The Lost Mite of the Irish Sea · The Hunt for Thinozercon

Shore browser: South Wales

Prioritisation, not prediction. Project page Field sheet (PDF)

Every shore here is scored out of 8 by a simple rule set built from the historical records of Thinozercon michaeli: shelter and estuarine setting (computed from the coastline), substrate (typed in by hand unless marked as sourced) and nearness to a known site. It is a way of choosing where to look first, not a prediction of where the mite is. Click a shore on the map or in the list.

About the model, and what is data and what is opinion

Coast colouring is computed: for every 100 m of shoreline, how many of 16 compass directions see more than 3 km of open water. Red = 0 or 1 (extremely sheltered), orange = 2 or 3, ochre = 4 or 5, faint = 6 or more. Tidal channels missing from the GSHHG coastline (the Daugleddau and its creeks, the pills, the Tawe, Neath, Afan and Ogmore) were digitised by hand and appear as grey bands.

Substrate is the weak layer: 2 = stones on sandy mud or mixed sediment, 1 = mud or sand with stony margins, 0 = clean sand or bare rock. Only four shores have a documented substrate (Beggar's Reach and Castle Reach from Pugh, King and Fordy 1987; Westport from Halbert 1915; Pennard Pill from our own visit). Dashed rings mark the rest: opinion, until habitat survey polygons replace it.

The Howth check. Of the three Irish shores where the mite has been found, Howth's south shore is the most exposed under this rule (4 open sectors). A shore with 4 or fewer is at least as sheltered as a place the mite has actually lived, so "sheltered" shores with the right stones should not be dismissed.

Sources. Halbert 1915, Proc. R. Ir. Acad. 31(39); Pugh, King and Fordy 1987, J. Zool. 211; Athias-Binche 1982, Proc. R. Ir. Acad. 82B; coastline GSHHG (Wessel and Smith 1996). Method notes and code: METHODS.

Filter

Minimum score 0 only shores whose substrate is sourced at least as sheltered as Howth (4 or fewer open sectors)

Layers

exposure colouring along the coast site names on the map digitised channels records from the papers (Milford Haven, 1987) GBIF records of the company

plate OpenStreetMap satellite

The plate coastline is coarse (about 200 m between points); switch to OpenStreetMap or satellite for the shape of a shore. Tiles load from OpenStreetMap or Esri only when chosen.

Shores

The company it keeps

Thinozercon has never been reported alone. Halbert (1915, p. 47) took it at Westport and Howth in a definite company under stones "well below high-water mark", where "small quantities of air are imprisoned": Halolaelaps glabriusculus, Gamasus trouessarti, Cyrthydrolaelaps hirtus, Pachylaelaps littoralis, Hydrogamasus giardi, Phaulocylliba berlesii, Bdella decipiens, Bdella capillata, Rhyncholophus rubripes (now Abrolophus rubipes), Rhagidia halophila and Halotydeus hydrodromus. In Milford Haven, Pugh, King and Fordy (1987) took it "from tidal debris and under stones in the upper littoral and supralittoral zones" together with the tortoise mite Phaulodinychus repleta at Beggar's Reach; they also report P. repleta from Picton Point and Jenkin's Point, and P. minor from tidal debris at Neyland (and all three Phaulodinychus from the Isle of Great Cumbrae, Scotland). The field sheet records the associated fauna and habitat around each search patch; these named species are for later identification under the microscope, not for the shore.

The mite glyphs on the map are those 1987 records: red where Thinozercon itself was taken, dark where only the companion tortoise mites were. Jenkin's Point is placed from its description (the Cleddau, about two miles north of Cosheston) and marked approximate. Later collecting at Howth by G. O. Evans and F. Athias-Binche found no Thinozercon (Athias-Binche 1982), a reminder that even the right company is no guarantee.

Legend

extremely sheltered coast (0 to 1 open sectors of 16)

very sheltered (2 to 3)

sheltered (4 to 5)

exposed (6 or more)

7 site score 7 to 85 5 to 63 3 to 41 0 to 2

dashed ring: substrate is a guess solid ring: sourced★ recorded site (1987)

Thinozercon taken here (1987) companion tortoise mite only (1987)◆ GBIF record of the company (genus or family where the species has none)

Score = shelter 0 to 3 + estuarine setting 0 to 1 + substrate 0 to 2 + known site 0 to 2. Fetch: 16 directions, 60 km cap, 100 m grid, GSHHG full resolution plus digitised channels. Tier 1 habitat model, August 2026 · Rosario-Lebron Entomology · The Thinozercon Project.