyblast used to eradicate signal crayfish

Summary The Signal crayfish is present in Scotland since 1980s and iscurrently in over 174km of catchment and spreading.

Its presence is having a huge negative impact on the Scottishfreshwater ecosystem and biodiversity

Biocide treatment is a successful method used to eradicate thespecies

By calculating the correct LC50 to be applied to the field, it willreduce both economic and environmental costs.

roject Outline

The fundamental objective of this study is to obtain reliable LC 50 concentrations ofthe selected biocides on the crayfish in a series of laboratory experiments. The LC50is the concentration that is lethal to 50% of the organism in a toxicity test to helppredict the effects of a toxin and define the maximum allowable toxicantconcentrations.Determine the 48hr LC50 of Pyblast on hatchlings, immature and mature adults in a48hr exposure in the laboratory.

Carry out analytics on selected concentrations used before, during after exposure tocompare the actual concentrations, to the concentrations believed to be used in thetests.Perform range tests on the toxicity of a select number of sea lice chemicals,Emamectin benzoate, Azamethiphos and Deltamethrin, on adult signal crayfish.Find an acute toxicity range on the Killer shrimp Dikerogammarus villosus (aninvasive species not in Scotland) using Pyblast.

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