Genetic Escapes

Genetic escapees are fish or invertebrate species that are non-native, or have been selectively bred or genetically modified, and have escaped from mariculture enclosures.

Escapees pose a threat to ecological and socioeconomic stability as they may cause “biological pollution” within an ecosystem. Non-native species, if accidentally released, may compete with or prey upon native species, eventually driving them to extinction. Even if native species are cultivated, they are often bred to emphasize traits that may outcompete local wild populations, including disease resistance, high growth rate, and decreased spawning activity. The release of these modified breeds may reduce the presence of native populations through competition or, if they interbreed, by diluting the native genotypes, or by causing the spread of foreign parasites.

Improving standards for containment methods, limiting the cultivation of exotic species, and restricting mariculture to sterile populations may effectively minimize the risk of genetic escapes.

Which Goals Does This Affect?

How Was It Measured?

Genetic escapes represent the potential for harmful genetic escapement based on whether the species being cultured is native or introduced. Data came from the Mariculture Sustainability Index (MSI), which reports data for 359 country-species combinations (53 countries represented). In the MSI analysis, negative species received the highest score (10), while foreign and introduced species received the lowest (1), based upon the premise of potential impacts to local biodiversity if these species were to escape. Uses of native but non-local species were scored intermediately, based upon the assumption that potentially negative alterations to genetic biodiversity can occur from non-local sources, but to a lesser degree. Where multiple scores exist for a country the weighted average of all scores (0-10) was used. All country scores were rescaled from 0 to 1, using the maximum raw score of 10 and minimum of 1.

What Has Been Done?


PHOTO(S): © Keith A. Ellenbogen
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