To ask the Secretary of State for Environment, Food and Rural Affairs what estimate his Department has made of the percentage change in levels of (a) tuna and (b) cod stocks in UK waters in each year since 1997. (279353)

Tuna stocks are distributed throughout the Atlantic. No stocks of tuna are found exclusively within UK waters. Only a small percentage of the distribution of the northern albacore and the east Atlantic and Mediterranean bluefin tuna stocks are located within UK waters—to the west of Scotland and in the Celtic sea.

Tuna stocks are assessed by the International Commission for the Conservation of Atlantic Tunas (ICCAT). ICCAT have not published absolute values for the stock biomass so that comparisons with historic estimates cannot be made. However, ICCAT does classify stock biomass levels relative to internationally agreed sustainable targets for biomass (BMSY—biomass at maximum sustainable yield) and exploitation rate (FMSY—fishing mortality at maximum sustainable yield).

For Northern albacore tuna, the most recent ICCAT assessment of stock status for northern albacore tuna was conducted in 2007¹. ICCAT considers that spawning stock size in 2005 was about one quarter of the peak levels estimated for the late 1940s. The analysis indicated that in 2005 the stock has rebuilt to 20 per cent. below the biomass expected at the optimum level for exploitation, compared to 50 per cent. below in 2000.

For East Atlantic and Mediterranean bluefin tuna, the most recent ICCAT assessment of stock status for the east Atlantic and Mediterranean bluefin tuna stock was conducted in 2008². Analysis indicates that recent (2003-07) spawning biomass is less than 40 per cent. of the highest estimated levels.

Cod stocks are distributed throughout the North East Atlantic in the waters that surround the UK. No stocks of cod are found exclusively within UK waters. The stocks are considered separate biological units and are usually referred to by geographic region; North sea Skagerrak and eastern English channel, West of Scotland, Rockall, Irish sea, Celtic sea and western English channel.

Cod stocks are assessed annually by the International Council for the Exploration of the Sea (ICES). The most recent ICES advice was issued in 2008. For each cod stock the change in the level of spawning biomass in each year since 1997 is presented in table 1:

¹ http://www.iccat.int/Documents/SCRS/ExecSum/ALB_EN.pdf

² http://www.iccat.int/Documents/SCRS/ExecSum/BFT_EN.pdf