Natural England Conservation Advice for Marine Protected Areas
Tamar Estuary Sites MCZ

Natural England guidance

This site collection contains Natural England’s conservation advice for this site. It fulfils Natural England’s responsibility under the Marine and Coastal Access Act 2009, to give advice on how to further the conservation objectives for the site, identify the activities that are capable of affecting the designated features and the processes which they are dependent upon.

Natural England's conservation advice for this site is made up of a number of components. You will need to consider: Additional information for consideration:

Site information

Overarching site: Plymouth Sound and Estuaries Marine Protected Area
Site name: Tamar Estuary Sites MCZ
Designation type: MCZ
Site identification: UKMCZ0016
Latest designation date: 12 December 2013
Designated features
(click to see site specific description):

General information on the site features:
The general information on the designated features from the MCZ features catalogue is useful for understanding the designated features, and should be used in conjunction with the site specific information.
Designated area (ha): 1530
Component Sites of Special Scientific Interest (SSSI):
Overlapping Protected Areas:

Last updated: 13th September 2019

Background information and geography

The Tamar Estuary Sites Marine Conservation Zone (MCZ) provides sheltered habitats which are subject to various salinity levels and tidal exposures. This diverse estuarine environment supports a number of features of ecological importance, including coarse sediments on the shore and biogenic reefs formed by the blue mussel (Mytilus edulis). These living reefs are ecologically important as they provide a home for numerous species including seaweeds and animals such as sponges, barnacles, winkles and crabs. Areas of biogenic reef exposed at low tide provide a feeding ground for birds, whilst submerged areas are used by predators and scavengers like fish and crabs.

The site is particularly important as it is the only MCZ where the migratory fish the European smelt (Osmerus eperlanus) is protected. The MCZ is also home to the native oyster (Ostrea edulis), a species which experienced significant declines during the 20th century in European waters.

The site is made up of two separate areas; one in the Lynher estuary and the other encompassing part of the Tamar and Tavy estuaries. Both parts of the MCZ fall within the Plymouth Sound and Estuaries European Marine Site.

Site maps

Use the MAGIC website to see site maps, including habitats, species and other marine designations.

These maps are based on best available evidence, there are some caveats associated with the maps on MAGIC.

Conservation objectives

The site’s conservation objectives apply to the Marine Conservation Zone and the individual species and/or habitat for which the site has been designated (the “Designated features” listed below).

The conservation objective of the zone is that the protected features:

  1. Are maintained in favourable condition if they are already in favourable condition, or
  2. Are brought into favourable condition if they are not already in favourable condition.

For each protected habitat feature, favourable condition means that, within the zones both:

  1. Its extent is stable or increasing
  2. Its structure and function, its quality, and the composition of its characteristic biological communities (including diversity and abundance of species forming part of or inhabiting the habitat) are sufficient to ensure that it remains in a condition which is healthy and does not deteriorate.

The second conservation objective of the zone is that, in relation to smelt and the native oyster:

  1. The quality and quantity of habitat available to the population and
  2. The composition of that population in terms of number, age and sex ratio are such as to ensure that the population is maintained in numbers which enable it to thrive.

Any alteration to a feature brought about entirely by natural processes is to be disregarded when determining whether a protected feature is in favourable condition. Any temporary reduction of numbers of a species is to be disregarded if the population is sufficiently thriving and resilient to enable its recovery.

This should be read in conjunction with the accompanying supplementary advice section, which provides more detailed information to help achieve the objectives set out above, including which attributes should be maintained and which recovered.

Designated features:

  • Blue mussel, Mytilus edulis beds
  • Intertidal biogenic reefs
  • Intertidal coarse sediment
  • Native oyster, Ostrea edulis
  • European Smelt, Osmerus eperlanus

Supplementary Advice on Conservation Objectives

See supplementary advice on conservation objectives for this site, which aim to describe the range of ecological attributes that are most likely to contribute to a site’s overall integrity.

Last updated: 20th March 2017

Advice on Operations

See the advice on operations for this site to view information on the sensitivity of features in this site to the pressures exerted by different activities.

Last updated: 13th March 2020

Advice on Seasonality

See the advice on seasonality for this site, to view the months in which each mobile feature occurs in this site.

Last updated: 20th March 2017

Feature Condition

In 2016, Natural England trialled and rolled out a new Marine Protected Area (MPA) condition assessment methodology that provides robust results and information on the condition of marine features designated within MPAs in England. With guidance from National teams and using all available evidence and condition monitoring data, Area Teams conduct these assessments following a standardised approach that assesses if the feature and sub feature conservation targets set for each MPA have been met.

To date, condition assessments have been completed for a number of features in a range of marine Special Areas of Conservation (SACs) by the National and Area Teams. Further marine habitat features in SACs and other MPAs will continue to be assessed in the future. The new method can now also be applied to complete habitat and species condition assessments for other MPAs in England, whilst still meeting the different processes in place to report on the results of condition of features in Marine Conservation Zones (MCZs) and Special Protection Areas (SPAs). Different processes are currently in place to decide and report on the condition of non-marine habitat and species features of SACs.

The main part of the assessment process is directly undertaken and stored here on Natural England’s Designated Sites View. The details for the most recent assessments of this site can be found here.

Management measures

If you are carrying out an environmental assessment, planning an operation or assessing an operation or proposal, it is important to consult with the following organisations where applicable. To find out if any management measures, byelaws or other restrictions apply to your activity see the management measure page or you can use the following links for more information.

The Marine Management Organisation license, regulate and plan marine activities in the seas around England and Wales so that they’re carried out in a sustainable way.
Environment Agency are responsible for regulating major industry and waste, water quality and resources, fisheries, inland river, estuary and harbour navigations, conservation and ecology.
Offshore Petroleum Regulator for the Environment and Decommissioning (OPRED) regulates oil and gas, CCS and gas storage activities in the marine environment.

Further information

For further information relating to this designated site you can refer to the following resources:
Site specific information: Other information:
For further information about this site contact: Natural England enquiries Telephone: 0300 060 3900. Email: