Tuesday, 9 October 2007

The Southern Shore of Poole harbour

This shoreline on the Southern shore of Poole Harbour is a very fruitful site for Foraminifera. Anchor mud as well as shore gatherings are equally rich in the summer months at least. The Photo is taken looking northwards from along the Redland Peninsula. The area is characterised by a graveyard of old hulks as pictured below

Foraminifera being scraped up with mud from the intertidal pools.

The mud will of course need to be passed through a 400 micron sieve to eliminate weed and then collected in a 100 micron sive for washing in clean water, before drying, cooling and the floatation process.

Monday, 8 October 2007


Digital image by Sue Fox of Kennedy School Warren Michigan U.S.A.


• Foraminifera are Biological indicators: The assemblage of species can indicate the effects and changes of temperature & salinity.
• There are millions of Foraminifera in the seas of the world, where they are deposited from inshore species and deeper sea deposits during rough weather.
• Although sometimes numerous, the deposition zones are usually restricted to the edge of the bays nearest the incoming tidal flow. i.e. The West end in South England ;The Northern end in the North East.
• Chalk cliffs and other exposures contain fossil Foraminifera.
• They are almost as primitive as the better known Amoeba, but grow a chalky shell called a test. Some species create an outer shell (Arenaceous) cemented from marine particles like fine sand or silt or biological remains like other Forams or sponge spicules.
• They live in sea water on the bottom, on weeds, rocks or mud. Others float in the open Sea as plankton.
• They can also be found rarely in brackish ponds over salt deposits as on the Austro-Hungarian border.
• They are very small being rarely more than 0.5mm in diameter, but some warm water species can grow up to an inch (Nummulites).

The study of Foraminifera could be an ideal component of the School Curriculum. It lends itself easily to cross-curricular development in the widest possible sense. The subject certainly impacts on Biology, Art, Mathematics, Geography and Geology. The Foraminifera are regarded as climate indicators, and faunal change may be significant in the future. Although Foraminifera figure in remote parts of higher education, limited US schools are beginning to take an interest in the subject.The Pioneer school is Kennedy Elementary (van Dyke Schools) Warren Michigan USA.

Art The empty tests or "shells" have considerable aesthetic appeal and are very diverse in shape, describing spirals from simple to compound as well a.s many other morphological developments. The natural colours and textures of the test vary considerably.
Mathematics. The treatment of statistically based biological counts of species in samples.Foraminifera shapes and forms provide interesting comparisons for geometric analysis and subsequent graphical representation.
Geography. The study of world wide distribution can lead to climate linked data. The components of a collection can indicate common climatic factors like temperatures and salinity.
Biology. Material from shore or deep water gatherings does not require to be killed or fixed, nor would their collection affect the environment in any significant manner. Investigation would be quite suitable for low magnification, low cost microscopes. The anatomy and physiology of foraminifera is quite varied and can be tackled in a simplistic or an in depth manner. The study of fossil tests is an essential part of more advanced Geology but also lends itself to the simplistic approach. Many teachers are unaware or their significance or even their existence.
Brian Darnton United Kingdom

Tuesday, 28 August 2007

Anchor mud as a means of foraminifera collection

This is a picture of a Spade anchor being used to collect raw mud from Poole Harbour sites. The resultant material must then be washed through 500micron sieves to eliminate weed and then collected in a 100 micron sieve which holds the forams. If you need the finer types a 60 micron sieve is better but of course much slower.

Although anchor mud gathering is thought to be a system preferred by the very first sailing ships before elaborate dredges were inventd, its very suitable for the amateur as it does not need to be purchased. An anchor generally comes with the boat. The use of the anchor has considerably increased the numbers of inshore species in my collection.The Image was kindly taken by the owner and skipper of the good ship "More Hopeful" which is moored on the southern edge of Poole harbour.

Saturday, 9 June 2007

Young test of Ammonia tepida

This test is about 190 microns in diameter and was still attached to the parent from which it was derived by a tough strand of protoplasmic like material.
This demonstrates Summer reproduction with a large primary chamber of 55 microns followed by a smaller one of around 30 microns. It is not until the 8th chamber that the size becomes greater than the primary one.It has not yet been cleaned but it emerged from floatation in this condition and the strand broke during mounting.The test was mounted in old canada balsam. The slide is interesting in that it clearly shows the early test development which is often obscured by subsequent growth in adult tests.

Saturday, 2 June 2007

Sunday, 27 May 2007

Victorian ideas on the Floatation of recent Foraminifera

The gathered tests and sand or mud must first be washed in a 100 micron sieve with flowing water to remove salt. They must then be dried and cooled.
A whisky glass is 3/4 filled with cool tap water and the powdery material from the sieve is sprinkled onto the surface. The best foram tests will float and drift towards the edge of the glass. The silica and other debris will either sink or float in the middle of the glass. If the water level is reduced with a bulb pipette then the tests will be stranded around the edge of the glass where they can be picked up with a brush which can be washed out in a petri dish of pure water. A 1/2" wick of kitchen towel can be used to dry out the dish by micro-siphoning. The dried tests can be sieved for mounting.

Friday, 25 May 2007

The main Deposition Zone in Swanage Bay

Empty tests *of the inshore Foraminifera are deposited on the beaches of the U.K. on the side of the bay from which the tidal stream flows. So on the South coast it`s on the most Westerly end of the bay. In Swanage the site is around the Public Hard near the Mowlem building. The tests have a similar density to the sea coal and together they provide a useful disinctive banding as in the picture. Detail will be revealed by clicking on the image. A flat plastic card is all that is required to scrape up the whiter parts in the banding. The mixture then needs to be washed in clean tap water to remove salt in a 100 micron sieve and then dried out by heat and cooled.Victorian type floatation may then be used to yield the better tests.
* Tests are the shelly remains of the Forams.

Below is a Plate of the more common Species at Swanage Bay.
Please click on the image for a view at greatest magnification.
The two most numerous species deposited during the whole year are
Elphidium crispum and Massilina secans q.v. below
Elphidium lives mainly on the seaweed and Massilina can be found in the numerous rock pools between stable stones.

Thursday, 24 May 2007

Collecting in the Saltmarsh of Poole Harbour

Collecting from the mud of a saltmarsh is a little trickier. little depressions where shelly remains lie is a good place to scrape. Near the high tide line there may be stranded pools. These areas particularly at Arne, are quite rich in a variety of uncommon Arenaceous types QV in laterPosts. Be on the look out for very soft muds that will not support walkers and are dangerous. The base of channels are generally the hardest areas for walking.