identified at Pebble include pyrite, chalcopyrite, molybdenite, and bornite, along with minor covellite, chalcocite, digenite and magnetite. Resources In 2008, Pebble was estimated to be the second-largest ore deposit of its type in the world in terms of the value of the contained metal, slightly smaller than Indonesia's Grasberg Mine, which contains more metal in a smaller amount of ore than Pebble. The last resource estimate for Pebble, as at December 2017, was a measured and indicated resource of 6.46 billion tonnes of ore grading 0.40% copper, 0.34 g/t gold, 1.7 g/t silver and 240 ppm molybdenum. Contained metals in the resource (at 100% recovery) were 56.9 billion pounds of copper, 70.6 million troy ounces of gold, 3.4 billion pounds of molybdenum and 344 million ounces of silver. The estimate used a 0.3% copper equivalent cutoff. As of August 2021 gross value of the contained metals, 57% was from copper, and 27% from gold and 14% from molybdenum. Co-products including silver, rhenium, and palladium might also be recoverable. Fisheries All five Eastern Pacific salmon species spawn in Bristol Bay's freshwater tributaries. The bay is home to the world's largest commercial sockeye salmon fishery. The Kvichak River has the world's single largest sockeye run. The Kvichak drains from Lake Iliamna, which is downstream of the deposit. Salmon, herring and other fisheries account for nearly 75% of local jobs. Sport fishing is another important local industry. Many lodges cater for sport fishermen exploiting the salmon and trout populations in the freshwater tributaries. Freshwater species include humpback whitefish (Coregonus pidschianpp), Dolly Varden trout (Salvelinus malma), arctic grayling (Thymallus arcticus) and rainbow trout (Oncorhynchus mykiss). Seasonal harvesting of salmon and year-round harvesting of freshwater fish is a critical part of life for rural residents, most of whom live downstream of the mine site. Human populations The Pebble site is within Lake and Peninsula Borough, about 1,600 inhabitants as of United States Census, 2010, adjacent to the Bristol Bay Borough of about 1000 inhabitants and the Dillingham Census Area, 4,800 inhabitants. Some 7,500 people live largely rural lifestyles within or near the area downstream of the Pebble site. The populations of Lake Clark National Park and other parts of the Bethel Census Area are upstream of the site or in a different watershed. The populations in the area rely heavily on wild resources for subsistence, harvesting moose, caribou and salmon. Wild resources play an important