AUT - Postgraduate Research Highlights
- ArionWhere applying and enrolled students can access AUT course information, check your enrolment status, make fee payments, update your personal details and view your academic results.
- AUTOnlineOnline access to course resources and learning activities through AUT's central learning management system.
- UnicentralUniCentral is the AUT University Student Portal. Here you will find useful information about you as a student and quicklinks to all the important online systems you will need to use while studying at AUT University.
Postgraduate Research Highlights
Monalisa Biodiversity database
Here is a classic example of just how postgraduate research can contribute tremendously to our understanding of the distribution, abundance and diversity of coastal species, their habitats, and community structures.
We are so very pleased to announce the online release of the Monalisa Biodiversity database©. Three years in the making, and involving multi-disciplinary collaboration between academics across Faculties, postgraduates, and stakeholders (environmental consultants, Regional Councils and the Department of Conservation), this database provides you with the most current and comprehensive data set detailing the distribution and abundance of marine species throughout the greater Auckland region, spanning Mimiwhangata Bay in the north to Tauranga Harbour in the south. Our data extend from intertidal estuarine habitats to sea-bed communities to depths of 50 metres within Hauraki Gulf, and our spatial and temporal coverage is forever expanding.
This database was the brainchild of Monalisa Palacio, to the lower right, who came to us from the Philippines to study the role of biodiversity databases in coastal conservation and resource management in New Zealand. Rather than throw her hands up in the air in horror, or walk away from something that was just too difficult, Monalisa immersed herself in her research, and as a consequence of this surveyed the coast with us at 296 marine and estuarine sites throughout the greater Auckland region, extending as far north as Mimiwhangata Bay (north of Whangarei) and south to Tauranga Harbour, in addition to more limited sampling on the west coast of this same region.
At each site Monalisa surveyed she collated full inventories of intertidal flora and fauna, and these data then were used to populate her new biodiversity database. It is named for her, and can be accessed at www.Monalisa.ac.nz
As a consequence of Monalisa's research we have embarked on series of subtidal surveys throughout the Waitemata Harbour and inner Hauraki Gulf (below), but have surveyed well beyond these regions (including the Great Barrier Island, Mercury and Cuvier Islands). The last time any comprehensive survey of subtidal communities was undertaken in Hauraki Gulf was 1936!
These new subtidal data complement Monalisa's intertidal data set, and will shortly be entered into the database. Additional surveys are also being undertaken to fill in the many blanks in our current sampling effort.
All of our sea-bed samples are collected with by one of Van Veen grab or Ekman box-core. At many biological stations we have also collected samples for sediment grain-size and composition analyses. Accordingly our biological data are augmented with environmental data, to relate the two and determine what environmental variables best describe species distribution and community structure.
All of our subtidal data are quantitative. Vouchers of all of our species are accessioned into the Institute's biological collections, for future reference to ensure continuity in identifications between researchers and surveys.
Sea-bed mapping
Benthic invertebrate communities throughout Hauraki Gulf
Building on the pioneering work of Powell (1937) and subsequent survey of Hayward et al. (1997) in the Waitemata Harbour, the EOS Institute has embarked on the most comprehensive survey to date to map the composition and distribution of sea-bed communities throughout the inner Waitemata Harbour and Hauraki Gulf. Numerous samples from throughout the region have been collected and are in the process of being sorted, their flora and fauna identified and counted, and the sedimentary and organic characteristics of the sea bed itself described. No comparable survey ever has been undertaken, and for a good reason — the task is simply enormous.
Our data relate the biological characteristics of the sea bed, species richness, abundance and diversity, to environmental variables, such as depth, sediment grain size, organic and carbonate composition, and the actual composition of the sediment, whether it be biogenic or inorganic, marine or terrestrial in origin, or an admixture of the two. Eventually all of these data will be liberated online, on the Monalisa Biodiversity database (above).
Although we already have excellent physical and biological data for areas off eastern Waiheke Island, the 'Noises' group of islands in the outer Hauraki Gulf, and Rangitoto Channel, there are many gaps in our survey effort. But we have already made significant progress, considering what we have achieved has been done within the space of two years.
We depend to a great extent on postgraduate researchers within the Institute to fill in our sampling gaps, but the Institute is also targeting certain areas throughout the Gulf for intensive and immediate study, and is archiving numerous samples for future research.
During June of 2009 the Institute collected numerous sea-bed samples off northern and northeastern Waiheke Island, within Hauraki Gulf, in addition to video, sedimentary and biological samples at those sites depicted below (red stars = our biological sampling sites, black circles = our sea-bed video stations).
Although all of our samples have yet to be fully processed, our preliminary findings are most interesting.
One important, preliminary finding is that images and/or video of the sea bed tell you very little about the species assemblages that live within the sediments — in fact the correlation between the two is extremely poor.
A concern arising from this is that habitat mapping programmes today regularly make use techniques like video to rapidly assess the distribution of sea-bed communities. Should the correlation between surface structure (visible) of the sea bed based on rapid-assessemnt techniques like video and the species composition of the sediments be poor, then how good are any habitat maps based on these data? Not very!
Another preliminary finding concerns the relationship between the sediments themselves and the species inhabiting them. Of those environmental variables that we have examined to date (sediment grain size, and carbonate and organic composition in residues on each sieve mesh size of 4, 2, 1, 0.5, 0.3, 0.15, 0.063 and < 0.063 mm), it proves that the % carbonate composition within the 63–150 micron (0.063–0.15 mm) grain-size fraction is the single-best variable to describe sea-bed community structure, in that it explains almost 80% of the variation therein. Although a combination of the organic content in the < 63 micron sediment grain size fraction, and the physical grain size fractions of 4.75 and 2 mm, and 500 and < 63 micron structure of the sediments, explains 90% of the variation in sea-bed community structure, none of these variables can be accurately determined from any surface video or photographic imagery.
Additional updates on this research will be posted as they become available, as more samples are processed. Our goal is to be able to reliably predict at least some aspects of the composition of sea-bed assemblages of species on the basis of sediment characteristics, whether this be assemblage structure, richness, abundance. Presently nobody can do this!
Great Barrier Island
Further to our work off Waiheke Island (above), the Institute has embarked on a similar survey of sea-bed communities off western Great Barrier Island, in the outer Hauraki Gulf. Over 200 sea-bed stations have been sampled, and species richness, abundance and community structure are now being determined for this region.
These are the first data for some of these Great Barrier Island locations, and these species data soon will be compared with those for similar substrata off Waiheke Island.
This research is being led by Severine Dewas, seen below with Monalisa Palacio.
Like our biodiversity data for off Waiheke Island, data from western Great Barrier Island similarly relate the biological characteristics of the sea bed to environmental variables. Likewise, these data also will be (eventually) liberated online, on the Monalisa Biodiversity database.
There is at least a year's work involved in processing all of these samples, and in identifying the myriad invertebrates and algae that occur within them. We'll post updates as these data become available.