The last blog I wrote was about what birds we can see in Riverside and how our area is special in having such a diverse environment. But as any ecologist will tell you, the majority of life forms on the planet carry out their day to day existence out of sight of humans - in fact 10% of the world's biomass is contained in the soil below our feet. For many of us our doorway into that world is when we turn the earth in our gardens and we bring worms and other beasties, and of course slugs, to the surface - feeling grateful for the former and if you grow lettuce, defeated by the latter. The fertility of our soil is to a great degree dependent upon these invertebrates and the huge number of microbial creatures, fungi and bacteria, whose eating, respiring, reproducing, competing, cooperating, and responding turn organic debris into a rich food source for plants.
The other part of Riverside where most of the creatures live out of sight is, of course, in the river itself. There's plenty see on the surface - ducks, gulls, the occasional otter, gray seals, and if you're really, really, really lucky the beaver which have taken up residence on the Forth. But how many of us have actually seen a salmon, a trout or a sea trout on our walks along the banks? Or the huge shoals of dace that anglers pursue in the summer months, the eels that the dabchicks eat or the flounders on the river bed. Or the even more elusive sparling?
Nope, it's not a typo.
The sparling (Osmerus eperlanus) is also known as the European smelt. It's a small fish about 20-30cm that spends most of its life in estuaries but, like sea trout and salmon, swims upstream to spawn in freshwater ... and it smells of cucumber! The spawning period is quite short, sometimes only a few days, and depends on a number of factors; water temperature, tide levels and availability of suitable sites being the most important.
They are found in the western edge of Europe and the Baltic and up until recently could be caught in many rivers where they were both a supplement to the local diet and an important component in the inshore fishing industry. In fact there was a sparling fishing fleet in the Forth until the 1970s when the decline in fish numbers meant it was no longer viable.
Despite the fact that across their range sparling are not seen to be under threat, nowadays they are only found in three Scottish rivers of which our very own Forth is one*, and they are protected under the Wildlife and Countryside Act 1981 (as amended).
Sparling are an important indicator species in identifying environmental quality as they require clean water and are highly susceptible to pollution. In the past the Forth was heavily polluted with untreated sewage and toxins from the heavy industry along its shores, but a huge investment of over £220m in water treatment plants in the early part of this century has had dramatic results which have not only benefitted sparling , but also herring, sprats and around fifty other species of fish in the estuary.
My only tenuous claim to having seen sparling was last spring when I saw a flock of goosanders corralling fish into a bend in the river at the old harbour area. They were small and silvery fish but I wasn't close to enough to either get a really good look, or check if they smelled of cucumber, but it was just after a high tide and they didn't look familiar. So maybe, just maybe, they were the rare, fragrant, anadromous** sparling.
*The Cree in Galloway and the Tay are the other two rivers.
* *An anadromous fish, born in fresh water, spends most of its life in the sea and returns to fre