Cone Bay proves reliable for acoustic recordings of humpback dolphins

/in , /by

Blog By: Josh Smith PhD, MUCRU

For what could be the last field trip in a project to determine the feasibility of conducting passive acoustic monitoring of snubfin and humpback dolphins, the research team headed to Cone Bay on the northeast tip of King Sound in the Kimberley to focus on recording humpback dolphins specifically.

I was fortunate enough to have the aid of fellow Murdoch University Cetacean Research Unit (MUCRU) researcher, Alex Brown, to help me in the field to focus on getting the recordings of the sounds that humpback and snubfin dolphins are making.

We were also fortunate to be joined and helped out by Dambimangari Rangers during several days of the fieldwork, who provided excellent dolphin spotting skills and assisted in photo-identification of the dolphins we encountered.

In September 2014, Alex and fellow MUCRU researcher Dr Simon Allen and Dr Stephanie King undertook a WAMSI trip to Cone Bay to determine the size of the dolphin populations there and reported consistent sightings of humpback dolphins around the Marine Produce Australia barramundi sea farm, in Cone Bay at Turtle Island.

Not only did Cone Bay provide consistent sightings of snubfin and humpback dolphins, it also provided an elevated land based platform that could provide information on the dolphins detection thresholds by comparing the dolphins location relative to the acoustic recorders.

The acoustic data that we are collecting will help to develop a better understanding of the acoustic repertoire of these species, whether there are geographical differences in the sounds they make within a species, and understand over what type of ranges these dolphins are using their sound.

The main objective is to determine the feasibility of conducting passive acoustic monitoring for these species, which is being conducted as a Bill Dawbin Fellowship and part of the Western Australian Marine Science Institution (WAMSI) Kimberley Marine Research Program dolphin project.

The trip to Cone Bay was a great success with encounters of humpback dolphins engaged often in very interesting social behaviour. The trip was divided up in effort with land based hilltop observations over the sea farm and boat-based recordings.

For the hilltop observations, we deployed several SoundTrap acoustic recorders around the farm and waited for humpback dolphins to come in around the sea farm. This did not always happen regularly and was difficult to determine exactly when during the day this would happen.

Hilltop observations using SLR camera and binoculars overlooking the barramundi sea farm
Hilltop observations using SLR camera and binoculars overlooking the barramundi sea farm

A humpback dolphin jumping not far from an acoustic recorder
A humpback dolphin jumping not far from an acoustic recorder

The hilltop observations (using a Canon SLR and mounted GPS unit along with Vadar software) allows information on the range that sounds can be detected by the acoustic recorders to determine detection thresholds. This is done by the SLR camera recording many attributes of the camera and lens settings and the GPS function being capable of determining the bearing the camera is pointed.

The software Vadar takes the elevation of the land based platform along with the camera settings and is capable of geo-referencing the dolphins’ location which is corrected for the tide. This is then related back to the known positions of the acoustic recorders.

Alex on the water as we pursure mobile acoustic recordings

Alex on the water as we pursue mobile acoustic recordings

It wasn’t long before Alex and I realised the humpback dolphins were not around the farm for the entire day and we needed to increase encounter rates. So, remaining within VHF radio contact of workers at the farm who could radio us if they saw dolphins, we went out on the six metre research boat to increase our dolphin encounters. Generally, we were quite successful, coming across either a group of snubfin or humpback dolphins.

The other objective of this trip to Cone Bay was to see whether we could increase the number of genetic samples of the dolphins from that obtained in September 2014 and from photo identification we could see whether many of the previously identified dolphins were still in Cone Bay. Almost straight away it became apparent that many of the same dorsal fins of the dolphins were being sighted from the photo ID, although there were also some new fins that Alex could not recognise.

Being on the boat meant that we could get close to the dolphins and use the mobile acoustic recorder, which was a SoundTrap attached to a rope on a float. When we had sighted a group of dolphins we would establish the type of behaviour they were exhibiting ie foraging, socialising or travelling, which would largely determine the possibility of getting acoustic recordings. When the dolphins are socialising, they are less worried about the boat and will often not travel as far, providing a better opportunity for good acoustic recordings.

The main objective of the mobile recordings was to increase our understanding of the different types of social sounds they were making to identify their acoustic repertoire. The boat recordings provided some interesting sound recordings, particularly from a mixed group of four humpback dolphins in what appeared to be attempted mating of a single snubfin dolphin.

A group of humpback dolphins socialising near the mobile acoustic recorder attached to the float
A group of humpback dolphins socialising near the mobile acoustic recorder attached to the float

Finally, after almost three weeks of what was pretty good weather and almost 12-hour days, we left Cone Bay for Cygnet Bay and eventually Perth, having collected as much data as the weather would allow.

In total, there is now approximately five hours of mobile recordings and 23 groups of humpback dolphin positional data to process to help with previous fieldwork to assess the feasibility of passive acoustic monitoring for humpback and snubfin dolphins.

Cone Bay definitely proved to be more reliable for acoustic recordings of humpback dolphins than previous Cygnet Bay fieldwork and provided a pretty amazing backdrop to this research.

This fieldtrip would not have been as successful or viable without the support of Marine Produce Australia and we are extremely grateful for their support.

The $30 million Kimberley Marine Research Program is funded through major investment supported by $12 million from the Western Australian government’s Kimberley Science and Conservation Strategy co-invested by the WAMSI partners and supported by the Traditional Owners of the Kimberley. 

Category:

Kimberley Marine Research Program

Giant corals reveal WA’s heatwave history

/in , /by

WAMSI oceanographic research has contributed to new findings documenting historic weather maps contained within WA’s coral reefs.

The research, led by The University of Western Australia (UWA), which involved researchers from Australian Institute of Marine Science (AIMS), Curtin University, CSIRO, and the University of California Santa Barbara, drilled into giant porite coral cores from Ningaloo Reef, the Abrolhos Islands and Rowley Shoals to find the marine climate data.

Each of the cores contains seasonal growth bands, similar to tree rings, and provides information about past climate conditions.

The study concentrated on the relationship between the climate conditions in the central-western Pacific and the southeast Indian Ocean referred to as the Maritime Continent, which includes Indonesia, Borneo, New Guinea, the Phillipine Islands, the Malay peninsula and the surrounding areas.

WAMSI researcher CSIRO’s Dr Ming Feng said analysis of the coral core growth bands enabled the team to successfully reconstruct ocean conditions of the West Australian shelf for 215 years and determine what conditions cause marine heat waves among WA’s unique coral reefs.

 “What we found is that when the Maritime Continent is warmer than the central Pacific, a pattern amplified during strong La Niña events in the tropical Pacific, it creates an ocean temperature gradient which reinforces warming in the far western Pacific and south-eastern Indian Ocean,” Dr  Feng said.

Dr Jens Zinke, Senior Research Fellow at UWA and lead author of the research paper published in the journal Nature Communications, said the long coral records allowed the scientists to look at the occurrence of marine heatwaves as far back as 1795.

Dr Zinke said the marine heat waves happened through a series of ocean-atmosphere interactions that resulted in a strengthened Leeuwin Current and unusually warm water temperatures and higher sea levels off Western Australia.

“A prominent example is the 2011 heat wave along WA’s reefs which led to coral bleaching and fish kills,” he said.

The international team found that the temperature gradient in the western Pacific was particularly strong after the late 1990s, which can be linked to the series of marine heatwaves off the WA coast in the recent decade. The coral cores also reveal that this temperature gradient was intensified in the early and late 1800s, yet against a much lower background ocean temperature off WA.

The authors concluded that strong warming over the past 215 years made it easier for natural climate events, such as La Niña and West Pacific temperature gradient events, to exceed the critical temperature threshold for marine heat waves and mass coral bleaching to occur off Western Australia.

Dr Feng, said it was likely that under a warming climate, future La Niña events coupled with a strong West Pacific temperature gradient would result in more extreme ocean warming and high sea-level events with potentially significant consequences for the maintenance of WA’s unique marine ecosystems.

This will likely reduce the future ability of the reefs of Western Australia to serve as a climatically stable area for coral under future ocean warming.

The research builds on previous work and contributes to more accurate thermal reconstructions necessary for better informed resource management.

Figure 1: Southeast Indian Ocean reefs and tropical Indo-Pacific SST variability.
From the paper, Coral record of southeast Indian Ocean marine heatwaves with intensified Western Pacific temperature gradient, by Jens Zinke, A. Hoell, J.M. Lough, M. Feng, A.J. Kuret, H. CLarke, V. Ricca, K. Rankenburg, & M.T. McCulloch, Nature Communications (DOI doi:10.1038/ncomms9562)

(a) Locations of the three reef areas (1–3) sampled for long coral cores, (b) rotated empirical orthogonal function 2 (REOF2) covariance of ERSSTv3b15 anomalies, and (c) REOF2 time series, 1960–2013, which explains 21% of the variance. The WPG11 is defined as the standardized difference between average SST over the Niño4 domain14 (black box) and the Western Pacific (WP; blue box), while the Western Australian region is highlighted in grey with coral sampling locations indicated, 1, Houtman Abrolhos, 2, Ningaloo Reef and 3, Rowley Shoals. The black-dashed box marks the Indonesian warm pool region (IWP06 (ref. 26)).

The $30 million Kimberley Marine Research Program is funded through major investment supported by $12 million from the Western Australian government’s Kimberley Science and Conservation Strategy co-invested by the WAMSI partners and supported by the Traditional Owners of the Kimberley. 

Category:

Kimberley Marine Research Program

Groundbreaking research to build instruments to measure net sediment deposition

/in , /by

Researchers in the WAMSI Dredging Science Node are developing new automated scientific instruments to measure sediment deposition in the field with prototypes deployed and tested.

Sediment deposition and subsequent smothering of marine habitats such as corals and seagrasses is one of the mechanisms by which dredging can impact on the environment.

This pressure parameter is incorporated into sediment transport models by proponents during the Environmental Impact Assessment (EIA) process to make predictions of the likely extent, severity and duration of their impacts on the environment.

However, according to Dr James Whinney from James Cook University there are no scientific instruments that can actually measure net deposition in the field.

“Measuring net sediment deposition is quite challenging” Dr Whinney said. “When sediment falls out of the water column and deposits on the seafloor, not all of it will stay there with the energy from waves and currents causing some of those sediments to resuspend and be transported elsewhere. This is what we mean by net deposition and is the actual pressure that will be exerted on an organism.

Deposition sensor deployed in laboratory experiments alongside traditional sediment traps and sedpods.

“The most common technique currently used to measure deposition is to use a sediment trap which typically comprise of vertical PVC tubes that are closed at the bottom and open at the top and mounted on a frame on the seafloor. These are generally deployed for months at a time before they are retrieved and the amount and characteristics of the sediment in the tube can be measured.” Dr Whinney said.

“The problem with this is that once sediments have settled in the tube, they get trapped there and can’t be resuspended by wave energy. So while they can accurately tell you the total amount of sediment that settles, they can’t tell you what the net deposition would be after some of this has been resuspended and transported elsewhere. “Another problem is that they can’t tell you how much settles each day. Just averaging the total amount of sediment by the number of days it was deployed is not accurate as on calm days more sediment would settle out of the water column whereas on rough and windy days less would settle.

This is important to know for organisms like corals as they can actively remove sediment that has deposited on them but only up to a point. If the rate of deposition becomes too great, they will not be able to keep up and begin to get buried by that sediment.

To address this problem Dr Whinney and his colleagues have been developing an automated deposition sensor that can measure net deposition as well as provide accurate information of the amount settling each day.

“The deposition sensor we are developing uses optical back scatter allowing readings to be taken every few minutes and uses a perforated plate on top of the sensors to mimic the surface of a coral so that deposition occurring on the instrument is similar to that on a coral.”

“During the development of this sensor it has been tested at AIMS, used in experiments at SEASIM and also deployed off Townsville and on the site of the Wheatstone Project, off Onslow. The data from the sensor is promising, measuring expected levels of sedimentation in the laboratory and gathering interesting data from the field which compares well with wave and turbidity data.”

Calibrating deposition sensor in laboratory by adding known quantity of sediment.

Dr Ray Masini from the Office of the Environmental Protection Authority and the Node Leader – Policy, said developing an instrument that can accurately measure net sediment deposition will be a major step forward and improve confidence during the EIA process.

“While proponents use sediment transport models to make predictions of the amount of sediment deposition that will occur, because we can’t actually measure net sediment deposition in the field, there is no way to verify and refine the sediment deposition rates that were predicted by those models” Dr Masini said. “This reduces confidence for both the Environmental Protection Authority and project proponents in the prediction of impacts during the EIA process.”

“It is also important for scientists conducting experiments to establish thresholds of response to dredging-related pressures.  To accurately define the sediment deposition rates that led to mortality, sub-lethal impact and first observable effect, you have to be able to accurately measure this in the first place.”

“Therefore the development of this deposition sensor will be an important step forward and provide both the Environmental Protection Authority and project proponents a greater level of confidence in the prediction of impacts during the EIA process,” Dr Masini said. “Which is what the Dredging Science Node is designed to do – to increase the confidence, timeliness and efficiency of the assessment, approval and regulatory processes associated with dredging projects.”

The WAMSI Dredging Science Node is made possible through $9.5 million invested by Woodside, Chevron and BHP as environmental offsets. A further $9.5 million has been co-invested by the WAMSI Joint Venture partners, adding significantly more value to this initial industry investment. The node is also supported through critical data provided by Chevron, Woodside and Rio Tinto Iron Ore.

Category:

Dredging Science

Can dredging sediments affect the reproductive cycle of corals?

/in , /by

A new review has found that turbidity and sedimentation, two of the most widely recognised threats to coral reefs, can have an effect on coral reproduction before, during and after spawning.

Elevated turbidity regularly occurs in shallow, tropical marine environments driven primarily by wind-driven waves but this can be exacerbated by anthropogenic activities such as dredging. The effects on adult corals and the sensitivity of their early life-history stages has been well documented, but the review, published in Marine Pollution Bulletin highlights new potential mechanisms that suspended sediments can have on the reproductive cycle including gametogenesis, spawning synchrony and on gametes in the water column.

The WAMSI study, conducted by researchers from the Australian Institute of Marine Science (AIMS) and The University of Western Australia (UWA), is working to help environmental managers predict how corals will react to changing pressures on their environment.

Co-author from UWA’s Centre for Microscopy, Characterisation and Analysis, Gerard Ricardo, said the review highlighted the need to be able to quantify the extent of the changes in the environment in order to accurately predict how coral spawning would be affected.

WAMSI researcher Gerard Ricardo (UWA) collecting freshly spawned eggs for laboratory experimentation. (AIMS)

“This review was partly motivated by the recent resources boom in tropical Australia, the need for dredging for coastal infrastructure and shipping channels to export mineral and petroleum products, and current environmental regulations around protecting coral spawning events during dredging campaigns,” Gerard explained. “However, the findings are equally as applicable to natural events in turbid-zone communities driven by wind-wave induced resuspension.”

Lead author AIMS’ Dr Ross Jones said that while sediments can act as an energy source for adult corals, there are overwhelmingly more than 30 possible causal pathways whereby turbidity-generating activities can negatively affect reproduction and early life-cycle stages.

“We know that it is only very subtle changes in light quantity and quality that trigger spawning,” Dr Jones explained. “A loss in natural synchronicity could ultimately affect the arrival of the gametes at the surface, which could affect the separation for each species, a process which prevents or reduces hybridization between closely-related species by spawning at slightly different times.

http://ars.els-cdn.com/content/image/1-s2.0-S0025326X15005251-gr1.jpg

Reproductive cycle of the broadcast spawning Acropora species with indicative timings based on the studies of Hayashibara et al. (1997), Okubo and Motokawa (2007), Okubo et al. (2008) and Ball et al. (2002).

In recognition of the sensitivity of the early life-cycle stages of corals, and their importance to the marine community, policy makers have attempted to protect coral spawning periods from sediments generated by dredging-related activities. Since 1993, dredging projects in Western Australia that are close to reefs are required to temporarily stop when corals are spawning five days before spawning and up to seven days afterwards.

This management approach has also been adopted in some dredging projects on the Great Barrier Reef and the possibility of introducing this practice to other locations such as Singapore has been suggested but it’s a contentious issue internationally because it can significantly inflate costs.

One of the most contested issues is the length of the window and also whether dredging-related turbidity-generating activities need to cease entirely or whether dredging can continue but must adhere to more conservative water quality guidelines.

Sperm tangled in sediment particles. WAMSI scientists are examining whether this impacts on the reproductive success of corals (Image: AIMS)

“The successful use of a coral spawning environmental window as a management tool depends on a shutdown period which encompasses the entire period that turbidity-generating activities could have an effect on spawning and ultimately the successful recruitment of juveniles into the next generation,” Dr Ross Jones said. “The window needs to contain sensitive stages such as settlement and early post-settlement survival.”

In Western Australia there is a well-known main autumn spawning period, but more recently a significant spring spawning period has been identified.

“The presently applied 12 days coral spawning shutdown period is too short to fully encompass the full settlement period, especially settlement and early post-settlement survival,” Dr Jones said.

“Extending the window before and after the predicted spawning date seems an obvious next step to also accommodate effects on gametogenic and spawning synchrony and to fully cover the settlement period. This may however significantly limit time that turbidity-generating activities could occur near coral reefs in any given year.

“Although the approach seems logical, the question is whether this approach is reasonably practicable and whether the resulting intermittent and protracted dredging operation would result in a better net environmental benefit than a shorter campaign.

“What we do know is that conducting dredging activities at a time that avoids coral spawning periods and settlement periods constitutes a best management practice,” Dr Jones said

[R. Jones,,G.F. Ricardo,,A.P. Negri, (2015) Effects of sediments on the reproductive cycle of corals. Marine Pollution Bulletin doi:10.1016/j.marpolbul.2015.08.021]

This project was funded by the Western Australian Marine Science Institution as part of the WAMSI Dredging Science Node, and made possible through investment from Chevron Australia, Woodside Energy Limited, BHP Billiton as environmental offsets, and by co-investment from the WAMSI Joint Venture partners. This research was also enabled by data and information provided by Chevron Australia. The commercial investors and data providers had no role in the data analysis, data interpretation, the decision to publish or in the preparation of the manuscript.

Category:

Dredging Science

New master plan for Swan and Canning rivers

/in /by

Perth’s much-loved Swan and Canning rivers will remain vibrant and accessible for all West Australians under a new State Government strategy released today (Tuesday 20 October).

Environment Minister Albert Jacob said the Swan Canning River Protection Strategy provided a master plan to guide investment, keep the rivers healthy and ensure they were accessible for the community to enjoy in the long term.

“For the first time, we have a whole-of-Government strategy that sets out a shared vision on what needs to be done to make sure our rivers are better protected while meeting the demands of a growing city,” Mr Jacob said.

“This strategy will better co-ordinate work between the government agencies involved in managing the rivers with the aim of improving benefits to the community and ensuring the rivers continue to be attractive and desirable places.

“This improved integration between agencies will lead to more efficient use of the State Government’s substantial investment in the management of our rivers with better outcomes for river health and community use and enjoyment.”

Read more…

 

 

Category: 

Estuary Science

Premier briefed on Kimberley marine research projects

/in , /by

WA Premier and Science Minister Colin Barnett released two AFL celebrity into waters off Broome as part of a broader program of marine research in the Kimberley.

The two green sea turtles Cyril and Sharrod, named after the AFL Hawkes forward Cyril Rioli and Eagles defender Sharrod Wellingham by the Yawuru Rangers, were caught in the waters off Roebuck Bay and tagged with a satellite tracking device. Premier Barnett released the turtles as part of the Yawuru Rangers marine turtle monitoring collaboration. The results will be updated daily on seaturtle.org.

Premier Barnett was also briefed on the Kimberley Marine Research Program by WAMSI program leader Stuart Field (DPaW); a $30million project under WA’s Kimberley Science and Conservation Strategy with 10 partner agencies and more than 100 scientists delivering 26 projects.

Researcher Scott Whiting prepares a turtle for release (Photo: Stuart Field, DPaW)
Tagged and ready for release
(Photo: Stuart Field, DPaW)

 

Premier Colin Barnett releasing Cyril the green sea turtle (@CollinBarnett: Twitter)
Monitor Cyril’s and Sharrod’s progress on seaturtle.org.

The Premier and Yawuru Rangers watch the sea turtles’ progress (DPaW)

 

WAMSI-DPaW Stuart Field briefs Premier Colin Barnett on WAMSI marine research in the Kimberley (DPaW)

FACT FILE:

DPaW Yawuru Rangers sea turtle monitoring:

  • Three species of marine turtle are common residents in Roebuck Bay (Green, hawksbill and flatback turtle), with other species (loggerhead, leatherback) less common.
  • Green turtles are abundant in Roebuck Bay and are ecologically and culturally significant.
  • Green turtles are a primary consumer of seagrass and algae and play a major role in the health of these systems.
  • Green turtles are highly significant in Yawuru culture and are important for food, ceremony, stories and songs.

Results from this study will provide information on:

  • Spatial (where) and temporal use (when) of habitats;
  • What habitats are important and how they use them;
  • How they use the proposed Roebuck Bay Marine Park and areas outside the park;
  • Identify any other spatial areas that are important (for example – are they frequently visiting areas 100 km away):
  • Identify areas where turtles and human pressures overlap (eg shipping lanes);
  • The results will be updated daily on seaturtle.org.
Category:

Kimberley Marine Research Program

Ancient building rite marks milestone for new collaborative research centre

/in /by

Published in AIMS Waypoint Spring 2015 Newsletter

 

An ancient ‘topping off’ ceremony was used in July to celebrate the successful installation of the final concrete beam in the new Indian Ocean Marine Centre in Perth.

The new marine centre is on the University of Western Australia’s (UWA) Crawley campus, and marks an exciting time for new collaborative partnerships in marine science. The ceremony was held with AIMS, CSIRO, UWA and Western Australian Department of Fisheries researchers and staff.

Dr John Chappell, AIMS’ Operations and Infrastructure Manager, said, “It’s exciting to reach this significant milestone in constructing the new state-of-the-art facility that will bring together the Indian Ocean’s leading marine research organisations.”

Northwest Australian marine waters will never be the same: researchers will focus on discovering, understanding and monitoring those tropical waters, and in doing so, supporting the protection and sustainability of our ocean heritage.

More than fifty guests watched UWA Chief Operating Officer, Gaye McMath, lead the topping out of the $60.6 million building.

Grateful for the success of the project to date, Ms McMath expressed excitement about expanded research opportunities because of the collaboration of partners the centre would enable. “It will continue to build Australia’s international marine research status.”

Symbolising growth and bringing luck, a bouquet of plants from the UWA campus was also hung from the top of the building.

It’s expected the building will be finished in mid-2016, and will then house more than 330 multi-disciplinary researchers specialising in fisheries, marine technology, marine ecology, geochemistry, governance and engineering.

The Indian Ocean Centre was enabled by contributions from the collaborating organisations and a $34 million grant from the Australian Government, highlighting the wide commitment to premiere tropical marine research.

Also celebrating were people from site contractor BGC Construction. Their work has brought together essential services within the six-storey building with sustainable design principles.

Signals from the sawfish nursery

/in /by

By Jeff Whitty and Dr David Morgan

Murdoch University’s Freshwater Fish Group (Centre for Fish & Fisheries Research) in conjunction with the Nyikina-Mangala Rangers, are unravelling the mysteries of one of the most threatened fishes in the world, the freshwater sawfish (Pristis pristis).

A WAMSI project funded by Chevron Australia, ‘Team Sawfish’ is helping to protect one of the world’s largest fishes that is found in freshwater. The freshwater sawfish has declined globally, and in Australia is listed as Vulnerable on the Environment Protection and Biodiversity Conservation (EPBC) Act.

Facing multiple threats including fishing pressure, often by means of bycatch and habitat modification, the numbers and ranges of all sawfishes have greatly declined. In Western Australia, the freshwater sawfish inhabits rivers as juveniles and as such it is likely to be impacted by habitat modifications such as instream barriers (e.g. dams), which may obstruct their migrations into freshwater nurseries. Murdoch University researchers are investigating what impacts these barriers may have on the freshwater sawfish.

In August 2015, Team Sawfish, consisting of Murdoch University researchers and the local Nyikina-Mangala Rangers, set out to continue their work studying the impacts of such barriers in the Fitzroy River, Western Australia.
Team Sawfish measuring a freshwater sawfish

Starting at 360rkm (i.e. 360 kilometres upstream of the river mouth), Team Sawfish systematically sampled pools for sawfish as they moved downstream, including those pools located in close proximity to  the various barriers on the river and ending within the estuarine pools near the river mouth.

The aim of this trip was to catch and tag freshwater sawfish with acoustic transmitters in order to monitor and thus better understand how anthropogenic barriers may affect the movements and/or behaviour of these fishes during the wet and dry seasons, noting movement over the barriers is only possible during peak flows during the wet season (December-April).
Nyikina-Mangala Rangers preparing to deploy an acoustic receiver to monitor the movements of tagged sawfish

During their sampling efforts, Team Sawfish found pools along the river to have become filled in and shallow, a likely result of the lack of flushing of introduced sediments during the past few small wet seasons.

The small 2014-2015 wet season also seemed to have led to the capture/presence of very few sawfish and no young of the year (those pupped within the 2014-2015 wet season).

This finding was congruent with findings from previous years, which suggested that the relative abundance of sawfish within the freshwater pools of the river is positively correlated with the size of the previous wet season.  

The Freshwater Sawfish that were captured were limited to size classes that would have been pupped in 2011-2012. Observing sawfish from the 2011 year class to still be present within the river provided further evidence that some juvenile sawfish do inhabit the river for more than four years, as previous data suggested.

The monitoring of sawfish continues and the team is continuing to tag and record freshwater sawfish in spring of this year.

If you catch a tagged sawfish, or would like to know more about these mysterious creatures, please contact fish@murdoch.edu.au.

 

Category: 

Sawfish Project

IGEM collaboration important first step in voluntary industry data sharing

/in /by

The success of a pilot project that generated a snapshot of environmental data relevant to impact assessment and monitoring off the northwest coast is on track to begin sharing industry meta-data from the many industry funded studies in Western Australia.

Several conscientious oil and gas companies have taken the initiative by agreeing to share information about the huge number of datasets they collect.

Woodside, Chevron, Inpex, Murphy Oil Australia, PTTEP, Quadrant Energy (formally Apache), Santos, Shell Australia, facilitated by their peak industry body APPEA, are creating a meta-database called the Industry-Government Environmental Meta-database (IGEM), which is being developed and operated by the Western Australian Marine Science Institution (WAMSI).   

Metadata is information about data. It tells you where, how, when and what data was collected.  As well as these companies, WAMSI, the Australian Institute of Marine Science and the state government Departments of Parks and Wildlife, and Fisheries are also contributing their own metadata to the IGEM.

“As an industry, we collect a huge amount of data,” Chair of the APPEA Environment and Safety Committee Gerry Flaherty said. “But right now only the companies who pay for the projects know what has been collected.  If we have an emergency we need to respond to quickly. Having a place where everyone can see what information is out there will dramatically improve our response.”

“This will be a great advantage for IGEM partners in projects to inform regulatory processes or for research purposes, not just response,” WAMSI CEO Patrick Seares said. “It means they can look at the IGEM to see what already exists, then negotiate access to it with the owners rather than doing expensive duplicate fieldwork.”

IGEM will have the capacity to increase its key datasets but it will begin with using metadata collected post-2008 in seven key areas: mangroves; benthic habitats; demersal fish, nesting turtles, seabirds and shorebirds, megafauna; and sediment quality.

Subscribers will be able to search for relevant environmental studies by research activity in a specific area; the date it was collected; the organisation that collected the data; type of data; and key words.

The in-development web-based platform should initially provide access to geospatial metadata records on key studies off Western Australia, but with the potential to expand nationally. The site will have a page accessible to the general public with limited information and a log-in interface for approved members who can generate reports.

“I hope as we can start seeing the system evolve that other companies, agencies and research groups see the positives in this process and follow the lead of the current participants,” Patrick Seares said. “Sharing metadata has so many upsides and really doesn’t expose the data owners to any risk.”

The IGEM platform is expected to be available by early 2016.

Field report from research vessels in Camden Sound, Kimberley region

/in , /by

The initial ship-based expedition to Camden Sound was conducted under the auspices of WAMSI’s Kimberley Benthic Biodiversity Project, which aims to provide a better knowledge base about what occurs where in the Kimberley’s diverse marine environments, especially in areas of management priority such as the state government’s proposed marine parks and reserves.

Cruise leader on board the RV Solander, Dr Andrew Heyward from AIMS in Perth, said that the vessel operated 24/7 during its 18-day itinerary. “Scientists and staff worked in shifts, doing towed video and sediment sampling during daylight, and multibeam sonar surveys during the night,” he said.

Although the weather was generally very good, extreme tides, strong currents, turbid waters and some uncharted areas provided plenty of challenges for researchers. They successfully completed more than 200 km of towed video and thousands of km of multibeam seafloor mapping, in the first of two expeditions to the Camden Sound area.

“We’ve seen large areas of dynamic sand across the open Sound, including some patches with underwater sand dunes,” commented Andrew, “but also rocky ground covered in a large variety of marine invertebrates, in particular sponges and soft corals.”

The turbid waters of Camden Sound prevent sunlight from penetrating more than ~10 m in depth, so organisms that need light – such as corals and seaweeds – appear to be restricted to the shallowest parts of rocky ground and the upper edges of fringing reefs around islands. As depth increases and light fades the filter feeding sponges, soft corals, ascidians and bryozoans become the dominant components of the seabed communities.

“Thanks to the combined efforts of the Solander and the Linnaeus this month,” said Andrew, “we’re beginning to understand a lot more about what the seafloor of the Lalang-garram-Camden Sound Marine Reserve looks like, and the benthic biodiversity that lives there.”

Dr Iain Parnum from Curtin University is busily compiling all the gathered multibeam sonar data now. “In terms of outputs, first of all, we’ll deliver some much-needed improved bathymetry information for Camden Sound,” he explained. “Secondly, sonar backscatter data – both from the seafloor and the water column – will give us good insights into the kinds of underwater terrain and ecosystems at each sampled location.”

In addition, Dr John Keesing from CSIRO took advantage of the presence of the RV Solander in the Kimberley to advance another WAMSI project investigating historic changes in water quality. He collected sediment cores (each ~1.5 m long) at ~20 m depth from two locations in Roebuck Bay. “These cores will be used to reconstruct a time series of water quality in the Bay, which is expected to go back about 100 years,” he said.

As with all WAMSI projects, the data and outputs will be freely available to everyone with an interest in the marine environments of the Kimberley.

Map showing sites in Camden Sound where towed video surveys were conducted in November 2014 

 

A still image from one of the towed video surveys showing mixed filter-feeding community (including bryozoans, sponges and soft corals) growing on a rock outcrop (Photo courtesy of AIMS)

Category:

Kimberley Marine Research Program