Burrill Lake Saltmarsh

Saltmarshes are key fish habitat. Research has found that they make a proportionally high contribution to fish diets.

Sadly, the saltmarsh at Burrill Lake is in a degraded state. This project aims to improve recreational fishing by restoring the degraded habitat. In addition to habitat restoration, the project also aims to answer some important questions about fish diets, and the effects of habitat restoration on fish and fishing.

Researchers from the University of Newcastle will analyse fish samples collected by recreational fishers. The results from this research will be used to guide future fish habitat restoration projects.

A man sitting in a boat holding a mid-sized fish in both hands
Local angler fishing Glen Sherriff fishing Burrill Lake on the NSW south coast.
An overhead drone image of a lake and it's surrounding landscape

We need your help

The next time you snag a fish, keep a small piece aside and make a valuable contribution to this fish habitat restoration project.

We are looking for recreational fishers to provide us with a small tissue sample from their catch. The samples will be used to determine which species rely on which habitats for their food. We also want to know if this changes over time as more saltmarsh becomes available within the system.

Sample collection packs

We have put together a number of sample collection packs that you can collect from the Big4 Bungalow Park on Burrill Lake that includes sample bags, tape measure, labels and simple instructions on how to prepare, label and store the tissue samples until we can collect them from you or the park. If you are taking your samples home, please register here so we can let your know when the next sample collection is for you to drop off your batch of samples.

The University of Newcastle will be conducting fieldwork seasonally on Burrill Lake during which we will do a sample collection pickup at the BIG4 Bungalow Park, and a central location which registered local participants will be notified of closer to the date if they decide to store the samples in their own freezer at home.

Saltmarsh in the foreground and trees in the background
A muddy section on the edge of the lake with cow hoof marks

Habitat Degradation

Unfortunately, primarily owing to cattle grazing, the saltmarsh at the northern edge of Burrill Lake is in a degraded state.

The cattle eat the saltmarsh and their hooves disturb new growth and compact the ground, making it difficult for regrowth to occur. To rehabilitate the site, a fence will be erected to keep the cattle out of the saltmarsh.

Further to this, new plants will be added to assist rehabilitation of the site. The project aims to improve the quality and quantity of saltmarsh in Burrill Lake and to investigate the flow on effects to the resident fish with the hope of improved recreational fishing within the lake.

Research and monitoring

The University of Newcastle has been monitoring the lake before, during and after the restoration of the site through a number of projects.

One way the importance of a food source to a particular species can be measured is by a natural chemical tracer – stable isotopes. Isotopes are atoms of the same element that are naturally present in nature. The isotopes of carbon and nitrogen are used most often to trace where species get their energy.

Gut content analysis shows what an organism has been eating, but doesn’t indicate which food items were most important. By measuring stable isotopes and using statistics, researchers will be able to determine the relative proportion of each food source

An up-close image of the fauna found in the saltmarsh

TAKING A SAMPLE

Whatever legal catch you are going to keep from Burrill Lakes, we want a piece!

We have split up the lake into four different zones, please make sure you record the zone where you caught the fish.

A map of Burrill Lake split up into sampling zones
Measurements taken from the fish can provide an estimate the weight and provide useful information needed for food web analysis.
  1. Measure Your Catch:
You can take a fork length measurement or a Total length measurement. Either is fine, just let us know which one you used with a ‘FL’ or ‘TL’ on the label.

  1. Sample Preparation:
Carefully cut a 1cm cube of muscle from above the lateral line, remove the skin making sure there is no scale and bone fragments. Bag and label each tissue sample separately for each individual fish using the zip-lock bags and labels provided. Alternatively, you can use your own clean plastic ziplock bag and labels, ensuring that it is labelled correctly.
You can drop your samples off at BIG4 Bungalow Park on Burrill Lake 123 Princes Hwy, Burrill Lake NSW 2539 at any time during opening hours, or alternatively take the sample home and keep it in your freezer. If you are taking your samples home, please register here to find out when the next sample collection is so you can drop off your batch of samples. Every three months or so a collection day will occur in the Burrill Lakes area and will provide an opportunity to discuss what the project is finding! If you are interested in attending one of these days to drop in your batch of samples.

REGISTER YOUR CATCH

This study relates to saltmarsh restoration within Burrill Lake so we are only interested in fish caught within Burrill Lake at this stage.

We are doing stable isotope analysis on the fish samples. This will tell us which habitat forms the base of the food web for fish in Burrill Lake. Essentially fish forensics!

As long as the sample is kept in the freezer it will be suitable for analysis. If you like you can drop a batch of samples off at BIG4 Bungalow Park on Burrill Lake every 3 months or so, or whatever is convenient for you. As long as the sample is kept in the freezer it will be suitable for analysis. If you like, you can drop your samples off at BIG4 Bungalow Park on Burrill Lake during opening hours. Otherwise, register here to find out when we will next be visiting to update participants on the project and bring your frozen samples along!

The project has started and will be ongoing for 12 months. Any legal-size fish caught in Burrill Lake between now and 2022 will be valuable to the study.

As many as you can give us. The more data we have, the better our information will be about the importance of saltmarsh habitat.

Yes! You can pick up a sample kit from BIG4 Bungalow Park on Burrill Lake and return your sample plus any unused kits to the same place before you leave Burrill Lake.

OTHER FREQUENTLY ASKED QUESTIONS

Saltmarshes are an ecologically important ecosystem that occupy the high tide zone. They link the land and sea, providing productive habitats for a range of species, including migratory shorebirds, and supporting commercial and recreational fishing.

They include plants such as sedges, rushes, reeds, grasses, succulent herbs and shrubs that can tolerate high soil salinity and occasional inundation with salt water. Saltmarsh areas have low vegetation, often interspersed with bare patches or salt pans.

Good habitat provides fish places to shelter, breed, seek protection from predators, and most importantly an abundant food source. Estuaries provide all these elements for fish through a mosaic of habitat types which play different roles for different species. The main contributors are seagrass, mangroves and saltmarsh.

Saltmarsh habitat plays a particularly important role as one of the foundations of the food web within estuaries. It has been found that they make a proportionally high contribution to fish diets.

Saltmarsh provides habitat and shelter for fish, especially juveniles and smaller fish species when it is inundated during higher tides. Studies have recorded over 40 species of fish inhabiting tidal saltmarsh areas. These include commercially and recreational important species such as:
  • Yellow-fin Bream
  • Sand Whiting
  • Mullet
  • Garfish
  • Eels
  • Crabs
And smaller species of fish than provide a food source for many recreationally important species such as:
  • Perchlets
  • Glassfish
  • Hardyheads
  • Gobbies

Better habitat means better fishing.

Improving our understanding of the role saltmarsh plays in Burrill Lake can lead to better management plans that protect and restore valuable habitat, resulting in a healthier more productive estuary, which means more fish.

There are a whole range of direct and indirect activities that are threatening saltmarshes.

Direct threats include soil compaction caused by off-road vehicles, damage to growth from humans and livestock walking, nutrient run off,  terrestrial plant and mangrove competition for space, development, illegal harvesting and dumping waste.

Indirect threats to saltmarshes include climate change, sea level rise and general degradation of the area.

Make sure if you’re visiting any saltmarsh habitat ensure that you only use provided access roads and remove any rubbish that is within your reach.

Enjoy the sights of the saltmarsh from a distance and do not walk directly on the saltmarsh.

Do not allow livestock to graze on saltmarshes as it damages plants and causes erosion.

Be mindful of nutrient and chemical runoff at home that might enter our waterways.

LATEST NEWS

Man holding mid size fish with both hands

18 DECEMBER 2020 | Rec fishers needed to help Burrill Lake saltmarshes shine

Local and visiting recreational anglers at Burrill Lake can contribute to important citizen science research over the next 12 months by collecting small samples from their catch and dropping them into Big4 Bungalow Park on Burrill Lake for habitat research.

Developed by the University of Newcastle in partnership with Australia’s fishing conservation charity OzFish Unlimited, the data will provide a better understanding of the benefits of saltmarsh habitat restoration for both fish and recreational fishers.

Find Out More

For any further queries feel free to contact:

Ryan Lungu – OzFish Program Manager NSW Coast
ryanlungu@ozfish.org.au

Lucas Kas – OzFish Project Officer
lucaskas@ozfish.org.au



Ben Cuerel – University of Newcastle
benjamin.cuerel@uon.edu.au

Mark Bennett – University of Newcastle
mark.a.bennett@uon.edu.au

This project was made possible thanks to the support of The University of Newcastle, NSW Local Land Services, Big4 Bungalow Park on Burrill Lake and BCF – Boating, Camping, Fishing.