Nutrients (compounds essential for life - not food, but more like vitamins and minerals Upwelling impacts

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1 Chapter 12 - Life in the Marine Environment Planktonic means Floating and Drifting Phytoplankton are Autotrophic (produce food through photosynthesis) Zooplankton are Heterotrophic ( eat things - living or decaying) Permanent Plankton (permanent meaning remain microscopic whole life) Diatoms & Radiolarians (siliceous phyto- and zoo-), Coccoliths & Foraminifera (siliceous phyto- and zoo-) Temporary Plankton - organisms that start micro-sized but grow larger Larvae (ex. Eel, Herring, Salmon, Copepod) Nektonic (Nekton are swimmers like fish) Benthos means live on the seabed - are Sessile or Mobile Feeding Characteristics of marine animals Filter and Suspension Feeders (ex. Wale Sharks, Baleen Whales) (ex. Crustaceans, Sponges) Deposit feeders (ex. Worms, Crabs) Factors Influencing Marine Life Water Transparency Visual adaptations for transparent waters - sea critters generally have good eyesight! Camouflage Countershading - dark on top, light on bottom Nutrients (compounds essential for life - not food, but more like vitamins and minerals Upwelling impacts Temperature environmental stability - impacts of food supply (such El Niño) cold vs. warm species: (temperature affects size, life span, diversity, biomass: Cooler seawater organisms are smaller, Tropical organisms grow faster, live shorter, More species in warmer seawater, More biomass in cooler seawater (where upwelling occurs) Poikilothermic - cold blooded Homeothermic - warm blooded Salinity - many species have tolerance range ph (acidity vs. alkalinity, range from 0 to 14, 7 is neutral) normal seawater is ph of many species have tolerance range Pressure - many species have air-compression adaptations Dissolved Gases - - many species have tolerance range; gills are for respiration, excretion Divisions of the Marine Environment Pelagic - open water environments, includes neritic [< 200 meters] and oceanic [> 200 meters] Benthic - seabed described as subneritic and suboceanic Four Pelagic biozones Epipelagic (only zone photosynthesis to about 200 meters) Mesopelagic (partial light, zone bioluminescence organisms in abundance to 1000 meters) Bathypelagic (continental slope to about 4000 meters) Abyssopelagic (abyssal plain depths below about 4000 meters)

2 oxygen minimum layer (OML) - below about 200 meters where photosynthesis stops nutrient maximum zone - below about 200 meters where photosynthesis stops Light availability Euphotic - top layer of ocean where photosynthesis effective Disphotic - partial light (not enough for significant photosynthesis) Aphotic - todal darknes Benthic Environments Supralittoral - above high tide except during storms Subneritic - shallow seabed Littoral - intertidal zone to wave base Sublittoral - below wave base Suboceanic Bathyal - shelf break and slope Abyssal - abyssal plain depths Hadal - deep sea trenches Symbiotic relationships mutualism - two or more species benefit each other (e.g., clown fish and sea anenomies) parasitism - one species benefits at the expense of a host species commensalism - one species benefits without harming another species Classification of Living Organisms Five Kingdoms Monera - bacteria, very primative microbial life forms Protoctista Fungi Plantae Animalia Taxonomy -branch of science concerned with classification, especially of organisms; systematics. Kingdom Phylum Class Order Family Genus Species How are plants and animals classified? (Example: lets look at whales) Kingdom - Animalia (animal) Phylum - Chordata Subphylum - Vertebrata Class - Mammalia (mammal) Order - Cetacea Family --- Genus Species

3 CHAPTER 13 - Biological Productivity Primary Productivity Photosynthesis uses solar radiation. Chemosynthesis uses chemical reactions. 99.9% of the ocean s biomass relies directly or indirectly on photosynthesis for food. Ocean productivity is equal to land productivity. Photosynthetic Marine Organisms (3 types) 1. Photosynthetic bacteria Extremely small May be responsible for half of total photosynthetic biomass in oceans 2. Microscopic Algae Produce food for 99% of marine animals Most planktonic Golden algae Diatoms tests made of silica Coccolithophores plates of calcium carbonate Dinoflagellates Red tide (harmful algal bloom) Toxins (Fish kills and Human illness) 3. Macroscopic (large) algae Seaweeds Brown algae Green algae Red algae Energy Flow in Marine Systems Factors Affecting Primary Productivity Nutrient availability - Nitrate, phosphorous, iron, silica - Upwelling and river runoff Cooler, deeper seawater is nutrient-rich. Areas of coastal upwelling are sites of high productivity. Solar radiation - Uppermost surface seawater and shallow seafloor - Compensation depth net photosynthesis becomes zero - Euphotic zone from surface to about 100 meters (330 feet) Polar Zone Productivity (highest in summer) Winter darkness vs. Summer sunlight Phytoplankton (diatoms) bloom in late spring, Zooplankton productivity follows No thermocline - Plankton remain at surface, Blue whales migrate to feed on maximum zooplankton productivity. Tropical Zone Productivity (lowest productivity) Permanent thermocline is barrier to vertical mixing (except when equatorial upwelling occurs) Low rate of primary productivity lack of nutrients Temperate Ocean Productivity (spring and fall seasonal blooms) Productivity limited by available sunlight and available nutrients Producers - photosynthesis or chemosynthesis (Autotrophic) Consumers - Eat other organisms (Heterotrophic) Decomposers break down dead organisms or waste Fisheries Management (regulation, education, enforcement, create self-sustaining ecosystems) 80% of available fish stock fully exploited, overexploited, or depleted/recovering Large predatory fish reduced. Much work needs to be done!

4 CHAPTER 14 Animals of the Pelagic Environment -- Pelagic animals use a variety of adaptations to help them survive. (pelagic means relating to the open sea, chiefly shallow layers ) -- Marine mammals share similar characteristics with land mammals. Adaptations -- Ability to float (Zooplankton some produce fats or oils to stay afloat) -- Ability to swim (Nekton larger fish and marine mammals) Microscopic Zooplankton: Radiolarians, Foraminifers, Copepods Macroscopic Zooplankton -- Krill ( resemble mini shrimp or large copepods, critical in Antarctic food chains) -- Floating Macroscopic Zooplankton ---- Portuguese man-of-war (gas-filled float) ---- Jellyfish (soft, low-density bodies) Swimming Organisms (fish, squids, sea turtles and sea snakes, marine mammals) -- Swim by trapping water and expelling it -- Swim by curving body from front to back Adaptations for Finding Prey -- Lungers wait for prey and pounce (grouper). -- Cruisers actively seek prey (tuna). Adaptations to Avoid Predation -- Speed -- Poison (to touch or eat: examples: sea snakes, blowfish, lion fish) -- Hiding: Transparency, Camouflage and Countershading -- Schooling (safety in numbers, appear as a larger unit, maneuvers confuse predator Marine Mammals -- Land-dwelling ancestors -- Warm-blooded -- Breathe air -- Hair/fur -- Bear live young -- Mammary glands for milk Order Carnivora (have prominent canine teeth) -- Sea otters -- Polar bears -- Pinnipeds ---- Walruses ---- Seals ---- Sea lions ---- Fur seals Order Sirenia (Herbivores living in coastal areas) -- Manatees (tropical Atlantic Ocean) -- Dugongs (Indian and western Pacific Oceans) Order Cetacea -- dolphins, porpoises, killer whales, toothed whales, baleen whales (have elongated skull with blowholes on top, use echolocation) (emit clicks and get return, used to detect fish, can be used to stun fish) ---- Sperm whales use echolocation to hunt giant squid ---- Intelligence in Toothed Whales (Large brains relative to body size; can communicate with each other, trainable ) Suborder Mysticeti: Baleen whales baleen - fibrous plates in whale mouths used to sieve prey items -- Blue, Finback, Humpback, Gray, Right whales

5 Evolution - Adaptation and Extinction (review concepts) What is a "Marine Community?"-- An area where a group of marine organisms live and interact with each other. Evolution is the process by which different kinds of living organisms have developed and diversified from earlier forms during the history of the earth. Darwinism - the theory of the evolution of species by natural selection advanced by Charles Darwin ( ). Natural selection: organisms better adapted to their environment tend to survive and produce more offspring. All living things (plants, animals, etc.) use a variety of adaptations to help them survive. Changes in in physical and biological factors create opportunity and misfortune/bad luck, operating under natural selection. Adapt, move, or die! Local die-offs happen frequently; when all viable reproducing members of a "species" or "biological organization" die off it is extinction. Extinction - the state or process of a species, family, or larger group being or becoming extinct. A mass extinction is a event when many different life forms (including plant and animal species) become extinct (over a "relatively short" period of geologic time). The last mass extinction occurred approximately 65.5 million years ago (Cretaceous/Tertiary Boundary). In the last 500 million years, there have been five major mass extinctions when more than 50 percent of animal species disappeared. Global environmental change and irresponsible exploitation are current driving forces of extinction in our present times. The current mass extinction began during the last ice age when humans migrated around the globe. Large numbers of species vanished at the end of the last ice age (they had survived previous ice ages). Extinctions are happening as human civilization expand. Humans are introducing species to many new environments. The change are beneficial to some, detrimental to others (competition and predation). Carrying Capacity in Marine Communities stable number of individuals in a community. Influenced by physical and biological factors including geography! ( zones ) Both physical and biological factors result in zoning and extinction of organisms in a specific environment. Physical factors: * Temperature/Salinity (very significant) * Tides, Waves ( energy) * Water Transparency * Nutrients * ph * Pressure * Dissolved Gases * Environmental Stability Biological factors: * Competition for food and space * Predators Distribution of Organisms - how are they distributed throughout an environmental setting? i. Random: rare in marine environment ii. Uniform: more common than random eels in holes or penguins on nests iii. Clustered: most common schooling fish, clusters of barnacles and mussels on rocks. iv. Zoned: species or community of species living together in a limited geographic range defined by physical and biological factor. Most organisms in marine environment are ZONED or CLUSTERED

6 Vertebrates are animals distinguished by the having a backbone or spinal column Invertebrates are animals lacking backbones Marine Environment: classes in the subphylum Vertabrata ( having a backbone ) Mammalia -! Whales, seals, otters, polar bears (mammals) Amphibia -! Frogs, salamanders (amphibians) - can inhabit brackish water but there are no true marine amphibians. Reptilia - Snakes, turtles, lizards, crocodilians (extinct varieties: ichthyosaurs, plesiosaurs, mosasaurs) Aves - Birds Osteichthyes - Fish with bony skeletons Chondrichthyes - Fish with cartilage skeletons- sharks (very old fish with cartilage; some are up to 280 million years old) Phylums of Invertebrates include: Protozoa - Single cell Porifera - Sponges filter feeders Coelenterada - Coral, Jellyfish Annelida - Worms Mollusca - Bivalves, squid, octopus, gastropods (things with shells or large cavities) Arthropoda - Crabs, shrimp and spiders Echinodermata - Sea Stars, urchins and sea cucumbers (all spiny skin) CHAPTER 15 Animals of the Benthic Environment Communities on Rocky Shores Species are: -- Attached to bottom -- Move over seafloor (e.g., crabs, snails) * Rocky Intertidal Zonation Rocky shore sub divisions: -- Spray and High tide zones -- Middle tide zone -- Low tide zone Spray and Upper Tide Zone -- Harsh-few organisms -- Large Temp/Salinity Changes -- Both Marine and Land Predators Middle tide zone (Transition zone) -- More Species Diversity -- More Organisms Low tide zone -- Life is easy here! -- Stable temp/salinity -- Lots of Species Diversity -- Space is limited

7 Communities on Sandy Beach Shores * Sandy Beach Intertidal Zone -- No stable, fixed surface -- Burrowing provides more stable environment -- Less risk of temperature extremes and drying out Burrowing critters Mollusks Soft body, hard shell (most, not all) Example: clams and mussels Worms (annelids) Sand Crabs Shallow Offshore Communities Rocky Bottoms Kelp and kelp forests Attaches to rocky bottoms Can grow up to 0.6 meters (2 feet) per day Provides shelter for other organisms Rich ecosystems Coral Reefs Shallow water Tropical settings Warm, clear, shallow water Polyps are individual corals animals Importance of Coral Reefs Largest structures created by living organisms Great Barrier Reef, Australia, more than 1250 miles long Great diversity of species Reefs protect shorelines and freshwater supplies Coral Reefs are in Decline 30% healthy today, 41% healthy in 2000 Threats to coral reefs: Hurricanes, Coral bleaching, Floods Deep-Ocean Floor Communities (deep ocean is largely unexplored Light absent below 3300 feet Temperature usually 28 F to 37 F High pressure Hydrothermal Vents (abundance of unusual life forms ) Life supported by Chemosynthesis Microscopic organisms (Base of local food chain) thrive on hydrogen sulfide from vents Manufacture sugar, carbon dioxide, and dissolved oxygen - Hydrothermal Vent Species -- Giant tubeworms -- Giant clams -- Giant mussels -- Crabs Vents active for years or decades Animals species similar at widely separated vents Larvae drift from site to site