Marine Science

Multiple Stressors in Coastal Ecosystems


Supervisor

Professor Simon Thrush

Discipline

Marine Science

Project code: SCI142

As in many terrestrial systems, a multitude of direct and indirect human influences have significantly altered the composition and diversity of marine communities. Understanding and predicting the combined impacts of multiple stressors however, is particularly challenging because observed ecological responses are not often additive, rather they are a product of the interactions between several stressors that do not necessarily occur simultaneously. The present study seeks to understand how the combined effect of representative stressors (nutrient enrichment, hypoxia and sedimentation) on the functioning of coastal intertidal communities is moderated by the order and magnitude of stressor exposure.

Experience is soft-sediment ecology, field research are essential. It is anticipated that the project will run over the summer 2017/18, with the successful candidate based at the Leigh Marine Laboratory.

Tolerance and adaptation of New Zealand seaweeds to increases in turbidity


Supervisor

Nick Shears

Alwyn Rees

Discipline

Marine Science

Project code: SCI143

Large brown seaweeds are important primary producers in coastal environments that are highly vulnerable to changes in turbidity (e.g. due to sediment runoff and coastal erosion). This study will investigate how different species of large brown seaweeds can tolerate and potentially adapt to high turbidity and associated low light levels. 

This project will use newly developed photo-respirometry chambers to measure photosynthetic rates of large seaweeds in the lab.  Photosynthesis versus irradiance curves (P vs. E) will be calculated and compared for a variety of seaweed species.  An experiment will be carried out where a range of species will be held in tanks at different light levels for a 2 month period.  Growth rates and changes in photosynthetic parameters over this period will be compared among species.

This project will be based at the Leigh Marine Laboratory. It will require field collection of seaweeds on snorkel so will suit someone with good practical skills in both the field and laboratory.  The project could also involve SCUBA diving if the candidate is qualified to Rescue Diver. 

Global patterns of biodiversity


Supervisor

Mark Costello

Discipline

Marine Science

Project code: SCI144

Our research group, based on the city campus, is working with international collaborators to build on world databases of all marine species and their distribution. Recent and current research is one latitudinal gradients in species richness, mapping marine realms (areas of species endemicity), ecosystems (based on environmental gradients), and biomes (biogenic habitats of plant life-forms). This knowledge is currently being used to design where marine reserves should be located in the Coral Triangle and globally, and predict the effects of climate change on biodiversity. New projects will predict what species are more or less likely to be introduced or become invasive.  By adding species traits to the databases the number of potential analyses and insights is multiplied. Examples of traits are body size, habitat, habit (life-form), pelagic-benthic, diet and trophic level (Costello et al. 2015. Biological and ecological traits of marine species. PeerJ 3:e1201 https://doi.org/10.7717/peerj.1201). We’d welcome a student interested in biological diversity and/or working with biological databases and developing digital skills, to help develop these databases by adding additional information which they would gather from the literature and scholarly online resources. There would be opportunities for data analysis and working with individual PhD students.