Monday, December 21, 2009

Stellar Sea Lions

Also known as, the Northern sea lion, the Stellar sea lion is the largest member of the Otariidae family. Its eastern Pacific population is listed as threatened.

Size: Males weigh up to 2,400 pounds and measure up to 11 feet in length; are much larger than females, especially in head, neck and shoulders. Females weigh up to 770 pounds and are seven to nine feet in length.

Description: Mature animals are light buff to reddish brown with furless flippers that appear brown or black. Males have manes resembling lion manes of long hairs extending from the back of their heads over their necks and shoulders.

Habitat: Range restricted to North Pacific Ocean and Southern Bering Sea. 2,000 estimated to live along Oregon coast. Found in coastal waters when foraging and migrating, but rarely in bays or rivers.

Behavior: Usually haul out on rocky reefs, gravel beaches; in some areas, may haul out on sandy beaches and onto sea ice in Bering Sea. For fear of losing harem of females, dominant mature males go hungry rather than leave territories during May-July breeding season to eat. Make roaring, lion-like noises.

Wednesday, December 2, 2009

Sportfishing (Rockfish)

Rockfish are a diversere and important group of marine fishes. Of 115 species of rockfish known world wide 97 of those can be found in the North Eastern Pacific. (In a range from Mexico to the Bering Sea). Their habitats vary in depth from very shallow tidal waters to thousands of feet deep. For that reason only about a dozen are within reach of hook and line fishers.

These fish are characterized by bony plates or spines on the head and body, a large mouth and pelvic fins attached forward near the pectoral fins. The spines are venomous and although not extremely toxic can still cause pain and infection. Some species are brightly colored and many others are difficult to distinguish from each other. Rockfishes are some what perch or bass-like in appearance and are often called seabass. All species have white flesh that is delicious to eat.

Also, rockfish have a type of swim bladder that uses a special gas-producing and absorbing gland to change the volume of gas in the swim bladder, which is used to maintain buoyancy at different depths in the water. This type of swim bladder is easily damaged when a fish is subjected to sudden changes in water pressure, such as when it is brought to the surface. The gas gland does not have enough time to absorb the gas in the swim bladder as the gas expands with a decrease in water pressure. Consequently, the swim bladder gets so large that it is too large for the fish's body cavity and it literally explodes out through the mouth of the rockfish. Countless rockfish are wasted when they are caught incidentally by fishers seeking other fish and are thrown back in the water.

Rockfish in our area can be divided into three ecological groups: shelf demersal, or those species that live in the nearshore, shallower waters, in rocky bottom areas shelf pelagic, or those species that also live mostly in the nearshore, shallower continental shelf waters, but that spend much of their time up in the water column and off the bottom, and slope, or those species that live in deeper waters, on the edge of the continental shelf.

Rockfish are extremely slow growing Rockfishes are slow-growing and extremely long-lived. Black rockfishes (Sebastes melanops), a common pelagic species, become sexually mature at about 10 years of age and have been aged to 40 years. Yelloweye rockfish( Sebastes ruberrimus), a shelf demersal rockfish, are a longer-lived species, becoming sexually mature around 15 years of age and living in excess of 100 years. There have been unconfirmed ages of fish at 114 years.

All rockfish, or species of the genus Sebastes, are ovoviviparous. This means that these fish give birth to live young after internal fertilization.

Food habits: Rockfish feed on a variety of food items. Juveniles eat primarily plankton, such as small crustaceans and copepods, as well as fish eggs. Larger rockfish eat fish such as sand lance, herring, and small rockfish, as well as crustaceans.

Species common to our area: Black, Blue, Quillback, Copper, Tiger Stripe, Vermilion, Canary, Yelloweye, Widow, Olive (or Yellowtail).

Yelloweye and Canary Rockfish are endangered and are not allowed to be retained.

More information to come on the other fisheries, Ling Cod, Halibut, Salmon, Tuna etc.