Loggerhead turtles reach maturity at about 35 years, but can live 50 years or more. Females lay about four clutches of eggs during the nesting season, each with 100-120 eggs. When the hatchlings emerge from the nests, they quickly move across the beach to the surf and swim offshore. Post-hatchling and juvenile loggerheads can travel great distances to reach food-rich coastal areas, where they remain until they mature. Adults return to nest at the beach where they hatched, known as the natal beach. The North Pacific population of loggerhead turtles in Southern California waters are juveniles that crossed the entire Pacific Ocean from natal beaches in Japan. They migrate back to natal beaches to nest and then remain in the Western Pacific Ocean as adults.
Strandings of loggerheads are rare events along the Pacific coast of North America. Since 1980, approximately 60 reports of stranded loggerheads have been recorded for the U.S. west coast and Alaska. Most stranded animals were found south of Point Conception within the northern extent of the Southern California Bight. The causes were largely undetermined, although entrainment in coastal power plants, entanglement in marine debris and fishing gear, and health-related incidents have been reported.
The unintentional capture of loggerheads during commercial fishing activities, or bycatch, has been documented off the U.S. West Coast only for the California large-mesh drift gillnet fishery that targets swordfish and thresher sharks. Since the federal observer program began documenting protected species interactions in this fishery in 1990, 16 observations of bycaught loggerheads have been recorded. All of the interactions took place south of Point Conception, and the loggerheads taken were most likely early and late oceanic stage juveniles.
The loggerhead turtle was listed under the Endangered Species Act (ESA) as threatened throughout its range on 28 July 1978. Following a review by the National Marine Fisheries Service and the U.S. Fish and Wildlife Service, 9 distinct population segments were identified. In 2011, five of these populations were reclassified as endangered under the ESA. This includes the North Pacific population, which ranges from the East China Sea to the waters off California and Mexico.
The California drift gillnet (DGN) fishery for swordfish and thresher shark is federally managed under the Federal Fishery Management Plan for U.S. West Coast Fisheries for Highly Migratory Species (HMS FMP), implemented in 2004. The fishery is also managed by California and Oregon via regulations to conserve target and non-target species. A drift gillnet is an unanchored panel of stretched mesh (14 inches or greater) suspended vertically in the water by floats along the top and weights along the bottom. Regulations require large mesh drift gillnet fishing off the West Coast to be equipped with acoustic pingers and extenders (> 36 ft. buoy lines to protect marine mammals).
The DGN fishery has been subject to a number of seasonal closures. Since 1982, it has been closed inside the entire U.S. West Coast exclusive economic zone (EEZ) from February 1 to April 30 of each year. In 1986, a closure was established within 75 miles of the California mainland from June 1 through Aug 14 of each year to conserve common thresher sharks; this closure was extended to include May in 1990 and later years.
NOAA Fisheries designated two Pacific sea turtle conservation areas off the U.S. West Coast with seasonal restrictions on the DGN fishery to protect endangered sea turtles. The larger of the two conservation areas, created in 2001, spans the EEZ north of Point Conception, CA (34°27’ N. latitude) to mid-Oregon (45° N. latitude) and west to 129° W. longitude. DGN fishing is prohibited annually within this conservation area from August 15 to November 15 to protect leatherback sea turtles. A smaller conservation area located south of Point Conception, CA, and east of 120° W. longitude was created in 2003, and amended in 2007, to protect Pacific loggerhead turtles (Federal Register 72 FR 31756). Within this conservation area, fishing with DGN gear is prohibited from June 1 – August 31 of each year during a forecasted or occurring El Niño event. DGN closures have been implemented three times, in 2014, 2015, and 2016, since the creation of the Pacific loggerhead conservation area.
The number of active vessels in the DGN fishery has remained under 50 vessels since 2003, and there has been an average of 20 active vessels per year from 2010 through 2015. Since 1990, NMFS has targeted 20 percent observer coverage of the DGN fishery each year, per recommendations from the Southwest Fisheries Science Center. The NMFS fleet-wide observer coverage target has been 30 percent since 2013. Since some DGN vessels are unobservable due to safety or accommodations requirements, the observable vessels are observed at a rate higher than 30 percent to attain the fleet-wide 30 percent coverage. Four to six DGN vessels have been unobservable during each fishing season from 2011 to present.