Northwest Airboats
"Willapa Bay- its secrets revealed."
Willapa Bay Charters- Fishing like it used to be.
- From 'Great White Sharks' by Richard Ellis and John E. McCosker 1991
Factoid #1: Sharks can find prey by following the electrical impulses that animals emit, and some species of sharks can smell a drop of blood in one million drops of seawater.
Those who think of sharks as something only found in tropical waters will be surprised to learn that there are 18 species of sharks in the cool waters of the Pacific Northwest, from the 27-inch brown cat shark to the 39-foot basking shark.
Oh and yes, and the Great White Shark
If that sparked your interested, you'll need to learn a little bit and meet a few Pacific Coast residents that you'll be coming across like the Salmon Shark, Six and Seven Gill, Thresher and maybe even Mr. Great White to name just a few.! After all, sharks are the biggest and baddest fish in the ocean, and inside the waters of Willapa Bay has the best shark habitat in the world.
Two sensory packages, the nasal lamellae and the ampullae of Lorenzini, have evolved over millions of years into detection systems for the very things that make prey more attractive to our friend - blood, indicating that something is injured and thus; easier to catch. This also tells them where their prey is and what state it might be in when the shark arrives.
1. Dorsal fin
2. Pectoral fins
THRESHER SHARK
The thresher shark, Alopias vulpinus, also called the thin tail thresher, is easily recognizable because of its long caudal fin which equals about half the total length of its body. This awesome shark also has a characteristic dorsal fin and pelvic fins. Color varies from metallic brown to blue on the dorsal side and white on the ventral side. It reportedly stuns prey with blows from its powerful tail. Thresher sharks inhabit temperate waters worldwide. Threshers prefer cool pelagic waters but will wander into coastal areas as well in pursuit of fish. Juvenile threshers are often found close inshore and in shallow bays.
BIG SKATE
The big skate is found along the coast in estuaries, bays, and over the continental shelf. Although this skate is sometimes observed in low stands of kelp, it is more common on sandy and muddy bottoms. It is usually seen hiding motionless in the bottom sediments with only eyes protruding, camouflaged from potential predators. When it does move, swimming occurs by the undulation of the pectoral fins, which makes the skate appear as though it is "flying" gracefully through the water.The big skate has a flattened diamond-shaped body with a stiff snout tapering to a blunt point. The small eyes are positioned on the dorsal surface some distance from the pointed snout with large spiracles just posterior to the eyes.Aptly named the "big" skate, this species is the largest skate in North American waters. The maximum reported size of the big skate is 7.9 feet total length, however this species usually does not reach lengths beyond 6 feet and weights of 200 pounds. Males reach maturity at approximately 7-8 years of age and lengths of 3.2-3.6 feet; females mature at about 12-13 years of age and lengths of 4.3-4.6 feet. Large predatory bony fishes and sharks consume big skates. One such documented predator is the sevengill sharkNotorynchus cepedianus). The egg capsules are sometimes eaten by elephant seals.The pectoral fins are sometimes marketed as "skate wings" and presumably as scallops (punched from the pectoral fins,) the flesh of skates is used in baking, chowders and fillets.
Washington State Sharks
Salmon sharks (Lamna ditropis) are large, powerful and streamlined predator adapted for high-speed swimming. Reports from the U.S. Navy have clocked salmon sharks exceeding 50 knots. This would make the salmon shark one of the fastest fish in the ocean! Salmon sharks inhabit coastal and oceanic waters of the northern Pacific Ocean.
They are reported to reach 11.9 feet in total length. Salmon sharks in the 700 pound range have been reported by sport fishermen in Alaska. The salmon shark is a member of the Lamnidae family of sharks which includes the great white shark.
Salmon sharks are opportunistic predators that feed on a wide variety of prey. Their primary prey is Pacific salmon, Pacific herring, capelin, pollock, and sablefish. They have been seen taking other prey including sea otters and marine birds. Salmon sharks are seen as direct competitors for several commercially important species including salmon, sablefish, and herring. In 1989, the abundance of salmon sharks in the northwestern Pacific was estimated to be at least 2,000,000 fish. Of these, 595,000 salmon sharks were age 5 years or older and inhabitant sub-arctic waters. The author of the paper, Nagasawa, estimated these salmon sharks could consume between 76,000,000 and 146,000,000 salmon per year. That's about to 25.2% of the total annual run of Pacific salmon (Nagasawa 1998).
The dramatic increase in salmon shark observations in some north west waters during the 1990's is unprecedented. The predation effect of so many salmon sharks may appear only as random salmon run failures. Nearly every year the northwest waters experiences unexpected run failures. Further research may reveal the importance of these predators and the part they play in the North Pacific Ocean.
Bluntnose sixgill & seven gill sharks (Hexanchus griseus & Notorynchus cepedianus) are found world-wide. A seasonal phenomenon (exclusive to the Pacific Northwest) coincides with our summer plankton blooms allows the light-sensitive sharks to come into the shallows to benefit from the local salmon and herring runs. It also appears to be part of the shark’s mating and birthing patterns. Newborns are often found in shallow waters in the summer and early fall.
Its length is up to 14 feet, although FishBase accepts that it could possibly reach 21 ft. In 1990, an enormous Pacific sleeper shark was attracted to a bait in deep water outside Tokyo Bay, Japan and filmed. The shark was estimated by Eugenie Clark to be about 23 ft.
