Wednesday, 24 October 2007

Falmouth and Truro Port Health Authority

Responsible for monitoring and classification of live bivalve mollusc harvesting areas. In regards to human health.

Viral infections and shellfish
Estuaries used for sewage disposal and oysters and mussels are filter feeders (oysters filter 10-24 litres of water per hour) and can concentrate pathogens. Shellfish are usually eaten raw or lightly cooked. Main pathogens are norovirus, causing gastroenteritis and hepatitis B, and E. coli which causes food poisoning.

DSP - Diuretic shellfish poisoning
PSP - Paralytic shellfish poisoning
ASP- Amnesiac shellfish poisoning

Outbreaks caused by shellfish
Scandinavia - 1997
China - 1998
Spain - 1999
France and Italy - 2002

E. coli is present in human and animal faeces and is used as an indicator when testing but its absence does not guarantee other viruses are not present. CEFAS manages monitoring on behalf of the Food Standards Agency, which dictates policy to local enforcement agencies.

50 local enforcement agencies
16 testing laboratories
75 production areas (371 rope, trestle and natural beds)

A - less than 230 organisms per 100g - direct human consumption
B - less than 4600 per 100g - purified by depuration before consumption
C - less than 46000 per 100g - relayed for at least 2 months before reclassification as B
D - more than 46000 per 100g - not for human consumption, prohibited

Figures for England in 2007
A - 2.6%
B - 88.4%
C - 7.1%
D - 1.9%

Classification based on trends not individual results, data sets based on 10 monthly examinations with randomised timings to accommadate environmental variables such as tide, winds, rainfall runoff, sewage discharge times and seasons.

Purification in tanks with circulated, purified seawater and UV lights for 42 hours which reduces E. coli to less than 230 per 100g (class A). Water temperature and salinity can be set for different species to induce filter feeding.

Wednesday, 17 October 2007

Shellfish and CZM

Main species exploited
Prawns - 50 species fished wordwide.
European lobsters - 5 years to grow to a saleable weight of 1lb, live up to 15 years.
Edible crabs - best meat yield April to November. Can move up to 100 miles in annual migration.
Oysters - Natives (wild) not sold May-August. Pacific (farmed) sold all year.
Scallops - Can live up to 10 years.
Mussels - Farmed in Scotland, Wales and southern England all year round. Best Oct-March.
Cockles - Dense beds in most estuaries.

Public right to fish
Right to collect shellfish if there is public access to the shore. Controlled by local bye-laws but not prohibited unless by specific several order.

Policy issues
Marine Bill - Shellfish industry fear resultant Act will enable subsequent Statutory Instruments controlling their exploitation. Proposals do not cover 6-12 nautical mile zone. Sea Fisheries Commitees being restructured. Marine Protected Zones/Areas could be commercially exploited.

Shellfish Waters Directive (79/923/EEC) sets mandatory or guideline standards for water quality but excludes crustaceans. Administered by DEFRA and implemented by Environment Agency.

Shellfish Hygiene Directive. CEFAS (Centre for Environment, Fisheries and Aquaculture Science) tests and collates samples of catch on behalf of local enforcement agencies (in Falmouths case the Port Health Authority).

33 of 124 shellfish grounds in the UK are in the South West and account for 44% of all landings.

Friday, 12 October 2007

The South Western Peninsula Marine Natural Area

Part of a series covering the waters and coastal areas around England published by Natural England. Billed as "a contribution to regional planning and management of the seas around England". Contains much useful information, especially on marine species and their exploitation.



1 Introduction......3
1.1 Definition and role of Marine Natural Areas.....3
1.2 The basis for Natural Area boundary selection....4
1.3 The audience for this document....5
1.4 The aim and structure of this document.....5
1.5 Geographic Information System.....6
1.6 Conservation objectives ....6

2 General summary....8

3 Physical environment and character of the Natural Area ...10
3.1 Geology....10
3.2 Bathymetry....11
3.3 Tidal currents and range.....12
3.4 Sea-level change ....12
3.5 Water temperature......13
3.6 Salinity ....14
3.7 Water quality.......14

4 Key habitats........24
4.1 The water column ........24
4.2 Seabed substrata.....25
4.3 Notable biogenic habitats......32

5 Key species.........49
5.1 Marine birds .......49
5.2 Cetaceans .......53
5.3 Seals.........57
5.4 Marine turtles .......57
5.5 Fish.........58
5.6 Shellfish ........65
5.7 Invertebrates......65

6 Human activity and use.......70
6.1 Fisheries .........70
6.2 Oil and gas extraction .......74
6.3 Aggregate extraction.......74
6.4 Shipping.........76
6.5 Waste disposal ......78
6.6 Litter.......79
6.7 Submarine cables ......80
6.8 Recreational uses .....80

7 Acknowledgements ........88

8 References........89
Appendix 1 Marine Natural Areas and the ecosystem approach.......99
Appendix 2 Biodiversity Action Plan and Habitats Directive Classifications .....102
Appendix 3 Wentworth and Folk sediment classifications .........103
Appendix 4 Glossary and abbreviations .......104

This report should be cited as:
MURRAY, A.R. South Western Peninsula Marine Natural Area Profile: A contribution to regional planning and management of the seas around England. Peterborough: English Nature.

Available at:

Friday, 5 October 2007

Coastal Zone Management - Questions

  • What natural processes shape the coastal environment?
  • What natural processes put the coastal environment at risk?
  • What anthropogenic processes put the coastal environment at risk?
  • What activities take place in the coastal environment?
  • Who owns what in the coastal zone?
  • How will climate change affect the coastal environment?
  • How is a shoreline management plan best developed?
  • What engineering techniques can be applies to coastal protection?
  • What is the impact of the marine leisure industry?
  • What are the sociological effects of coastal erosion and over-exploitation?
  • How effective a tool is GIS mapping?
  • What has been the effect of historical catastrophes - e.g. the Boxing Day tsunami?

These are some of the questions we will be addressing as part of our CZM course.