: Casgliadau ac Ymchwil

Mae Juliet Hodgkiss yw Uwch Gadwraethwr Gerddi Amgueddfa Cymru. Mae hi'n arwain tîm ymroddedig o arddwyr a gwirfoddolwyr yn Sain Ffagan, sy'n gofalu am y gerddi a'u casgliadau o blanhigion treftadaeth arbennig. Mewn ymateb i ddiddordeb cynyddol yn ein gerddi ein hunain, a dyhead cynyddol am harddwch rhai o erddi godidog ein cenhedloedd yn ystod y cyfyngiadau symud, dros yr ychydig ddyddiau diwethaf rydyn ni wedi bod yn casglu'ch cwestiynau chi i Juliet am ei gwaith. Dyma ei hatebion yn ein fersiwn ‘treftadaeth’ ni o Gardener’s Questiontime.

Beth yw'r peth gorau am eich swydd?

Y peth gorau am fy swydd yw cael fy nhalu i weithio mewn gerddi mor brydferth. Mae gennym ni amrywiaeth eang o erddi, felly rydw i'n gwneud rhywbeth gwahanol bob dydd. Rwyf hefyd yn cael cwrdd â chymaint o bobl wych trwy fy ngwaith - staff, gwirfoddolwyr, ymwelwyr, cyd-arddwyr a mwy.

Pa un o erddi Sant Fagan yw eich hoff un a pham?

Yr adeg hon o'r flwyddyn, fy hoff ran o'r gerddi yw'r ardal ger y pyllau. Trwy gydol y gwanwyn, mae banciau'r teras wedi'u gorchuddio â bylbiau gwanwyn; cennin Pedr, clychau'r gog a ffritil, i gyd uwchben carped o anemonïau. Daw’r godidog Magnolia ‘Isca’ i'w blodau yn gyntaf, ac yna’r ceirios a’r afalau. Y goeden ddiweddaraf i flodeuo yw'r Davidia, gyda'i bracts gwyn anferth sy'n siglo yn yr awel, gan roi ei henw iddi - y goeden hances.

Pa un yw'r planhigyn prinnaf yn y casgliad?

Un o'r planhigion prinnaf sydd gennym yw rhosyn Bardou Job, a oedd yn un o'r rhosod gwreiddiol yn yr Ardd Rhosod. Credwyd bod hwn wedi diflannu, yna cafodd ei ail-ddarganfod gan grŵp o selogion rhosyn, yn tyfu yn hen ardd prif warder ar Alcatraz! Fe'i lluosogwyd, a danfonwyd 6 rhosyn atom i dyfu yn ein gerddi. Mae gennym hefyd gasgliad o datws treftadaeth, a roddwyd i ni gan Asiantaeth Ymchwil Amaethyddol yr Alban.

Un o'r tatws rydyn ni'n eu tyfu yw'r Lumper, y tatws a dyfwyd ar adeg newyn tatws Iwerddon. Ni ellir prynu'r rhain, felly mae'n rhaid i ni eu tyfu bob blwyddyn i gynnal ein casgliad.

Pa un yw'r planhigyn anoddaf y mae'n rhaid i chi fynd i'r afael ag ef - un sydd anoddaf i'w gynnal?

Y planhigion anoddaf i'w cadw yw'r tatws treftadaeth. Mae'n rhaid i ni dyfu'r rhain bob blwyddyn i gynnal ein casgliad, ac mae'r rhan fwyaf o'r hen amrywiaethau hyn yn agored iawn i falltod, felly mae angen eu rheoli'n ofalus i sicrhau cnwd da.

Pa un yw'r planhigyn anoddaf i'w reoli?

Y planhigyn anoddaf i'w reoli yw Oxalis, chwyn parhaus gyda deilen debyg i feillion, sy'n lluosi trwy fylbiau. Mae'r bylbiau hyn yn cael eu lledaenu pan fydd y pridd yn cael ei drin. Mae bron yn amhosibl ei ddileu. Ar ôl treulio blynyddoedd yn ceisio ei chwynnu, rydyn ni nawr yn ei gadw dan reolaeth gyda phlannu a gorchuddio tomwellt.

Pa un yw eich hoff amser o'r flwyddyn yn yr ardd?

Fy hoff amser o'r flwyddyn yw'r gwanwyn, gyda bylbiau'r gwanwyn, coed yn blodeuo, y rhedyn yn agor eu ffrondiau, a'r holl blanhigion yn yr ardd yn blaguro i dyfiant. Mae popeth yn edrych yn ffres a newydd, ac rydyn ni arddwyr yn llawn gobaith am flwyddyn wych o'n blaenau yn yr ardd.

For our avid blog readers, you might recall previous articles about a group of worms which certainly dig! They are the shovel head worms, or to give them their scientific name, magelonids. Shovel head worms are a small group of marine bristle worms (polychaetes), which are sea worms related to earthworms and leeches, with bristles along their bodies. Shovel head worms get their name from their spade-shaped heads, which they use to dig in soft sediments such as sands as muds. They are pretty small and delicate, so although we have them around our coasts, they are often tricky to find. Therefore, they are not as well-known as other marine bristleworms such as lugworms and ragworms, often used by fisherman as bait! Their size also means that they can be pretty difficult to collect, ever tried looking for a worm less than 1 mm wide on a beach? We have! Despite their size they are quite beautiful worms (although, I may be slightly biased!) and like other marine bristleworms they are an important food source for many other sea creatures, and also are the gardeners of the ocean, re-working the sediments like earthworms do on land.

Although, I wear many different hats in the museum, one of my principle jobs is being a taxonomist. Taxonomy is the science of naming, describing and classifying life on earth. That may be finding new species, or re-describing species which were discovered many moons ago. When we find a new species, we draw it, take photographs of it (sometimes using Scanning Electron Microscopes enabling us to Zoom in really closely!), describe it and then pick a name for it in Latin. To give you an example here is a species that I described with colleagues in China.

So, what have we been up to recently? We have been reviewing the shovel head worms of Europe, of which there are currently nine species known. Four of which were first described from the UK, three off France, one off Portugal and one off Sweden. Although, these are worms we know, back when the species were first described we didn’t know all of the features/characters that we needed to know in order to correctly identify and seperate them. Unfortunately, this means that the worms get mis-identified, causing problems for people who monitor the health of our seabeds! This is where we step in, re-describing the species and producing identification keys and guides to help people in the future. Over the last year we have been busy reviewing the species, a paper on which has just been published. Now scientists all around the world will be able to correctly identify their European shovel head worms.

We have been doing this with a Professional Training Year Student from Cardiff University, and colleagues from Spain and Portugal. 

 

Find out more about our work on ‘Worms that Dig!’

West African Worms that Dig 

More on West African shovel head worms

Species new to science, Shovel head Worms from around the world

 

 

In the previous blog (What are Non-native (or alien) Species?) I talked about non-native species and how they are transported around the planet. In this blog I’ll tell you a bit more more about rafting bivalves that can cross the Atlantic on plastics and about some of the UK hotspots for these non-native (alien) hitchikers.

 

What is rafting?

Rafting has occurred throughout geological time, and it is how many terrestrial (land-dwelling) species colonised islands and other regions across the seas. A good example of this is the lemurs of Madagascar. 60 million years ago there were no lemurs on the island of Madagascar, but their ancestors were on the mainland of the African continent. So how did they actually get to Madagascar? Palaeontologists tell us that rafting is the answer. Back then, Madagascar was closer to the mainland and currents in the Mozambique Channel were much stronger towards the island than they are now. The lemurs’ ancestors must have found their way onto mats of vegetation or branches and by chance rafted to Madagascar. A completely fluke event! 

 

Today, our litter ends up in the oceans and provides unnatural vehicles for marine non-native species. Over the last decade more than 20 species of Caribbean bivalve shells have ended up on British and Irish beaches attached to plastic buoys, bait buckets, ropes and others items – even a piece of a car running board! The latter had three different types of Caribbean bivalves attached, one of which, the Bicolor Purse Purse Oyster, is an invasive species in Brazil. Violent storms help to throw the plastic objects high onto our shores and they are then found by beach cleaners, beachcombers and others on the strandline at the top of the beach. Many of the shells or photographs are sent to Amgueddfa Genedlaethol Caerdydd - National Museum Cardiff to be identified and hence to work out where they came from.

 

Conveyor belts and hotspots

The rafting species that we are studying start off attaching to plastics in the Caribbean. These plastics eventually float into the warm ocean currents of the Gulf Stream, which originates in the Gulf of Mexico, and provides a conveyor belt to transport non-native species across the Atlantic Ocean to the British Isles. Once here, violent storms then deposit the plastics, with their hitchhikers still attached, onto our shores. 

The hotspots for non-native species records are in the southwest of England and western Ireland, but there are also records for western Scotland. Strangely enough there are no records for Wales, even though some of the beaches are prime, exposed shores similar to those in Ireland and England. 

I want to discover if there are any welsh hotspots for rafting bivalves, find out which beaches to search and to encourage people to go out to those locations to try and get some records for Wales. 

 

Why should we monitor these species?

It is important to establish points of entry for any non-native species, which is why we need to map where the rafting species are arriving so that we can monitor numbers of any species arriving alive that could possibly pose a threat. When a species moves to a new location, the species that already live there have to adapt to cope with the newcomer. This can put a strain on populations that use the same food source or habitat as the invading species, which is why we want to know where these rafting species are washing ashore. All the rafting species that we’ve encountered so far cannot reproduce in our waters as they need warmer sea temperatures of 20°C or more to breed. However, if sea temperatures continue to rise, climate change could aid more rafting species to create self-sustaining populations here which could become a real problem

 

The Bicolor Purse Oyster – an invasive species in Brazil

Of the non-native rafting species found so far in the UK, the Bicolor Purse Oyster (Isognomon bicolor) is the one that has shown up in the greatest numbers. It was first described as a species in 1846 by C.B. Adams who collected it in Jamaica. It has been spotted around the coasts of Florida, Texas and Bermuda and several of the Caribbean islands all of which are considered its natural range. However, in 1970 it was recorded outside its natural range in the eastern state of Rio Grande do Norte in Brazil. It has since moved further southwards and is considered an invasive species in Brazil as it is competing with native oysters and mussels for space and is spreading quickly. 

The Bicolor Purse Oyster in Britain and Ireland

The Bicolor Purse Oyster has been found in Cornwall, Dorset and western Ireland by eagle-eyed beachcombers. They noted locations, objects that the oysters were attached to, and they collected the shells. The beachcombers are great photographers so we have a record of the variety of sizes, shapes and colours of the shells found here. The Bicolor Purse Oyster is small (up to 28mm), flattened and elongated. The outside is beige and white, sometimes with purple blotches and is smooth apart from being a bit flaky-looking. The front of the shell has byssus threads of pale to dark brown that protrude ready to attach to hard surfaces. In its natural range this species attaches to rocks and is commonly found in the Florida Keys. 

 

What next?

Although there are lots of records of rafting species in Ireland and England, there are none for Wales. Does that mean that they do not wash ashore in Wales? Doubtful! This is why I’ve set up a project to get people out onto beaches looking for any plastics that could be likely rafts. The project involves citizen scientists – volunteers from the general public – who can help to spot these rafting species in Wales.

To find out more about this part of the project see next week's blog entitled Rafting Bivalves - the Citizen Science project.

Cofrestrwyd tafarn y Vulcan fel ‘ale house’ am y tro cyntaf ym 1853. Erbyn iddi gael ei datgymalu gan yr Amgueddfa yn 2012 gwelwyd sawl cyfnod o addasiadau. Roedd gwaith addasu 1901 ac 1914 mor sylweddol fel bod rhaid ceisio am ganiatâd cynllunio drwy Gyngor y Sir. Heddiw, mae’r cynlluniau yn Archifdy Morgannwg.

Mae’r cais cynllunio o 1914 yn cynnwys dau ddarlun (does dim darlun o’r ffasâd ar y cais o 1901) – labelwyd un darlun yn At present, a labelwyd y llall yn Proposed. Does dim esboniad ysgrifenedig wedi goroesi i gyd-fynd â’r darluniau. Serch hynny, wrth edrych yn fanwl mae modd bwrw mwy o olau ar y newidiadau arfaethedig. Y gwahaniaeth mwyaf amlwg yw’r cynnydd ar y llawr cyntaf o ddwy ffenest i bedair, a chodi pileri newydd o frics coch naill ochr. Gwaredwyd y parapet oedd o flaen y to – sydd i’w weld fel cyfres o linellau llorweddol uwchben y ffenestri, ac fe addaswyd y simneiau a gosodwyd to newydd o lechi. Bu un newid arall, sydd ddim yn amlwg yn y darlun, a hwn oedd y newid mwyaf yn hanes y Vulcan – cynyddwyd uchder yr adeilad yn sylweddol. Mae’r darlun gwreiddiol yn dangos y dafarn yn rhannu to gyda’i gymdogion, lle mae’r darlun arfaethedig yn dangos adeilad cryn dipyn yn dalach na’r cymdogion.

Doedd dim bwriad i newid strwythur y ffasâd llawr gwaelod – dau ddrws, a dwy ffenest wedi eu rhannu yn ddwy a ffenestri linter (fanlights) uwch eu pen. Ond, wrth edrych yn fanwl mae modd gweld bod nifer o wahaniaethau allweddol, a digon i awgrymu fod y ddau ffasâd yn rhai gwahanol. Yn y darlun gwreiddiol mae dau banel hirsgwar o dan bob ffenest, ond yn y darlun arfaethedig dim ond un sydd. Mae’r nifer o baneli drws yn wahanol hefyd. Yn y darlun gwreiddiol, naill ochr i’r ffenestri mae’r pileri yn rhai rhychiog ac yn gorffen cyn cyrraedd y ffris. Dyw’r pileri ddim yn rhychiog yn y darlun arfaethedig ac maent yn cario ymlaen mewn i’r ffris nes cyrraedd y cornis uwch ei ben. Mae’r darlun arfaethedig hefyd yn dangos tri ffenest linter uwch ben pob gwydr ffenest, lle mae saith yn y darlun gwreiddiol. Dyw’r terfyniad addurniadol ddim i’w weld yn y darlun arfaethedig chwaith. Dim ond yn y darlun arfaethedig mae’r gwahaniaeth mwyaf oll i’w weld, sef yr arysgrif newydd THE VULCAN HOTEL, WINES & SPIRITS ac ALES & STOUTS.  

Er nad yw’n glir yn y cynlluniau, rydym yn sicr fod y darlun gwreiddiol yn dangos ffasâd llawr gwaelod o bren – tebyg iawn i flaen siop Fictoraidd draddodiadol, a newidiwyd hwn yn 1914 am un tebyg o deils gwydrog a arhosodd yn eu lle nes tynnu’r adeilad yn 2012.