Lundy Marine Protected Area

A drawing celebrating the MPA’s 50th birthday (depicting a stunning sunset cup coral cake) was specially commissioned from Bob Foster-Smith

The chance to immerse yourself (yet stay dry!) and play with seals under water whilst wearing a Virtual Reality headset, proved popular with visitors and staff alike! © Issy Irving

As the voluntary marine nature reserve was established in 1972, we made a point of celebrating its 50^th anniversary in 2022 by holding a Marine Festival. The Festival lasted for two months (mid-July until mid-September) and had the following aims:

To highlight the existence of the island’s Marine Protected Area (MPA);
To celebrate its 50^th anniversary (the oldest MPA in the country);
To undertake a number of projects designed to contribute towards the on-going management of the MPA;
To leave a worthwhile legacy behind once the Festival was over; and
To promote the cause (by raising awareness) of marine conservation in general.

The core of the Festival was holding a week-long Marine Bioblitz, about which more can be read here. Those less keen on getting wet could enjoy a dive with seals at Lundy using Virtual Reality headsets, whilst remaining bone dry!

A summary of the projects undertaken during the Marine Festival can be found here. A full report on the outcomes of the Marine Festival can be found here.

Portraits of the five species of cup corals found at Lundy: (1a) Balanophyllia regia (in water); (1b) Balanophyllia regia (out of water); (2) Caryophillia smithii; (3) Hoplangia durotrix; (4) Leptopsammia pruvoti; and (5) Caryophyllia inornata [Lundy MPA Marine Monitoring Manual]

To date, Lundy is the only place in the British Isles where all five species of cup corals that occur in British waters are found. The five species are (1) scarlet and gold star coral Balanophyllia regia; (2) Devonshire cup coral Caryophyllia smithii; (3) Weymouth carpet coral Hoplangia durotrix; (4) sunset cup coral Leptopsammia pruvoti; and (5) southern cup coral Caryophyllia inornata.

Four of these corals (#2-5) have been found in one small area within a few centimetres of each other. The fifth, the scarlet and gold star coral, is restricted to very shallow water and may be exposed at extreme low water spring tides.

Cup corals resemble sea anemones but they possess a hard, stony skeleton which only becomes apparent when the polyp is withdrawn. They favour growing in low light conditions on vertical or overhanging recesses, as they lack the photosynthesising algal cells within their tissues which most tropical corals possess.

Notes:

Scarlet and gold star cup coral Balanophyllia regia may be found on the lower shore (under overhangs) to about 25 m depth. It is found at a limited number of sites in SW England and SW Wales and possibly southern Ireland, SW Europe and the Mediterranean. The corallum (skeleton) is porous, spongy in texture and fragile, making it less durable than other British cup corals.

Devonshire cup coral Caryophyllia smithii is the commonest cup coral species around the British and Irish coasts, only being absent from the southern half of east England and the south-east of Ireland. It is certainly not restricted to Devonshire – this being the county where it was first recorded. Its distribution extends from the Mediterranean as far north as southern Norway.

Weymouth carpet coral Hoplangia durotrix is a colonial coral growing up to 5 cm across. It is common in the Mediterranean, with its distribution extending around the Iberian peninsula to the English Channel (as far east as West Sussex), around the south-west as far north as Skomer.

Sunset cup coral Leptopsammia pruvoti is the largest of the solitary cup corals. Lundy is the furthest north it has been found, though it occurs at a few other sites in south west England, Sark, and in the northern Mediterranean. Its numbers at Lundy have been steadily decreasing over the past 40 years but it is unclear why.

Southern cup coral Caryophyllia inornata is widespread in the Mediterranean where it is typically found in sublittoral caves. In Britain and Ireland, it is rare, being found as far north as the Sound of Jura and as far west as Lough Hyne (Co Cork).

Goldsinny wrasse <em>Ctenolabrus rupestris</em> © Keith Hiscock Goldsinny wrasse Ctenolabrus rupestris © Keith Hiscock

Goldsinny wrasse Ctenolabrus rupestris are a common sight in the shallows at Lundy, frequently seen close to the seabed at the edge of the kelp forest. Together with certain other wrasse species, they are known to act as ‘cleaner fish’, a behaviour exhibited by their tropical cousins. It turns out goldsinny are also excellent at ‘picking’ lice off farmed Atlantic salmon Salmo salar in their netted cages in the Outer Hebrides and the Northern Isles. In order to reduce the amount of anti-lice chemicals being used to treat the salmon, fish farms pay for wrasse from the south coast of Devon to be exported live to Scotland to assist local wrasse species with this process.

The northern pair of mile markers at Tibbets Point on the east side of Lundy, with the tops of the Knoll Pins apparent behind © Michael Pitts

Low down on the sidelands of Lundy’s east coast, separated by an exact distance of one nautical mile (= 1.151 miles or 1,852 m), are two pairs of white-painted metal poles with diamond shapes on their tops. You should be able to see the southern pair when you arrive on the Oldenburg; it’s just above a small embayment known Ladies Beach. The lower East Side path passes just above it. The northern one is at Tibbets Point, about 3/5^th of the way up the island.

They look completely out of place, against a backdrop of bracken and rugged scenery. So what are they there for? Well, they do indeed have a specific function. They are a simple way of allowing a ship to check if its actual speed through the water is the same speed its instruments on the bridge are indicating. To test this out, a ship will run on a parallel course to the markers a short distance offshore at, say, 10 knots (or 10 nautical miles per hour). When perpendicular to the first marker pair (indicated when the diamond on each pole is in line), a stopwatch is started, being stopped when the ship passes the second marker pair. If there was no tidal current at the time, then the time elapsed would be expected to be 60 mins/10 = 6 mins. This calculation gets a little trickier when there is a tidal current running, which may either allow the ship to move faster (“over the ground”) or slower, depending on the direction and speed of the current.

A nautical mile is defined as “the meridian arc length corresponding to one minute (1/60^th of a degree) of latitude at the equator”, so the Earth’s polar circumference is very near to 21,600 nautical miles (that is, 60 minutes x 360 degrees).

Nudibranchs (commonly referred to as sea slugs) are many divers’ favourite invertebrates. They’re typically small and brightly coloured (indicating their unpleasant taste to would-be predators) and are thus understandably appealing. But this little snippet is all about how they produce their next generation.

Nudibranchs are hermaphrodites; that is, each individual possesses both male and female sex organs. When they meet and decide to mate, they arrange themselves head to foot so they can exchange sperm. They will then separate and each will find somewhere suitable (usually a hard surface) to lay their eggs. The eggs are fertilized as they emerge and are laid as a ribbon whose form and colour are characteristic of that species. Nudibranchs are also quite specific about what they eat, so always note their prey organism if you can, often a species of hydroid or bryozoan, which may assist in identifying the nudibranch.

Did you know...?

The MPA had its 50th birthday in 2022

Cup coral mecca

Notes:

The goldsinny wrasse

The Lundy Mile Markers

Nudibranch sex