Chapter 4
Detrimental Genetic Effects of Interactions
Between Reared Strains and Wild Populations
of Marine and Anadromous Fish
and Invertebrate Species
T.F. Cross
1,
*, G. Burnell
1
, J. Coughlan
1 , S. Culloty
1 , E. Dillane
1
,
P. McGinnity
2 , and E. Rogan
1
Abstract Cultured strains of marine and anadromous species reared for aquaculture
can be either inadvertently (as in farm escapes) or deliberately (as in stocking/
ranching) introduced into the wild, where they may interact with wild conspecifics
or other species. This chapter concentrates on the potentially detrimental genetic
aspects of these interactions, largely in the context of species cultured in Europe
but considering general principles, which have worldwide applicability. Most
previous experimental work in the area has involved Atlantic salmon, which has
the highest production of any finfish produced in Europe. These investigations have
shown generally detrimental results for wild salmon populations, when interactions
occur with reared strains. The various European species which might be affected
by cultured introgressions (the major aquaculture species) are then considered
under several headings: genetic composition of cultured strains compared with
wild populations; modes of introduction into the wild; direct and indirect genetic
interactions with wild populations/species; consequences of such interactions;
establishing the severity of effects of wild/reared interactions with different species, utilising opportunist situations and field experiments; and, methods such as
induction of sterility in reared strains to reduce detrimental effects. Relative risks
for wild populations of the major aquaculture species are then considered, and
general and specific genetic recommendations are presented.
Keywords Conservation of biodiversity, genetic interactions, molecular methods,
reared strains, wild populations
1 Department of Zoology, Ecology and Plant Science/Aquaculture and Fisheries Development
Centre, University College Cork, Ireland. Tel: + 353–21–4904652; Fax: + 353–21–4904664;
E-mail: t.cross@ucc.ie
2 Marine Institute, Aquaculture and Catchment Management Services, Newport, County Mayo,
Ireland
*Correspondence: t.cross@ucc.ie
M. Holmer et al. (eds.), Aquaculture in the Ecosystem.
117
© 2008 Springer
Detrimental Genetic Effects of Interactions
Between Reared Strains and Wild Populations
of Marine and Anadromous Fish
and Invertebrate Species
T.F. Cross
1,
*, G. Burnell
1
, J. Coughlan
1 , S. Culloty
1 , E. Dillane
1
,
P. McGinnity
2 , and E. Rogan
1
Abstract Cultured strains of marine and anadromous species reared for aquaculture
can be either inadvertently (as in farm escapes) or deliberately (as in stocking/
ranching) introduced into the wild, where they may interact with wild conspecifics
or other species. This chapter concentrates on the potentially detrimental genetic
aspects of these interactions, largely in the context of species cultured in Europe
but considering general principles, which have worldwide applicability. Most
previous experimental work in the area has involved Atlantic salmon, which has
the highest production of any finfish produced in Europe. These investigations have
shown generally detrimental results for wild salmon populations, when interactions
occur with reared strains. The various European species which might be affected
by cultured introgressions (the major aquaculture species) are then considered
under several headings: genetic composition of cultured strains compared with
wild populations; modes of introduction into the wild; direct and indirect genetic
interactions with wild populations/species; consequences of such interactions;
establishing the severity of effects of wild/reared interactions with different species, utilising opportunist situations and field experiments; and, methods such as
induction of sterility in reared strains to reduce detrimental effects. Relative risks
for wild populations of the major aquaculture species are then considered, and
general and specific genetic recommendations are presented.
Keywords Conservation of biodiversity, genetic interactions, molecular methods,
reared strains, wild populations
1 Department of Zoology, Ecology and Plant Science/Aquaculture and Fisheries Development
Centre, University College Cork, Ireland. Tel: + 353–21–4904652; Fax: + 353–21–4904664;
E-mail: t.cross@ucc.ie
2 Marine Institute, Aquaculture and Catchment Management Services, Newport, County Mayo,
Ireland
*Correspondence: t.cross@ucc.ie
M. Holmer et al. (eds.), Aquaculture in the Ecosystem.
117
© 2008 Springer