Looking at aquatic wildlife in Britain and Ireland, AoF member Susanne Masters’ book Wild Waters is a guide to seeing the stories of plants and animals around us when we are near water.  Here is an excerpt from Chapter 1: Immersed on Land:

Lamb that has grazed on salt marsh is sold for a premium. It is thought the salt-marsh plants flavour the meat of sheep which eat them.  Salt marsh lamb has ancient roots. Written records show that medieval England’s expanses of salt marsh were used for grazing.   Buried evidence uncovered by archaeologists shows that in the Bronze Age, people relying on domestic grazing animals made use of salt marsh around the Severn Estuary area of England as productive land on which to feed their animals.

Lamb isn’t the only product that attracts a premium when it is nurtured by coastal plants, the world’s most expensive potatoes are fuelled by seaweed.  On the French island of Noirmoutier new potatoes are harvested young and sold as ‘La Bonnotte'. Along with sandy soil and excellent marketing, these potatoes are shaped by using seaweed as a fertiliser. Jersey potatoes have never reached the peak of £400 per kilo that La Bonnotte potatoes have achieved, but Jersey is also an island that markets its potatoes as seaweed-fertilised. Alongside the nutrients that seaweed contains, there is an advantage in comparison to compost—seaweed contains no agricultural weed seeds.  17^th and 19^th century records of penalties and fines imposed in Jersey include matters concerning the collection of vraic, as seaweed was locally named.  Seaweed featuring in the legal system indicates how valuable it was to people living on Jersey.

Landlocked gardeners who don’t have a nearby seashore for collecting seaweed often use seaweed as a fertiliser for tomatoes without realising—since one of the most popular tomato fertilisers sold in shops uses liquid seaweed extract as a key ingredient. Seaweeds are also showing promise as a way to boost plant health and thereby reducing economic impacts of plant diseases such as blight.  Improving plants’ resistance to disease is appealing as a sustainable means of looking after crops without applying chemicals that are toxic not just to pathogens but also ecosystems by leaving residue in soil and on crops, and killing insects.

Another marine-derived fertiliser is fish blood and bone that supplies the three main nutrients that plants need to grow: nitrogen, phosphorus, and potassium. An advantage this organic fertiliser has over chemical extracts is that it yields these nutrients slowly.  Slow-release fertilisers need less frequent application and they don’t leach so many nutrients into waterways as there is more time for plants to absorb them.

Harpoon weed—as well as having potential in our antibiotic armoury— might also help to reduce the environmental impact of food production.  Cows are notorious for farting out methane and accelerating climate change. In fairness climate change can’t entirely be blamed on cows, and pasture-fed cattle are essential elements in maintaining some of our rare meadow wildlife through grazing.  One target in identifying ways to have beef, milk, and leather with a lower environmental footprint has been reducing the amount of methane that cows produce.  Including Harpoon weed in cattle feed has been found to reduce their methane production by up to 67%. It isn’t unnatural for cattle to eat seaweed. In a few locations around Ireland and the UK herds with coastal grazing will wander on the beach and eat a little seaweed along with other food they find there.