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Salmon Sharks & Local Strandings. Photo: Delvin. Wade D. Smith. Sharks are a diverse group of fishes. Biological Traits. Slow growth Long life spans Few offspring Accustom to few natural predators Combined, these traits = low potential for population growth & resilience. Spiny dogfish.
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Salmon Sharks & Local Strandings Photo: Delvin Wade D. Smith
Biological Traits Slow growth Long life spans Few offspring Accustom to few natural predators Combined, these traits = low potential for population growth & resilience
Spiny dogfish Squalus acanthias May live to 100 years Doesn’t reproduce until reaching 20 or more years of age
Salmon Sharks – Lamna ditropis Predominant predatory fish in the North Pacific Along our coast, salmon sharks are found from Alaska to Baja California
White Sharks & Salmon Sharks White Shark Salmon Shark
Salmon Sharks – Lamna ditropis Average size: 6-8 feet, maximum 12 ft. Mature at 8-10 years (females) 5 years (males) Females give birth to 2-5 pups each year May live to at least 30 years
Warm-bodied Sharks Able to maintain body temperature as high as 13°C above water temperature
Warm-bodied Sharks Wide range of prey: salmon, herring sablefish, dogfish, squid
Tagging & Tracking Salmon Sharks Ongoing research by Alaska Dept. of Fish & Game, Stanford University (Hopkins Marine Station), and Tagging of Pacific Pelagics program
Tagging & Tracking Salmon Sharks Prince William Sound
Tagging & Tracking Salmon Sharks Weng et al. (2008) Each point = daily position Wide range of habitats used
Tagging & Tracking Salmon Sharks Seasonal tracks of 34 sharks Weng et al. (2008)
Salmon Shark Movements Adult male & female sharks tend to segregate
Salmon Shark Nursery Grounds Salmon sharks born in late spring – early summer off BC, WA, OR & CA coasts
Salmon Shark “Strandings” Dead or dying young salmon sharks often wash up on beaches along their nursery grounds
Thanks to: Aaron Carlisle & Ken Goldman TOPP: http://www.topp.org/species/salmon_shark