Oceanography Test 7

Gray Whale Eschrichtius robustus

- 16 meters (52 ft) - Weight of 36 tonnes - Lives 50 - 60 years 2 populations -- Eastern North Pacific Population (along the coast of Russia and China) ~20,000 - 22,000 -- Western North Pacific (along the western coast of the US and Canada up to Alaska) - ranked as endangered, only ~100 - Because they were hunted to extinction in the North Atlantic in the 18th century

Right Whale

- Adults 13-18m - 60 tons - Females larger than males - Diet: zooplankton, primarily copepods. Feed by skimming through dense concentration of prey with mouth open --> Right whales are affected by noise pollution, noise that's made by humans near the sea

Fin Whale

- Adults 17-24 m - ~70 tons - At birth approx 6.5m, 2 tons - Diet: Variety of small schooling fish (herring, capclin, sand lance), squid and planktonic crustaceans. Gulp large swarms often by swimming on their right side. -- They have 6 second feeding - it carries the whale some 35 feet and they collect as much as 25 pounds of shrimp like krill -- The volume of water the fin whale engulfs is about the size of a school bus

The Humpback Whale

- Adults range in length from 39-52 feet and weigh approximately 36,000 kg - They fish in a very different way

Sei Whale Balaenoptera borealis

- Adults to 18m - 30 tons - Females slightly larger than males - At birth approx 4.5 m --> Diet: primarily copepods and euphausids. Skim through schools of crustaceans, often leaving trail of bubbles just prior to surfacing

Blue Whale Balaenoptera musculus

- Diet: zooplankton, primarily krill (euphausids) - May consume an estimated 4 tons per day during peak summer feeding period

Cetacea

- Elongated (telescope skull) - Blowholes on top of the skull --- (Mammals they need to breathe oxygen) - Very few hairs - Horizontal tail fin - Swim fast because they have an elongated body, skin - Deep diving

Seabirds Characteristics

- Endotherms (warm blooded) - Feathers - Hollow bones -- Allows them to fly - Highly efficient respiratory system - Lay eggs on land -- Even though they're sea birds they have to come back to land to lay their eggs - Incubate and care for young -- Characteristics of birds in general

Northern Fur Seal - Callorhinus ursinus

- Found throughout the northern Pacific - Solitary, except when mating or nursing young - Remain in the water except for mating - Eats most types of fish - Have extremely long hind flippers - Only 15 in captivity

Seals Found Around Boston

- Harbor Seal - Harp Seal - Hooded Seal - Gray Seal - Ringed Seal

Deep Diving

- Herbert Nitsch - 702 ft (214m) - Egypt's Ahmed Gabr ~1090 feet - 12 minutes to get down, 14 hours to get to surface again

Leopard Seal (Hydrurga leptonyx) → 2nd largest species of seal

- Keystone predators (sea otters, and kelp are as well), very important to the overall ecosystem - Second largest species of seal in the Antarctic (after the Southern Elephant Seal), and is near the top of the Antarctic food chain -- Leopard seal is highly evolved for its role as keystone predator -- Although it is a true seal and swims with its hind limbs, it has powerful and highly developed forelimbs similar to sea lions, giving it a similar maneuverability, a classical example of convergent evolution - Like these eared seals, the Leopard Seal is a shallow water hunter, and does not dive deep like other seals of the Antarctic (the Weddell seal, the Ross seal and the two species of elephant seals) which can all dive to several hundred meters in search of squid. → have been known to eat humans - It also has an unusually loose jaw that can open more than 160 degrees allowing it to bite larger prey -- Kind of like a snake

Whale Lice

- Large scaly gray-white patches on their skin, whose patterns are unique from animal to animal - Colonies of crustaceans known as whale lice which can exist in the tens of thousands up on each whale - The parasitic creatures subsist on algae and dead skin, and while they are irritants, they do not cause significant harm to the whale.

Baleen Whales (Mysticeti)

- Larger (15m to 30m long) - Often solitary - Long annual migrations - Feed on aggregations of krill, copepods, small fish - Use sound only to communicate

Mysticeti

- No teeth - Two blow holes - Baleen - made of keratin (like our hair and nails) - Includes the largest whales

California Sea Lion (Zalophus californianus)

- Opportunistic feeders - Found in the Western Pacific (California south to the Galapagos) - Incredibly common (found in groups of hundreds) - Can be territorial during breeding season (the ones that usually do tricks with the ball in the air) - Often found in aquariums for shows - Migrate seasonally -- Weigh in at 390 kg and about 8 ft

Three Orders

1. Carnivora -Pinniped 2. Sirenia 3. Cetacea (Whales) -Odontoceti -Mysticeti

Definition of Mammal

1. Warm blooded 2. Breathe air 3. Have hair or fur at some stage of development 4. Bear live young 5. Females have mammary glands that produce milk --> Approximately 116 species of marine mammals

Adaptations for Marine Life

Like marine reptiles, seabirds have special salt-excreting glands in their heads to eliminate the excess salt taken in with their food Voracious feeders - They eat a ton True seabirds avoid land unless breeding

Penguins

Lost ability to fly Solid bones Greasy peg-like feathers Large size and weight Neutral buoyancy Good swimmers Native to southern hemisphere

Narwhal

Males avg ~ 4.1 m Females avg ~ 3.5m ~800 - 1600kg -- Greenland halibut, polar and Arctic cod, cuttlefish, shrimp and squid What is their horn for? --Their horn is actually a tooth - Both males and females can have them, but males tend to have them more -- So many people don't know they're seeing a narwhal because the tooth can fall off - There are lots of theories for what this tooth is and what it's for -- narwhal of different temperature and salinity, their temperature changes - It's a tooth... hard parts in the middle, soft parts on the outside, very sensitive. Maybe used for sensing environmental conditions (i.e. temp, salinity, pressure). Only about 15% of females have them. They spiral to the left... some whales have two of them

Killer Whales (Orcinus orca)

Males: 19 to 26 feet long; weigh in excess of 6 ton Females: 16 to 23 feet long - weigh 4 to 5 tonnes (up to 11,000 pounds) -- Fish → Salmon, cod, herring, hake and halibut. They eat surface fish as well as bottom-living fish -- Mammals → Some killer whales eat mammals like seals, sea lions, walruses, baleen whales, other toothed whales and even sea otters -- Birds → Penguins and seabirds -- In some places → some types of sharks and sea rays -- Not frequently → polar bears, some other killer whales ~500 pounds of food per day Up to 60% of their time is spent looking for food There are about 50,000 total world wide (NOAA)

Sirenia

Manatees -- coastal areas of Tropical Atlantic Ocean Dugongs -- tropical Indian and western pacific ocean → only vegetarian marine mammal; shallow water grasses -- Very curious, not super bright -- Manatees have a more bulbous face while dugongs have more of a vacuum face and their tail shape is also different

Offshore

Northeast Pacific was discovered in 1988 when humpback whale researcher Jim Darling observed them in open water Diet - feed primarily in schooling fish. However, because of the large scarred and nickel dorsal fins resembling those of mammal-hunting transients, they may also eat mammals and sharks. They have mostly been encountered off the west coast of Vancouver Island and near the Queen Charlotte Islands Offshores typically congregate in groups of 20 - 75 with occasional sightings of larger groups of up to 200.

Pelicans and their relatives

Pelicans, cormorants, frigate birds, and boobies - Peruvian booby, peruvian pelican Throat pouches Webbed feet

Killer Whales groups

Residents, transients, offshore

Pinnipeds Include:

Seals Sea lions and fur seals Walruses - Pinnipeds "fin-footed" evolved from a terrestrial carnivore - They are predators, feeding mainly on fish and squid - Streamlined bodies for swimming - Thick layer of fat, or blubber for insulation, food reserves, and buoyancy

Seals

Seals (earless pinnipeds; family Phocidae) have 19 representative species - Rear flippers cannot be moved forward - No external ear flap - Claws (and fur) on flippers - Short, robust neck

Gray Whale Migration

Southbound - mid november to mid Feb Northbound, mid feb to mid may - They move up the west coast and spend their summer feeding in the Arctic - Towards the fall, they head back down to spend their wintering grounds towards California and coast of Baja 12,000 mile long, roundtrip journey Distance of 120 km per day at an average speed of 8km/h Was known to have one of the longest migrations of any known mammal, but it was found to be the humpback whale - Used to be called the devil fish because they were aggressive to humans but since we stopped hunting them they've become very friendly

Dolphin

Suborder: Odontoceti - teeth (pointed shaped), single blow hole

Porpoise

Suborder: Odontoceti -- teeth (spade shaped), single blow hole

Gulpers/swallowers (baleen whale group 1)

Swim a bit faster and most feed more intensely to satisfy their food requirements. A meal consists of a series of separate mouthfuls; each time the animal takes in a huge amount of water along with the plankton or fish, then forcefully expels the water through the baleen → Blue whales, fin whales, Bryde's whales, minkes, humpbacks, and infrequently, sei whales

Skimmers (Baleen whales group 2)

Swim very slowly with their mouths open, "filtering constantly until enough food has accumulated on the baleen to be scraped off and swallowed." This category includes right whales, bowheads, and sei whales

Residents

These are the most commonly sighted of the three populations in the coastal waters of the northeast Pacific Diet - consists primarily of fish and sometimes squid, and they live in complex and cohesive family groups called pods They visit the same areas consistently British Columbia and Washington resident populations are amongst the most-intensively studied marine mammals. Researchers have identified and named over 300 killer whales over the past 30 years

Bird groups

Tubenoses, Pelicans and their relatives, Gulls, Penguins

Peru Upwelling

Upwellings happen because there is wind blowing, coriolis is turning the earth so in the southern hemisphere the water is going to move to the left and it comes off the coast and the deep nutrient rich water gets brought upwards to the surface which leads to high amounts of primary production There's a mountain made of bird poop This primary production supports huge bird populations - All the nutrients trapped in the bird poop are from upwelling - It's a mountain of bird guano - The bird poop is preserved and makes these giant mountains Mining guano is still going on today, it is hard work

Benthic feeders (baleen whales group 3)

Vacuum up sediment... eating things Inside... example -- grey whale.

Potential Risk Factors

Vessel disturbance - In their summer range, there is a large whale watching industry and at any given day, you can see anywhere from 20 to 80 whale watch and private boats surrounding these whales Quality and quantity of prey are also considered a potential risk factor. Chinook salmon are their primary prey in the summer, however they do consume other salmonids as well. Lastly, contaminants such as PCBs are considered a risk for this population

Baleen Whales Groups

gulpers/swallowers, skimmers, benthic feeders

Mammals -- are not ideal diving machines

- Pressure -- the deeper you go, the more pressure, and if you come to the surface too fast you get bubbles → "The Bends" (remember at sea level 1 atm pressure = 14.7 lbs per square inch of pressure... another atm is added every 10m, so a 1000m dive, 100x surface pressure) - Oxygen storage - best free divers ~5 min up to 9, most of us less than 1 minute (some marine mammals will stay down 90 minutes or more) - Nitrogen narcosis - too much nitrogen gas dissolved in your blood - causes drunken like conditions, disorienting and eventually toxic - Cold - deep ocean is cold, lose body heat quickly - water conducts heat away from the body 20x faster than air - Float - mammals float easily (makes hard to get to the bottom) --> Sperm whales are the deepest divers of marine mammals --> Over 90 minutes, nearly 10,000 feet

Carnivora

- Prominent canine teeth - Skin covered flippers Examples: Sea otters Polar bears

Southern Elephant Seal

- REALLY BIG - Males are up to 3000 - 4500 kg - Very aggressive - Dive to 1900 m -- Skates, rays, squid, octopuses, eels, small sharks, and large fish -- Very fast and tactile swimmers, and can also move really fast on land ---- It's not uncommon for humans to be attacked by them

Sealions and Fur Seals vs Seals

- Sea lions have a long neck, ability to turn in water - External ear - uses anterior flippers in swimming - anterior flippers rotate backward

Harbor Seal - Phoca vitulina

- Shy and quiet - Only social during mating and resting - Haul out in large groups - Globally distributed - Eat mainly fish

Manatees and Dugong

- Sirenians are the only herbivorous marine mammals; feed on aquatic plants and algae - Some species live in fresh and/or brackish water - Inhabit temperate or subtropical waters - Severely threatened by motor boat collisions, harmful algal blooms, pollution and severe winters

Toothed Whales (odontoceti)

- Smaller (1.5 to 17m long) - Social - Most are not migratory - Chase and capture individual fish, squid, crabs - Use sound to echolocate, communicate → Killer whale, smaller whales, etc

Stellar's Sea Cow (the sirenian you'll never see)

- The Stellar Sea Cow was a large herbivorous marine mammal formerly abundant in the North Pacific - Described by naturalist Wilheim Stellar in 1741; hunted to extinction within 27 years of discovery! -- 8 meters long -- Fed on kelp They were very sweet and curious so it was easy hunting

Sea Otters

- The smallest marine mammal, which lacks a layer of blubber - Instead the sea otter has extremely dense fur, which traps air against the body for insulation -- Hunted extensively for fur nearly to extinction - Found only in the Pacific Ocean and have the densest fur of all animals - They inhabit nearshore environments and dive to the sea floor to forage on mollusks, crustaceans and echinoderms (sea stars and urchins) -- Must eat ~25-30% of their body weight per day - Raft together in big groups - they take kelp and wrap it around their bodies to keep them in place - They are a keystone species

Elephant Seals

- There are 2 species: the Northern Elephant Seal (M. angustirostris) and the Southern Elephant Seal (M. Ieonina). - The Northern Elephant Seal, somewhat smaller than its southern relative, ranges over the Pacific coast of the US, Canada and Mexico - The Southern Elephant Seal is found in the southern hemisphere on islands such as South Georgia, Macquarie Island, and on the coasts of New Zealand, South Africa, and Argentina in the Peninsula Valdes, which is the fourth largest elephant seal colony in the world -- Bulls - 16 ft and a weight of 6000 pounds -- Cows - measure about 10 ft and 2000 pounds -- The largest known bull elephant seal weight 5000 kg and measured 22.5 ft in length -- This makes the elephant seal the largest member of the order Carnivora 80% of its life is spent out in the sea

Polar Bears

- They are semi-aquatic mammals that spend a good deal of their life drifting on sea ice in the Arctic - They feed primarily on seals, which they stalk at breathing holes - World's largest land carnivore Thick blubber; translucent fur, black skin! - Threatened by the loss of Arctic sea ice! - It is the youngest of the eight bear species. Scientists believe that the polar bear evolved about 200,000 years ago from brown bear ancestors - Polar bears range throughout the Arctic in areas where they can hunt seals at open leads. The five polar bear nations where the bears are found include the US (Alaska), Canada, Russia, Greenland and Norway - They are the world's largest non-aquatic predators. They top the food chain in the Arctic, where they prey primarily on seals. - They are perfectly adapted for survival in the Far North. They are well-insulated against the cold, with two layers of fur that include a thick undercoat topped by guard hairs. - They have a superb sense of smell -- They also have excellent hearing and eyesight -- These heightened senses are necessary for survival in the changing conditions of the Arctic -- Current polar bear population is 22 - 31,000 19 distinct sub-populations 60-80% of polar bears are in Canada

Walrus

- Walrus (family Odobenidae) are large pinnipeds with a distinctive pair of tusks -- Both male and female have tusks; can reach 1 meter in length! -- Used for defense, and anchoring onto ice - Strictly Arctic!!! - Benthic-feeder; feeds primarily on clams - Neither a seal nor a sea lion, they have their own group - Found only in the arctic, on shallow-water ice floes - Have tusks up to 1m long - Males can grow to about 3m long - Are usually reddish to a pale grey - Feed mostly on echinoderms

Seabirds History

- We think they evolved from dinosaurs about 160 million years ago because they're birds - They also have scaly legs and claws

How do whales dive so deep?

-- Pressure - many marine mammals have lost external ears and sinuses (sea lions and fur seals do have ears but they fill w/ a bloody fluid when diving - push air out). And - they give a big exhale before diving, removing up to 90% of the air in their lungs -- Oxygen storage - store more O2 in blood and muscles - have more red blood cells, high amounts of hemoglobin in blood and myoglobin in muscles - two molecules that have a high affinity for O2. And they slow their heart rate - the "mammalian diving reflex" -- Decompression Sickness - because they exhale before they dive, no problem. -- Cold - large and sausage shaped - gives them a low surface to volume ratio, less skin exposed to water. And they have blubber... -- Buoyancy - exhale air out of lungs, makes them less buoyant

Tubenoses

Albatrosses, petrels Most oceanic Large efficient wings Plumbing in beak responsible for - Sensing air speed - Detecting smells - Disposing of excess salt

Transients

Generally travel in small groups, usually of two to six animals, and have less persistent daily bonds than residents Diets - consists almost exclusively of marine mammals; they do not eat fish They roam widely along the coast -- some individuals have been sighted in both southern Alaska and California

Gulls

Gulls and terns Efficient flyers - They migrate really long distances Live near the shore - coastal birds Buoyant swimmers Good runners - helps them get various types of food