MISA Ecosystem Program: Benthic research capabilities and needs
A preliminary draft by Sean D. Connell and Jason E. Tanner: 22nd Feb 2012
This document outlines a research plan focusing on benthic ecology to contribute
towards the broader ecosystem-based programs that MISA is currently
developing for the Great Australian Bight and SA gulfs. Planned oil exploration in
the GAB has the potential to lead to adverse environmental outcomes if not
managed properly, yet we currently understand very little about the benthic
habitats and ecosystem processes occurring in this region. Similarly, there is a
large amount of planned activity for Spencer Gulf especially, including the
expansion of mining, ports, aquaculture and desalination, on top of existing
recreational, social and economic uses. Currently each development is managed
independently, with little scope for assessing or managing whole of system
impacts from multiple activities. Both regions also have existing, as well as
proposed new, marine parks, and these need to be managed within the context of
surrounding development.
Here we outline our capabilities that include two universities (University of
Adelaide, Flinders University of South Australia), two government agencies
(Department for Environment and Natural Resources, South Australian Research
and Development Institute) and private consultancies with a reputation and
history for solving environmental issues and tracking any approved impact
through the EIS process (Care of Our Environment).
What research is needed?
1. Lack of long term monitoring datasets spatial-temporal variation in the
structure and functioning of the benthic ecosystem
2. Fragmented understanding of ecosystem processes, especially benthicpelagic coupling, offshore-onshore interactions, land-sea interactions, and
trophodynamic interactions
3. Sediment Dynamics
4. Need a more comprehensive understanding of the affects of biogeochemical
processes; e.g. chemical pollutants and nutrients
5. Whole ecosystem models driven by environmentally realistic physical,
chemical and biological data-streams
6. Forecasting ecosystems as a function of future climate and its combination
with local, non-climate stressors
7. Connectivity as a process that sustains populations and ecosystems
8. Develop an entrepreneurial hub for Australian marine science (eAMS) for
sustainable industries through marine biotechnological applications
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Research Capacity
The integration of previously disparate approaches to the study of marine
resources enables a comprehensive framework for understanding how local
activities (e.g. new drilling, new aquaculture) relate to the broad spectrum of
broad-scale climate, local biotic and abiotic interactions interrelate to maintain
the diversity and function of ecosystems.
1. Spatial-temporal variation in benthic ecosystem structure (P.
Fairweather, S. Dittman, D. Currie, S. Sorokin, M. Loo, J. Tanner, S. Nayar, S.
Benger, S. Connell, W. Zhang, S. Leterme, J. Mifsud, D. Miller, A. Wright, P.
von Baumgarten, D Fotheringham, etc)
While some initial work has been undertaken, we still know relatively
little about the distribution of benthic habitats and species in the waters
of the GAB, especially those deeper than 200 m. We need to initiate an
exploration program to determine what is present, and map it in relation
to both proposed oil exploration activities, as well as the existing GAB
Marine Park. This will enable us to determine what could potentially be
affected by oil exploration, as well as to assess the effectiveness of the
marine park for protecting benthic systems. We also need to establish a
network of key monitoring points, to enable the collection of long-term
data on ecosystem change. This network of points will be informed by
oceanographic modeling that will show potential sites for benthic impacts
of oil spills, operational discharges etc. A difficulty with acquiring data
from deep waters often centers on a lack of technology. The autonomous
Underwater Vehicle (AUV) based with IMOS (Integrated Marine
Observing System) allows the collection of stereo imagery and water
chemistry that will allow conducting geo-referenced, high resolution,
repeatable surveys of the benthic habitats and communities beyond diver
depths.
More is known about benthic habitats in the gulfs, however little longterm repeated monitoring is available in most habitats, and data on
habitat distribution is often disjointed, although the marine parks group
in DENR have been addressing the later in recent years. Available
datasets show large inter-decadal change in benthic species and
ecosystems as a function of fishing and land-based activities. Some of
these changes have become renowned international examples of the
management of natural resources and the potential positive influence of
government policy in reducing unwanted change.
2. Ecosystem processes (D. Currie, P. van Ruth, S. Nayar, S. Benger, S.
Connell, B. Russell, J. Mitchell, S. Dittman, P. Fairweather, J. Tanner etc)
Even less is known of the ecosystem processes in the GAB than of
structure. In deep waters, with limited or no light, most of the resources
are likely to be derived from surface waters, and thus benthic-pelagic
coupling becomes an essential structuring force for this system. We need
to understand what food sources are being utilized by the benthic
ecosystem, and where these are derived.
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Despite being more accessible, there is a similar lack of knowledge about
the gulfs. Includes benthic primary productivity (microbes,
microphytobenthos, seagrass, kelp) and the role of consumers in
maintaining net productivity of primary processes that maintain
ecosystem functions. Whilst there is a history of research on fundamental
aspects of ecosystem processes, only recent work has begun to connect
this understanding to processes under the control of human activities and
levers of management.
3. Sediment dynamics
The GAB is relatively unique in being one of the largest deep temperate
areas of carbonate sediments in the world, and this is likely to have
impacts for ecosystem functioning, and particularly in relation to
buffering of any acidification related to climate change. We thus need to
understand better the distribution, nature and origin of these sediments.
Sediment dynamics also play an important role in the gulfs, where
sediment movement is a major problem on the Adelaide coast, and sand
mega-ripples are a major component of the environment in upper
Spencer Gulf. Changes in current patterns and wave activity are likely to
have unanticipated impacts on these processes, and they thus need to be
more thoroughly understood.
4. Biogeochemical processes (J. Mitchell, J. Tanner, S. Connell, B. Russell, J.
Mifsud, S. Bryars, etc)
A key aspect for assessing the potential for both regions to accommodate
further development is the need to develop an understanding of nutrient
cycling and other biogeochemical processes. Many of the potential
impacts will be mediated by the introduction of nutrients and other
chemical pollutants, and so we need to understand their likely fates, and
how they will be transferred through the ecosystem in order to develop
models that will be useful for predicting the extent of impacts and
identifying potential mitigation strategies. This will incorporate not only
traditional biogeochemistry, but also investigate the potential to use
genomic indicators to assess the potential for biogeochemical activity.
Bacteria are the group most able to breakdown oil from either spills or
natural seeps. Some natural communities breakdown oil at orders of
magnitude faster than bacterial communities. South Australia has a
strong skill set in marine microbial ecology and nutrient pollution and
several different groups have provided landmark cases for the use
microbes and the benefits of reducing nutrient pollution for restoration
and sustainability of marine ecosystems.
5. Ecosystem models (J. Tanner, S. Nayar, C. Mellin, P. Fairweather, etc)
The current early ecosystem models being developed for the GAB and
gulfs are largely focused on oceanography and lower level pelagic
biological and chemical processes. There is an urgent need to incorporate
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the benthic system into these models. While this aspect is covered more
fully in the ecosystem modeling document, the benthic ecology group will
work closely with the modeling group to identify important processes and
provide the required data.
6. Climate change (D. Currie, J. Tanner, S. Connell, B. Russell, etc)
Any research program aimed at determining mid to long-term impacts of
anthropogenic activities needs to do so in the context of climate change.
The oceanography group will provide key information on the potential
physical and chemical impacts of climate change, and these will be
translated into impacts for benthic systems through a combination of
experimental studies and ecosystem modeling. In the GAB, it is likely that
the key impact will be related to changes in upwelling frequency and
intensity, and thus it will be important to establish the consequences of
upwelling for benthic systems.
The influence of climate is likely to be strongly felt in the gulfs given the
strong gradient in water temperature and salinity which are under the
influence of climate. South Australia is one of the world leaders in
ecological forecasting of future climate; improving theory, landmark cases
on approach and methodology, and acclaimed discoveries. Our state has
available some of Australian’s most advanced infrastructure that is
currently being used as a framework for linking together laboratory and
field experiments, comparative, and theoretical approaches in order to
recognise the combined effects of climate and non-climate stressors and
species interactions on community persistence.
7. Connectivity (B. Gillanders, I. Nagelkerken, Z. Doubleday, M. Doubell, etc)
Understanding how different habitats and regions are connected will be
crucial for ongoing management of our marine systems. It will be
especially important to understand if proposed marine parks are sources
or sinks for larvae, but we also need to understand how well connected
potentially impacted areas are to the rest of the system. South Australia
pioneered a key set of approaches and methods that resulted in a global
windfall of information on connectivity. South Australia has the most
advanced and comprehensive set of dedicated infrastructure available for
such analyses in Australia, rivaling the best international institutions.
8. Marine biotechnology (N. Bott, S. Nayar, W. Zhang, etc)
Current impact assessment techniques rely very much on traditional
methodologies that require often large samples, along with access to
extensive taxonomic expertise to identify the organisms collected. These
methods are thus time consuming and expensive. Modern technology
places us in a position to develop some novel monitoring techniques that
have the potential to provide a cheaper and speedier means of assessing
impacts. Potential techniques include molecular biosensors based on cell
culture techniques, and next generation DNA sequencing along with
environmental genomics to rapidly assess the suite of organisms present
in a sample.
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9. Benthic-Pelagic Coupling (S. Leterme, J. Kaempf, etc)
An understanding of benthic ecology is incomplete without understanding
the oceanographic context of the localities of study. South Australia has
expertise in physical oceanography, data interpretation, model
development, hydrodynamic modelling, field observations, particularly
the South Australian Coastal Upwelling System and oceanography of SA
Gulfs. We are also able to model development and field-based drifter
studies in gulfs. GPS drifter studies can be used to determine the key
physical properties: physical connectivity and turbulent diffusivity, the
latter being crucial for model development.
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