Thursday, October 23, 2008

Marine Resource Management

"The life-cycle, exploitation and use of ostrea edulis".

Also known as the common oyster and the European flat oyster .

Life cycle

Ostreil edulis - Literature Review
Shell width: up to 11 cm

Description of Oyster

‘The native oyster is a bivalve mollusc, which means ‘two shells', and is rough, scaly and yellowish-grey in colour. Each valve differs in shape and size; the left one (the one used by the oyster to attach itself to a surface) is concave, while the right one is flat and fits snugly inside the left. The right valve has concentric rings of a bluish colour, and the whole animal is roughly pear-shaped. Inside the shell, the colours range from blue to grey and include the opalescent ‘mother of pearl'. Mother of pearl is secreted by the oyster around any foreign body that gets trapped between the shells, for example, a piece of sand or grit. In time, this builds up and forms a pearl’ (


Throughout, this literature review the main literature, Journals and Resources from The World Wide Web will be discussed and compared, according to their similarities and differences in concern with the life cycle, exploitation and use of Ostrea edulis.
Life cycle, Exploitations and uses
Consider The Oyster A Shucker’s Field Guide
Ostrea edulis is also known as the common oyster and the European flat oyster. In Patrick Mc Murray’s ‘The Oyster A Shuckers Field Guide’ he describes the best places in the world to eat oysters and different ways of preparing them for eating. As an example he cites the use of Guinness stout in Kelly’s of Kelcolgan in Ireland. The French apparently have around 3,400 different growers in France. (McMurray 2005)
He goes on to describe some growing methods such as the simple method of letting them grow and then harvest in oyster parcs. Other people like to finish the oysters by holding them in brackish water ponds or pools called Claires. The book also gives details of where Ostrea edulis grows naturally. For example Norway, Sweden, France, the Netherlands, Britain and Ireland. (McMurray 2005)

Evaluation of source

This book provides a useful overview, and descriptions of oysters. However, it only has a few pages dedicated to Ostrea edulis and it does not go into any scientific detail. It is mainly a book for tourists who have a passion for eating and preparing oysters. The book also has a useful index and web links to certain restaurants, recipes and locations.

Bottom Feeder

In the book ‘Bottom Feeder’ written by Taras Grescoe (2008) he tells us the dangers that some species of fish are facing due to poor marine management, over fishing and aquaculture being used inappropriately. The book explains how oysters act as the filter of the sea by cleansing the water. It also states that due to poor aquaculture techniques the quality of the oysters is beginning to deteriorate. Furthermore, as a result of pollution oyster populations are beginning to decrease. (Grescoe 2008)The book in my opinion is very basic and subjective, However, It is hard to fault Grescoe as you can see through this book how much he cares for the ocean environment and the crustaceans and cetaceans which live in it. There are also lots of scientific facts. To back up his opinion.

Objective and Evaluation

The main objective of the book is to discover which fish are sustainable to eat and which fish are poor choices due to them being endangered. The moral of his analysis is that if we do not change our ways we will be left with a sea full of jelly fish and bottom feeders. The book does not contain an index which makes the book harder to research. The book also mentions some cooking and preparations mentioned in Murrays – consider the oyster and where they are most commonly found.
In addition to Bottom Feeder, Mark Kurlansky’s book ‘The Big Oyster A Molluscular History Of New York’ describes the differences between oyster reproductions. For instance oysters of the ‘’Genus Ostrea produce fewer eggs than do crassostrea, only about one million, and the eggs have 3 times the diameter’’ (Kurlansky page 54 05). The book also compares ideal conditions depending on the type of oyster. For instance Oyster edulis live in much saltier waters and begin spawning when the water reaches fifteen degrees. (Kurlansky 2005)
Comparison between Bottom Feeder and the Big Oyster
The book unlike Bottom Feeder gives us a detailed history of Ostrea eduils, its taxonomy, life cycle tradition and modern cultivation techniques as well as the best ways to eat them. The book is much more informative and scientific than Bottom feeder. In terms of how to prepare and eat the oyster it tells us as much if not more than Patrick Mac Murrays A Shucker’s field guide. The book was an excellent read which gave me a new understanding of different types of Oysters and there use. Furthermore like bottom feeder the book explains how Ostrea edulis is being exploited and over fished. The use of aquaculture which is resulting in them becoming more sustainable. Also bottom feeder has a very subjective point of view; however the big oyster is objective and less bias. The book contains a detailed index. Of course though since The Big oyster is written only about oysters there is going to be more information and detail than bottom feeder. These to certain books are both relatively new and agree on most aspect surrounding exploitation and use of osteil edulis

Evaluation of Shore Guides and relation To Literature pieces

Whilst conducting this literature review I analysed 3 shore guides. The usborne Spotter’s guide to the seashore gives us a very brief description of Ostreil edulis in fact it only refers to Ostreil edulis as the common oyster furthermore, It does not tell us anything about the oyster life cycle. It is very basic and probably aimed at lemans .On the other hand the illustrations and presentation of the guide is fantastic. Although Bob Gibbons Seashore life of Britain and Europe has dull illustrations the description of Ostrea edulis is much wider giving us a detailed analysis of where they are most likely to be found, taxonomy etc. This description also supports Bottom Feeder and The big oyster a molluscular history of New York in connection with the locations and physical properties of the Oyster. The Collins Pocket guide to the seashore is by far the most beneficial guide. Giving the names of all the species of Oysters comparing their reproductive patterns, physical properties and where they are found also a detailed analysis of the oysters life cycle, although this guide is much older it consists of great illustrations and is presented very efficiently and easy to use.

World Wide Web Resources used (Similarities and differences between resources)

However, In contrast to these pieces of literature the internet site for Marlin was extremely detailed which included everything from basic information taxonomy habitat and distribution, reproduction and importance. The site was informative and easy to use. Where the guides lacked in detail the Marlin website explained and specified in detail. Fantastic resource.

Fishier and aquaculture Department

The website Fishier and aquaculture department was also efficient resource describing fish and aquiculture techniques however, unlike Bottom feeder it expands on the importance and necessity of aquaculture and how it contributes not only scientifically but economically to some counties , but this I feel is bias as it is not exactly going to criticise its main source of profit . Overall it’s a good website which gives us a deep analysis of the oyster including taxonomy, habitants fishing methods, but fails to explore the possibilities that aquaculture may by damaging to other marine ecosystems and habitats and a detailed illustrations of the Oyster life cycle.

Action Plan

According to the action plan for ostrea edulis the oyster has been over exploited, since the oyster filters sea water, in some areas parts of the seas are becoming more polluted as a direct result of other fishing. This agrees with both bottom feeder and the big Oyster a Molecular History of New York but disagrees with the website Fishier and aquaculture department. Furthermore, the site also predicts the fate of the oyster if more is not done to guarantee its rising numbers .The site is a good resource well worth visiting.
Work Experience at Falmouth Oyster Bay Company Fig 3 Oyster life cycle (Marlin 2008)
Whilst working for a day for Falmouth bay Oyster Company I learned the process that oysters have to go through before they can be eaten. It was very interesting getting a full tour of the factory and seeing the process and conditions that the oysters are kept. This experience broadened my horizons of the oyster industry. Their website also gives different recipes for eating and preparing Oysters some of which are mentioned in a shukler’s field guide.

Do resources agree?

Fig 1

This map taken from the fishier and aquaculture website shows the main countries of where ostrea edulis is farmed through the method of Aquaculture. A shukler’s Field guide and bottom feeder agree with this map. A shuckler’s field guide mentions all of the above countries on the map; however, Bottom feeder only mentions U.S.A Britain and France. This particular source is extremely useful as it clearly shows the main Countries of where Ostrea edulis is farmed. The map also tells us the main countries which utilise and exploit Ostrea edulis.
Global aquaculture production of Ostrea edulis (Fao Fishery Statistic) Fig 2

This graph also from the fisheries and aquaculture website shows us the Dramatic decrease in Ostrea edulis in Aquaculture due to disease and a consequential shift to the rearing of the Pacific cupped oyster (Crassostrea gigas). All other sources which I have read agree with this As Oysters are packed into small areas overcrowding increase the chance of disease and parasites. Furthermore in The book The big oyster the consequential shift of pacific oysters is mentioned. Bottom feeder states that the main reason for the decline in Oyster populations is poor aquaculture practices; disease is not only affecting farmed oysters, but is spreading top wild Oysters.

Arkive ( and The common Oyster (

The website Arkive consists of Fantastic images of Oysters in their natural habitat The site gives us a complete overview of the current position of the oyster which areas it is in abundances or endangered. This is one of the most useful sources that I have used. (
The website ( is very similary to the website Archive they both consist of amazing images that capture the oyster in its nature habitat. They both seem to have the same objective and both understand the true threats to Ostrea edulis due to over fishing and poor aquaculture practices.


Whilst conduction this literature review I discovered many important factors surrounding ostrea Edulis such as it’s Biology, life cycle, taxonomy and preferred habitats.
Most important of all I was educated in the fact that Ostrea Edulis a sustainable, however due to poor aquaculture techniques farmed oyster quality is beginning to deteriorate, as a result of overcrowding in farmed areas disease and forms of parasites are becoming evermore,common. By over exploiting and to use more that is in

supply Ostrea edulis will soon begin to dwindle. Fig 2 shows the impact of how disease and poor management can affect a species over time. It is vital for ostrea edulis to stay plentiful as they are the filter of our ocean. I would recommend anyone who was going to be doing a study of Ostreil edulis to read Bottom feed as well as The Big Oyster A Molluscular History of New York as they are both new pieces of literature and both have up to date knowledge of the currents situation and position of Ostreil edulis . Furthermore, I would suggest visiting the website Marlin and The fisheries and aquaculture as they are very informative about Oyster fishing and have detailed graphs and statistics on Oyster populations as well as detailed illustrations of life cycles and habitants.


Fisheries and aquaculture department, Available at [online]. [27/10/08].

UK Biodiversity action plan Available at: [online]. [27/10/08].

Hayward P, Nelson T, Shields C, Collins Pocket Guide to The Seashore of Britain and Northern Europe. Page 240 First Edition Published by Collins.

The MARLIN website: Available at [ONLINE] [27/10/08].

Falmouth Oyster Bay company [online] [27/10/08]

Thursday 12 May springer berlin Marine biology ISSN 0025-3162(PRINT)1432-1793 Volume 147 number 4 page 965

Biodiversity action report system Available at [online] [27/10/08] 08] [online 08] image - FIG 3
Available at [online]. [30/10/08]

Kurlansky.M 2005 The big Oyster A Molecular History of New York – Pages 49,50,53,138,230 First published in the United States of America Balantine Books Random House,inc New York 2005 .

Swallow.S . 2006 Usborne Spotter’s Guide The Seashore –page 36 Edition first published in 2006 by Usborne Publishing.

Gibbons.B 2001.Green guide – Seashore Life of Britain and Europe .Pages 70. First Edition, New Holland Publishers 2001.

McMurray.P .December 2007. Consider the oyster a shucker’s field guide pages- 65,74,75,81 First edition Thomas books.

Grescose.T .2008. Bottom feeder –How the fish on our plates are killing our planet .Chapter 2 Chesapeake Bay And Brittany ,first edition MacMillan Publishing .

How to do a literature review
Relevent sites which explain the purpose and how to construct a literature review -