EDITS COMPLETED 23 November 3 PM
Mammals
fur and blubber insulation; also thermoregulators lke birds, but almost all are viviparous via a placental connection with the mother (exchanges nutrients and carries off waste, including CO2, and engage in post-natal feeding from milk glands (aka lactation or mammary glands)
Mammal order Pinnipedia ("feather feet")- all breed on land or ice
has three families in it representing 1) true seals, 2) fur seals and sea lions and 3) walruses (in Arctic only)`
all are carnivores
Largest true seal is an elephant seal; can dive to almost a mile
Fur seals are often hunted for their pelts, but others are hunted for their meat and alleged health products, especially those that promote virility.
Baby harp seals called "whitecoats"are found only in the Canadian Atlantic and Greenland. Nearly 300,000 of them are clubbed to death every year in Canada by permit. See p. 186
Order Sirenia ("Sirens" were bird-women whose singing lured sailors to their death): the manatees (sea cows)- all are strict vegetarians, no rear flippers. Includes manatees and dugongs. Manatees live in fresh and estuarine waters; a relative, the dugongs, live in the marine environment, but are only found in the Indo-west Pacific (they are smaller and have a distinct fluke (p. 188). They are hunted and in most regions, endangered or at least threatened.
Steller's sea cow was the largest species (25 ft long) and was found around the Bering Sea until they were all killed by human predation within about 30 years in the mid-1700's.
Their meat was said to resemble "the finest veal" (which cannot be verified anymore)
Order Cetacea ("cetus" is Latin for "whale"): two subgroups- 1) toothed whales, including dolphins, porpoises, narwhals (with their spiral tusks), white beluga whales, sperm whales and killer whales
Note that narwhals and belugas are strictly Arctic (like walruses- which of course are not cetaceans)
and 2) baleen whales, which are all filter feeders.
Note that all baleen whales develop teeth and lose them before they are born. Some species (known only as fossils) had both teeth and baleen as adults. What does that suggest about the evolution of baleen, now found among the majority of whale species?
All breathe air and exhale through dorsal nostrils (= blowhole)
Phonic lips below the blowhole allow dolphins and relatives to make
echolocation clicks and whistles (including a personal "signature whistle)
whaling and the International Whaling Commission
"scientific whaling" is done by one country as a means of getting around the IWC moratorium on whaling.
Which nations hunt whales (there are three)?
One scientist found whale meat for sale in Japan that came from endangered whale species that were not supposed to be on the menu.
He used DNA barcoding to do this. What kind of DNA seems to correlate very well with vertebrate (and many invertebrate) species and
is used for barcoding?
What do sperm whale spermacetti and the dolphin "melon" have in common?
What happened aboard the whaling ship Essex in 1821?
What was spermacetti used for and why was it valuable?
What is ambergris? Mentioned in class, but look it up on Mr. Google
Likewise, what was whale blubber used for?
Marine Ecology
What are trophic levels?
What are food webs (as opposed
to food chains).
UPWELLING: (p. 355)
The average ecosystem makes
about 0.5 grams of carbon per m2 per day; the average upwelling
ecosystem makes 4x this much during the times when favorable winds blow.
Which direction, with regard
to the coastline, is most favorable for winds to produce most upwelling?
Where do favorable winds for coastal upwelling blow for the longest time?
Coastal Upwelling is directly driven by favorable winds and by Coriolis and the Ekman spiral (text figure 3.19).
Look at and compare text figure 3.19 for Ekman transport in the northern hemishere (e.g., off California) which used to have a sardine fishery before it was overfished,
and Figure 15.30 to see coastal upwelling as it occurs in
the southern hemisphere (e.g., Peru).
The Peruvian anchovetta Engraulis ringens is a keystone species
anchovetta fishery/Peru Current
gill rakers in anchovettas
purse seines
keystone species
El Niño-aka ENSO. what is it, how does it work? See pp. 357-359.
How does it affect the anchoveta fishery? See p. 393
What are the top 5 fishing nations of the world according to their yield in metric tons? (p. 386).
What is the Peruvian anchoveta used for commercially?
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Antarctic and Ocean Convergences
Warning: Not much in the book on these topics!
Convergent upwelling at Bering Sea and Grand Banks. Which currents are involved?
The Antarctic and Subtropical Convergences: what are they? Where are they fouind?
Which currents enter into the subtropical convergence, and which ocean is defined by where that occurs?
Antarctic Krill: Euphausia superba is a keystone species (see pp. 390-391).
Note that penguins are only found south of the equator, and mostly in the Southern Ocean (although one species lives only in the Galapagos Islands right on the equator)
Many species in the Antarctic feed primarily on krill
What do crabeater seals and Adelie penguins eat?
What special adaptation do Weddell seals have that enable them to live in the Antarctic region during the winter months?
What limits primary production in the Antarctic? Nitrogen & Phosphorous? Light? Both?
What are Antarctic Icefish and how do they keep from freezing in the Antarctic winter?
Antarctic whales= Blue, Fin, Sei, Southern Right, humpbacks, Minke and sperm
Baleen whales (most are, which one of the above is not?)
Minke whales are relatively small (~10 meters), but are the most hunted.
The Indian Ocean part of the Southern Ocean is supposed to be a whale sanctuary, but....
Coral Reefs:
The larger species are referred to as frame builders and function like bricks or blocks in construction of a house
Coralline algae (also called calcareous red algae) and certain corals can be impotant cementing agents if they grow as flat sheets that seal the spaces between frame builders
High energy wave zones in shallow water may support the growth of an algal ridge composed of thick sheets of calcareous red algae
These structures are often found facing the wind on atolls. This promotes the formation of islands by preventing erosion
on the wind-facing side (windward side) see below
Zooxanthellae and their contribution to reef corals: contribution of glucose and other organics via photosynthesis,
uptake of host waste products like nitrogen and phosphorous.
The zooxanthellae-host relationship is obligatory and requires
corals to live in clear water, usually less than 60 meters deep.
Reef growth is measured in cm/decade or hundred years and is a NET process of carbonate accumulation and destruction.
All of the above are growth processes. Organisms that bore or scrape or bite into the reef are called bioeroders (the process is bioerosion)
There are boring bivalves and worms, excavating sponges, and strong-jawed parrotfishes that bit and scrape reefs
Some species only consume coral tissue. This includes certain fishes, gastropods and echinoderms. See page 327-328.
Sometimes, coral predators explode and cause large scale destruction. Example used in class: the crown-of-thorns seastar (COTS see p. 316). Recent research shows that nutrient-rich river discharge (nutrients from farming, etc.) gets carried to reefs and promotes the survival of COTS larvae
Coral diseases are becoming more prevalent than they were 30 years ago
Coral bleaching is getting much more frequent than it was 30 years ago.
Research suggests that the
two (diseases and bleaching) are related to increasingly warmer water.
Reef formation:
Reefs and corals that produce them require a specific temperature range, typically no lower than 20 degrees C and no higher than 30 degrees.
This confines them to the tropicals and just beyond in many places as far as 30 degrees of latitude north and south of the equator.
Miami is at 26 degrees north, so we are "subtropical" and near the limit of coral reef growth due to cold winter temperatures like those in 2010.
This caused severe coral bleaching and killed large areas of corals, esp. in shallow water
Under more normal conditions, coral growth is fastest in shallow water, slower in deeper water where light becomes limited
Max depth for coral reef development depends on zooxanthellae, but depends on water clarity.
In very clear water, corals may grow to 60 m deep or more
In Florida the max depth is generally closer to 20 m
The rule of coral reefs and the tropic does not apply to places where river discharge occurs, so the coasts of
Venezuela and northern Brazil (for example) have very few reefs (even though they are very much tropical) due to the Orinoco and Amazon rivers
Corals also are sensitive to pollution including high levels of nutrients. Note this is called eutrophication- see p. 314 about Kaneohe Bay in Hawaii for a good example of this.
Types of Reefs
fringing, barrier and atoll reef types p. 316
where is the largest barrier reef in the world?
where is the largest barrier reef in the Atlantic (Caribbean)?
Charles Darwin: what did he do for coral reef science?
Note that Darwin was the first to suspect that in the Pacific (where most atolls are located), volcanoes that would become atolls were sinking (subsiding) and that vertical coral growth over millions of years could account for so many atolls. Pacific atolls are called Darwinian atolls becuase they are slowly subsiding, but not all atolls can be accounted for on this basis. For example there are two atolls that sit on the continental shelf off the coast of Belize. The coast of Belize is NOT sinking, so they are not Darwinian atolls.
What is the significance of the Tuamotu Archipelago in the SW Pacific (near Tahiti & Bora Bora)?
73 atolls! (All Darwinian of course).
Reef zones: reef flat, lagoon, reef crest, outer reef slope (to deep water)
Which reef type of the three above does not have a lagoon?
The algal ridge- calcareous red algae that cements the windward side of reefs.
Would you be able to tell from an aerial photo which side of an atoll is the windward side, and which is the leeward? See p. 319
What is the significance of the coral triangle and where it it located?
Hint see http://www.coraltrianglecenter.org/ and click on the map for a brief description.
Chapter 16 and 15, pp. 333-339
The Epipelagic Zone corresponds
to the photic zones of the open ocean region, which generally = the first
100-200m
fishes are countershaded (what
is that???)
Deep Sea Pelagic zones:
mesopelagic: 200-1000 m: twilight zone during the day
mostly silvery, bioluminescent organisms
photophores contain luciferin and the enzyme luciferase which react and produce biological light
lanternfish & hatchetfish, each species with its own pattern of lights
daily vertical migrations of up to 700-800 meters each way
large, sometimes tubular eyes
red shrimp might as well be black; emit luminescent secretions when disturbed
small squids with multi-colored photophores emit luminescent ink
Bathypelagic zone (1000-4000 m; 0-2 oC) The most volume of any zone in the ocean: 75% of all water!
Constant darkness
Fish mostly small and black; flabby musculature, poorly calcified bones and small eyes (sometimes absent)
Even so, all are predators and none of these animals migrate. How might a blind fish find its prey or a mate?
Your book refers to pheromones, external hormones that act as a "perfume"
Organisms tend to be bioluminescent (less so toward the deeper part of this zone)
Deep sea anglerfish; parasitic males
viperfish (double-hinged jaws) and dragonfish (luminescent chin whiskers)
gulper eels may be 2 m long
Remember quick way to calculate the pressure of 15 psi/10 m at any depth.
What is the pressure at a depth of 4000 meters?
Abyssopelagic zone: (4000-6000; close to 0 oC)
conditions: constant salinity, high pressure, low temperature and darkness
Not much known, but fishes and other groups are often represented by the same families that are found in the bathypelagic, but are usually different species
Hadopelagic zone (in trenches, >6000 m deep); <0 oC
Even less is known about the pelagic organisms inhabiting trenches
Deep sea bottom:
Bathyal zone includes the continental slope, but runs all the way from 200-4000 m
bottom can be rocky shelves or muddy, depending on local conditions
uppper part is lighted; lower part is not
temperatures vary from 10-2 degrees C
bottom trawls are used to sample
fish not usually bioluminescent
large eyes
scrotum fish
greeneye fishes
giant isopods
Abyssal zone: 4000-6000 m; correponds to the abyssopelagic zone, but refers only to organisms on or near the bottom
bottom is mostly muddy; cold (2 degrees C or less); lightless
fish black; little bioluminescence
Organisms (some of which are described in Fig. 15.25) are often deposit feeders and consume organic matter
in sediments or the burrowing animals that live in the sediments.
Many are also "croppers", a term meaning they are both scavengers and predators.
These are the three most common ways of finding food in this zone
hydrothermal vents and black or white smokers
Not restricted to the Abyssal zone, but most often at 2000 m or more, associated with rifts or cracks in the Earth's surface, called "transform faults",
places where parts of a plate slide across their edges (as opposed to subduction or spreading zones at the edges of plates)
However, transform faults are common along the Mid-Atlantic ridge, which pulls its peaks from east to west making it zig-zag rather than straight
These are places where the molten interior of the Earth contacts and heats seawater forming an underwater geyser
(as opposed to seeping or blowing out lava as a volcano might)
The mineral content of the surrounding rock is responsible for the color of the "smoke", which is really mineral particles that condense in the relatively cool water surrounding the vents
See p. 35-38
A special oasis in the deep sea where CHEMOSYNTHETIC bacteria become primary producers and are able to fix carbon chemically- no sunlight involved
meter-long plume worms (genus Riftia- named after deep sea rifts-get it? Deep sea humor.) Thay lack a digestive system
and live symbiotically with them like zooxanthellae and corals, but without the requirement for light
Certain large clams, shrimp and crabs, also unique to these hydrothermal vent regions, feed on these bacteria directly
see pages 379-381