or increasing effort in the core albacore fishing grounds is likely to result in further declines in albacore biomass. All of the tuna Regional Fisheries Management Organizations noted that there is uncertainty surrounding the life history and biology of tunas and tuna like species including age and growth, maturity, and natural mortality rates; uncertainty about the quality and completeness of available data; and uncertainty about recruitment. The WCPFC has assessed the South Pacific Albacore are not overfished. In the 2014 assessment, the International Scientific Committee for Tuna and Tuna-like Species in North Pacific Ocean (ISC), Albacore Working Group (ALBWG), found estimates of total stock biomass (age-1 and older) show a long-term decline from the early 1970s to 1990 followed by a recovery through the 1990s and subsequent fluctuations without trend in the 2000s. The ALBWG concludes that the stock is likely not in an overfished condition at present. South Pacific albacore stocks have recently (2007 to 2015) shown a 40% reduction in stock. Population genomic research supports the distinction of separate North and South Pacific stocks, but results indicated that interbreeding occurs between these populations and some potential migrants were genetically identified. Other organizations A number of programs have been developed to help consumers identify and support responsible and sustainable fisheries. Perhaps the most widely accepted of these programs is that of the Marine Stewardship Council (MSC). Several albacore fisheries have been certified as sustainable according to MSC standards, including the U.S. North and South Pacific albacore pole and line and troll/jig fisheries ("pole and troll"), Canadian North Pacific troll fishery, and the New Zealand South Pacific troll fishery. SeaChoice ranks albacore as a "best choice" for consumers, although notes some "moderate concerns" regarding the management effectiveness (in particular, no definitive assessment of the albacore stock of the Indian Ocean fishery has taken place), and "moderate concern" over the fishing stock, especially regarding the North Atlantic albacore population, which the National Marine Fisheries Service (NMFS) considers overfished with overfishing still occurring. In 2007, SeaChoice considered the southern Atlantic stock to be overfished but not currently experiencing overfishing. They regarded North Pacific albacore stocks as not overfished and not likely to be experiencing overfishing. Mercury levels Like other fish, albacore accumulate methylmercury in body tissue over time. Methylmercury is removed from the human body naturally, but it may take over a year for the levels to drop significantly. Thus, it may