Sand Bay, 4 September 2024

Above: Bath Nats members inspecting strandline vegetation at Sand Bay © Helena Crouch

Leader Helena Crouch
This meeting was planned as a follow-up to the Presidential Address given by Rob Randall in December 2023 on Strandline Plants and Dune Formation. Sixteen members attended and the weather was fine all day.

The walk began with high drama in the car park, as an attractive brown moth was observed, and followed in the hope that it would settle: it did, and was promptly attacked by a fearsome Garden Cross Spider (Araneus diadematus). A rescue occurred and the poor Vapourer (Orgyia antiqua) was left recovering on a flower.

Eventually we crossed the road to the beach, admiring Rest-harrow (Ononis repens) and Lady’s Bedstraw (Galium verum) in the dune grassland and Sea Radish (Raphanus raphanistrum subsp. maritimum) and Sea Spurge (Euphorbia paralias) on the dunes. Numerous Starlings and Swallows were seen overhead.

Along the top of the beach, we soon found typical pioneering annual species: Sea Rocket (Cakile maritima) and Prickly Saltwort (Salsola kali subsp. kali). The latter traps sand as it grows, then persists as a wiry structure as it dies, so is important for early dune formation.

The foredunes were dominated by Sea Couch (Elymus athericus) and the broad blue leaves of Lyme-grass (Leymus arenarius). We observed some exposed long rhizomes of these two species, indicating how they successfully bind and stabilise the sand.

Later we also saw Marram (Ammophila arenaria), another grass with deep fibrous matted roots, also important for dune stabilisation. An ornithological highlight of the day was a smart Wheatear, posing on the beach, feeding before his long flight to Africa.

Along a winter strandline, we found several annuals including succulent Annual Sea-blite (Suaeda maritima), Frosted Orache (Atriplex laciniata), which has a glaucous mealy appearance, Spear-leaved Orache (A. prostrata) and Babington’s Orache (A. glabriuscula) with leaves which snap audibly. Meanwhile, entomologists were busy turning logs on the beach, disturbing many Seashore Springtails (Anurida maritima) in their search for beetles. Piles of seaweed yielded more impressive explosions of springtails. Eventually, the beetle search was successful as a smart Lesser Stag Beetle (Dorcus paralellapipidus) was found.

The saltmarsh at Sand Bay is extending: we soon reached its southern edge. Here we found Sea Plantain (Plantago maritima), tasty Common Glasswort (Salicornia europaea), Sea Arrowgrass (Triglochin maritima) which tastes of Coriander, Sea Milkwort (Lysimachia maritima), Saltmarsh Rush (Juncus gerardii), Greater Sea-spurrey (Spergularia media) and Sea Lavender (Limonium vulgare).

Huge clumps of Sea Rush (Juncus maritimus) were admired. Meanwhile a smart black beetle was found under a log: Broscus cephalotes, a voracious hunter. Green-veined Whites and an Angle Shades moth were spotted as we headed north to the promised picnic spot.

A circle of logs and the sea wall provided seating for lunch. We were joined by four tiny 22-spot Ladybirds (Psyllobora vigintiduopunctata) and a Small Tortoiseshell, and Alvan saw a Long-horned Bee (Eucera longicornis). Replenished, we headed south along the back of the saltmarsh, stopping to admire Marsh-mallow (Althaea officinalis), Strawberry Clover (Trifolium fragiferum) and a single plant of Trifid Bur-marigold (Bidens tripartita) which was new to the 10km square!

The large well-established Spanish-dagger (Yucca gloriosa), known here since 2011, was attracting many bees, bumblebees, flies and entomologists! Meanwhile botanists observed the similarity and differences between basal rosettes of Wild Clary (Salvia verbenaca) and Ragwort (Jacobaea vulgaris). We finished with well-deserved ice creams back at the car park.

Helena Crouch