Survey of Oceanography

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32NektonanIntroductione.pptx

Nekton an Introduction

By: John Van Leer

November 19, 2020

The great whales are divided into toothed whales, like the Killer whales and baleen whales, who filter feed like Hump-Back whales.

The Blue whales are thought to be the biggest animals to ever live.

Dolphins acoustically locate prey.

A few Whale Characteristics

Recent Population Estimates

A harpoon gun is seen mounted on the bow of an Inuit owned ship in Ilulissat Harbor in Western Greenland. The International Whaling Commission allows 11 bowhead whales to be taken each year in Greenland.

Bowhead Skull in Barrow Alaska

Proud Whaling Captain and former mayor of Barrow, Alaska.

Model Bowhead hangs at the Heritage Center in Barrow showing the typical white chin markings. Painting of an Umiaq hunting Bowhead in Barrow.

Hunter in the bow is preparing to strike a bowhead with his harpoon. Bowhead baleen seen below the painting.

Tour guide reaches for harpoon which is resting atop an Umiaq frame.

30’ skin boat called an Umiaq used for whaling in Barrow Alaska, hunting Bowhead is easy to haul across the pack ice and is much quieter than modern designs.

Waterproof stitching is difficult to do.

Interior shows framing detail.

Narwhals are favorite prey items for killer whales, who sometimes hunt cooperatively with the Inuit. As killer whale range expands with retreating sea ice, the narwhals are in serious trouble.

Polar Bears are marine mammals which are increasingly threatened by global warming and loss of sea ice, while Killer whales have an growing ice-free territory to hunt.

More marine mammals with flippers instead of feet, except the sea otter, which was hunted nearly to extinction.

Walruses are also mammals which are loosing sea ice to pup on and to rest on while being carried to new shallow feeding areas. If they must live ashore, they quickly exhaust the local shellfish resources.

Manatees are marine mammals native to Florida and much of the Caribbean, while the Dugong is native to Asian waters.

Sea Birds range from penguins and pelicans to turns and seagulls.

Marine reptiles.

Fish with cartilage skeletons are some of the most ancient and sucessful species. Basking shark and Manta ray filter feed.

Squid are among the most abundant Nekton. Giant squid can grow to 50’.

Reef fishes and a moray eel.

Boney fishes have been extremely sucessful, until factory fishing began.

Annual anchovy catch show wide variations due to El Nino and other factors.