Neptune’s Necklace (Hormosira bansi), also known as sea grapes or bubbleweed, is made up of fronds of water-filled beads attached to the substrate by a thin disc (holdfast). When foraged responsibly, it makes a healthy addition to your diet and your soil.
Neptune’s Necklace is found in the rocky intertidal zone from Albany in Western Australia through to northern New South Wales, and around Tasmania and New Zealand. It can also be often found free-floating among mangroves.
It can be harvested all year round but is at its most prolific in the cooler months. Like all seaweeds, Neptune’s Necklace provides important protective habitat for lots of species, offering both moisture at low tide and shade. Reducing its canopy by as little as as 25 percent can dramatically impact the animals residing within it.
How To Collect It
Before foraging for seaweed, it’s important to familiarise yourself with the laws in your area. Your local Department of Fisheries website is an excellent resource which will outline your state’s or area’s specific regulations. Some states allow only beach-cast seaweed to be collected, whereas others allow a small amount above the low-tide mark to be taken – but never in marine parks.
The safest place to harvest Neptune’s Necklace is in rock pools, away from river mouths, urban areas and wastewater outlets. Avoid collection from estuaries or mangroves. Remove only one or two fronds from each plant from the base, but ensure the holdfast is left in place for the plant to regenerate. It is susceptible to trampling so try not to burst the beads while walking over the reef. Foraging just one frond from a series of plants which are spread across a shoreline is the most sustainable way.
Given the edible seaweed industry in this country is still very much in its infancy, and that 62 percent of southern Australia’s species aren’t found anywhere else in the world, it’s best to avoid collecting seaweed from highly urbanised areas until there’s enough data to suggest it’s safe to do so.
It’s not just potential danger to our own health we need to think about, but also the effect it can have on aquatic life. Seaweeds are often foundation species in coastal marine ecosystems; the engineers that rest of the ecosystem rely on. They provide food and habitat for many other species living within it and often alter the physical environment, for example by reducing light and wave action.
Seaweed accumulates nutrients, trace elements and minerals from the water in which it lives. Some of these, such as zinc and iodine, are important additions to our diet and are often lacking in terrestrial-grown food. By eating seaweed, we are increasing our important vitamin and mineral consumption.
Unlike mushrooms, seaweeds have few if any naturally occurring toxins. Any seaweed is potentially edible; it’s just a matter of how they taste as to whether you want to eat them. The problem is, though, the same processes that enable seaweed to concentrate beneficial dietary nutrients also enables them to accumulate metals, pesticides, herbicides and other contaminants.
A great way to preserve your harvest is to pickle it with salt, vinegar, seawater, a bit of pepper, ginger and any other pickling herbs and spices of your choice. Seaweeds can also be used as a base for steamed fish.
As well as our own, seaweed can play an important role in our garden’s health and wellbeing. Adding seaweed to your garden introduces a range of minerals and trace elements from the ocean that aren’t always readily available in the soil.
To make a seaweed fertiliser for your garden, use the same process as you would when making a weed tea (Pip, Issue 22). Gather beach-strewn seaweed, place in a large container, cover with water and let sit for several weeks. Cover with a lid to reduce the smell and to stop mosquitoes breeding in it. Once ready, dilute to 1:10 and add to your soil once a week.