Non-native marine species in British waters: a review and directory 1997

Abstract

This publication details the outcomes of a study that was undertaken to collate details and review information about introductions of marine fauna and flora to Great Britain (England, Scotland and Wales). The focus of this review is on nature conservation, and the work will be used to formulate policy on marine introductions in relation to nature conservation interests.

The study evaluates non-native macro fauna and flora, which have been introduced from outside their natural range and have become established in the wild in British waters. This report evaluates their origin, date and method of introduction; the reasons for their success; rate of spread; current distribution; actual and potential effects on native ecosystems and nature conservation, as well as commercial interests; and methods of control. Micro-organisms (< 20 μm) are not considered.

Although the frequency with which introduced species have been recorded in Europe has increased with time, there is no trend in the number of non-natives which have become established in Britain. Species have been introduced directly from primary sources or areas within their natural range or from secondary sources to which they had previously been introduced. In general, species were found to have only become established if they were introduced from similar latitudes of either hemisphere. More than half the total number of species described here are considered to have been introduced to Britain in association with shipping, whilst half of the non-native marine algae found in Britain are believed to have been introduced to Europe in association with deliberate introductions of shellfish for mariculture. Of the species deliberately introduced for aquaculture, only some of the bivalve molluscs have become established in the natural environment beyond the confines of their cultivation.

The different aspects of the biology and etiology of non-natives are discussed in relation to determining their presence and monitoring their distribution, and developing ways of avoiding further introductions.

Part 2 of the review, the directory of non-native marine species, was also provided as a series of web-pages; a few new species were also added subsequent to publication of the review. This information can be found in The National Archives; the species are split into Flora and Fauna.