Download Marine Examen projects VT 2015

Förslag till
Marina exjobb
vår o sommar 2016
1: Live in a flume - local adaptation to extreme physical stress from wave
action
Where: Tjärnö Supervisor: Kerstin Johannesson
[email protected]
(The student will be part of the CeMEB project, www.cemeb.science.gu.se)
Background: Periwinkle snails, Littorina saxatilis, live in the splash zone of rocky
shores. Snails are under strong selection from waves, and, in particular, the snails
living in rocky shores facing strong wave action have to resist very rapid water
movements (2-3 metres per second or more).
Problem: A basic question is: Do snails from shores with more wave action resist
higher speeds of water flow than snails from snails with less wave action? This
question is presumably trivial (although very few studies have been performed
earlier), and will therefore be expanded to include more detailed questions of how
snails adapt. Is this only by means of natural selection, or can snails be trained to
resist more wave action? How much is the resistance a matter of physical strength,
foot area, and behaviour of the snail? How long time can snails resist high water
speed before they become tired, and how does this differ between snails exercised in
high water flow and those not exercised? Depending on the length of the study, it
may also be possible to include a part in which gene expression are measured in
relaxed and wave stressed snails to identify what genes are key actors in the
physiology of resistance to wave stress.
Method: A special high-speed flow tank is already available, built specifically for
testing snails and other smaller organisms in strong water flows. The tank can be
equipped with a laser beam to measure speed of water.
Level: Master level (45-60 hec)
2: Phenotypic and genetic variation in the seaweed Fucus vesiculosus over
small spatial gradients of wave exposure.
Subdiscipline: Marine Evolutionary Ecology
Where: Tjärnö
Supervisor: Kerstin Johannesson & Rick Pereyra
(The student will be part of the CeMEB project, www.cemeb.science.gu.se)
[email protected]
Background: The common brown algae Fucus vesiculosus (bladder wrack) is
phenotypically variable with a more slender and less often vesiculated thallus in wave
exposed areas, as compared to protected areas. This can be due to one or several of
the following hypotheses; (1) phenotypic plasticity, (2) inherited differences
accumulated in spite of strong gene flow between sites of different exposure, (3)
inherited differences as a result of both isolation and differential selection.
Problem: To assess the importance of the three possible explanations outlined above
requires a combined approach assessing both gene flow and the level of inheritance
of trait differences. Gene flow will be assessed using so called microsatellite genetic
markers (which are available for this species). Plasticity versus inheritance is best
evaluated using a common garden approach, in which newly settled algae from
different environments are brought into the lab and raised in a common environment.
The phenotypes being analysed using morphometric approaches and possibly also
resistance to water speed can be measured using a high-speed flow tank.
Level: Master level (45-60 hec)
3: Benthic habitats and associated fish-fauna in Kosterhavet
National park
Contact: [email protected]
Kosterhavet national park was opened in 2009 in order to protect its unique marine fauna and
flora (see link). The park is managed by the County administrative boad of Västra Götaland
according to an existing management plan but continuous collaboration with the research
community is aimed at developing better monitoring and protection of biodiversity. As an
example of this, an extensive survey of the distribution and composition of bottom-dwelling
fish and benthic habitats is currently being performed in the park. Using standardised
sampling methods for fish and video-recordings of benthic habitats in 200-300 localities (at 130 m), we have access to data for quanitifying, modelling and mapping both fish and benthos
in this unique area.
We invite one or preferrably two students to develop projects in quantitative analyses of biodiversity of fish and benthic organisms (e.g. estimation of structural biodiversity and spatial distribution of fish and benthos, analyses of interactions between fish-­‐ and benthic assemblages, etc.). The project will be done in collaboration between the Department of Marine Sciences, the Department of Aquatic resources at the Swedish Agricultural University and responsible and the national park (see www.prehab.gu.se for examples of earlier collaborations and methodological toolbox). The data and conlusions will be shared and communicated through existing channels to responsible authorities for the benefit of future management. The detailed final project plan will be decided based on the potential students’ background and interests. It is mainly suitable for 30-­‐60 ECT projects but shorter projects can be discussed if this is not possible. 4: Bivalve adaptation potential to ocean acidification and selection of resilient strains
Master or Bachelor student project
Place: Kristineberg
Time frame: May-July 2016
Contacts:
Sam Dupont ([email protected])
Alexander Ventura ([email protected])
Background
The purpose of the project is to understand if and how bivalves of high commercial value in
Europe (e. g. blue mussels and oysters) may adapt to environmental change. The focus is on
bivalves’ evolutionary responses to ocean acidification, which is an increase in ocean acidity
linked to human-induced rise in atmospheric CO2 concentrations. The effects ocean
acidification has on sea water chemistry may negatively impact organisms with calcium
carbonate shells. However all species are able to adapt to changes in their environment
through evolution based on natural selection. The problem may arise if changes in
environmental parameters are too abrupt as this may not allow a species to adapt in time. The
possibility of artificially selecting ocean acidification resilient bivalve strains will also be
explored. This will be attempted by picking out those individuals in a population that better
withstand low pH conditions in the lab.
M.Sc/B.Sc student involvement
Next summer a cross-breeding experiment will be conducted to investigate heritability of
selected traits in mussel larvae in the face of ocean acidification which will shed some light
on the adaptation potential of these organisms. Gametes will be collected from several male
and female mussels and eggs will be fertilized in all possible combinations to generate several
larval lines through which heritability of traits such as growth and calcification will be
determined using quantitative genetic techniques. The experiment would suit both a Masters
and a Bachelor project. The work will include: monitoring mussel larval cultures and
measuring several physiological parameters daily, culturing of microalgae (as food for the
larvae) and measuring water chemistry parameters.
5: Miljöeffekter av utsläpp från konstgräsplaner: hur påverkas fiskar av partiklarna
som hamnar i våra vattendrag?
Fotbollsplaner med konstgräs blir vanligare allt eftersom naturligt gräs ersätts med dessa
produkter, som är gjorda av nyproducerad och återvunnen gummi. Studier har visat att
konstgräs släpper ifrån sig en del farliga kemikalier som tex PAHer och metaller.
Kemikalierna är kända mutagener och cancerogena ämnen. Vi vet inte exakt vilka mängder
gummi som hamnar i miljön och en del av projektet gäller undersökningar av dagvatten samt
dess utlopp i Göteborgs hamn. Vi vill också använda gummipartiklarna i toxicitets tester för
att mäta effekter av dessa på magtarmkanelens fysiologi och barriäregenskaper hos fisk.
Studenten kommer att få möjlighet att arbeta delvis med fältprovtagningar samt laborativt.
Projektet är baserat på fysiologiska samt ekotoxikologiska frågeställningar.
Projektet bäst lämpad för masters nivå. Kan göras vilken tid på året som helst.
Plats: Zoologen i Göteborg.
Kontakta
[email protected] eller [email protected]
6: Predictive biogeography – studying the invasive potential of marine alien species
Contact to: Mattias Obst. [email protected]
Project description: Biological invasions have dramatically increased in coastal
environments over the past decades, causing homogenization of communities and
contributing to global decline of biodiversity. Statistical correlation approaches such
as species distribution modelling (SDM) are invaluable methods to predict the impact
of potentially invasive species and allow preventive measures to be put in place
before alien organisms establish breeding populations. The Department of Marine
Sciences offers research opportunities to interested students who want to analyse
such invasive patterns in the North East Atlantic, or other regions of the world. The
work will imply some activity in the field of citizen science, collection of taxonomic,
ecological, and environmental information, as well as species distribution modelling
under present and future climate scenarios for a number of marine alien species. The
student will analyse the data to better understand the invasive potential of the aliens
and anticipate the impacts from anthropogenic activities. Examples for possible
target groups are harmful algal blooms, aquaculture pests, disease carriers, or any
other ecological key species. Methods will come from the fields of taxonomy,
biogeography, species distribution modelling, and statistics. An example for
inspiration is here:
http://www.sciencedirect.com/science/article/pii/S0025326X15002350
Level: BSc, MSc
Qualities: The students has to speak fluent english.
Period: Spring 2016
Where: The student will be located at the Zoologen building and/or one of the Marine
stations. The project supervisors will be Matthias Obst, for more information see
http://marine.gu.se/english/about-us/staff?languageId=100001&userId=xobsma
Norwegian*Sea*
*Atlan/c*
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7: DEVELOPMENT OF ANALYTICAL METHODOLOGY FOR STUDIES OF INTRACELLULAR PROCESSES IN MARINE ORGANISMS WITH CONFOCAL RAMAN
SPECTROSCOPY
Contact:
Katarina Abrahamsson, [email protected]
Alexandra Walsh, [email protected]
Where:
Campus Johanneberg, Gothenburg
BACKGROUND
There is a need to advance methodology to decode how changes in environmental factors and
industrial processes influence ecosystems and human health, i.e. increase our understanding
of cellular processes from molecules to organisms to ecosystems. Environmental factors alter
molecules, cells and physiological processes inside organisms. Therefore, one major
challenge is to develop an increased understanding of the different responses to environmental
changes at many biological levels including molecules, cells, cellular communities, tissues
and organisms.
Raman spectroscopy, especially in its combination with microscopy, is a tool for advanced
studies on a molecular level in environmental research. It has unique features, including little
or no sample preparation, non-destructive, etc. Raman spectroscopy is unique in the sense
that it is possible to perform detailed studies of cells in their natural state without
perturbations of e.g. dyes, mechanical sectioning or other preparation procedures.
AIM
The aim of this master thesis project is to optimize the introduction of gold or silver colloids
in algae cells. The colloids are necessary to achieve singal enhancement of individual
molecules. You will specifically study the enzymatic formation of ozone depleting
compounds such as bromoform.
METHODOLOGY
The instrumentation used is our confocal Raman spectrometer equipped with three laser lines.
The reults will be evaluated with multivariate statistics such principal component analysis.
[email protected]
tel:
7869051
a
b
c
031
8: Crustaceans in a changing environment
Contact: Susanne Eriksson [email protected]
Climate change has led to a significant change in a number of abiotic factors, such
as, temperature, ocean acidification, oxygen saturation and salinity. Invertebrate
early life stages are generally considered most vulnerable to these changes, but only
few studies have concerned brooding species such as the Norway lobster Nephrops
norvegicus and the European lobster Homarus gammarus. During early life history
the lobsters undergoes several habitat shifts, and thus encounter a range of ambient
conditions. The lobsters response to the intensified abiotic stressors due to future
climate change will have a large economic as well as biological impact. At
Kristineberg we are currently running several projects associated with the early life
stages of these two large decapod lobsters. Most of the work is focusing on
laboratory studies on ecophysiological and health effects of multiple stressors on
early life stages.
Individual projects can be suited for most seasons and can range from 15 to 60 ECT.
The experimental part of the project will be conducted at the research station Sven
Loven Centre – Kristineberg. Analysis and writing can be done both at the station
and in Gothenburg, whatever is most convenient.
Juvenile European lobster and Norway lobster in the laboratory.
8: Age structure analysis of the invasive Pacific oysters (Crassostrea gigas)the way forward to determine establishment year, growth rates and
population structures?
Åsa Strand, [email protected],
The invasive Pacific oyster emerged in large numbers in Sweden in 2006, which is often
considered to be the original establishment year of the species. However, already at that time,
adult oysters were observed at one site during surveys. Age analysis of these individuals may
thus provide additional information to the establishment event. Moreover, as the growth rate
of Pacific oysters is often measured as length of the individuals, and as shell appearance is
highly variable and is affected by both substrate conditions and oyster densities, evaluation of
growth rates and demographic patterns is hard to achieve using length frequency analysis
only. However, by combining age and length of individuals at a site specific a “key” can be
developed to facilitate demographic analysis.
Determining the age of oysters is very difficult by just looking at the shell, thus other methods
must be used. Acetate-peels of shell sections has previously been used as a successful
technique to determine age of oysters. However, the method is quite labor intensive. As an
alternative, photo luminescence may be used to develop age-length relationships. The purpose
of this project is thus to;
a) evaluate different techniques to perform age analysis of Pacific oysters
b) use the most appropriate technique to evaluate questions relating to the
establishment and population development of the invasive Pacific oyster in
Sweden.
Both the practical work and the field work connected to this project will be performed at the
department of Marine Sciences at Tjärnö. The project can be adjusted to a 15 hp applied
project, 30 hp bachelors thesis or 60 hp masters thesis. For more information, please contact
Åsa Strand, [email protected], tel. +(46) 31 786 96 34.
9: Evaluating the enemy-release hypothesis as a potential cause of the
successful establishment of the invasive Pacific oyster (Crassostrea gigas) in
Sweden
Åsa Strand, [email protected],
The accelerating spread of non-native species is currently one of the most serious
environmental threats worldwide and constitutes one of the biggest pressures on local
biodiversity and endemic species. As a species arrive in a new area, both attributes of the
invaded environment (abiotic conditions and native community structure) and characteristics
of the invader, will determine the success of the establishment. If abiotic conditions in the
new environment are within the non-native species tolerance limits and can support successful
reproduction, biotic factors will act to determine the success or failure of the invasion. One of
the theories explaining the success rate of establishment of invasive species is the enemyrelease hypothesis. The theory claims that non-native species will experience less regulation
by enemies (predators, parasites and pathogens) at a new site than native species, thus
allowing them to increase in abundance and distribution and become invasive.
So far we have established that the Pacific oyster constitute a resource for two native
predators, the shore crab Carcinus maenas, and the starfish Asterias rubens, and we have
estimated consumption rates of oysters by these predators. However, in order to evaluate the
effects of these predators on wild populations, we also need to know the prevalence of the
predators in bivalve areas. The aim of this project is therefore to quantify the number, and size
structure, of crabs and starfish in oyster and blue mussel banks and to use this information to
evaluate the potential restrictions predation may impose on population development of the
Pacific oyster. The practical work will be based on field studies performed in the area of
Tjärnö, preferably during summer 2016. The field data will be combined with previously
obtained data on consumption rates from lab studies, which, if time allows, may also be
complemented with additional predator sizes during the project. The project can be adjusted
to a 15 hp applied project, 30 hp bachelors thesis or 60 hp masters thesis. For more
information, please contact Åsa Strand, [email protected], tel. +(46) 31 786 96 34.
10: Harmful Algal Bloom Dynamics at the Swedish West Coast
Where: Gothenburg and at sea
Supervisors: Anna Godhe (GU) and Bengt Karlson (SMHI)
[email protected] and [email protected]
(The student will be contribute to the JERICO NEXT project, http://jerico-fp7.eu/)
Background: Phytoplankton from the genus Dinophysis (Dinophyta) produce
diarrhetic shellfish toxins that may accumulate in shellfish. Diarrhetic shellfish toxins
are a major concern for the mussel farming industry along the Sweish West coast.
Dinophysis occur in the open sea and in fjord systems. Dinophysis are often found in
thin layers, at or near the pycnocline. Dinophysis are mixotrophic feeding on other
plankton. Dinophysis are also good swimmers.
Problem: The basic question is: Are the Dinophysis off shore transported to the coast
causing shellfish toxicity. Detailed questions are: How are Dinophysis distributed in
the water mass? What conditions favour transport of Dinophysis to the coast? What
are the effects of growth rate, feeding and swimming? The master thesis project will
be part of a larger project investigating the physical and biological oceanography of
harmful algal blooms. A cooperation with another master student focussing on the
physical oceanographic aspects of the problem is suggested.
Method: The work will include participation in oceanographic cruises on the Göteborg
university new research vessel during an eight week period starting in mid August
2016. Sampling will also be carried out near a mussel farm at Tångesund (near
Mollösund). Water samples will be concentrated and the abundance of Dinophysis
and their prey will be estimated using microscopy and by automated analysis using
Imaging Flow Cytometry. In situ cell division rates will be estimated using the
frequency of dividing cells method. Behaviour will be studied in live samples.
Level: Master level (45-60 hec)
11: Exchange processes in the Stigfjord/Tångesund area.
Where: Gothenburg and at sea
Supervisors: Lars Arneborg (GU) and Kari Eilola (SMHI)
[email protected], [email protected]
Background: Toxins produced during the bloom of certain phytoplankton (Dinophysis)
are a concern for mussel farms along the Swedish west coast. These may bloom
offshore and in fjord environments. In order to predict whether a bloom will pass a
mussel farm, one needs to know under which circumstances different water masses
flow past the farms. Water exchanges in the fjords and archipelagos along the
Swedish west coast are caused by sea level fluctuations, density fluctuations, winds,
etc. Some of these processes are parameterized in a model system called the
Swedish Coastal zone Model (SCM) that is used for water quality calculations in the
coastal zone waters around Sweden.
Problem: What is the origin and transport time of the water masses that are advected
past the mussels in the mussel farm at Tångesund on Orust, and how does that
change with different conditions? What are the main processes driving the water
exchanges and determining the physical properties of the water masses? Are these
water exchanges properly described in existing coastal zone models and
parameterizations? Are the offshore conditions sufficiently well described in such
models to predict the origin of water passing Tångesund? A cooperation with another
master student focussing on the biological aspects of the problem is suggested.
Methods: The work will include literature studies, collection of in-situ data and
analysis of observations and model data. This includes setting up and deploying
oceanographic moorings and participation in a number of oceanographic cruises on
the Göteborg university new research vessel during an eight week period starting in
mid August 2016. The moorings will be deployed during the entire study period to
record variations in stratification and water levels inside and outside Stigfjorden and
currents will be recorded near the mussel farm. Results from the SCM will be
available for analysis and comparison with the observations. If time allows there is a
possibility to visit SMHI to perform sensitivity tests with the SCM using e.g. different
forcings and parameterizations.
Level: Master level (45-60 hp)
12: How does marine benthic fauna respond to adding of activated carbon to the sediment surface? A laboratory experiment MSc thesis project, 2015-­‐2016 1-­‐2 students Capping with thin layers of activated carbon is a new and promising technique to reduce bioavailability of pollutants from marine sediments. This remediation technique has become more commonly used worldwide in the past years. However, the benthic community’s response to activated carbon is still poorly understood. Results from previous research are in many ways contradictory. The intention of this experiment is to give us a better understanding of underlying causes to the negative responses on the fauna that we have observed in a large scale capping project in two Norwegian fjords. The experiment will be performed with a setup of sediment mesocosms including intact fauna communities. The aim is to study the effect of activated carbon on various species, especially in relation to their feeding strategy and bioturbation activity. The results will increase our understanding and how to interpret our results in the ongoing field project, which started in Norway 2009. For example, we have observed a severe decline in abundance of the brittle star Amphiura filiformis in the test-­‐fields capped with active carbon. A crucial question to answer is therefore if the treatment is direct lethal to the brittle stars, or if they have the ability to escape the area when conditions become unfavorable? The experiment is suitable for 1-­‐2 master students. The thesis will for example be a god background for future work in environmental management. The thesis will also be a good training in species analysis and give an understanding of several ecological functions in marine sediment habitats. Since activated carbon is a new remediation technique, the results of the experiment will be published in a scientific article, where you as a master student can choose to take part. The participants also have the opportunity to take part in the follow up work in the ongoing field project in Norway. The experimental setup will be located at Sven Lovén center Kristineberg, Gothenburg University. It is a jointly project between Stockholm and Gothenburg universities. For further information, please contact: Caroline Raymond: [email protected], 0736-­‐949463 (Stockholm University) Stefan Agrenius: [email protected], 031-­‐786 95 24 (Gothenburg University) 13: Big appetite or good food – why some snails are much bigger than the
other?
Where: Tjärnö
When: Start March or June 2016
Supervisors: Marina Panova ([email protected]), Sarah Bourlat
([email protected])
Background: Rocky shore snail Littorina saxatilis has an extreme capacity to adapt to
local environment and is a very good model to study evolutionary biology. In Sweden,
there are two morphologically different ecotypes: Crab-ecotype that lives on the
boulder shores and evolved to resist carb predation, and Wave-ecotype that lives on
exposed cliffs and evolved to resist wave exposure (see Figure). The most striking
phenotypic difference between
these ecotypes is size; the Crabecotype grows much faster than
the Wave-ecotype. To do this,
they would need to obtain more
energy from food.
Figure. Crab and Wave ecotypes of Littorina saxatilis at Saltö island close to Tjärnö laboratory. Problem: How do Crab-ecotype
snails get enough energy for their
fast growth? Do they spend more
time feeding than the Waveecotype? Or may be they have
much better food in their
environment? The goal of this project is to investigate these alternative hypotheses.
This information will be very important for our studies of Littorina evolution and our
search of genes that “make” ecotypes. In addition, this project will give some insight
on what limit food consuming in snails – food availability or their appetite. In insects
for example it is known that there are receptors and hormones that regulate feeding
behaviour, but no one looked in snails.
Methods: There are three different approaches in this project:
1) A laboratory experiment to estimate feeding time/food consumption by quantifying
snails’ grazing tracks in aquaria.
2) Analysis of food composition in two different habitats by sequencing. Take
samples from the rock and cliff surfaces, extract DNA, sequence and identify what
species of microalga, bacteria etc. are present and at what abundance level.
3) Analyses of food composition eaten by snails by sequencing. Take samples of
snails gut content and faeces, extract DNA, sequence and identify what species of
microalga, bacteria etc. are present and at what abundance level.
Level: Master level (45-60 hec; preferably 60 hec to apply all 3 approaches).
14: Effect of climate change on the behaviour of the shrimp Pandalus borealis (30 hec)
The northern shrimp (Pandalus borealis) is an important commercial
fishery species in Scandinavia. How this species responds to climate
change may therefore have a large impact on these countries
economically in addition to the ecological consequence. There is a
larger project running on this species examining the potential
tolerance, and interpopulation variation of tolerance, of this shrimp
to ocean acidification and
warming (OWA). The main
project will work on
physiological changes and
the genetic basis for these
changes. As an extension of
this project a 30 hec. masters
project is available to investigate if and how OWA
impacts upon shrimp behaviour, specifically feeding
and predator avoidance. The project will be based at
Kristineberg Marine Station to begin in April 2016. Please note that due to the seasonality of
the practical experimental work this project will require working over the summer, with
holiday to be taken later instead.
Contact: Dr Hannah Wood,
Email: [email protected]
15: Effect of climate change on the energy budget of the shrimp Pandalus borealis (60
hec)
The northern shrimp (Pandalus borealis) is an important
commercial fishery species in Scandinavia. How this
species responds to climate change may therefore have a
large impact on these countries economically in addition
to the ecological consequence. There is a larger project
running on this species
examining the potential
tolerance, and
interpopulation variation
of tolerance, of this
shrimp to ocean acidification and warming (OWA). The main
project will work on physiological changes and the genetic
basis for these changes. As an extension of this project a 60
hec. masters project is available to investigate the energy
budget of the shrimp, and how this is affected by temperature
and ocean acidification. The project will be based at
Kristineberg Marine Station to begin in April 2016. Please
note that due to the seasonality of the practical experimental
work this project will require working over the summer, with
holiday to be taken later instead.
Contact: Dr Hannah Wood,
Email: [email protected]
16: Effect of climate change on the shrimp Pandalus borealis (XX hec)
The northern shrimp (Pandalus borealis) is an important commercial
fishery species in Scandinavia. How this species responds to climate
change may therefore have a large impact on these countries
economically in addition to the ecological consequence. There is a
larger project running on this species examining the potential
tolerance, and interpopulation variation of tolerance, of this shrimp
to ocean acidification and
warming (OWA). The main
project will work on
physiological changes and
the genetic basis for these
changes. As an extension of
this project there is potential
for complimentary masters projects to run alongside
the main project. If you are interested in working in
this area and have your own project idea, please
contact me via mail to discuss this. The project will be based at Kristineberg Marine Station
to begin in April 2016. Please note that due to the seasonality of the practical experimental
work this project will require working over the summer, with holiday to be taken later instead.
Contact: Dr Hannah Wood,
Email: [email protected]
17: Local adaptations in crab larvae to fish predation and dispersal in a microtidal environment Where: Kristineberg Marine Research Station, Fiskebäckskil, Gullmarsfjord Supervisors: Per Moksnes and Per Jonsson. [email protected], [email protected] 3
Background: The suggested master project will explore a novel hypothesis about mechanisms explaining from the
Channel to
(Moksnes…Jonsson
2014, Fig.
1).tIn
areas by the oceanographic patterns of English
local adaptations in Kattegat
marine invertebrates with planktonic larvae ransported where tides
significant,
shore
crab larvae
display
inherited endogenous
circulation. The are
core hypothesis is related to ‘isolation by an
adaptation’ and proposes that many coastal species vertical
migration
rhythm,
which twhen
synchronized
withfor local
tides
is believed
to the probability of with planktonic larvae are exposed o very strong selection larval traits that increase facilitate
cross-shelf
and
recruitment
success
(Zeng
and Naylor
1996,
surviving the planktonic transport
stage and returning to coastal habitats suitable for recruitment. Recent studies show Moksnes…Jonsson
2014).their Our vmodels
oceanographic
water
transport
predictdepth-­‐dependent that
that many larvae can control ertical pofosition in the water column and exploit this rhythmic
vertical
migration
increases
local
retentionand of free-drifting
larvae
and
variations in water transport to modify their n
et dispersal the probability of successful recruitment. leads tolittle higher
terms
oftrade-­‐offs recruitment
in shallow
habitatsdclose
to the
However, is kfitness
nown ain
bout how are success
made between optimizing ispersal vs food availability and coastline.
This endogenous
tidal rhythm
in larvae
from
areas
where
thea combination of predator avoidance in the plankton. In the pdisappears
roposed project this w
ill be assessed using tide is insignificant,
wherebinstead
larvae
show aan
with
empirical field experiments, iophysical modeling nd exogenous
analyses of circadian
available prhythm
lankton data. The student will be part of a larger research group during
assessing hese questions also with molecular tools. of
migration
to deeper
waters
the tday
possibly
reducing
predation.
Modeling
dispersal also suggests that observed larval behavior results in restricted gene flow
Research Question: Earlier studies have shown that shore crab larvae (Carcinus maenas) from the Swedish west along the tidal gradient. This rare example of a putative local adaptation (larval
coast do not display the inherited swimming behavior with a tidal rhythm displayed in larvae from tidal areas, behavior) in a species with potential for long-distance dispersal points to an intriguing
but instead display a nocturnal vertical migration behavior. These results have lead to the yet untested interaction between natural selection of larval behavior and the potential for evolution
hypotheses that Swedish larvae show a local adaptation to microtidal conditions where they migrate to the of local adaptations in coastal species with planktonic larvae. This environmental
surface only at night to avoid visual fish predators, and use sea-­‐breeze transport to return to shallow gradient also coincides with the deglaciation about 10000 BP indicating that the cline
settlement habitats (Moksnes et al. 2014, Limnol Oceanogr, 59:588-­‐602). The aim of the master-­‐project is to in larval behavior is recent.
assess these and alternative explanations to the observations. "
Methods: The work will include literature studies, field experimentation, analysis of available field data and model data. description
The field experiment include measuring predation on crab larvae in situ using novel planktonic Project
tethering-­‐techniques developed in tproject
he research group here crab m
are glued to drifting long-­‐lines We here propose
a research
with the
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explore
a egalopae novel hypothesis
deployed a
t d
ifferent d
epths t
o a
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redation r
ates. T
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vailable f
ield data consist of depth-­‐specific about mechanisms explaining patterns of local adaptations in marine invertebrates
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amples o
f d
ecapod l
arvae a
nd h
oloplankton t
hat h
ave b
een i
dentified to species and larval stage. with planktonic larvae transported by the oceanographic circulation. The core of the
A hhypothesis
igh-­‐resolution, 3
-­‐D o
ceanographic c
irculation m
odel o
f t
he G
ullmarsfjord a
rea i
s a
lso available within the is related to ‘isolation by adaptation’ (e.g. Nosil et al. 2005) and proposes
research g
roup, i
n w
hich h
ypotheses r
egarding d
ispersal a
nd r
etention o
f l
arvae w
ith different swimming that many coastal species with planktonic larvae are exposed to very strong selection
behaviors c
an b
e t
ested. T
he f
ield w
ork w
ith s
hore c
rab l
arvae h
as t
o b
e c
arried o
ut i
n July-­‐September 2016 for larval traits that increase the probability of natal retention or returning to the
when t
he l
arvae a
re p
resent i
n t
he f
ield, b
ut a
nalyses o
f a
vailable p
lankton a
nd m
odel d
coastal boundary harboring shallow habitats suitable for recruitment and adult life. ata can be started earlier the spring, or carried out direct
in the effect
fall of that
2016. Suchin larval
traits may
have the
realized dispersal distance is
reduced, or the indirect effect that dispersing larvae are maladapted leading to low
Level: Master or Bachelor level (30-­‐60 hp) connectivity and gene flow between local populations, which promotes local
adaptation also in the adult stage.
Fig. 1. The difference in rhythmic larval behavior of the shore crab (Carcinus maenas) between (A)
micro-tidal areas with no rhythm, (B) and in meso-tidal areas with an endogenous circatidal rhythm
(from Moksnes…Jonsson 2014).