Marine Ecosystems Marine Shoreline Ecosystems I. Habitats 1. Habitat Zones 2. Locations 3. Perspectives in Geological Time II. Ecosystems 1. Oceanic & Neritic Ecosystems 2. Littoral Ecosystems III. Human Interactions 1. Introduced Species 2. Harvesting 3. Mariculture 4. Chemical Pollution 5. Land Conversion
Marine Ecosystems Marine Habitat Zones
I. Habitats TIDAL SUBMERGED
1. Habitat Zones Littoral Neritic Oceanic Intertidal Shallow subtidal A. Oceanic Zone Deep subtidal Nearshore to B. Neritic Zone continental shelf CLittC. Littora lZl Zone
What is the BASIS for classification being used here?
Marine Habitat Zones Marine Ecosystems Typical Habitats within Zones I. Habitats Littoral 1. Habitat Zones • Rocky intertidal Neritic • Seagrass beds Oceanic A. Oceanic Zone •Beach •Pelagic •Pelagic •Salt marsh • Moderate benthic B. Neritic Zone •Deep water • Shallow benthic: CLittC. Littora lZl Zone Kelp beds benthic
Pelagic
•1 Oceanic Zone Habitats Oceanic Zone Habitats
Photic zone Classifying Marine Organisms by Habitats depth incorrect on figure Pelagic Habitats photic zone (0 – 200 m depth) Pelagic Organisms aphotic zone •Nekton •Plankton (> 200 m depth) Pelagic •Neuston Benthic Habitats * Habitats Benthic Organisms Benthic Habitats Benthic •Epifaunal Habitats on a solid Habitats surface within an • Semi-infaunal aqueous medium • Infuanal
Pelagic Habitats Habitats surrounded by an aqueous medium
* Continental shelf extends 10-300 km offshore with depths up to 1-200 m
Marine Ecosystems Neritic Zone Habitats I. Habitats Neritic Habitats All habitats are subtidal 1. Habitat Zones •Kelp • Deep water •Pelagic beds benthic A. Oceanic Zone B. Neritic Zone Littoral Zone Neritic Zone CLittC. Littora lZl Zone • up to 40 – 80 m deep • Can occur in littoral zone also (up to ~ 0.5 m below mean LL tide)
Marine Ecosystems Littoral Zone Habitats Littoral Habitats I. Habitats All habitats are intertidal (Kelp 1. Habitat Zones Salt Beach / Rocky Seagrass intertidal beds beds) A. Oceanic Zone marsh Dune B. Neritic Zone CLittC. Littora lZl Zone
•2 Marine Ecosystems Marine Habitats: PNW Locations
San Juan I. Habitats Islands & Straits 1. Habitat Zones Puget A. Oceanic Zone Sound B. Neritic Zone Outer Coast CLittC. Littora lZl Zone (Ocean) 2. PNW Locations
3. Perspectives in Geological Time Outer Coast Islands & Puget Straits Sound High Energy Low Energy
Marine Habitats: PNW Locations The Puget Sound: Channel Depth & Water Flow Strait of San Juan Georgia Islands Mean depth of ~ 450 ft. Max depth of ~ 930 ft. Strait of The Puget Typical channel depths 0-100 m > 200 m Juan de Fuca Sound of ~ 3 - 600 ft. 100 -200 m Mean depth of 450 ft. Sills Channel sills ~ 150 - 200 ft. high Minor sills ~ 10 – 70 ft. high
Seattle
Sill Pg. 64 in textbook
Marine Ecosystems Perspectives in Geological Time I. Habitats I. Continental Shelf / Outer Coastline 1. Terrane accretion – evolutionary template 1. Habitat Zones Accreting land masses bring new organisms A. Oceanic Zone This alters the biogeographic picture of nearshore organisms B. Neritic Zone CLittC. Littora lZl Zone 2. PNW Locations 3. Perspectives in Geological Time
•3 Perspectives in Geological Time Perspectives in Geological Time I. Continental Shelf / Outer Coastline II. Puget Sound 2. Continental glaciation – sea level, coastlines & nutrients Puget Sound waterways formed during retreat of Vashon Stade of the Fraser Glaciation (14 – 18,000 YBP) Recent glacial retreat begins 14 – 18,000 YBP Ecosystems are relatively young: 10 – 15,000 yrs old Sea levels rise rapidly (~ 100 m) inundating coastlines. Nearshore land rich in nutrients is now part of the submerged Short time for development of ecological community through primary continental shelf succession
Continent rises slowly (isostatic rebound) but not to the extent it Marine systems have rapid dispersal rapid community development was submerged. Much of the nutrient-rich former shoreline remains as subtidal benthic habitat. Short time for evolution & coevolution relationships to be established
This rich nutrient base of the subtidal / continental shelf Implications for susceptibility to biological invasions? zone is critical in nearshore primary productivity. Its availability is controlled by upwelling (more on this later).
Marine Ecosystems Marine Ecosystems
I. Habitats Patterns in Primary 1. Habitat Zones Productivity 2. Locations 3. Perspectives in Geological Time II. Ecosystems 1. Oceanic & Neritic Ecosystems Many of these nearshore marine 2. Littoral Ecosystems ecosystems we will examine are III. Human Interactions among the most productive on Earth 1. Introduced Species 2. Harvesting 3. Mariculture 4. Chemical Pollution 5. Land Conversion
Marine Ecosystems Oceanic & Neritic Ecosystems I. Abiotic Environment & Primary Productivity II. Ecosystems What are the principal constraints to primary productivity? 1. Oceanic & Neritic Ecosystems 2. Littoral Ecosystems Resources Stresses
O O C
Carbon Temperature dioxide Solar Energy
+ - K - NO3 PO4
++ ++ Water Ca Mg Nutrients Salinity
•4 Oceanic & Neritic Ecosystems Oceanic & Neritic Ecosystems
I. Abiotic Environment & Primary Productivity I. Abiotic Environment & Primary Productivity Which constraints to primary productivity are 1. Light most important in these ecosystems? Rapid attenuation with depth even in clear marine waters scattering, Resources Stresses reflection Note that the “effective” photic zone is on O O the order of 10 m or less. Pelagic primary Clear water productivity can sometimes be linked to C the DEPTH of the photic zone Carbon What factors influence the rate of dioxide Temperature Solar Energy light attenuation (i.e., depth of the photic zone)? What would the light extinction
+ curve look like in turbid - K - NO3 PO4 1) Suspended particulates waters, such as an estuary Water • Living organisms (plankton, neuston) during tidal action? Ca++ Mg++ • Dead and inorganic materials Nutrients Salinity 2) Wave action (surface losses)
Oceanic & Neritic Ecosystems Oceanic & Neritic Ecosystems I. Abiotic Environment & Primary Productivity I. Abiotic Environment & Primary Productivity 2. Nutrients 2. Nutrients A) Major limiting nutrients: A) Major limiting nutrients: Nitrogen – N Nitrogen – N Phosphorus – P Phosphorus – P Potassium – K Potassium – K B) Nitrogen Sources B) Nitrogen Sources
+ + Nitrogen fixation (N2 NH4 ) Nitrogen fixation (N2 NH4 ) Terrestrial (riverine) input Terrestrial (riverine) input Benthic upwelling Benthic upwelling
Offshore or alongshore winds C) Phosphorus & Potassium Sources displace surface water. Water from Terrestrial (riverine) input near benthos rises to replace surface waters, bringing nutrient-rich Benthic upwelling particulates to photic zone where they can be used in photosynthesis
Oceanic & Neritic Ecosystems Oceanic & Neritic Ecosystems I. Abiotic Environment & Primary Productivity I. Abiotic Environment & Primary Productivity 2. Nutrients 2. Nutrients D) Patterns of coastal primary productivity: D) Patterns of interactions of nutrients and light primary productivity: interactions of nutrients and light along the Photic Nutrient Georgia coastline zone availability depth
Primary Productivity Patterns of availability of two principal limiting resources (light and Shore Open Ocean nutrients) result in peak in primary productivity somewhere offshore
•5 Oceanic & Neritic Ecosystems Oceanic & Neritic Ecosystems
I. Abiotic Environment & Primary Productivity I. Abiotic Environment & Primary Productivity 4. Water Temperature 3. Carbon Dioxide & Oxygen Epilimnion A. Vertical Patterns: Gas diffusion (supply rate) more limited in a liquid medium than in air Epilimnion – upper photic zone Thermocline Factors influencing soluble gas availability • Temperature influenced by patterns A. Physical aeration (wind, wave action) of solar radiation • Diurnal & seasonal temperature B. Photosyy/pnthesis / respiration fluctuations Hypolimnion C. Water temperature (↑ °C →↓gas solubility) Thermocline – lower photic to aphotic zone • Zone of rapid temperature drop Bottom line • Thermocline depth can vary Soluble gases are usually not a major limitation except under seasonally in temperate latitudes conditions of algal blooms (nutrient loading) and stagnant water Hypolimnion –aphotic zone • Cold, constant temperatures
Oceanic & Neritic Ecosystems I. Abiotic Environment & Primary Productivity
I. Abiotic Environment & Primary Productivity 4. Water Temperature C. Water Temperature & 4. Water Temperature Primary Productivity: B. Geographical Patterns: Puget Sound vs. Outer Coast Global Patterns Do global patterns of Surface water temperature (°F) primary productivity appear Jan Mar May Jul Sep Nov to follow expected water NeahBay454751535349 temperature patterns? Seattle474651565651 Productivity is more Puget Sound surface waters warmer than outer tightly tied to nutrients coast, except following cool down into late winter High productivity only near coastlines Does this temperature difference influence productivity? Low latitude coastlines: nutrient input from terrestrial landscape High latitude coastlines: nutrient input from benthic upwelling
Oceanic & Neritic Ecosystems Oceanic & Neritic Ecosystems
I. Abiotic Environment & Primary Productivity I. Abiotic Environment & Primary Productivity 4. Water Temperature 5. Salinity B. Geographical Patterns: Puget Sound vs. Outer Coast A. Principal Influences Surface water temperature (°F) Organism water balance Jan Mar May Jul Sep Nov Species diversity NeahBay454751535349 Habitats with variable salinity (space & time) Seattle474651565651 are difficult to adapt to; results in few species Puget Sound surface waters warmer than outer coast, except following cool down into late winter So, do these temperature differences likely result in primary productivity differences?
•6 Oceanic & Neritic Ecosystems Oceanic & Neritic Ecosystems
I. Abiotic Environment & Primary Productivity II. Pelagic Biota 6. Puget Sound & the Outer Coast: Primary Producers: phytoplankton Comparing Productivity Constraints Consumers: Puget Sound Outer Coast Herbivores: almost nothing strictly herbivorous Relative Nutrient Availability Higher ? Omnivores: Terrestrial nutrient input High Low Zooplankton Upwelling nutrient input Low High Filter feeders (fish & whales) Photic Zone Depth Higher Schooling fish: Pacific herring, Northern anchovy, Pacific sardine (streamlined bodies) Water clarity Low High Baleen Whales: grey, blue, right, humpback Input of suspended particulates High Low Detritivores: Dissolved gases Higher Flat fish (bottom fish): sole, halibut, flounder Turbulence Low High Various invertebrates (e.g., marine worms, sand dollars, clams) Water temperature High Low Pelagic stages of these benthic organisms
Oceanic & Neritic Ecosystems Oceanic & Neritic Ecosystems II. Pelagic Biota
Carnivores: some zooplankton III. Kelp Beds: A Shallow Benthic Ecosystem Predatory fish : e.g., tuna, mackrel, salmonids Sharks Toothed whales (orcas) & dolphins / porpoises Octopus & squid (e.g., giant pacific octopus & opalescent squid) Pinnipeds: seals, otters, sea lions [Pelagic feeding birds (e.g., gulls, cormorants, shearwaters, albatrosses) ]
NOAA Photo Library
“Floating” Kelp Beds (Kelp Forests) Floating Kelp Beds: Seasonal & Geographical Dynamics
Puget Sound # Macro
2 Strait of JDF 40 20 / m cystis P. californica 10 20 / m Nereocystis 2 #
Dominated by 3 large brown algal species (kelp): Nereocystis luetkeana (bull kelp) Jan Mar May Jul Oct • Up to 20 m tall Nereocystis beds in Puget Sound : strong seasonal dynamics. Kruckeberg (1991) • Annual • Puget Sound, straits, protected outer coast Nereocystis beds in the Strait: less seasonal dynamics & different seasonal peak. Macrocystis integrifolia (giant kelp) However, Nereocystis beds in the strait are dominated by another brown alga, • Up to 10 m tall; perennial Pterygophora californica. This is a perennial, providing these Nereocystis beds • Outer coast nearshore & western straits with year round cover, unlike those in Puget Sound. Macrocystis pyrifera • Up to 40 m tall; perennial Macrocystis beds in the strait show moderate seasonal dynamics, with an autumn • Outer coast further away from shore peak and considerable presence year round. • In water up to 80 m deep data from Shaffer, J. (1998)
•7 Floating Kelp Beds: Seasonal & Geographical Dynamics
Puget Sound # Macro Kelp Bed Distribution in 2 Strait of JDF 40 20 Puget Sound & San Juan / m Islands cystis P. californica 10 20 / m Nereocystis 2 # NtNote the grea ter Jan Mar May Jul Oct abundance on more exposed shorelines Bottom Line: Not all kelp beds are created equal! This has large implications for understanding kelp bed ecology and for conservation & mitigation of human impacts! Can a restoration of a Puget Sound Nereocystis bed replace destruction of a Nereocystis bed in the strait?
data from Shaffer, J. (1998)
Marine Ecosystems Kelp Bed Primary Productivity
Patterns in Primary Why do kelp beds have such high primary productivity ? Productivity 1. Typical limiting resources are less limiting Nearshore position results in good nutrient input / availability Nearshore position & buoyancy of photosynthetic structures provides good access to light Kelp beds are as productive as tropical rainforests Kruckeberg (1991) Bladder takes advantage of water’s buoyancy to position bldblades in phtihotic zone Blades
Stipe
Bladder (float) Holdfast This slide NOT on handout – simply a repeat of slide from page 3
Fun fact: kelp float works by Kelp Bed Primary Productivity containing extraordinarily high Kruckeberg (1991) Why do kelp beds have such high primary productivity ? levels of CO Blades 2. Buoyancy of habitat medium allows resource investment to maximize productivity energy available to structural Buoyancy invest in photosynthetic Stipe needs structures Bladder (float) Holdfast Kruckeberg (1991)
Which organism requires more investment to access light?
•8 Kelp Bed Energy Flow Kelp Bed Energy Flow Primary Producers Consumers Dominated by large brown algae – kelp (surprise ☺) Invertebrates feeding on kelp: urchins, snails, etc. Nereocystis leutkeana (bull kelp) is characteristic but there Filter feeders using kelp as structural resource (sponges, bryozoans, tunicates, is a high diversity of others marine worms, etc.) Understory species in kelp beds vary greatly with: Invertebrates: crabs, shrimp, etc. • dominant overstory species • energetics of water at the site Pinnipeds: sea otters • region (PS, straits, outer coast) • season Fish: bass, lingcod, perch, sculpins, etc. Kelp act as ecological engineers in influencing habitat for other organisms, even other primary producers There is a rich variety of consumers that vary through time & space – we cannot do them justice here Crustose epiphytic algae are important primary producers
Kelp Bed Energy Flow Kelp Bed Energy Flow Trophic Relationships Trophic Relationships Otter Top-down control of trophic system Top-down control of trophic system decline
Sea otters Kelp Bed Carnivore (Enhydra lutris)
Urchin increase Sea urchins Herbivore (Strongylocentrotus sp.)
Urchin Barrens
Urchin Urchin Primary Bull Kelp barrens barrens Producer (N. leutkeana)
Kelp Bed Energy Flow Kelp Bed Succession Effects of urchin grazing demonstrated by a controlled experiment Succession following disturbance in a kelp bed ecosystem Urchin barrens High algal Urchin diversity at population moderate declines urchin density Year 2 Mixed kelp bed
Perennial kelp Lamanaria outcompete Nereocystis for space Remove urchins Conclusion:
MODERATE Urchin Perennial kelp Year 1 Nereocystis bed presence maintains algal Lamanaria BOTTOM LINE species diversity excludes Low algal competitors Disturbance necessary diversity with to maintain diversity no urchins Perennial kelp Year 3 Lamanaria dominates until disturbance Lamanaria bed and/or recovery of urchin population
•9 Kelp Bed Energy Flow Are Kelp Beds “Leaky” Ecosystems? Nutrient / Energy Retention
Energy flow in a kelp – urchin system
Potential of 80% energy consumed being exported to other nearshore systems
Lamanaria kelp ecosystem in Nova Scotia (Carefoot 1977)
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