The distribution of seabed habitats within the extent of the voluntary marine nature reserve © Robert Irving in Hiscock, 1983
Intertidal reefs at Devil’s Kitchen, the most biodiverse shore on Lundy © Keith Hiscock
Sunset cup corals on vertical & overhanging deep rock, Knoll Pins © Paul Naylor/marinephoto
Muddy gravel is an unusual habitat to encounter in relatively shallow water (12-18 m below chart datum) © Keith Hiscock
Lundy’s coastline is pock-marked by numerous caves at sea level © Robert Irving
Fragile sponge and anthozoan community, off Battery Point, Lundy © Keith Hiscock
Communities on wrecks – here plumose anemones seen growing on the hull of the MV Robert © Mike Deaton
The ‘shaping’ of Lundy’s scenery, both above and below the sea, has taken millennia to get to the stage we see it at now. This has come about through both the process of weathering (wind, rain and even ice) for the above-water features; and the process of erosion (resulting from wave action and tidal currents) for the underwater features. Effectively, these processes have shaped the underlying geology into the geomorphological features we see today: vertical cliffs, deep intertidal caves, boulder and bedrock beaches with rockpools; and then below low water, sloping seabeds of bedrock and massive boulders, deep and narrow gullies, steep ‘drop-offs’ formed of near-vertical cliffs plunging up to 30 m into the dark depths, extensive mixed sediment areas of mud, sand and gravel, and lastly extensive sandy plains towards the fringes of the MPA.
All of these seabed types constitute the 3-dimensional physical forms which natural forces have further modified, becoming adorned with attached marine lifeforms. Determining which species ends up where is largely down to the influence of various physical determinants such as light, water movement, suspended sediment load, substratum type, etc.
Certain of these physical features (listed in the table below) are recognised as being of particular importance at Lundy, either because of their extent, their rarity or their abundance in a small area.
Table listing features of particular importance within the Lundy MPA.
|
Legally protected features at Lundy |
Sub-feature |
Listed under the… |
|---|---|---|
|
Intertidal reefs |
Rocky shore communities |
SAC & SSSI |
|
Under-boulder communities |
SAC |
|
|
Subtidal reefs |
Kelp forest communities |
SAC |
|
Vertical & overhanging deep rock communities |
SAC |
|
|
Deep bedrock and stable boulder communities |
SAC |
|
|
Fragile sponge and anthozoan communities |
SAC |
|
|
Subtidal sediments |
Muddy gravel off the east coast |
SAC |
|
Intertidal & subtidal caves |
SAC |
Lundy is well known for its colourful and diverse marine wildlife. It is largely for this reason that it has attracted the attention of marine conservationists over the years – there’s a lot here, in a relatively small area, to get excited about – especially if you’re able to venture beneath the waves.
The Marine Protected Area hosts a number of marine communities which are regarded as being of international or national nature conservation importance. These occur both on the shore in the intertidal, or under water in the subtidal and are set out in the table below.
Table showing the marine communities of high nature conservation interest present around Lundy (after Hiscock, 1983 and English Nature, 2001). Note that these assessments were originally made in 1983.
|
IMPORTANCE | ||
|---|---|---|
|
International |
National |
Regional |
|
INTERTIDAL |
||
|
|
|
|
SUBTIDAL |
||
|
|
|
Changes in community composition over time
The MPA is fortunate to have detailed records of its intertidal marine life which stretch back to the late 1940s, when Leslie Harvey and his wife Clare spent several summers undertaking fieldwork on the island. Repeat surveys from the same shores were undertaken in 2008 and in 2015 under the supervision of Dr Keith Hiscock to assess what changes had taken place during the intervening 60 years. It turns out there have been relatively few, the main differences being a few new species occurring and a few recorded species not being re-found.
The following paragraph is taken from the conclusions section of Hiscock and Brodie’s 2016 paper entitled The character and status of rocky shore communities at Lundy: historic and recent surveys (Journal of the Lundy Field Society, 5: 35-54)
“The rocky shores of Lundy range from those subject to extreme wave action, particularly on the west and south coasts, to ones in the Landing Bay that are sheltered from wave action for much of the time. The marine life that colonizes particular shores reflects that degree of exposure to wave action and the sub-habitats that are present such as rockpools, under boulders, overhangs and caves. The rocky shores are thus very varied providing a range of habitats that encourages an overall rich variety of species. Such physical conditions are unchanging and the species recorded in recent years are therefore unsurprisingly similar to those in the late 1940s and earlier. What is changing is climate and the arrival of non-native species, something that has the potential to greatly change the character of some shores.”
In the sublittoral, changes in communities over time have also been noted, although the acquisition of measurable data confirming these changes has been sparse. Reports of perceived changes have been published by Dr Keith Hiscock, often in Lundy Field Society Annual Reports but also, on occasion, in more widely-read journals.
In the LFS Annual Report of 2022, it was stated (p116):
“Observations of subtidal species by Keith Hiscock suggest a continued reduced abundance of many anthozoans (sea anemones, corals, soft corals) compared to the period from 1970 to the mid-1980s. Only sunset cup-corals Leptopsammia pruvoti and pink sea fans Eunicella verrucosa have been regularly monitored since the early 1990s (and have declined in abundance) but other species such as the southern cup coral Caryophyllia inornata, the Weymouth carpet coral Hoplangia durotrix and the red sea fingers Alcyonium glomeratum appeared to have also declined in abundance. However, long-lived and slow growing branching sponges appear to be present in similar abundance since early surveys. An accurate account of the status of often rare or scarce and long-lived species requires more targeted monitoring. One notable difference in the appearance and likely health of many branching species is the great increase in the abundance of egg cases of bull huss, Scyliorhinus stellatus, entangled around those species (Observations over the past approximately five years; and Bullimore, 2023).”
