Link to the Adur Nature Notes 2004 Index page


World of Widewater (Community Friends Group)

Link to the Adur Levels habitats page

Link to the Adur tidal reaches habitats web page

Link to the chalkhill Downs habitats pages

Link to Town & Gardens habitats page

Link to the Sea and Seashore habitats page

 Coastal Fringe
 Chalk Downs
 Intertidal (Seashore)
 River Adur Estuary
 River Adur Flood Plain
 Sea (off Sussex)
 Town & Gardens
 Widewater Lagoon
Shoreham Beach Weather provided by Softwair Publishing
 Saline Lagoon Links
 Brooklands Boating Lake



       Adur Valley Wildlife 

Widewater is a landlocked brackish lagoon approximately 1200 metres long and 50 metres at its widest point when the lagoon is in flood. It was created by Man from the original Adur estuary after been landlocked by longshore drift and violent storms. The waters are replenished by the sea, which filters up through the basin of the lagoon on very high tides, and also by rain water. There is a dramatic rise in the level after heavy rainfall, more than can be explained by the rain landing directly on the lagoon flood plain. Man has built up banks on the perimeter of the lagoon to prevent flooding to this nearby reclaimed land, now turned to residential use. The quantity of water contained within the lagoon and salinity are liable to fluctuate wildly. The flood plain covers an area of 18.5 acres.

Since May 2013 a pipeline has been installed to supplement the water levels in Widewater during the summer when the water levels would previously fall to a very low level. 

Key to the Map & Habitats Link

Street Map (Link)

This area can be reached from Shoreham-by-Sea railway station following the purple route on the Map. Click on the underlined text. 

Cycle Path Information

    Underwater Critters

    Stickleback (Photograph by Andy Horton)

    3-spined Sticklebacks, Gasterosteus aculeatus. This fish seems to have disappeared from Widewater Lagoon in 2002 and the reason for this is not known. The fish has been replaced by thousands of small prawns. A stickleback was seen again on 9 September 2004.

    Hoglice Idotea chelipes (=I. viridis). 

        Photograph by Andy Horton

    One species of this large woodlice-type crustacean has been identified from the lagoon. It is an inhabitant of non-tidal lagoons and can tolerate full salinity to almost fresh water down to 0.4%. It will also inhabit the pools that are cut off from the main body of  the lagoon during the summer. 
    Bilge Bug (or Sea Slater) Ligia oceanica

       Photograph by Steve Barker

    The largest of the British wood lice feeds on decaying vegetation at the margins of the lagoon.


    Lagoon Cockle  Cerastoderma glaucum

    Lagoon Cockle
    Photograph by Ray Hamblett from an idea by Andy Horton

    Lagoon Cockle and Glasswort 

    A recent survey (1997) has rediscovered this cockle which resembles the Common Cockle, Cerastoderma edule, but has a much thinner shell and is only to be found in brackish water.

    Lagoon Cockles have byssus threads and I found juveniles often attached to seaweeds and other substrates. I never noticed byssus threads in Common Cockles. Grown Lagoon Cockles may bury themselves as well, but never so deep as Common Cockles.

    Link to MarLIN Biological Information on the Lagoon Cockle

    Some notes on the Lagoon Cockle

    Sea Anemone Edwardsia ivelli
    A recent survey (1997) failed to discover this sea anemone and it has now been pronounced extinct. It was last recorded in 1983. 
    The 1997 survey by Robert Irving took 8.5 cm diameter cores from various positions (about 10 in all) throughout the lagoon, marked on the site map in the Report. Cores were to a depth of approx. 8 cm, but also surface scrapes into polythene bags under water, probably the top 5 cm or so.
    A search will be undertaken next summer. See notes
    This sea anemone is protected under Schedule 5 of the Countryside and Wildlife Act 1981, but a proposal has been penned to remove it. 
    JNCC Proposal to remove Edwardsia ivelli from Schedule 5 protection (Link)
    The grid ref for the collected specimens was TQ 202 043
    As the anemone may still be extant, the proposal to remove the sea anemone from the list has now been removed. 
    Countryside and Rights of Way Act 2000

    UK Biodiversity  Edwardsia ivelli

    There is a possibility that the above sea anemone was a deformed specimen of Haliplanella lineata (my surmise AH). This latter typical brackish water sea anemone has been discovered and identified in July 2002.

    BMLSS Sea Anemone page

    Thieliana navis (=Clavopsella navis)
    A rarely recorded brackish water hydrozoan is found in brackish water down to a salinity of 0.8% and its only habitat of note in the United Kingdom is the Widewater Lagoon, where it is found attached to the seaweed Chaetomorpha linum and Ulva. This hydrozoan does not have a medusa stage. It grow to a length of 30 mm. This species has been discovered in the Kiel Canal and probably occurs in the Baltic Sea, a traditional and current trading area with Shoreham Harbour. It is possibly an alien species introduced a long time ago, although Widewater has been cut off from a direct link to the sea for over a century. The numbers of this hydroid may be reduced by the 3-spined Sticklebacks
    The 1997 survey failed to discover this hydroid.
    The species was added to Schedule 5 of the Wildlife and Countryside Act 1981 in 1998, after being penned for inclusion in August 1996 (included in Torpedo Issue 5). 
    More Information and Protection Status
    The origin of this hydrozoan is apparently unknown and the only recent records come from Widewater Lagoon and several localities in the SW Netherlands. In the past is has been recorded from ship's hulls in Cape Town (South Africa) and from one locality in the Baltic near Kiel (Germany).
    Its present name is Thieliana navis. It seems to prefer a salinity of about 20 ppt. It grows on boulders, invertebrates, algae and plants. In the Netherlands and GB it occurs in enclosed man-made water bodies of relatively recent (last century) origin.

    Notes by Marco Faasse
    UK Biodiversity:  Brackish hydroid (Clavopsella navis)

    Black-spot parasite Cryptocotyle lingua
    There do not appear to be any large winkle-sized gastropods living in Widewater. This is interesting as it appears as one of the stages in the life cycle of the flatworm Cryptocotyle lingua. The host Sticklebacks seem to have disappeared and were not seen in 2003.

    Algae in Widewater Lagoon

    Chaetomorpha linum
    Cladophora dalmatica
    Enteromorpha flexuosa
    Ulva lactuca
    Ulva rigida
    Rhizoclonium tortuosum

    (Information supplied by Robert Irving)

    By 2004, the algae I Widewater Lagoon has changed and these species will not occur in abundance.

    Green Tufted Seaweed

    The algae in the lagoon includes the annual Cladophora. The Sticklebacks used to make their nest amongst it in the spring. By late summer, it breaks free and forms a mat on the surface of the remaining water. During 2003, it was noticed that most of the Cladophora had disappeared and there were no sign of the thousands of Sticklebacks

    Flowering Plants

    Glasswort, Salicornia, grows on the margins of the lagoon where patches turn red in autumn. There are several species but this plant is so variable in appearance that it will need experts to distinguish them to species level.

    Glasswort showing the varying appearances of the plant (September 2001)
    The plant on the far right is the young shoots of Sea Blite, Suaeda maritima.
    Click on the image for a large view
    Glasswort: Query, still under investigation (Link)

    Frequently, but by no means always, the species that turn red are referred to as Salicornia ramosissima. (Tony Davy)

    Glasswort Web page

    Sea Heath, Frankenia laevis, was recognised in 2000, in a area that had previously been fenced off to the public to protect the breeding area of the Ringed Plover. A large patch of this plant was discovered. This plant is very rare in Sussex known only from Rye Harbour, but it has possibly been missed on the fringes of salt-marshes.
    This plant has now been found be a genuine wild specimen and NOT a garden escape. It was already listed in Betty Bishop's, Flora of Shoreham-by-Sea (1984). 

    (Link to) Widewater Page (by Ray Hamblett) including a photograph of the Sea Heath

    The rooted plant with the scientific name of Ruppia maritima seems to have disappeared from Widewater Lagoon in the second half of 2003. This straggly plant is only an occasional inhabitant of the lagoon in any noticeable amounts.

    Brackish Water Book


    World of Widewater (Community Friends Group)



Link to News Reports 2005

20 July 2004
Management of Widewater Lagoon Nature Reserve  is undertaken by the Widewater Management Committee who meant to discuss aspects relating to the operation of the pipeline and other environmental issues. The full minutes of the meeting held in the afternoon will be available on a web page later for public scrutiny. The operational committee consists of representatives from West Sussex County Council Rural Strategy Unit (the Chairman is Neil Mitchell), Lancing Parish Council (principal land owners), Friends of Widewater Lagoon (FOWL, representing the interest of local resident groups), Shoreham & District Ornithological Society and Adur Valley Biodiversity Network.

28 May 2004
With the noisy earth moving diggers, rusty pipelines etc., the foreshore looked more like a building site for the rock sea defences. 

May 2004
A new barge load of syenite (Larvikite) rock sea defences have arrived from Norway and are being arranged on the shore by Widewater Lagoon. 

The beach has been fenced off to prevent public access.

Link to News 2003

Wildlife Reports

Link to Widewater Reports 2005

29 December 2004
The Mute Swans seemed to be in a querulous mood, one adult intimidating and attempting to frighten off another. The Redshank and Little Egret were also vocal. There were two large ducks on the island. They looked distinctly marked and tame, but I do not recall seeing them before. 

An old dessicated mushroom (photographed on the right) found on an old wooden groyne on the shingle part of Shoreham Beach near the kiosk at the eastern end of Widewater Lagoon car park was possibly a species of Agrocybe. It was incongruous on the beach, but it looked like a common species on a poor condition, so I did not stop to examine it closely. 

15 December 2004
Three Mute Swan cygnets seen near the bridge had nearly lost of their brown feathers and were virtually all white, the remaining dark feathers were on their back. 

1 December 2004
An unidentified wader was seen in the shallows just to the east of the footbridge over Widewater Lagoon. I really did not get a chance to get a look in the poor light, but it was about the size of a Grey Plover, but it had a slightly longer black (or dark) beak, and it was in water deep enough to obscure its legs, picking up visible mouthfuls of mud in its beak, quite unlike the behaviour of the common wading birds seen around.

Little Egret, Black-headed Gull and Turnstone on Widewater
Photographs by Brenda Collins on 4 December 2004

On reflection, I think this is more likely to have been a Turnstone than anything else, the deeper water hiding its orange legs, and its beak looking longer than it was.

Turnstones and Sanderlings have been reported feeding on Widewater, undoubtably encouraged because of the low water levels because of the lack of rain. The Sanderlings will pitter-patter over the beach sand on a low spring tide, but on the neaps and at high tide, I am not sure where they go? 

23 November 2004
Three Little Egrets were feeding in the shallows. The low level of the lagoon, measuring only about 1 metre 35 cm on the gauge, may have been favourable to them (although four Little Egrets have been seen before when the lagoon was in flood). There was a Redshank present as well on the spit at the eastern end, and this bird has been seen before at all states of flood of the lagoon. 

17 November 2004
The Glasswort on the Widewater flood plain that had turned spectacularly red in the last two years, still remains largely green this year. Although the reason could be the elevated lagoon water level because of the new pipeline from the sea, this is not proven or even likely to be the cause. The weather is just as likely to be the reason. Last year the reds were dramatic on the Adur estuary as well, but this year they were also green. 

3 November 2004
There were two chirms of Goldfinches by the scrub next to Widewater of eight and five birds respectively. A Cormorant was diving in the lagoon and a Little Egret fishing in the shallows, as usual.

20 October 2004
As the weather changes the birds are on the move. Two chirms of Goldfinches arrived  One flock over the wild wasteland area between Widewater Lagoon and the beach huts and the sea, numbered at least 16 finches but in the second group over Lancing Beach Green there were only eight birds. There were a handful of pipits, looking more like Rock Pipits than the commoner Meadow Pipits

14 October 2004
A couple of Mute Swans appeared to be having a bit of a barney in the shallows of Widewater Lagoon at the eastern end. 

These may have been a quarrel with intruders. This years' cygnets are still greyish in colour. 

12 October 2004
The salinity readings taken by West Sussex County Council Rural Strategy Unit with the electronic meter measured 34.7 which is full strength seawater. This matched my hydrometer readings from previous years since the pipeline has been installed. 
Widewater Salinity
The Strong Breeze (Force 6) and showers were from the south and south-east. 

9 September 2004
Sticklebacks have been seen again in Widewater Lagoon. An adult 3-spined Stickleback swam in open water under the bridge, between the fronds of Enteromorpha and Ulva green seaweeds and the straggly Ruppia plants. 

Stickleback fro Widewater (Photograph by Andy Horton, several years ago)

The Sticklebacks have not been seen regularly for about two years. The depth of water in the lagoon measured 1 metre 42 cm on the gauge. 
A pale blueish looking dragonfly flew by too quickly to be identified. It could have been a Southern Hawker

September 2004
A Yellow Wagtail was a surprise and colourful visitor to the western end of Widewater Lagoon. This migrant bird is seen on passage through Shoreham and Lancing and there has been one report of a bird staying around for a few days. 

Report by David Wood

3 September 2004
An immigrant Clouded Yellow Butterfly fluttering over Widewater Lagoon, south Lancing, was a surprise.

The depth gauge by the bridge read 1 metre 55 cm.

1 September 2004
Widewater Lagoon was at a high water level after the spring tides. John Knight (West Sussex CC) will be photographing the height as part of the monitoring of the water levels of the lagoon. If the level gets too high, it hampers the ability of wading birds to feed. 

21 August 2004
Birds everywhere are on the move, with flocks of Starlings of over one hundred over the Hasler Estate (north of Widewater) and three Wheatears flying around Widewater car park east, before embarking on their long migration south. 
There are two groups of Mute Swans on Widewater Lagoon, one with six cygnets and the other group with either six or seven cygnets. The Cladophora fluffy seaweed, also known as Blanketweed is now visible in the lagoon, with Ulva (green algae) and Ruppia (flowering plant). The small fish amongst the straggly Ruppia were Common Gobies, Pomatoschistus minitus, and not Sticklebacks. There were several insects on the surface of the saline lagoon, which I have not identified at the time of writing. No prawns were seen.
Rarely, a Cormorant had found it worthwhile to visit the lagoon.

Early August 2004
A Swallowtail Moth, Ourapteryx sambucaria, was a surprise and colourful observation at the western end of Widewater Lagoon. This spectacular moth may be regarded as nothing special by moth enthusiasts, but to the ordinary nature spotter it is an unusual and usually unrecognised insect when first seen. This is the first report on these Nature Notes pages of a nocturnal native moth with a short flying time in July. 

Report by David Wood

28 July 2004
Seven Little Egrets all actively feeding in the shallows of Widewater Lagoon was an unprecedented number as there is usually only one, and rarely more than three.

5 July 2004
The Little Egret feeding in the shallow separate lagoon to the west of Widewater (joined up when the lagoon is in flood) was larger than the usual birds, with a long white crest and without a leg ring. 

16 June 2004
The blue of the Viper's Bugloss was looking particuarly impressive this year on the flood plain of the lagoon. It was accompanied in flower by Yellow-horned Poppy and Opium Poppy. 

The Mute Swan family with their seven cygnets swam amongst where the straggly weed Ruppia was seen again in the shallow parts of the lagoon near the submerged Tamarisk north of the bridge near the multiple islands. The Ruppia seeds may have been introduced by birds. 

4 June 2004
A foot long (30 cm) pencil thin snake with a forked tongue was reported from a garden on the edge of Widewater Lagoon. It was an Atlantic Eel, Anguilla anguilla.

2 June 2004
A Grey Heron was fishing east of the bridge over Widewater Lagoon. It took off in two short flights, on the second occasion mobbed by a Lesser Black-backed Gull. Grey Herons used to be regular visitors to the lagoon but they have not been seen by me for several months. The Little Egret was present as usual. The water level has risen with the latest spring tides. (The pipeline is open.)

28 May 2004
Despite the pipeline still being open the level is down to 39 mm leaving muddy margins and the bar near the island exposed. A black and white dog disturbed a pair of Ringed Plovers which may be nesting on the Thrift covered flood plain
There are now seven cygnets, the offspring of the parent Mute Swans that nested on Widewater Island

There were at least two Little Egrets feeding on the lagoon margins, but in the shallow water, there was not the thousands of prawns normally seen, just a score or so were visible. Near the pipeline inlet a dozen Common Gobies, Pomatoschistus microps, could be seen darting to and fro over the silt.

May 2004
A bloom of plankton, probably Phaeocystis pouchetti, has turned the River Adur almost orange and considerably reduced visibility in the enriched sea. The colonies of this flagellate organism Phaeocystis can be seen in the water at over 1 mm long and plankton will be continuous for miles of sea water. The sea is then by various local terms like Slobweed or Baccy Water because of its appearance. When the plankton dies it can create hypoxic conditions and generally the inshore fauna is diminished in quantity and variety. 
The seawater pipeline is on a setting that is not letting in much water so the plankton bloom is less likely to pollute the lagoon. This is fortunate* because the plankton bloom is excessive and it would have caused an unsightly mess (the remains of the dying plankton looks like sewage) in the lagoon. 
*The possibility of plankton blooms in May and June was included in my first and second reports (before the bloom occurred). 
Revised Final Report (Second Draft)

15 May 2004
A year ago a large expanse of the Widewater flood plain was bare gravel because it all had been churned over to construct the new pipeline. 

Widewater gravel where the pipeline disturbed the ground one year later

Colonisation was expected to be swift and one year later the shingle is covered by the blue-violet of Ivy leaved Toadflax, with splatterings of other ground-hugging plants like Scarlet Pimpernel, small patches of Stonewort, clumps of Sea Campion, one or two Bird's Foot Trefoil, and a few small Sea Kale plants. Sea Thrift produced the usual attractive sweeps over the gravel, but none of this had actually sprouted forth from the disturbed ground. A Ringed Plover was well camouflaged against the shingle and plants. 

Common Goby

Common Goby

There were thousands of small prawns, probably Palaemon elegans but there were still no 3-spined Sticklebacks, Gasterosteus aculeatus, to be seen. There was one new very small fish species though: the Common Goby, Pomatoschistus microps, which was to be expected* with the new pipeline and might have even have occurred before. (* It is found in Hove Lagoon.) A handful were seen, but there are probably hundreds. 

12 May 2004
After the Widewater Lagoon Management Committee meeting, I compiled an article on part of the ecology of Widewater Lagoon relating to salinity, concluding that the seawater pipeline intake would confer advantages to the biodiversity of the lagoon during the summer months but would show little or no benefits during the winter and none around the time of the equinoctial spring tides. 
Article:  Is Widewater Lagoon turning into a Seawater Inlet?
Report and Conclusion

6 May 2004
High spring tides had raised the water level in Widewater Lagoon to 65 mm. 

The Sea Campion (illustrated above) was in flower on the lagoon flood plain

13 April 2004
A small greenish-brown bird made a short flight immediately in front of me as I cycled past Widewater. It was nestled down amongst the shingle and its camouflage was not all that successful. When it scrambled to action stations it looked exhausted. This bird was most likely an immigrant Chiffchaff, but it did not call. 
Adur Coastal

24 March 2004
A chirm of Goldfinches flying from the vegetation between the beach huts and the lagoon numbered about 16 birds, which is a larger flock than normal for March. 

Little Egret in the mist
18 March 2004
On the ridge of the shingle by the beach huts a female Black Redstart stood out where I would expect to see a Ringed Plover. A pair of Ringed Plovers were together on gravel by the pipeline outlet into the lagoon with a feeding Little Egret. Another Little Egret stood statuesque like a Heron in the mist, just to the west of the bridge, (where the gardens were before World War II).

Immigrant Wheatears have been seen on the beach in the last few days. 

Various Wheatear reports, including the beach next to Widewater

10 March 2004
It will come as no surprise to rockpoolers that marine life is coming in through the pipeline from the sea to Widewater Lagoon, the first spores of seaweeds growing on the rocks, was a brown species prevalent in Shoreham harbour. It is not the most attractive of algae and it readily breaks off into loose tufts. I think this group of brown seaweeds is Maiden's Hair, Ectocarpus sp. and similar species which are difficult for non-specialists to identify to species level. This seaweed may be able to tolerate salinity lower than full strength seawater as it will sometimes be found in tidal pools. Some of the small prawns were getting tangled up with small tufts of this seaweed and swimming in a jerky peculiar manner. 
The lagoon now appears to be full strength seawater at a salinity of 35 (ppt). Widewater Lagoon may now no longer be regarded as brackish but more like a fully saline seawater inlet like the canal section of Shoreham harbour. The water cannot flow out by a direct route but the lagoon bottom is porous or has holes where the water runs out rapidly when in flood. 
The amount of suspended sediment in the seawater coming through the pipe and being deposited in the lagoon near the outlet is less than I expected. 

11 February 2004
Five Little Grebes (Dabchicks) were on Widewater Lagoon. 

Report by Bob Kent (Lancing) on the the Sussex Birds Yahoo Group

6 January 2004
Amongst the  prefabricated huts on Golden Sands Caravan Park, near Widewater Lagoon, Lancing, a female Black Redstart was recognised.  This bird was not been recorded before on these Nature Notes pages and has probably been overlooked as the bird is plain in colour.  This bird is usually a fairly common Winter Visitor.


EMail for Wildlife Reports

EMail Address for sending in wildlife reports from the lower Adur valley
Only a selection will be included and only reports with the name of the reporter

28 December 2003
After over 40 mm of rain the previous day and over night, the water level of Widewater Lagoon on the gauge by the bridge is 1 metre 66 cm, the highest level recorded in 2003.

The area between the lagoon and the beach is particularly good for small birds including:

Ringed Plover
Greenfinch  (not so many in the last couple of years)
Pied Wagtail
House Martin (especially in autumn prior to migration)
Wheatear (especially in autumn prior to migration)

The Habitat Action Plan for Sussex on Saline Lagoons has been published by WSCC. 

UK Biodiversity:  Action Plan for Saline Lagoons

Adur Biodiversity:  Notes on Action Plan

UK Saline Lagoons: Links for more Information

Specific Gravity/Salinity calculations

Script and page design by  ©  Andy Horton 1997-2004

Widewater has not been designated a Site of Special Scientific Interest (SSSI). It is a Local Nature Reserve.

Conjectural outlet of the River Adur in medieval times (link)

1960 TO 1992


Orford Ness:  Coastal Ecology of a Shingle Bank (excellent references)

Local Wildlife Links  (SE England)

Adur Biodiversity Exhibition 2001
Adur & the Downs: Protected Sites
Adur Valley Nature Notes 2003
Adur Valley Nature Notes 2002
Adur Valley Wildlife
Adur Wildlife Gallery 
Birds of Sea & Seashore (BMLSS)
Brooklands Boating Lake
Carmarthen Bay Saltmarsh SAC
Dungeness, Kent, England
Friends of Widewater Lagoon
Orford Ness:  Coastal Ecology of a Shingle Bank (excellent references)
Ralph Hollins Nature Pages  (Chichester Harbour area)
Rockpooling Page
RSPB Saline Lagoons
Rye Harbour Nature Reserve
Seashore Page
Shingle Coast  (Coastal Fringe of Shoreham Beach)
Shoreham-by-Sea Wildlife Page
Sussex Wildlife Web Sites
Verdant Mud (Glasswort)
Widewater Lagoon Slide Show (by Ray Hamblett)

British Isles Nature Reserves WebRing British Isles Nature Reserves WebRing
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