Porcupine Society Field Meeting October 1988 - Aldeburgh to Shingle Street

PORCUPINE SOCIETY FIELD MEETING OCTOBER 1988 ALDEBURGH TO SHINGLE STREET D.

J.

LAMPARD

On 29th and 30th October, 1988, members of Porcupine, a society concerned with recording the distribution of North Atlantic marine species, held a field meeting in Suffolk. This article is a summary of the account by Sheader and Bamber published in the Porcupine Newsletter of February 1989.

There have been several studies of this area, particularly in regard to the brackish water lagoons at Shingle Street (Barnes & Heath, 1980). A recent account of the flora was given by Randall (1988). The main purpose of this meeting was to find the nationally-rare startlet sea anemone, Nematostella vectensis, a species protected under the Wildlife and Countryside act, previously recorded at Shingle Street.

The expertise of Porcupine members present also allowed a wide ränge of the more difficult taxonomic groups to be identified. Düring the weekend seven lagoons at Shingle Street and one at Sudbourne beach, south of Slaughden were studied. The lagoons were numbered in order of examination, the Porcupine numbering system is prefixed with a 'P', a brief description of each lagoon is given.

Shingle Street Cobb (1958) introduced a numbering system for the Shingle street lagoons, subsequently followed by Barnes (1985, 1987).

Cobb's lagoons 2 and 3 no longer exist and his lagoon 5 was dry. There are no previously published surveys of lagoons P5, P6, P7, or P8.

PI. Grid ref. TM372434 (Cobb's lagoon 4), salinity 32 parts per thousand (%„).

Elongate lagoon behind shingle bank, seawater percolation observed; bottom rapidly sloping gravel to hard shingle; surrounded by saltmarsh flora.

P2. Grid ref. TM374437 (Cobb's lagoon 7), salinity 34%o. Large lagoon behind shingle bank, shallow with gravel and soft mud bed; surrounded by saltmarsh flora.

P3. Grid ref. TM373437 (Cobb's lagoon 6), salinity 33%c. Narrow elongate lagoon inland of P2, shallow with muddy bottom and much algal growth; surrounded by saltmarsh flora, apart from open shingle to south.

P4. Grid ref. TM363419 (Cobb's lagoon 1), salinity 34%c. Largest lagoon just south of Shingle street, has a central island, gravel bottom with softer mud; much algal growth and localised areas of sulphur reducing bacteria.

P5. Grid ref. TM362418.5, salinity 26%c. Small circular pond surrounded by dense grass, no noticable fauna.

P6. Grid ref. TM362.5418.5, salinity 26%c. Companion to P5 beneath sea wall, muddy gravel bed showing signs of recent drying out (sun cracks).

P7. Grid ref. TM363421, salinity I6%c. Shallow lagoon in corner of sea Trans. Suffolk Nat. Soc. 26 (1990)

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walls, muddy bed again showing evidence of recent drying-out; much plant life and dense swarms of planktonic copepods.

P8. Grid ref. TM458527, salinity 37%c. Large lagoon with smaller offshoots, Sudbourne beach south of Slaughden, in corner of sea walls and shingle bank, connected by stream-like spur to shingle bank percolation.

Fine mud over gravelly bed, much algal growth and local areas of sulphur reducing bacteria.

Samples of mud were collected and sieved in situ through a 500nm mesh sieve and fixed in formalin with Rose Bengal. A final sieving via a 250nm mesh sieve was made before sorting. Lagoon 1 had no soft sediment; lagoon 5 was not sampled; samples at lagoons 6 and 7 showed no obvious microfauna, and no samples were kept. Fauna associated with weed was collected with a similar size mesh. Samples of deeper water fauna were made with a long handled pond net of 1mm mesh.

The lagoon fauna is similar to previously published records from this area (Barnes & H e a t h , 1980). It includes typical lagoon species such as the cockle, Cerastoderma glaucum, rough periwinkle, Littorina saxatilis tenebrosa, and spire shell, Hydrobia ventrosa, the ostracod Cyprideis torosa, the harpacticoid copepod Paramphiascopsis giesbrechti rarely seen in such a high density, and the isopod, Idotea chelipes.

The oligochaete, Limnodrilus hoffmeisteri is normally a low salinity species and it is unusual to find it here.

Nematostella vectensis has previously been found at lagoon P4, (Cobb 1), (Williams, 1975; Barnes, 1985), but was not recorded. It was present at lagoons P3, P6, and P8, the records in lagoons P6 and P8 are new sites for the species.

Sheader and Bamber (1989) report that the specimens of the sea slug Akera bullata are the first live records of the species in East Anglia, however in two articles, C. G . Doughty (1929, 1932) records it from Slaughden, Martlesham Creek, and Walton marshes. The identification of this species seems to have puzzled an earlier member of the Suffolk Naturalists' Society, who on finding specimens, called them 'Witches'.

A. bullata has an interesting distribution in Britain, it has been recorded most f r o m southern and western coasts of the British isles, and north from the Scottish border on the east coast. T h e Suffolk observations are some of the few f r o m the English east coast.

Aldeburgh Area The coast between Aldeburgh and Lantern marshes was visited on the 30th.

T h e saltmarsh was situated at TM462547 on the seaward side of the River Aide. It's surface was covered in small pools and drainage Channels. The marsh flora included cord grass, Spartina sp., sea purslane, Halimione sp., and saltmarsh grasses.

A ditch located near the saltmarsh at TM461542, contained a varied fauna Trans. Suffolk Nat. Soc. 26 (1990)

48

Suffolk

Natural History,

including the prawn Palaeomonetes and Urticina sp.

Vol. 26

varians, shore crab, Carcinus

maenus,

O n t h e u p p e r s h o r e , south of the salt marsh, was a b o u l d e r rubble slope left over f r o m the n e a r b y sea wall construction. Samples of algae, their epiphytes, and o t h e r material were e x a m i n e d .

T a b l e 1 lists species r e c o r d e d f r o m lagoons, table 2 saltmarsh species, and table 3 species f o u n d on the b o u l d e r slope. Species recorded with a / were o b s e r v e d but not collected, * d e n o t e s observations of d e a d shells, r = rare, o = occasional, f = f r e q u e n t , c = c o m m o n , a = a b u n d a n t .

A s f e w of the animals listed below have c o m m o n n a m e s n o a t t e m p t has been m a d e to apply t h e m .

Table 1 Species found

in lagoons

Species

Lagoon number

ALGAE Enteromorpha sp.

Ulva sp.

Chaetomorpha sp.

l/,2/,3/,8/ 2/,3/,4/,8/ 3/, 4/,8/

ANGIOSPERMAE Ruppia cirrhosa Ruppia spiralis

l/,6/,7/ 8/

PROTOZOA Elphidium williamsoni

4r,8o

COELENTERATA Sagarlia troglodytes Nematostella vectensis

lc,2c,3c,4o,8a 3o,6a,8c

NEMATODA Enoplus brevis Indet.

8o 2a,3f,4f,8f

NEMERTEA Lineus ruber Amphiporus lactifloreus

lo,3o,4a,6o,8a 4r,8r

SIPUNCULIDA Golfingia minuta

lr

Trans. Suffolk

Nat. Soc. 26 (1990)

PORCUPINE SOCIETY FIELD MEETING OCTOBER 1 9 8 8

ANNELIDA Tubificoides benedii T. cf diazi Tubifex costatus Limnodrilus hoffmeisteri Capitella capitata Arenicola marina Nereis diversicolor Malacocerus fuliginosus Scolelepis foliosa Manayunkia aesturina Fabricia sabella

la,2a,3a,4c,6c,8c 4r,8o 4c 3o.4o,85 lo,2a,3,4c,8c 3/,4/,8/ lc,3c,8c 2a, 8o 2o 3r,4r 8r

MOLLUSCA Abra tenuis Cerastoderma glaucum C. edule Acteon tornatilis Hydrobia ulvae H. neglecta H. ventrosa Leucophyta bidentata Litlorina saxatilis tenebrosa Akera bullata Retusa obtusa

2o,3c,4a 4f,8c l/Âť,2/* 4fÂť 2a 3c la,3c,6a,7a,8a la,4r 3c,4c,8a 8a 8a

ARTHROPODA Chironimid indet.

Ephydra sp.

Coleopteran indet.

Dipteran larva Sigara stagnalis Cyprideis torosa Paramphiascopsis giesbrechti Eurytomora velox Idotea chelipes Microdeutopus gryllotalpa Gammarus finmarchicus G. locusta Orchestia gammarellus Corophium volutator Melita palmata Palaemonetes varians

3c,4o,5c,6c,8f 7r 7r 7r 3r,7a 3o,4r 4c,8o 7a 7a 2c,3o,8a 2c 3o,6a 4c 3c,6o 3a,8c 8o

ECHINODERMATA Amphipholis squamata

lc,8c

CHORDATA Anguilla anguilla Gasterosteus aculeatus

8r 4r,8r

49

Trans. Suffolk Nat. Soc. 26 (1990)

Table 2

Species found on Saltmarsh south of PROTOZOA Elphidium williamsoni Limapontia depressa

1 1

PLATYHELMINTHES Uteriporus vulgaris

1

MOLLUSCA Hydrobia ulvae Ovatella myosotus Littorina saxatilis

a c o

ARTHROPODA Chironimid indet.

Praunus flexuosus Halectinosoma sp.

Harpacticus obscurus Paradactylopodia latipes

1 c 1 1 1

Aldeburgh

ARTHROPODA cont'd Stenhalia palustris Amphiascoides debilis Mesochra lilljeborgi ldotea chelipes Sphaeroma hookeri Chaelogammarus marinus Orchestia gammarellus Carcinus maenus Palaemonetes varians Copidognathus brevirostris Machrocheies superbus

1 1 1 o a 0 c 0 c 1 1

ECHINODERMATA Amphipholis squamata

a

CHORDATA Molgula manhattensis Pomatoschistus microps

1 o

Species marked 1, were found on a small log, in one of the marsh pools. A female Paragnathia formica with larvae was found in the mud cliff at the seaward edge of the marsh.

Table 3

Species found on boulder slope ALGAE Enteromorpha sp.

Fucus vesiculosus (Bladder Wrack) Ascophyllum nodosum (Knotted Wrack) Chondrus crispus Polysiphonia lanosa FORAMINIFERA Protelphidium germanicum COELENTERATA Dynamena pumila Hydrallmania falcata BRYOZOA Electra monoslachys Alcyonidium gelalinosum ARTHROPODA Faradoxostoma abbreviatum Jaera albifrons Ectinosomid indet.

Microarthridion fallax Harpacticus obscurus Tisbe sp.

Parathelestris clausi

ARTHROPODA cont'd Stenhelia palustris Ameirid indet.

Enhydrosoma curticauda E. curvirostrata Nannopus palustris Mesochra lilljeborgi Pseudonychocamptus koreni Laophontid indet.

Cyclopoid indet Elminius modestus Baianus balanoides B. improvisus B. crenatus basal scars only Chaetogrammarus marinus Orchestia gammarellus Praunus flexuosus Palaemonetes varians Carcinus maenas Copidognathus oculatus C. dentatus Thallassarachna baltica Rhombognathus notops R. mucronatus Isobactrus setosus Chironimid indet.

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Acknowledgements I am most greateful to the members of Porcupine who attended the two day field meeting and others for the identification of the more difficult species.

References Barnes, R. S. K. (1985). The coastal lagoons of East Anglia, U.K. A report submitted to the Nature Conservancy Council, 33pp.

Barnes, R. S. K. (1987). The coastal lagoons of East Anglia, U . K . , J. Coastal Res. 3, 417.

Barnes, R. S. K. & Heath, S. E. (1980). The shingle-foreshore/lagoon system of Shingle Street, Suffolk: a preliminary survey. Trans. Suffolk Nat. Soc. 18. 168.

Cobb, R. T. (1958). Shingle Street, Suffolk, a brief geographical introduction. Rep. Fld. Stud. Court. 3, 31.

Sheader, M. & Bamber, R. (1989). The fauna of land-locked lagoons and saltmarshes - Aldeburgh to Shingle Street. Porcupine Newsletter 4, 79.

Doughty, C. G. (1929). Molluscan 'witches' at Slaughden. Trans. Suffolk Nat. Soc. 1,102.

Doughty, C. G. (1932). Local distribution of 'witches'. Trans. Suffolk Nat. Soc. 2, 188.

Randall, R. E. (1988). The Vegetation of Shingle Street, Suffolk in relation to it's e n v i r o n m e n t . Trans. Suffolk Nat. Soc. 24,41.

David J. Lampard, c/o The Museum, High Street, Ipswich, IP1 3 Q H

A Sparrowhawk at Elmswell (The numbers of Sparrowhawks in the county appear to be increasing (Suffolk Birds 1989, p. 62) and it is nice to be able to publish a story about one which has a happy e n d i n g - if not for the Sparrows. Editor) One morning in May, 1989,1 found a hen Sparrowhawk in my greenhouse, which is reached through a very large shed, the door of which is always open.

I was worried that the bird would panic and injure itself, but it hardly fluttered and allowed me to pick it up. I took it back into the house to show my wife and then let it go. When I first opened my hands it gripped my finger with lts talons, but not so that I was scratched. It then flew away. It was indeed a delightful experience for me.

P. W. Glassborow

Trans. Suffolk Nat. Soc. 26 (1990)