Basin-scale patterns of mtDNA differentiation and gene flow in the bay scallopArgopecten irradians concentricus

• Published in: Marine ecology. Progress series (Halstenbek) 2007-11, Vol.349, p.139-150
• Main Authors: Marko, Peter B., Barr, Kelly R.
• Format: Article
• Language: English
• Subjects: Bays; Gene flow; Haplotypes; Inlets; Larvae; Mitochondrial DNA; Population genetics; Population migration; Scallops; Straits
• ISSN: 0171-8630; 1616-1599

The bay scallopArgopecten irradians concentricusSay is a commercially and recreationally important species along the East Coast of the US that consistently shows evidence of recruitment limitation. To determine if limited planktonic larval exchange between populations inhabiting lagoonal basins or sounds contributes to recruitment limitation in central North Carolina, a hypervariable portion of mtDNA (885 bp) was sequenced from 219 adults from 4 sounds (Topsail, Bogue, Back, and Pamlico), 3 of which (Bogue, Back, and Pamlico) are connected by inshore waterways. Although the largest sound (Pamlico) harbored the greatest genetic diversity, diversity was high in all 4 sounds, with no evidence of recent bottlenecks. An analysis of molecular variance indicates significant genetic structure among sounds (ϕCT= 0.0069, p = 0.023); all pairwise comparisons among sounds were significant, with the exception of those involving Pamlico Sound. Despite being connected by a short (3 km) inshore waterway, adjacent Bogue and Back Sounds were highly significantly differentiated (ϕCT= 0.0145, p = 0.000). Coalescent-based estimates of gene flow indicated that most sounds exchange ≤4 migrants each generation. Bogue and Back Sound populations, which were heavily impacted by a localized red tide outbreak in 1987 and which subsequently experienced a recruitment failure, each receive