Shellfish prices paused over the quarter after a strong year. As of 4 November 2026, the family's 14 indexed materials were 0.2% lower on average over three months but 8.6% higher over twelve. Eight rose and six fell. The family's 15 materials run from mussels and oysters to clams, cockles, scallops and sea urchin.
Atlantic deep-sea scallop led the risers at +6.2%. Chilean sea urchin gained 4.6%, Mediterranean mussel 4.2% and mussel 3.9%. Patagonian scallop, Peruvian scallop and Yesso scallop each rose 1.4% and share identical moves, including +8.6% over a year. Razor clam edged up 0.5% over the quarter and is 9.7% higher on the year.
Clam stands apart, down 17.6% over three months, the family's steepest fall. Elsewhere the declines were modest: oysters -3.5%, surf clam -2.1% and Chilean mussel -1.9%. Every indexed shellfish line remains higher than a year ago, led by Chilean mussel at +17.7% and cockle at +16.9%.
Market notes point to production problems. French mussel production was reported sharply down over the summer on 14 September, with heatwaves, declining nutrients and sea-spider attacks cited. On 23 October, riots in France and a transport strike in Italy were reported to have hit mussel exports from Galicia.
The clam note, dated 6 October, describes a poor start to the Arousa estuary harvest on 1 October, with few boats and low prices, and scarce red clam catches there by 5 October.
In the Bay of Saint-Brieuc, the stock of marketable-size cockles was described as severely deteriorating on 21 October. In Normandy, the king scallop grounds opened on 1 October with fewer shells than expected and a declining resource, while the Bay of Saint-Brieuc scallop campaign began the same day.