Marine habitats

Intertidal habitats

The intertidal habitat map has been compared with aerial photographs taken in 1944, 1980, 2003 and 2005. This suggests that the intertidal area at Les Minquiers is in good condition and there has been little measurable change in the type, size and location of its habitats. With the exception of some sand movement, the reef’s intertidal ecology seems to have remained stable during the past 70 years.

Unfortunately, not measurable from historical aerial photography is small scale ecological damage that can result from activities such as low water fishing and boating, such as not returning boulders. In 1956 it was reported that ormer fishermen were not returning rocks and that this was killing off under-boulder fauna to such an extent that it was affecting shellfish stocks on the reef. Survey work at Les Minquiers since 2013 suggests that while some ormer fishermen still do not return rocks, this is not happening enough to cause widespread habitat and species destruction.

Low water fishing activities should periodically be quantified to avoid some of the problems that have occurred on the nearby Chausey Islands. Compared with the French coast, pursuits such as raking, digging and ormering are at a low level on Les Minquiers and much that does occur tends to be within the anchorage at Maîtresse Île or on adjacent sandbanks. Raking has the potential to disrupt or destroy stable infaunal communities and is especially problematic in areas of eelgrass but when conducted on a small scale, habitats can recover and be repopulated from nearby areas. Promoting good practice regarding low water fishing will assist with the conservation of key intertidal habitats. Other potential but currently minor problems include the placing of moorings in eelgrass areas, the dumping of fishing gear and the threat from oil or other chemical spillages.

Subtidal habitats

Assessing the nature and quality of subtidal habitats at Les Minquiers has been problematic and there is much work left to do in this area. Diving, aerial photography and fisheries data all suggest that the seabed from chart datum to around five to ten metres in depth is probably in good condition with little obvious evidence of degradation. An exception to this is an eelgrass area to the south-west of Le Rocher du Sud which, in 2003, showed clear evidence of having been heavily dredged causing considerable damage.

Deeper water areas have not been assessed since the 1970s but modern fisheries data indicate that the seabed to the east, south-east and north-east of the plateau has been regularly fished using mobile gear. The state of these seabed areas has not been ascertained but it is possible that they may have been damaged by commercial fishing and be in a degraded condition and/or affected by the accumulation of the American slipper limpet (Crepidula fornicata).

Some form of seabed survey, possibly by remote camera, is desirable, especially in areas that the PhD study of Retière (1979) records as having had maerl. Non-mobile métiers, such as potting and line fishing, do less harm and, apart from instances of lost gear, are unlikely to cause long-lasting seabed damage.

Rocky subtidal habitats are of less interest to dredgers and trawlers and evidence from divers, and the fisheries data, suggest that there has been little damage to rocky reefs or large areas of exposed bedrock on the seabed. Subtidal rocky habitats contain many delicate species such as sea fans, sponges and anemones and should be conserved whenever possible.

Marine Species

A general lack of data pre-1992 makes it difficult to discern any population trends for marine species found at Les Minquiers. There is sufficient anecdotal information to suggest that a number of species have either disappeared from the reef or have noticeably declined. This includes the conger eel, sea bass, common octopus, slipper lobster, flat oyster and eelgrass, although their decline is probably related to factors outside of the reef such as regional overfishing, disease and climatic events. A severe decline in the ormer population is related to a combination of historical overfishing and, in 1999, disease. There has been some recovery since the 1990s but the population is at an historical low and further conservation measures may be needed to assure the ormer’s long-term regional future.

The reef has also gained some new species, some of which have migrated up from southern Europe and there are seven invasive species that have arrived from neighbouring coasts. Invasive species can present a real threat to the local marine environment and some, such as wireweed (Sargassum muticum), have permanently changed habitats within Les Minquiers. Fortunately, the Plateau des Minquiers seems to have fewer invasive species than neighbouring coasts although it is possible that the American slipper limpet may be affecting deeper water sediment areas. It is only through international regulation and meaningful biosecurity measures that future arrivals can be minimised in the north-west European area.

Biodiversity on Les Minquiers

The table below summarises the number of species recorded from Les Minquiers from three separate periods of time: pre-1950; 1950 to 1999; post-1999. These periods broadly reflect elevated levels of recording that occurred either side of World War II and individual surveys during the 1950s, 1970s, 1990s and at the start of the current century.

It is probable that the number of species recorded on Maîtresse Île is an accurate reflection of the island’s overall biodiversity and that there has been a loss of plant and breeding bird species since the end of World War II. The resident arthropods have probably remained stable and may even have increased with the renovation of the huts from the 1970s onwards. Microscopic animals, such as mites and diatoms, and lichens have only recently been studied.

It is probable that the number of recorded marine species in the table is an underestimate with the total diversity probably being double or treble this total. Further targeted research will produce more records, especially in subtidal areas. Historical records are not good enough to discern whether there has been a decline in most marine species although this it is suspected in some cases.

Environmental threats, causes and solutions

The information gathered during the course of this project suggests that Maîtresse Île is under considerable environmental pressure. Of particular concern is the issue of soil erosion which presents an immediate threat to the island’s wildlife and infrastructure. Addressing it is primarily a matter of awareness, stakeholder cooperation, management and infrastructure maintenance although there are some factors, such as rising sea levels, that cannot be tackled solely at a local level.

In the marine realm the greatest threat is from the fishing industry and especially the use of mobile gear (such as dredges and trawls) on the seabed which can cause serious and irreparable damage to habitats and species. A review of ecosystem services suggests that Les Minquiers is an area of high biological productivity with habitats that make it an important nursery area for commercial fish and shellfish species. This has been suspected for some time and as early as the 1930s it was suggested that the reef was important to regional fish stocks.

It is probable that conserving the nursery function of Les Minquiers will have a greater long-term economic return for the fishing industry than the short-term rewards gained from damaging its benthic habitats. It is, therefore, important that as much of the reef as possible is designated as a no mobile fishing gear zone but especially the shallow marine habitats on the Plateau des Minquiers most (but not all) of which are at present undamaged.

Some other common solutions include the need for increased management, monitoring and awareness and there are a number of major potential threats (such as climate change, oil slicks and invasive species) that require international cooperation. However, in the short term it is local and regional management that offers the best and most immediate means of conserving the key ecological, infrastructural and cultural attributes of Les Minquiers.

Historically Les Minquiers has been managed via an informal relationship between the States of Jersey, the Crown, hut owners and regional fishing authorities. However, in recent years other organisations and groups have been founded whose remit covers the reef including the Ramsar Management Authority, the National Park and the Maîtresse Île Residents’ Association. Exactly how the reef should best be managed and how this may best be accomplished without becoming intrusive or overbearing to its stakeholders, remains a matter for discussion.

About Les Minquiers Project

The project to study Les Minquiers was begun in 2012 by three members of the Société Jersiaise’s Marine Biology Section. They had been working on Les Écréhous and Paternosters and were aware of the importance and fragility of Jersey’s offshore reefs. They were aware that little was known about Les Minquiers and decided that they would take a look to see what could be done to rectify this.

The initial plan was to just look at the reef’s marine biology (its most obvious natural asset) but it became quickly apparent that almost every aspect of Les Minquiers needed documenting. The team soon expanded to include botanists, ornithologists, entomologists, divers, geologists, archaeologists, meteorologists and all manner of other specialists. Every conceivable thing was studied, from single-celled organisms through to the reef’s complex political and cultural history. In the end the project had nineteen principal contributors plus over 50 others who assisted with fieldwork, data crunching, logistics and archive research.

The projects results have been written up into a book which is available in a limited edition hardback (from Société Jersiaise only here) and a paperback. Any profit from the hardback edition will be used to pay for the project’s cost, most of which has been funded by the participants themselves.

 

From the States of Jersey Department of the Environment

The Department commissioned Amphibian and Reptile Conservation to analyse and prepare a report on 10 years of citizen science data collected under the Toadwatch survey.

Jersey residents were asked to take part in Toadwatch by reporting sightings of our crapauds (spiny toads) using ponds. Data has now been collected for over 10 years (2005 – 2014) and this analysis has created an up to date toad distribution map for Jersey.  It has highlighted features of the Jersey landscape that are most important for toads and suggested areas to create new breeding ponds.

A breakdown of the types of ponds used for toad breeding overwhelmingly supports the suggestion that man-made habitats are critical for the species’ survival in the island. Ensuring that these habitats are maintained and connected across the Island is considered to be a critical task to conserve our toads into the future.

The main document Ten Years of Jersey Toadwatch: Analysis & Recommendations contains much technical information which will allow the modelling approaches described in the report to be repeated in future.

Records of Jersey toads were received from 281 locations between 2005 and 2014 and used to create a distribution map. The same data were used to create a GIS model indicating which features of the Jersey landscape are most important for toads. Ponds and gardens were most important, along with other man-made habitats like parks, golf courses and recreational fields, indicating the reliance of toads on anthropogenic features in the modern Jersey landscape.

Further modelling combined with an analysis of barriers to connectivity between populations (roads) revealed that many toad populations in the centre and north of the Island, especially, are isolated from the larger clusters of breeding ponds found in St. Brelade and St Helier-St Saviour. This can be used to suggest areas where creation of new breeding ponds and other habitat will be most effective as a tool for toad conservation in the Island – specifically:

1. Between La Crabière and Les Landes, and between St Ouen’s Village and Grève de Lecq, as well as La Crabière and St Peter’s Village (to link populations in the west of the Island);
2. Approximately between Beaumont and Sorel, and along almost any north-south valleys (to link the St Mary – St John population cluster to other populations);
3. Eastern Trinity, St. Martin, south-east to Gorey and through Grouville (to restore connectivity in the east of the island);
4. Approximately between Beaumont and Bellozane (reconnects the southern population clusters to one-another);
5. Between Noirmont, Woodbine Corner and Ouaisné (the latter population not currently recorded as part of Toadwatch) (to connect Noirmont with other populations and improve population robustness in this key area).

Analyses of the Toadwatch monitoring data showed that timing of toad breeding was very variable (starting usually any time between early January and early March) but there was no discernible trend towards earlier breeding. Analysis of any population trends 2005-2014 is difficult due to inconsistencies by recorders; however, the average number of spawn strings per pond was <4, indicating generally small populations. The majority of ponds (81%) also had <30 toads in any one year.

A breakdown of the types of ponds used for toad breeding in Jersey overwhelmingly supports the suggestion that man-made habitats are critical for the species’ survival in the Island. Nevertheless, almost half of the reporters recorded toads being killed on nearby roads – a consequence of their dependence on urban habitats.

Toadwatch has not yet provided much data on other key species (such as grass snakes), though some islanders have begun to record these species. The adoption of an on-line recording system, hosted by Jersey Biodiversity Centre will help improve collection of these data, improve consistency of reporting and allow for more revealing future analyses of e.g. population trends.

Summary of Key Recommendations

• Create new breeding ponds in the areas suggested to improve population resilience
• Continue to support collection of Toadwatch data on-line as a key component of monitoring the species’ status in the island
• Use signage and patrols, where likely effective, to reduce road mortality
• Update the available information on creating toad habitat/ponds.

Download the report Ten Years of Jersey Toadwatch: Analysis & Recommendations here

Jersey Toadwatch has its own Facebook page here

How many birds are there in the islands? That is bird species. Not individual birds as we can never really know that (well, except for the choughs). Each, since year since 2006 we have jointly published a list of the species seen on Jersey, Guernsey, Alderney, Sark and the sea area and smaller islands associated with each. The latest list, updated to the end of December 2015 is now available to download here and on our islands’ local bird sites.

Disappointingly there were no new species for the region recorded during 2015 but there were some minor changes to the individual Islands’ lists. Guernsey picked up its first glossy ibis (one at Vale Pond in October) and Alderney its first long-tailed skua (at sea in August). Alderney (on 8th November) and Jersey (on 22nd November) saw their first rose-breasted grosbeak – both records presumed to be the same bird (Guernsey had one of these North American vagrants in 1987 and Sark one in 1975).

A remarkable 26 roseate terns were recorded in Jersey during the year and may possibly have bred. A tree sparrow put in a rare appearance in Guernsey – this bird has been recorded each autumn flying over Noirmont, Jersey, in recent years – and 22 bee-eaters were recorded in Jersey. Dartford warblers had mixed fortunes with two of these former breeding birds recorded in Guernsey but none were in Sark where the species had been breeding since 2002.

Other notable birds included Canada geese in Jersey and Guernsey, Guernsey’s sixth record of the rapidly increasing great egret, Alderney’s third black stork and second great bustard (like the 2014 bird the latter came from the UK reintroduction project), Guernsey’s second and the islands’ third little (or house) swift, Jersey’s fourth red-footed falcon, Alderney’s third rose-coloured starling and Guernsey’s fifth black-headed bunting (all Channel Island records of this bird are from Guernsey).

And, of course, the first red-billed chough (Dusty) to hatch in the wild in Jersey for around 100 years put in an appearance in June.

Jersey’s bird total has risen to 330 and Alderney’s to 287. Guernsey’s, however, has actually dropped to 323 as they have removed three species of wildfowl from their list as their provenance is unknown (i.e. they could have hopped over someone’s fence). These three, barnacle goose, mandarin and red-crested pochard are renown escapees but two (the goose and the pochard) have been recorded reliably in Jersey. Mandarin have established, from formerly captive birds, a small but seemingly self-supporting population in Jersey as they have in the UK. Interestingly, a flock of, at least formerly, captive barnacle geese commute regularly between Guernsey and Jersey.

How will 2016 change things? One thing is certain, since the launch of the Alderney Bird Observatory, we could have a much clearer idea of bird migration through our islands.

Download the Working list of Channel Islands birds to December 2015 here 

 

The decline and subsequent disappearance of the cirl bunting in Jersey was one of the catalysts behind the formation of Birds On The Edge. With 17 singing males recorded across the Island in 1997 (by Mick Dryden and Nick Milton) the species appeared extinct locally when the ‘last’ one was seen at Beauport in 2004. Cirl buntings had undergone a longer decline in the UK but conservation efforts, led by the RSPB, were initiated in the late 1990s. Jersey watched the UK work closely, and liaised with the RSPB to see whether there were areas of the work that we could replicate over here (Note BOTE’s Cris Sellarés was part of the UK bunting team – report here).

We discussed in Jersey the bunting’s decline with the RSPB’s Cath Jeffs, RSPB Cirl Bunting Project Manager, who visited the Island to look at the bird’s former sites and assess possible measures that could be addressed to restore the bunting to its Channel Islands’ home. In June 2011 our hopes (fanciful dreams?) of the species’ return were realised when a male cirl was found at Les Landes Racecourse (by Mick again). Later that month a pair were found in Grouville on one of the BOTE bird monitoring transects (see the BOTE report here). Breeding was confirmed in 2012 when Mick found a chick with the adult pair.

We held a meeting to discuss how best to manage the habitat of the one bunting pair in October 2012 (report here) and were grateful to the Société Jersiaise Ornithology Section, National Trust for Jersey, Durrell, Grouville Tenants, Royal Jersey Golf Club in Grouville, Department of the Environment and Cath Jeffs for their support. Areas discussed included sensitive management of the existing breeding habitat of the cirl buntings and the monitoring and supplementary feeding of the birds.

Food has been provided for the buntings, notably by the fantastic Richard Perchard, without whose tireless effort our story might have been different, to ensure that any food-finding problems the buntings might encounter in the remaining Jersey habitat throughout the year were cancelled out. The bunting’s story was updated in 2013 and 2014 and, despite setbacks (see report of a fire here) they appeared settled.

This year, 2016, was chosen for a British Isles-wide survey (well, Devon, Cornwall and Jersey in the most part) to see just how the cirl bunting population was doing with all the effort being put in. And so, we waited to discover what Jersey’s population had done in 2016. Mick Dryden once again led surveys of the site in south-east Jersey and with a team of volunteers counted each and every bird in April, at the start of the breeding season, and again in July.

So, how are we (well, the buntings) doing? Mick reported that there were six birds in April, at four territories – this meant that potentially there were also unseen (nesting?) birds. And, in July, after they’ve had a chance to breed? Mick and the team reported 17 birds including eight young from three pairs!

 

 

From Jersey Bat Group

Last week the Jersey Bat Group held a week-long course with BatCRU, a bat research unit from the UK, in order to help advance the bat woodland project which has been running since 2014.

Using a combination of harp traps and mist-nets we managed to capture 151 bats of eight different species.  Bats are normally relaxed in a harp trap and sometimes appear to use it as a roost.  Mist-nets are useful as they cover a much larger area but must be watched constantly in case a bat flies in so it can be extracted quickly and does not get too tangled. This is only done by experienced bat workers. The bats are then identified, measured and released.

The jewel in the crown during this latest week was the capture of a Daubenton’s bat (Myotis daubentonii) at Val de la Mare Reservoir.  This adds a second new species to the Jersey list this year following the discovery of the Alcathoe’s bat (M. alcathoe) in St Catherine’s woods in May (story here).  A Daubenton’s bat was seen skimming over the water and, although recorded using ultrasonic bat detectors in the Island last year, had not been confirmed until now.  Daubenton’s bat has a large range and is known for hunting insects low over water. It weighs between 6-10 grams and has large feet with which to capture small insects.  We can now add a new island species to our list which makes a total of fourteen species.

By far the majority of bats caught last week were common pipistrelle (Pipistrellus pipistrellus) including many juveniles which was encouraging considering the poor weather conditions in June.  We also caught three other species of pipistrelle: soprano (P. pygmaeus), Kuhl’s (P. kuhlii) and Nathusius’ (P. nathusii) and two long-eared bat species: brown (Plecotus auritus) and grey (P. austriacus).  Finally two species of Myotis were found in the harp traps and mist-nets: Natterer’s bat  (M. nattereri) (of which there were many) and the newly discovered Daubenton’s.

Whereas it was always assumed that bats in Jersey were using tree-roosts like they do elsewhere, none had previously been observed here. During the course, two female bats, one brown long-eared caught at Grève de Lecq and one Natterer’s caught at St Catherine’s Woods were fitted with radio tags. The tags, weighing around 0.3 grams and attached to the dorsal side of the bat which makes it difficult for them to be groomed off, were fitted by Daniel Whitby, a licenced professional ecologist and founder of BatCRU. We chose post-lactating females for this as the roost they may lead us to would most likely be a maternity roost. Members of the Bat Group then used receivers and antenna to track the bat using a VHF signal.

Excitingly, we discovered two tree-roosts in Rozel and in Grève de Lecq Woods. The first contained several brown long-eared bats and the other around forty Natterer’s bats. Bats were also filmed emerging from the tree-roosts soon after sunset by using infra-red camera equipment; this enabled us to count the numbers of bats within each maternity roost.

Both tagged bats moved from the original tree-roost to another tree nearby which is normal for woodland bats so in effect we have discovered four active tree-roosts whereas before the course we had not discovered any. We expect the bats to move again thereby creating more tree-roosts for us to observe in the future. The tiny transmitter could last up to 10 days unless it is groomed off sooner by bats in the roost.

During the remaining summer and early autumn we will be continuing our research and may discover more new species. We will certainly learn a lot about our local bats and collect plenty of data which will be useful for future projects.

Dr Amy Hall, Chair of the Jersey Bat Group said ‘this is a very important discovery which will likely lead to a change in woodland management and arboricultural practices in order to protect tree-roosting bats’.

Annika Binet, a research ecologist from Annyctalus Ecology who helped arrange the week-long course said “this has been a fantastic week for bat conservation in Jersey, with the help of BatCRU and the course participants we have been able to confirm some of our suspicions relating to the use of trees and breeding status of two bat species along with the presence of another species in the island”

The Bat group would like to thank the following for allowing us to conduct bat research on their land: Jersey Water, Rozel Manor, La Hanniere Farm Ltd, The National Trust for Jersey and Ken Syvret. We would also like to thank the BatCRU team for their useful input.

By Annika Binet and the Jersey Bat Group

It’s not often that we get a new mammal species in the Channel Islands so when we do it’s a pretty exciting event!

During a recent Jersey Bat Group bat trapping session in St Catherine’s Woods as part of the Woodland Project a small Myotis bat was caught which we were unable to formally identify. Following DNA analysis of a faecal sample by Warwick University Ecological Forensics Service we are delighted to confirm that the bat was an Alcathoe’s bat – Myotis alcathoe. This is the first record for this species in the Island.

Alcathoe’s bat is a rare species with narrow ecological requirements.  It was only identified as a separate species in Greece in 2001, and was first found in the UK in 2010. It has only been confirmed in a few locations in the UK (in Sussex and Yorkshire) as well as from limited sites across Europe.

The IUCN Red List assesses Myotis alcathoe as Data Deficient, but it is considered threatened in several areas because of its rarity and vulnerability to habitat loss.  The species is a woodland specialist, with a strong preference for roosting in trees.

Dr Amy Hall, Chair of the Jersey Bat Group said ‘We are very excited to find this species in the Island for the first time.  As the Woodland Project moves forward there may be further exciting new discoveries’.

The majority of bat work in Jersey has been through sound recordings from emergence surveys and activity walks. Myotis bats have very similar calls and, therefore, cannot easily be confirmed through sound analysis alone. Myotis alcathoe is a woodland specialist and normally roosts in trees. As we currently have no known tree roosts in Jersey, this is another element of the research project we are currently undertaking. If this bat had been a male it would be possible that it is a vagrant from France, they sometimes get blown across in storms, or hitch a ride of boats, but as it was a pregnant female the odds are that it is a resident species, which we have always had but never previously come across.

We have only just started this type of research in Jersey, very few trapping sessions have been done previously, and therefore we are only now getting to see some species which are resident in Jersey for which we have no known roosts. The next step is to go back and see if we can catch any more using a harp trap and acoustic lure, with which we can attract the bats to the trap. If we are lucky enough to catch more then we hope to be able to attach a radio transmitter and track the bat back to the roost – this can currently only be done with assistance from UK bat workers as although Jersey Bat Group members are licenced to trap bats none are licenced to attach radio transmitters at the moment.

From the Société Jersiaise Marine Biology Section

Since December 2012 the Marine Biology Section of the Société Jersiaise has been coordinating a citizen science project with mermaids’ purses (eggcases from rays and catsharks). In the autumn and winter empty mermaids’ purses wash up on our coasts in large numbers and can be identified back to the ray or catshark species that laid them. The Shark Trust have been running an eggcase project for several years and it was this that inspired the Société Jersiaise to start its own project (all our data goes to the Shark Trust but we are also looking for local trends).

Since starting the project we have collected and identified nearly 6,500 eggcases. The aim is to get five years’ data before running a full analysis but some basic trends can already be discerned. For example, Jersey’s commonest eggcases (44%) come from the undulate ray, a species which is rare elsewhere and listed as threatened in the EU, but is common here. Almost as common is the blonde ray (39%) with other species being much rarer: small spotted catshark (10%); thornback ray (3%); small-eyed ray (2%); and nursehound and spotted ray (both >1%). The below chart shows the situation as at end of February 2016.

We have also noted a seasonal trend in some of the eggcases – e.g. the gap between undulate and blonde ray numbers in the autumn (between weeks 39 and 46 on the chart below) seems to be an annual thing but we’re purposefully not looking at trends in detail until the five years are up.

Now, we’ve been doing this for over three years and in that time we’ve consistently had the same seven species handed in. Then, in 2016, we’ve suddenly had four eggcases from a cuckoo ray handed in, three of which are in perfect condition. This is unexpected because there has never been a single record of cuckoo ray in Channel Island waters – nor are there any commercial or amateur fishing records (we’ve checked with Marine Resources and the JFA and there are no angling records). It does not appear in historical lists by Joseph Sinel or Ronnie Le Sueur although, before the 1980s, there was a model of a cuckoo ray in the old Jersey Museum but it was not thought to be local.

Three of the cuckoo ray cases were collected by Sabina Danzer on the west coast and they are perfectly preserved. The other one was more battered and collected by Geoff Walker in Grouville. The appearances are probably not a coincidence but whether it means that this species (which normally prefers deeper waters than ours but which can stray into shallower seas) has entered our waters is not known. It may simply be that the eggcases have been swept in from the central English Channel but, if so, then why haven’t we had them previously? All very mysterious.

Cuckoo ray eggcases are distinctive as they have very long ‘horns’ that overlap one another. Most of our eggcases are collected by dog walkers and beach cleaners and so if anyone spots a cuckoo ray or fancies participating in the eggcase research, please contact the Marine Biology Section on marinebiology@societe-jersiaise.org