SEEDS FOR SNAPPER

With the help of recreational fishers, OzFish is working to restore seagrass habitat in Cockburn Sound, Western Australia.

For the second consecutive year, hundreds of recreational fishers and community members in Western Australia will be taking part in the Seeds For Snapper project this November to restore the lost seagrass of Cockburn Sound and help our fish habitat.

The immense loss of seagrass meadows affects Pink Snapper as it’s also a nursery habitat for baby snapper, calamari, whiting, blue swimmer crabs and many other fish species.

The trial project was first implemented in 2018 in partnership with OzFish and the University of Western Australia – Oceans Institute and community members from the Cockburn Power Boat Club. Community volunteers including drivers and fishers collected floating seagrass fruit for processing on-shore which were placed in tanks with circulating seawater to separate the seed before they were dispersed in a predetermined location.

COMMUNITY VOLUNTEERS NEEDED NOW

OzFish Unlimited is set to ramp up the Seeds for Snapper Project this November and are currently looking to recruit volunteers to get involved. Volunteers are needed to support the collection of fruit, processing of seed and dispersal. It is hoped that 1 million seeds can be processed, potentially restoring 10,000 m2 (1 Ha) of lost Seagrass habitat per year for the next three years.

As a volunteer, you will be trained in fruit collection, seed processing, digital record keeping and operational safety. The main activities will be occurring at the Cockburn Power Boat Club. Community volunteers are required to register below to be involved.

 REGISTER TO BE A VOLUNTEER

UPCOMING EVENTS

SEEDS FOR SNAPPER FAMILY SEEDING DAY

As part of the Cockburn Power Boat Club Open Day, OzFish will be also having a family Seeding Day where the public can help disperse the Seagrass seeds in a location offshore. This is a free family event with entertainment, displays and an opportunity to support our local fish habitat and try out boating.

Date: Saturday 23 November 2019
Time: 10:00am – 4:00pm
Location: Cockburn Powerboat Club, 28 Jervoise Bay cove, Coogee WA

FREQUENTLY ASKED QUESTIONS

  • 1. What is Seagrass?

    Seagrasses are flowering plants that have evolved to live in the marine environment. Seagrasses are different from seaweeds or algae. Seagrasses grow like our urban lawns, sending out runners or rhizomes to cover available space, forming large underwater meadows. Seagrasses also produce flowers. The male flowers release pollen which fertilizes the female flowers.  Once fertilized, the seed and fruit develop. Once mature, the fruit release from the flower head and float to the surface. Floating fruit tend to be dispersed by the wind and currents until they split open, releasing the seed, and the seed sinks to the sea-floor where it will put down roots to establish. Research from the University of Western Australia has shown that seeds are potentially an effective way of restoring many Australian seagrasses because we can collect large amounts efficiently, which therefore can be used to cover large areas of sea-floor needing to be restored.

  • 2. What is ribbon-weed?

    Ribbon-weed is a large species of seagrass that has long, blade-like leaves and can grow up to 1m in length, but typically around 30-60 cm.

    Ribbon-weed forms a dense canopy that is important for sheltering many marine animals, particularly juvenile Pink Snapper. Adult Pink Snapper also use the seagrass meadows to hunt for food.

    In Western Australia, we find Ribbon-weed in sheltered coastal locations and estuaries, but it also grows along the south coast and up the east coast to northern NSW.

    Ribbon weed begins to produce flowers in winter between May-June and the flowers become mature in August. The flowers, when mature, are easily identified as they are taller than the seagrass canopy, and have a distinct red colour where the pollen is released from. Mature flowers undergo fertilization in September, the time the pollen is released. Fertilized flowers will be easily identifiable as you will see multiple small fruit developing on each flower head during September-October. Fruit mature over these 6-8 weeks and the seeds are fully developed by November.  Fruit can be highly abundant in some meadows with as many as 60-80 flower heads per square meter equalling 300-800 fruit.

  • 3. How do I collect fruit?

    Ribbon-weed fruit are found in large numbers floating as drift material on the ocean surface in November each year within Cockburn Sound and its surrounds (incl. Owen Anchorage, Parmelia and Success Banks, Fremantle, Garden Island, and Carnac Island). Fruit can be collected from the ocean surface using a dip-net with mesh size of less than 10mm.

  • 4. What do the floating fruit look like?

    A healthy fruit that has a seed inside is green/yellow in colour, 1.5-2cm in length.  A fruit that has recently split open is still green/yellow and looks like a banana peel. An old fruit that has split open turn brown after 1-2 days in the sun. If you have intact fruit mixed with split fruit that is fine, there is no need to sort through, unless the majority of your catch is split fruit then it would be great just to pull out the intact fruit. Ideally, we want you to target fruit that is still intact and the seed is still inside. If we collect only fruit husks we risk having lots of fruit material but no seeds and this can be very time consuming to separate.

  • 5. How do I store fruit once they have been collected?

    Once fruit have been collected they need to stay in seawater (or at least kept moist) and out of direct sunlight. The best method is to place fruit within a bucket or esky and put a lid or wet towel over them to stop them from drying out. We often use large eskies to keep the fruit well insulated so they don’t get too hot in the sun (Fig. 8). Please do not split open the fruit using your hands to get seed out.  This can cause damage to the seed, and its shoot or roots, and the seedling will not survive.

  • 6. What do I do with the fruit?

    Once you have collected fruit, kept them wet and out of direct sunlight, and you have finished your days fishing, fruit need to be brought back to Jervoise Bay boat ramp and handed to our designated team member. If eskies are too heavy to lift, then fruit will need to be manually scooped out into a tub the designated team member supplies.

  • 7. What happens to the fruit after I hand them over?

    Fruit collected at the boat ramp will then be transported to the University of Western Australia’s Seagrass Research Facility where fruit will be put through a process to speed the natural seed release. This typically involves fruit being placed in a large circular aquaculture tank filled with seawater. The seawater is heated to 25-27 degrees Celsius. Vigorous aeration is supplied to the tank to agitate the fruit and the water is also circulated. The elevated and stable temperature combined with the agitation promotes rapid splitting of fruit. It simulates the seed at the ocean surface in the sunlight and being agitated by waves. Seeds sink to the bottom of the tank while the fruit husk remains at the surface for 24-48 hours. Because the fruit and seed separate, we can collect pure seed from the tank bottom (Fig. 10). If we wait too long, then the fruit degrades and sinks to the tank bottom and it is a time-consuming process to separate seeds from the fruit.

  • 8. How is the number of seeds determined?

    Once we have separated split fruit from seeds, pure seeds are counted using a water displacement method. This method works on the premise that a known quantity of seeds displaces a volume of water. For example, we initially count out 1000 seeds into a container that contains a known volume. This container has graduated volume marks so we know the volume before we put seeds in. Once 1000 seeds have been added we can determine how much water volume has been displaced by this quantity of seeds. We repeat this process 3 times to get an average volume of water displacement. Once we know this average volume, we can then add seed until this displacement volume has been reached without counting the seeds, and get a good estimate of the number of seeds.  This results in a rapid and relatively accurate count and we can easily scale this up to count seeds in larger batches.

  • 9. How do I obtain seeds before heading out to restoration sites?

    Once we have separated split fruit from seeds, pure seeds are counted using a water displacement method. This method works on the premise that a known quantity of seeds displaces a volume of water. For example, we initially count out 1000 seeds into a container that contains a known volume. This container has graduated volume marks so we know the volume before we put seeds in. Once 1000 seeds have been added we can determine how much water volume has been displaced by this quantity of seeds. We repeat this process 3 times to get an average volume of water displacement. Once we know this average volume, we can then add seed until this displacement volume has been reached without counting the seeds, and get a good estimate of the number of seeds.  This results in a rapid and relatively accurate count and we can easily scale this up to count seeds in larger batches.

  • 10. How do I deliver seeds to the restoration sites?

    The total restoration site area will be quite large, approximately 1 hectare. Therefore, each participant will be delivering seeds to only a designated GPS fix. Each designated GPS fix will be 10m x 10m (100m2) in area. The GPS fix will be central to that area. Within each 10m x 10m area each participant will be required to deliver 20 000 seeds (200 seeds per square meter). We DO NOT want participants to anchor since this may potentially disturb nearby areas where seeds have been delivered. The process of delivering 20 000 seeds is quite quick. Handfuls of seeds can be thrown over the side your vessel. You will be able to throw 20 000 seeds over the side of the boat by hand in 1-2 minutes. If the weather conditions are calm (glass-off), you can get your vessel on top of the GPS fix as close as possible, stop your vessel, then throw handfuls of seeds from different points of your boat – being careful not to throw the seeds too far away (1-2 m from your boat will be sufficient). If it is windy, we will provide you with a weighted float and line that you can use as a marker at your GPS fix. Once this marker is in place you will just need to position and/or maintain the position of your vessel as close to the marker as possible where you can then disperse seed around it by throwing handfuls of seeds. Remember each GPS fix is the central point of your designated site which is 10m wide by 10m long. By throwing handfuls of seeds, seeds will naturally spread out and result in a relatively even coverage as they sink to the seafloor. Once finished, collect the marker and return the marker to staff at the Jervoise Bay boat ramp.

If you’d like to hear more about the project contact Andrew Matthews on 0449 059 912 or email andrewmatthews@ozfish.org.au. The ‘Seeds for Snapper’ project would not be possible without the support of our major partners the University of Western Australia, Recfishwest, Cockburn Power Boat Association and BCF – Boating Camping Fishing.